VESTIGE VESLIM SHAKE POWDER

Indications

• Vitamin B6 deficiency
• Isoniazid-induced neuropathy (prophylaxis and treatment)
• Idiopathic sideroblastic anaemia
• Prevention of penicillamine-induced neuropathy in Wilson's disease
• Metabolic diseases such as cystathioninuria and homocystinuria
• Premenstrual syndrome

Mechanism of action

Pyridoxine hydrochloride is converted in the body to pyridoxal phosphate, which is the active form of vitamin B6. It serves as a cofactor for more than 100 enzymatic reactions, particularly those involved in the metabolism of amino acids, the synthesis of neurotransmitters (such as serotonin, dopamine, and gamma-aminobutyric acid), and the production of hemoglobin. Its role in neurotransmitter synthesis makes it crucial for normal brain function and mood regulation.

Pharmacodynamics

Pyridoxine hydrochloride exerts its effects by facilitating the conversion of amino acids into neurotransmitters and is involved in the synthesis of heme. It impacts the metabolism of tryptophan to serotonin and is essential for the production of norepinephrine and gamma-aminobutyric acid, which are vital for proper neurological function. Deficiency of vitamin B6 can lead to neurological symptoms, including peripheral neuropathy and cognitive disturbances.

Pharmacokinetics

Pyridoxine hydrochloride is readily absorbed from the gastrointestinal tract. It is primarily metabolized in the liver, where it is converted to its active form, pyridoxal phosphate. The elimination half-life of pyridoxine is approximately 15-20 days, and it is excreted primarily through the urine. Renal impairment may affect the metabolism and excretion of pyridoxine, necessitating dose adjustments.

Contra-indications

• Hyperkalaemia
• Severe liver damage

Adverse effects

• Peripheral neuritis
• Hepatitis
• Hypoglycaemia
• Urine discolouration

Interactions

• Potassium aminobenzoate
• Isoniazid

Precautions

• Caution in renal impairment (increased risk of hyperkalaemia)
• Interrupt treatment during periods of low food intake (such as fasting, anorexia, and nausea) to reduce risk of hypoglycaemia
• Monitor liver function tests monthly during high-dose therapy

Pregnancy

Manufacturer advises avoiding use in pregnancy due to potential risk of birth defects; however, no adverse effects have been reported at normal dietary levels.

Breast-feeding

Theoretical risk of toxicity in infants if mothers take large doses.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Formulations

• Pyridoxine hydrochloride 10 mg tablets
• Pyridoxine hydrochloride 20 mg tablets
• Pyridoxine hydrochloride 50 mg tablets
• Pyridoxine hydrochloride oral solution 20 mg per 1 ml

Indications

• Vitamin C deficiency
• Scurvy
• Adjunct therapy in iron overload conditions

Dosage

Children: Child 1 month–3 years: 125–250 mg daily in 1–2 divided doses; Child 4–11 years: 250–500 mg daily in 1–2 divided doses; Child 12–17 years: 0.5–1 g daily in 1–2 divided doses.

Adults: 500 mg daily, taken in 1-2 divided doses, depending on the clinical condition and dietary needs.

Mechanism of action

Ascorbic acid functions primarily as a reducing agent, facilitating enzymatic reactions in the body, including the hydroxylation of proline and lysine in collagen synthesis. It also plays a role in the absorption of iron from the gastrointestinal tract and enhances the immune response.

Pharmacodynamics

Ascorbic acid is crucial for the maintenance of connective tissue and is involved in the metabolism of several amino acids. Its antioxidant properties help to mitigate oxidative stress and may play a role in reducing the risk of chronic diseases.

Pharmacokinetics

Ascorbic acid is absorbed in the intestines and is widely distributed throughout the body. The renal clearance of ascorbic acid is dose-dependent, with higher doses leading to increased excretion. The half-life varies but is generally around 15 to 30 minutes in healthy individuals, with tissue saturation levels influencing its retention.

Contra-indications

• Hypercalcaemia
• Hyperoxaluria
• Patients with cardiac dysfunction

Adverse effects

• Abdominal pain
• Headache
• Nausea
• Vomiting
• Diarrhoea
• Constipation
• Weight loss
• Polyuria
• Sweating
• Thirst
• Vertigo

Interactions

• Increases risk of cardiovascular adverse effects with iron chelators
• Increases risk of cardiovascular adverse effects with deferiprone
• Increases risk of cardiovascular adverse effects with desferrioxamine

Precautions

• Use with caution in patients with iron overload
• Monitor for symptoms of overdose

Pregnancy

High doses teratogenic in animals but therapeutic doses unlikely to be harmful.

Storage

Store in a cool, dry place away from direct sunlight.

Formulations

• Ascorbic acid 50 mg tablets
• Ascorbic acid 100 mg tablets
• Ascorbic acid 200 mg tablets
• Ascorbic acid 250 mg tablets
• Ascorbic acid 500 mg capsules

Indications

• Vitamin B2 deficiency
• Isoniazid-induced neuropathy (prophylaxis and treatment)
• Metabolic diseases
• Cystathioninuria
• Homocystinuria
• Wilson's disease
• Prevention of penicillamine-induced neuropathy

Mechanism of action

Riboflavin acts as a precursor to flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), which are essential coenzymes in various enzymatic reactions. It binds to riboflavin hydrogenase, riboflavin kinase, and riboflavin synthase, facilitating the production of FMN and FAD. These coenzymes are critical for normal tissue respiration and energy metabolism, influencing hydrogen transport in oxidative enzyme systems such as cytochrome C reductase and succinic dehydrogenase. Moreover, riboflavin contributes to the antioxidant activity by aiding in the production of reduced glutathione, a key antioxidant in the body.

Pharmacodynamics

Riboflavin is an easily absorbed, water-soluble micronutrient that supports energy production by assisting in the metabolism of fats, carbohydrates, and proteins. It is vital for red blood cell formation, antibody production, and regulating growth and reproduction. The vitamin plays a significant role in maintaining healthy skin, nails, and hair, as well as supporting thyroid activity. Riboflavin also has therapeutic implications in preventing or treating various eye disorders, including cataracts.

Pharmacokinetics

Riboflavin is rapidly absorbed in the gastrointestinal tract, with its bioavailability influenced by dietary intake. It is primarily excreted through urine, with excess intake leading to bright yellow urine, which is a harmless side effect. The vitamin does not accumulate in the body, necessitating regular dietary intake to maintain adequate levels.

Adverse effects

• Urine discolouration
• Peripheral neuritis

Precautions

• With intravenous use, risk of cardiovascular collapse; resuscitation facilities must be available and monitor closely.

Pregnancy

Crosses the placenta but no adverse effects reported; information at high doses limited.

Breast-feeding

Present in breast milk but no adverse effects reported; information at high doses limited.

Storage

Store in a cool, dry place away from direct sunlight.

Formulations

• 100 mg modified-release tablets
• 50 mg capsules
• 100 mg capsules
• 100 mg tablets
• Oral solution

Indications

• Selenium deficiency
• Supportive therapy in conditions requiring antioxidant support
• Potential adjunct in cancer prevention strategies

Dosage

Children: Refer to BNF for Children for specific dosing information.

Adults: Initially 100–500 micrograms daily, adjusted according to response and serum levels.

Mechanism of action

Selenium is metabolized to selenophosphate and selenocysteine, which are essential for the synthesis of selenoproteins. This process involves the incorporation of selenium into proteins through a specialized tRNA that recognizes the RNA sequence UGA, which is facilitated by SECIS structures and SBP-2 proteins. Key selenoproteins, like glutathione peroxidases, help protect cells from oxidative damage, thus playing a significant role in reducing the risk of diseases such as atherosclerosis and certain cancers.

Pharmacodynamics

Selenium is incorporated into various selenoproteins that perform essential functions, including antioxidant activity, redox balance, and regulation of thyroid hormones. Its role in antioxidant defense mechanisms is particularly important for protecting cells against reactive oxygen species (ROS). Selenium supplementation has been linked to improved immune function and potential cancer prevention.

Pharmacokinetics

Selenium is absorbed through the gastrointestinal tract, and its bioavailability can vary based on the source and form of selenium. Once absorbed, it is distributed to various tissues, where it is incorporated into selenoproteins. Selenium is primarily excreted through urine, and its half-life can depend on dietary intake and individual metabolism. Selenium status can be assessed through blood levels of selenoproteins and selenium itself.

Adverse effects

• Nausea
• Anaemia
• Aplastic anaemia
• Skin reactions
• Gastrointestinal disorders

Precautions

• Selenium supplementation should not be given unless there is good evidence of deficiency.
• Use caution in patients with a history of hypersensitivity to selenium or its compounds.

Pregnancy

Limited information is available regarding selenium supplementation during pregnancy. Consult specialist sources for guidance.

Breast-feeding

Limited information is available; the effect of selenium on copper levels in milk is conflicting, and its impact on the infant is unknown.

Storage

After opening, store in a refrigerator (2–8°C).

Formulations

• Tablets (e.g., L-Selenomethionine 200 micrograms, SelenoPrecise 100 micrograms)
• Capsules (e.g., Trientine dihydrochloride 250 mg)
• Injection solutions (e.g., Sodium selenite 50 micrograms per 1 ml)

Indications

• Vitamin B1 deficiency
• Wernicke-Korsakoff syndrome
• Beriberi
• Isoniazid-induced neuropathy (prophylaxis and treatment)
• Severe depletion or malabsorption of vitamins B and C

Dosage

Adults: For vitamin deficiency: 25–100 mg daily. For severe deficiency: 200–300 mg daily in divided doses. For

Mechanism of action

Thiamine functions primarily as a precursor for several phosphorylated active forms, which act as coenzymes in metabolic pathways. It reduces intracellular protein glycation by redirecting glycolytic flux and supports the synthesis of nucleic acids necessary for cell survival and proliferation. Additionally, thiamine has been shown to inhibit glucose-induced proliferation of endothelial cells, thus possibly playing a role in the modulation of vascular health.

Pharmacodynamics

Thiamine exhibits antioxidant properties and contributes to erythropoiesis, cognitive function, and mood regulation. It has protective effects against oxidative stress, particularly in neuronal tissues, where deficiency can lead to neuronal death due to increased free radical production. Thiamine also modulates glucose metabolism, influencing smooth muscle cell proliferation and potentially impacting the progression of atherosclerosis.

Pharmacokinetics

Thiamine is rapidly absorbed from the gastrointestinal tract, primarily in the jejunum, and is distributed throughout the body, with higher concentrations found in the liver, heart, and brain. It is excreted in urine, and its half-life is relatively short. The vitamin is converted into active forms within tissues, including thiamine diphosphate (TDP), which is the coenzyme form involved in carbohydrate metabolism. The body does not store significant amounts of thiamine, making regular dietary intake essential.

Adverse effects

• Allergic reactions
• Anaphylaxis (rare)
• Gastrointestinal disturbances

Precautions

• Facilities for treating anaphylaxis should be available when parenteral thiamine is administered
• Use with caution in patients with a history of hypersensitivity to thiamine

Pregnancy

Thiamine crosses the placenta but no adverse effects have been reported. Information regarding high doses is limited.

Breast-feeding

Severely thiamine-deficient mothers should avoid breast-feeding as thiamine is present in breast milk.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Formulations

• Thiamine hydrochloride 20 mg/ml oral solution
• Thiamine hydrochloride 50 mg tablets
• Thiamine hydrochloride 100 mg modified-release tablets
• Thiamine hydrochloride oral suspension

Indications

• Type 2 diabetes mellitus
• Insulin resistance
• Impaired glucose tolerance
• Metabolic syndrome
• Hyperlipidemia

Dosage

Children: Refer to the BNF for Children for specific dosage recommendations suitable for pediatric patients.

Adults: Refer to the BNF for specific dosage recommendations based on the condition being treated.

Mechanism of action

Chromium enhances insulin signaling by upregulating insulin receptor-mediated pathways. It affects downstream effector molecules after insulin binds to its receptor, leading to the activation of phosphatidylinositol 2-kinase (PI3K) and protein kinase B (Akt). This process promotes the translocation of glucose transporter-4 (Glut4) to the cell membrane, facilitating increased glucose uptake. Additionally, chromium can promote GLUT-4 transporter translocation independently of insulin receptor activity under insulin-resistant conditions and aids in cholesterol efflux by increasing membrane fluidity.

Pharmacodynamics

Trivalent chromium is essential for the glucose tolerance factor, which activates insulin-mediated pathways. It enhances insulin binding to cells, increases the density of insulin receptors, and activates insulin receptor kinase, all of which contribute to improved insulin sensitivity. Chromium deficiency can lead to impaired glucose metabolism, and supplementation can normalize glucose tolerance in individuals exhibiting diabetic-like characteristics due to deficiency.

Pharmacokinetics

Chromium absorption occurs primarily in the intestines, but its bioavailability is influenced by various dietary factors, such as the presence of other minerals and vitamins. The mineral is transported in the bloodstream bound to transferrin and is predominantly stored in the liver, spleen, and bone. The elimination of chromium occurs mainly through urine, with small amounts excreted in feces. The half-life and exact metabolic pathways for chromium can vary based on its form and the individual's nutritional status.

Pregnancy

Chromium is generally considered safe during pregnancy when taken in appropriate amounts, but it is advisable to consult a healthcare provider.

Breast-feeding

Chromium is excreted in breast milk, and while it is deemed safe in moderate amounts, consultation with a healthcare provider is recommended.

Storage

Store in a cool, dry place away from light. Keep out of reach of children.

Indications

• Copper deficiency
• Occipital Horn Syndrome
• Menke's disease
• Contraception (via copper IUD)

Dosage

Children: Refer to the BNF for Children for specific dosing information.

Adults: Refer to the relevant clinical guidelines and BNF for specific dosing information.

Mechanism of action

Copper is absorbed from the gastrointestinal tract via high affinity copper uptake proteins and low affinity copper uptake proteins, likely being reduced to the Cu1+ form prior to transport. Inside enterocytes, it binds to the copper transport protein ATOX1, which facilitates its transport to copper transporting ATPase-1 on the Golgi membrane for incorporation into the Golgi apparatus. Once in systemic circulation, copper binds primarily to ceruloplasmin, albumin, and alpha 2-macroglobulin. It acts as a cofactor in a variety of oxidase enzymes and also influences sperm motility when released from copper IUDs, contributing to its contraceptive effect.

Pharmacodynamics

Copper is essential for the activity of many enzymes and plays a vital role in processes such as iron metabolism, neurotransmitter synthesis, and antioxidant defense. Copper ions, particularly when released from intrauterine devices, have been shown to decrease sperm viability, thereby impacting fertility.

Pharmacokinetics

Copper is absorbed from the gut and is predominantly transported in the plasma bound to proteins such as ceruloplasmin and albumin. The absorption efficiency can vary; however, a significant portion of dietary copper is usually absorbed. The body regulates copper levels through hepatic excretion and storage mechanisms, ensuring homeostasis. Excess copper can lead to toxicity, while deficiency results in various health issues.

Pregnancy

Copper is considered essential during pregnancy, but excessive intake should be avoided due to potential toxicity.

Breast-feeding

Copper is excreted in breast milk, and adequate maternal intake is important for infant development.

Storage

Store in a cool, dry place, away from moisture and heat.

Indications

• Biotin deficiency
• Seborrheic dermatitis
• Alopecia
• Neurological symptoms due to deficiency

Dosage

Adults: Refer to the BNF for specific dosing guidelines

Mechanism of action

Biotin is necessary for the proper functioning of enzymes that transport carboxyl units and fix carbon dioxide. It acts as a cofactor for the enzymatic carboxylation of four substrates: pyruvate, acetyl coenzyme A (CoA), propionyl CoA, and beta-methylcrotonyl CoA. The process of carbon dioxide fixation involves a two-step reaction where carbon dioxide binds to the biotin moiety of the holoenzyme, followed by the transfer of the biotin-bound carbon dioxide to an acceptor molecule. This mechanism is essential for metabolic pathways, including carbohydrate and fat metabolism.

Pharmacodynamics

Biotin is a water-soluble vitamin that contributes to cell growth, fatty acid production, and metabolism of fats and amino acids. It plays a significant role in the Krebs cycle, facilitating the release of energy from food. Biotin is also involved in maintaining stable blood sugar levels. A deficiency in biotin can lead to symptoms such as dry skin, seborrheic dermatitis, hair loss, and neurological symptoms, including changes in mental status.

Pharmacokinetics

Biotin is absorbed in the intestine and distributed throughout the body via plasma protein binding. The vitamin is excreted primarily in the urine as metabolites. The body does not store biotin in significant amounts, which necessitates regular dietary intake for maintaining adequate levels. Biotin bioavailability can be affected by various factors, including the presence of specific food components and the individual's health status.

Adverse effects

• Dry skin
• Seborrheic dermatitis
• Fungal infections
• Erythematous periorofacial macular rash
• Fine and brittle hair
• Hair loss or total alopecia
• Neurological symptoms including mild depression
• Changes in mental status

Precautions

• Monitor for signs of biotin deficiency in patients with malabsorption syndromes
• Evaluate dietary intake in patients at risk of deficiency
• Consider possible interactions with other B vitamins

Pregnancy

Biotin is generally considered safe during pregnancy, but supplementation should be discussed with a healthcare provider.

Breast-feeding

Biotin is safe during breastfeeding; however, adequate maternal intake should be ensured.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Formulations

• Oral tablets
• Capsules
• Powders

Indications

• Constipation
• Irritable bowel syndrome (IBS)
• Diverticular disease
• Cholesterol management
• Blood sugar control in diabetes

Dosage

Children: For children, it is recommended to consult a healthcare provider for appropriate dosing based on age and weight, as specific pediatric dosing

Adults: For adults, the typical dosage is 1 to 2 teaspoons (5 to 10 grams) of psyllium husk taken 1 to 3 times daily, mixed with at least 8 ounces of water or other liquid.

Mechanism of action

Psyllium husk acts as a bulk-forming laxative. It is not digested by the body, but when mixed with water, it expands and forms a viscous gel. This gel increases the bulk of the stool and triggers peristalsis, enhancing bowel movements. Additionally, it may slow down the absorption of carbohydrates and fats, contributing to its cholesterol-lowering and blood sugar-regulating effects.

Pharmacodynamics

The primary pharmacodynamic effect of husk is its ability to increase stool bulk and water content, which facilitates easier passage of stool through the intestines. This leads to improved bowel regularity and relief from constipation. Furthermore, psyllium husk has been shown to have a mild effect on lowering serum cholesterol levels, particularly low-density lipoprotein (LDL) cholesterol, and may improve glycemic control in patients with type 2 diabetes.

Pharmacokinetics

Psyllium husk is not absorbed systemically; it remains in the gastrointestinal tract, where it exerts its effects. The onset of action for bowel regulation typically occurs within 12 to 72 hours after ingestion, depending on the individual's digestive transit time and fluid intake. Adequate hydration is essential to maximize its efficacy and prevent potential gastrointestinal obstruction.

Adverse effects

• Bloating
• Abdominal cramping
• Diarrhea
• Nausea

Precautions

• Ensure adequate fluid intake when using husk to prevent gastrointestinal obstruction
• Monitor for allergic reactions in sensitive individuals

Pregnancy

Generally considered safe to use during pregnancy, but always consult a healthcare provider.

Breast-feeding

Considered safe while breastfeeding, but consult a healthcare provider for personalized advice.

Storage

Store in a cool, dry place, away from direct sunlight and moisture.

Formulations

• Psyllium husk powder
• Psyllium husk capsules
• Psyllium husk granules

Indications

• Iodine deficiency
• Goiter
• Hypothyroidism
• Thyroiditis
• Fibrocystic breast disease

Dosage

Children: Refer to the BNF for Children for appropriate dosing guidelines based on age and weight.

Adults: Refer to the BNF for appropriate dosing guidelines based on condition and clinical judgment.

Mechanism of action

Molecular iodine inhibits the induction and promotion of carcinogenesis in mammary tissues and has shown beneficial effects in fibrocystic breast disease. It temporarily decreases thyroid hormone production through the acute Wolff-Chaikoff effect, followed by a return to normal hormone synthesis due to down regulation of the sodium-iodide symport. This mechanism can lead to a transient hypothyroid state in some individuals with underlying thyroid conditions.

Pharmacodynamics

Iodine is vital for the synthesis of thyroid hormones thyroxine (T4) and triiodothyronine (T3). It affects the metabolism of amine-derived hormones and plays a role in amino acid metabolism. The acute excess of iodide can lead to decreased circulating levels of T4 and T3 in susceptible individuals, while most people can escape this effect and maintain normal thyroid function.

Pharmacokinetics

Iodine is absorbed primarily in the gastrointestinal tract and is distributed throughout the body, particularly in the thyroid gland, where it is concentrated for hormone synthesis. The kidney plays a significant role in the excretion of excess iodine. The half-life of iodine in the body varies and can be influenced by dietary intake and underlying health conditions.

Adverse effects

• Hypothyroidism
• Hyperthyroidism
• Iodine allergy
• Gastrointestinal disturbances

Interactions

• Thyroid hormones
• Antithyroid drugs
• Lithium
• Diuretics

Precautions

• Use with caution in patients with thyroid dysfunction
• Monitor thyroid function periodically during treatment
• Pregnant or breastfeeding women should consult a healthcare provider before use

Pregnancy

Iodine is essential for fetal thyroid hormone synthesis, but excessive iodine intake should be avoided.

Breast-feeding

Iodine is excreted in breast milk; consult a healthcare provider regarding supplementation.

Storage

Store in a cool, dry place away from light.

Formulations

• Iodine solution
• Iodine tincture
• Potassium iodide tablets

Indications

• Vitamin B3 deficiency
• Hyperlipidemia
• Dyslipidemia

Mechanism of action

Niacin decreases lipids and apolipoprotein B (apo B)-containing lipoproteins by modulating triglyceride synthesis in the liver and inhibiting lipolysis in adipose tissue. It inhibits hepatocyte diacylglycerol acyltransferase-2, preventing the final step of triglyceride synthesis, leading to reduced VLDL production. Additionally, niacin inhibits HDL catabolism receptors, increasing HDL levels and half-life. Acute effects include inhibition of nonesterified fatty acid release from adipocytes and stimulation of prostaglandin release from skin Langerhans cells, although these acute effects diminish over time.

Pharmacodynamics

Niacin is used therapeutically to treat vitamin deficiencies and to manage conditions like hyperlipidemia and dyslipidemia. It effectively reduces levels of VLDL and LDL while increasing HDL levels. Niacin has a wide therapeutic window, with typical oral doses ranging from 500 mg to 2000 mg. Caution is advised in patients with diabetes, renal failure, uncontrolled hypothyroidism, and in elderly patients, particularly when combined with simvastatin or lovastatin, due to an increased risk of myopathy and rhabdomyolysis.

Pharmacokinetics

Niacin is absorbed from the gastrointestinal tract and undergoes hepatic metabolism. It is excreted primarily in the urine. The pharmacokinetics can be affected by factors such as age, renal function, and concomitant medications. Peak plasma concentrations are typically reached within 30 minutes to 2 hours after oral administration, depending on the formulation used.

Contra-indications

• Hypersensitivity to niacin or any of its components
• Active liver disease
• Peptic ulcer disease

Adverse effects

• Flushing
• Itching
• Nausea
• Vomiting
• Diarrhea
• Abdominal pain
• Hepatotoxicity
• Hyperglycemia
• Gout exacerbation

Interactions

• Increased risk of myopathy and rhabdomyolysis with statins such as simvastatin or lovastatin
• May enhance the effects of antihypertensive medications
• Potential interaction with anticoagulants

Precautions

• Caution in patients with diabetes due to potential for hyperglycemia
• Monitor liver function tests periodically during prolonged therapy
• Use with caution in patients with renal impairment
• Elderly patients may be more susceptible to adverse effects

Pregnancy

Niacin should only be used during pregnancy if clearly needed and the benefits outweigh the risks. Consult with a healthcare provider for individual assessment.

Breast-feeding

Niacin is excreted in breast milk. Caution is advised when administering to nursing mothers, and a decision should be made whether to discontinue breastfeeding or the drug.

Storage

Store at room temperature, away from moisture and heat. Keep out of reach of children.

Formulations

• Immediate-release tablets
• Extended-release tablets
• Sustained-release tablets

Indications

• Wound healing
• Oral health (e.g., gingivitis, mouth ulcers)
• Anti-inflammatory conditions
• Gastrointestinal disorders (e.g., dyspepsia)
• Antimicrobial applications

Dosage

Children: Refer to established herbal guidelines as specific dosing information may vary based on preparation and condition being treated.

Adults: Refer to established herbal guidelines as specific dosing information may vary based on preparation and condition being treated.

Mechanism of action

The active compounds in officinale, such as resins and essential oils, exhibit their effects through various mechanisms, including the inhibition of pro-inflammatory cytokines and modulation of immune responses. These actions contribute to its analgesic and antimicrobial properties, making it beneficial in treating wounds and oral infections.

Pharmacodynamics

Myrrh has demonstrated a range of pharmacodynamic effects, including analgesia, anti-inflammatory activity, and antimicrobial action. The resin contains various terpenoids and phenolic compounds, which interact with biological pathways to exert these effects. Studies suggest that myrrh may inhibit the growth of certain bacteria and fungi, as well as reduce inflammation by blocking the synthesis of pro-inflammatory mediators.

Pharmacokinetics

The pharmacokinetics of myrrh are not well-defined due to variability in preparation and formulation. However, it is generally believed that the compounds are absorbed through the gastrointestinal tract when ingested, with some components potentially being metabolized in the liver. The onset of action may vary depending on the method of administration, with topical applications likely providing localized effects.

Pregnancy

Safety during pregnancy has not been established; consult a healthcare provider before use.

Breast-feeding

Consult a healthcare provider before using, as safety during breastfeeding is not well established.

Storage

Store in a cool, dry place away from direct sunlight.

Indications

• Constipation
• Irritable bowel syndrome
• Diverticulosis
• Hyperlipidemia
• Diabetes management

Dosage

Children: For children aged 6 to 12 years, the typical dosage is 1 to 2 teaspoons of psyllium husk mixed with water, 1 to 3 times a day. For children under 6 years, consult the BNF for Children for appropriate dosing guidelines.

Adults: The usual adult dosage is 3.5 to 7 grams (1 to 2 tablespoons) of psyllium husk taken with at least 240 ml of water, typically 1 to 3 times a day. Refer to the BNF for specific product formulations and dosing.

Mechanism of action

Psyllium works by absorbing water in the intestine to form a gel-like substance, which increases stool bulk and promotes peristalsis. This action helps to alleviate constipation and maintain bowel health. By enhancing fecal mass, psyllium also helps in reducing cholesterol absorption in the intestines.

Pharmacodynamics

Psyllium's pharmacodynamic properties are characterized by its ability to swell in water, producing a viscous gel that enhances stool consistency and frequency of bowel movements. It does not undergo metabolism in the body but influences gastrointestinal motility and fluid absorption.

Pharmacokinetics

Psyllium is not absorbed systemically as it is a soluble fiber. It passes through the gastrointestinal tract largely intact, with its primary action occurring in the intestines. The onset of action for constipation relief typically occurs within 12 to 72 hours after ingestion, depending on the individual’s hydration status and dosage.

Contra-indications

• Bowel obstruction
• Severe abdominal pain of unknown origin
• Fecal impaction
• Hypersensitivity to psyllium or any of its components

Adverse effects

• Abdominal cramping
• Diarrhea
• Nausea
• Vomiting
• Flatulence
• Esophageal obstruction
• Allergic reactions

Interactions

• May reduce absorption of concomitant medications if taken simultaneously
• Increased risk of gastrointestinal obstruction when taken with certain medications that can cause constipation

Precautions

• Ensure adequate fluid intake to prevent esophageal or intestinal obstruction
• Use with caution in patients with a history of gastrointestinal disorders
• Monitor for signs of allergic reactions

Pregnancy

Psyllium is generally considered safe for use during pregnancy, but it is always advisable to consult a healthcare provider before use.

Breast-feeding

Psyllium is not expected to pose a risk during breastfeeding, but consult a healthcare provider for personalized advice.

Storage

Store in a cool, dry place, away from direct sunlight. Keep out of reach of children.

Formulations

• Powder for oral suspension
• Capsules
• Granules

Indications

• Vitamin B6 deficiency
• Peripheral neuropathy associated with isoniazid therapy
• Supplementation in specific dietary deficiencies

Dosage

Children: Refer to the BNF for Children for specific paediatric dosing guidance.

Adults: Refer to the BNF for specific dosing details, typically 10-50 mg daily for deficiency.

Mechanism of action

Pyridoxine, mainly in its active form pyridoxal 5'-phosphate, is involved in numerous biochemical reactions, including amino acid metabolism, glycogen breakdown, nucleic acid synthesis, and the production of key neurotransmitters. It aids in the synthesis of hemoglobin and sphingolipids, and its deficiency can impair several physiological processes, including immune response and vascular health.

Pharmacodynamics

Pyridoxine is utilized for the prevention and treatment of vitamin B6 deficiency, particularly in individuals undergoing treatment with isoniazid, which can deplete vitamin B6 levels. It may also have beneficial effects on blood pressure and lipid profiles, as studies have shown it can lower both systolic and diastolic blood pressure, inhibit platelet aggregation, and improve cholesterol levels. Additionally, it plays a role in enhancing immune function and protecting endothelial cells from injury.

Pharmacokinetics

Pyridoxine is rapidly absorbed from the gastrointestinal tract. It is transported to tissues where it is phosphorylated to its active form, pyridoxal 5'-phosphate. The vitamin is primarily excreted in urine as pyridoxine and its metabolites. Its half-life varies depending on the individual’s nutritional status and other factors. Adequate dietary intake is essential for maintaining optimal levels in the body.

Pregnancy

Pyridoxine is generally considered safe during pregnancy. However, high doses should be avoided unless specifically prescribed.

Breast-feeding

Pyridoxine is excreted in breast milk, but at normal dietary levels it is considered safe for breastfeeding mothers.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Formulations

• Tablets
• Oral solution
• Injectable form

Indications

• Vitamin A deficiency
• Night blindness
• Impaired wound healing
• Epithelial disorders

Dosage

Children: Refer to BNF for Children for specific paediatric dosing information.

Adults: Refer to BNF for specific adult dosing information.

Mechanism of action

Retinol is converted in the retina to 11-cis-retinal, which is crucial for the conversion of light into neural signals necessary for vision. It binds to opsin in rhodopsin, facilitating the isomerization to all-trans-retinal upon exposure to light, thus triggering visual signaling. Additionally, retinol interacts with retinoic acid receptors (RARs) and retinoid-X receptors (RXRs) as transcription factors, modulating gene expression related to cellular differentiation and growth.

Pharmacodynamics

Vitamin A is effective in treating Vitamin A deficiency, which can lead to vision impairment and other health issues. It plays a critical role in various biological processes including vision, cellular differentiation, reproduction, and immune system function. Its deficiency can cause symptoms such as night blindness and impaired wound healing, while adequate levels support growth and development.

Pharmacokinetics

Retinol is absorbed from the gastrointestinal tract and stored in the liver, where it can be mobilized as needed. It undergoes metabolism primarily in the liver, where it is converted to retinal and retinoic acid, the active forms of Vitamin A. The elimination half-life varies, but retinol is generally excreted in urine and bile. The bioavailability can be affected by dietary fat intake.

Adverse effects

• Nausea
• Vomiting
• Headache
• Dizziness
• Fatigue
• Irritability
• Dry skin
• Peeling of skin
• Itching
• Blurred vision

Precautions

• Use with caution in patients with liver disease due to potential hepatotoxicity.
• Monitor for signs of vitamin A toxicity, especially in patients on high doses or prolonged therapy.
• Caution in patients with a history of alcohol abuse, as it may exacerbate liver conditions.

Pregnancy

Retinol should be used with caution during pregnancy due to the risk of teratogenic effects. High doses of vitamin A can lead to fetal malformations.

Breast-feeding

Retinol is generally considered safe during breastfeeding, but excessive intake should be avoided to prevent potential adverse effects on the infant.

Storage

Store in a cool, dry place away from light. Keep out of reach of children.

Formulations

• Capsules
• Tablets
• Oral solutions
• Topical preparations

Indications

• Nausea and vomiting
• Osteoarthritis
• Rheumatoid arthritis
• Digestive disorders
• Inflammatory conditions
• Muscle pain

Dosage

Children: Refer to specific herbal product guidelines, as dosing can vary widely based on the preparation and intended use.

Adults: Refer to specific herbal product guidelines, as dosing can vary widely based on the preparation and intended use.

Mechanism of action

The active compounds in rhizomes, such as gingerol in ginger and curcumin in turmeric, exert their effects through various pathways. Gingerol has been shown to inhibit pro-inflammatory cytokines and enzymes such as cyclooxygenase and lipoxygenase, which play a key role in inflammation. Curcumin modulates multiple signaling pathways, including nuclear factor kappa B (NF-kB) and mitogen-activated protein kinase (MAPK) pathways, ultimately reducing inflammation and oxidative stress.

Pharmacodynamics

Rhizome extracts demonstrate a range of pharmacological effects, including analgesic, anti-inflammatory, and gastroprotective actions. The compounds are known to enhance gastric motility and may help in alleviating nausea and vomiting, particularly in motion sickness and chemotherapy-induced nausea.

Pharmacokinetics

The bioavailability of rhizome compounds can vary significantly depending on the plant source and the method of preparation. For instance, curcumin has low bioavailability due to rapid metabolism and systemic elimination. However, formulations that include piperine (found in black pepper) can enhance the absorption of curcumin. The compounds are generally metabolized in the liver and excreted through urine and feces.

Pregnancy

Limited data is available on the safety of rhizome in pregnancy. Consultation with a healthcare professional is recommended before use.

Breast-feeding

Limited data is available on the safety of rhizome during breastfeeding. Consultation with a healthcare professional is recommended before use.

Storage

Store in a cool, dry place, away from direct sunlight and moisture.

Indications

• Thiamine deficiency
• Wernicke's encephalopathy
• Beriberi
• Alcoholism-related complications
• Certain metabolic disorders

Dosage

Children: Refer to BNF for Children for appropriate dosing information.

Adults: Refer to established clinical guidelines or BNF for specific dosing recommendations.

Mechanism of action

Thiamine is a coenzyme for several important enzymatic reactions, including the pyruvate dehydrogenase complex and alpha-ketoglutarate dehydrogenase. It is essential for converting carbohydrates into energy, facilitating the metabolism of glucose, and maintaining normal nerve function.

Pharmacodynamics

Thiamine deficiency leads to impaired carbohydrate metabolism, which can result in neurological and cardiovascular dysfunction. Supplementation with thiamine helps restore normal metabolic function and can alleviate symptoms associated with deficiency, such as Wernicke's encephalopathy and Beriberi. It also plays a role in the synthesis of neurotransmitters and in maintaining myelin integrity.

Pharmacokinetics

Thiamine is readily absorbed from the gastrointestinal tract, with peak plasma concentrations occurring within 1-2 hours after oral administration. It is distributed throughout the body, primarily in the liver, kidneys, and heart. Thiamine is metabolized in the liver to its active form, thiamine pyrophosphate. It has a biological half-life of about 9-18 days and is excreted primarily in the urine. Excess thiamine is excreted, making toxicity rare.

Adverse effects

• Allergic reactions
• Hypersensitivity reactions
• Gastrointestinal disturbances

Interactions

• May interact with certain diuretics, leading to altered thiamine levels

Precautions

• Use with caution in patients with renal impairment
• Monitor patients with a history of thiamine deficiency

Pregnancy

Thiamine is considered safe during pregnancy, as it is an essential nutrient.

Breast-feeding

Thiamine is excreted in breast milk, but supplementation is generally considered safe for breastfeeding mothers.

Storage

Store in a cool, dry place away from direct sunlight.

Formulations

• Thiamine hydrochloride injection
• Thiamine hydrochloride oral tablets
• Thiamine hydrochloride oral solution

Indications

• Prevention of vitamin E deficiency
• Antioxidant therapy
• Support in conditions related to oxidative stress

Dosage

Children: Refer to BNF for Children for specific dosage guidelines.

Adults: Refer to BNF for specific dosage guidelines.

Mechanism of action

Tocopherol acts as a radical scavenger, primarily functioning as an antioxidant for lipid bilayers. It donates hydrogen atoms to free radicals, trapping them and preventing cellular damage. Its effectiveness is influenced by its location within the membrane and its interaction with cytosolic reductants like ascorbate. Tocopherol can trap multiple radicals, including alkyl and peroxy radicals.

Pharmacodynamics

The antioxidant properties of tocopherol lead to significant pharmacodynamic effects, including the inhibition of cell death through modulation of protein kinase C (PKC). Tocopherol also exhibits anti-inflammatory effects, which can be attributed to its influence on cytokines, prostaglandins, prostanoids, and thromboxanes. These interactions may contribute to its protective effects in various pathological conditions.

Pharmacokinetics

Tocopherol is absorbed in the intestines and its bioavailability can be influenced by dietary fat intake. It is transported in the plasma primarily bound to lipoproteins. Tocopherol is stored in adipose tissue and the liver, and its elimination occurs through bile and urine. The half-life of tocopherol can vary depending on the individual's nutritional status and other factors.

Pregnancy

Tocopherol is generally considered safe during pregnancy, but it is advisable to consult a healthcare provider before use.

Breast-feeding

Tocopherol is excreted in breast milk, and while it is considered safe, a healthcare provider should be consulted for specific recommendations.

Storage

Store in a cool, dry place away from direct sunlight.

Indications

• Vitamin deficiency syndromes (e.g., scurvy for vitamin C deficiency, rickets for vitamin D deficiency)
• Support for immune function
• Antioxidant support
• Bone health maintenance
• Vision health
• Energy metabolism support

Dosage

Children: Refer to the BNF for Children for specific vitamin dosing guidelines, which depend on age and nutritional requirements.

Adults: Refer to specific vitamin guidelines as dosage varies significantly depending on the type of vitamin and individual needs.

Mechanism of action

Vitamins function primarily as coenzymes or precursors for coenzymes in enzymatic reactions. For instance, B vitamins are involved in energy metabolism, while vitamins A, C, D, E, and K support various physiological functions including vision, antioxidant activity, calcium regulation, and blood clotting. Each vitamin has a unique mechanism of action based on its structure and role in the body.

Pharmacodynamics

Vitamins exert their effects at the cellular level, influencing metabolic pathways, gene expression, and immune responses. For example, vitamin D regulates calcium and phosphate homeostasis, while vitamin A is crucial for vision and immune function. Deficiencies in vitamins can lead to a range of disorders, highlighting their importance in maintaining health.

Pharmacokinetics

The pharmacokinetics of vitamins vary widely. Fat-soluble vitamins (A, D, E, and K) are stored in liver and adipose tissues and can be released into circulation as needed. Water-soluble vitamins (B-complex and C) are not stored and must be consumed regularly, with excess amounts excreted in urine. Absorption rates, half-lives, and distribution can also differ based on the specific vitamin and individual metabolic factors.

Interactions

• tretinoin+vitamin: Severe (increases risk of vitamin toxicity)
• retinoids+vitamin: Severe (increases risk of vitamin toxicity)
• retinoids+vitamin: Moderate (increases risk of toxicity)
• carbamazepine+vitamin: Unknown (decreases effects)
• cobicistat+vitamin: Unknown (increases exposure)
• vitamin D substances+digoxin: Unknown (increases risk of toxicity)
• idelalisib+vitamin: Unknown (increases exposure)
• clarithromycin+vitamin: Unknown (increases exposure)

Pregnancy

Consult healthcare professional before use. Vitamin supplementation during pregnancy should be carefully managed to avoid hypervitaminosis.

Breast-feeding

Consult healthcare professional before use. Some vitamins can pass into breast milk and may affect the infant.

Storage

Store in a cool, dry place, away from direct sunlight. Ensure it is kept out of reach of children.

Formulations

• {'name': 'Vitamin A', 'form': 'Capsule', 'strength': '10000 IU'}
• {'name': 'Vitamin D', 'form': 'Tablet', 'strength': '1000 IU'}
• {'name': 'Vitamin E', 'form': 'Softgel', 'strength': '400 IU'}

Indications

• Nausea and vomiting associated with motion sickness
• Nausea in pregnancy (morning sickness)
• Post-operative nausea and vomiting
• Osteoarthritis and other inflammatory joint conditions
• Dyspepsia and gastrointestinal discomfort

Dosage

Children: Refer to established guidelines and consult a healthcare professional for appropriate dosing based on formulation and indication.

Adults: Refer to established guidelines and consult a healthcare professional for appropriate dosing based on formulation and indication.

Mechanism of action

Ginger contains bioactive compounds, including gingerol and shogaol, which exhibit anti-inflammatory and antioxidant effects. The mechanism of action involves the inhibition of pro-inflammatory cytokines and enzymes, such as cyclooxygenase and lipoxygenase, leading to reduced inflammation. Ginger also enhances gastrointestinal motility and may exert a protective effect on the gastric mucosa.

Pharmacodynamics

The pharmacodynamic effects of ginger are primarily attributed to its active constituents, which modulate various physiological pathways. Gingerol and shogaol have been shown to influence the release of serotonin and other neurotransmitters, thereby alleviating nausea. Additionally, ginger's antioxidant properties help to mitigate oxidative stress in cells, contributing to its anti-inflammatory effects.

Pharmacokinetics

Ginger is rapidly absorbed in the gastrointestinal tract, with peak plasma concentrations of its active compounds occurring within 1-2 hours after ingestion. The bioavailability of gingerol and shogaol can be affected by the formulation and method of preparation (e.g., fresh, dried, or as an extract). The elimination half-life of these compounds is variable, with metabolism occurring primarily in the liver. They are excreted through urine and bile, and their effects can last for several hours.

Adverse effects

• Gastrointestinal discomfort
• Heartburn
• Nausea
• Diarrhea
• Skin irritation

Interactions

• Anticoagulants (e.g., warfarin)
• Antidiabetic medications
• Antihypertensive medications

Precautions

• Use with caution in patients with gallstones
• May affect blood sugar levels; monitor in diabetic patients
• May increase the risk of bleeding when used with anticoagulants

Pregnancy

Zingiber (ginger) is generally considered safe in food amounts during pregnancy. However, high doses should be avoided due to potential risks.

Breast-feeding

Zingiber is likely safe in food amounts while breastfeeding, but high doses should be avoided.

Storage

Store in a cool, dry place, away from direct sunlight.

Formulations

• Dried root
• Powder
• Capsules
• Tinctures
• Essential oil

Mechanism of action

Binds to riboflavin hydrogenase, riboflavin kinase, and riboflavin synthase. Riboflavin is the precursor of flavin mononucleotide (FMN, riboflavin monophosphate) and flavin adenine dinucleotide (FAD). The antioxidant activity of riboflavin is principally derived from its role as a precursor of FAD and the role of this cofactor in the production of the antioxidant reduced glutathione. Reduced glutathione is the cofactor of the selenium-containing glutathione peroxidases among other things. The glutathione peroxidases are major antioxidant enzymes. Reduced glutathione is generated by the FAD-containing enzyme glutathione reductase. Riboflavin is converted to 2 coenzymes, flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), which are necessary for normal tissue respiration. Riboflavin is also required for activation of pyridoxine, conversion of tryptophan to niacin, and may be involved in maintaining erythrocyte integrity. Riboflavin functions as the coenzyme for flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN), which primarily influence hydrogen transport in oxidative enzyme systems (eg, cytochrome C reductase, succinic dehydrogenase, xanthine oxidase). Two active forms of riboflavin exist ... coenzyme flavin mononucleotide (FMN) and coenzyme flavin adenine dinucleotide (FAD). They are formed by reaction of riboflavin with 1 and 2 molecules of ATP as follow: riboflavin + ATP = riboflavin-P (FMN) + ADP; FMN + ATP = riboflavin-ADP (FAD) + PP. Riboflavin is a water-soluble, yellow, fluorescent compound. The primary form of the vitamin is as an integral component of the coenzymes flavin mononucleotide (FMN) and flavin-adenine dinucleotide (FAD). It is in these bound coenzyme forms that riboflavin functions as a catalyst for redox reactions in numerous metabolic pathways and in energy production. ... The redox reactions in which flavocoenzymes participate include flavoprotein-catalyzed dehydrogenations that are both pyridine nucleotide (niacin) dependent and independent, reactions with sulfur-containing compounds, hydroxylations, oxidative decarboxylations (involving thiamin as its pyrophosphate), dioxygenations, and reduction of oxygen to hydrogen peroxide. There are obligatory roles of flavocoenzymes in the formation of some vitamins and their coenzymes. For example, the biosynthesis of two niacin-containing coenzymes from tryptophan occurs via FAD-dependent kynurenine hydroxylase, an FMN-dependent oxidase catalyzes the conversion of the 5'-phosphates of vitamin B6 to coenzymic pyridoxal 5'-phosphate, and an FAD-dependent dehydrogenase reduces 5,10-methylene-tetrahydrofolate to the 5'-methyl product that interfaces with the B12-dependent formation of methionine from homocysteine and thus with sulfur amino acid metabolism. For more Mechanism of Action (Complete) data for Riboflavin (7 total), please visit the HSDB record page.

Pharmacodynamics

Riboflavin or vitamin B2 is an easily absorbed, water-soluble micronutrient with a key role in maintaining human health. Like the other B vitamins, it supports energy production by aiding in the metabolising of fats, carbohydrates, and proteins. Vitamin B2 is also required for red blood cell formation and respiration, antibody production, and for regulating human growth and reproduction. It is essential for healthy skin, nails, hair growth and general good health, including regulating thyroid activity. Riboflavin also helps in the prevention or treatment of many types of eye disorders, including some cases of cataracts.

Mechanism of action

Selenium is first metabolized to selenophosphate and selenocysteine. Selenium incorporation is genetically encoded through the RNA sequence UGA. This sequence is recognized by RNA ste loop structures called selenocysteine inserting sequences (SECIS). These structures require the binding of SECIS binding proteins (SBP-2) to recognize selenocystiene. The specialized tRNA is first bound to a serine residue which is then enzymatically processed to a selylcysteyl-tRNA by selenocystiene sythase using selenophosphate as a selenium donor. Other unidentified proteins are required as part of the binding of this tRNA to the ribosome. Selenoproteins appear to be necessary for life as mice with the specialized tRNA gene knocked out exhibited early embryonic lethality. The most important selenoproteins seem to be the glutathione peroxidases and thioredoxin reductases which are part of the body's defenses againts reactive oxygen species (ROS). The importance of selenium in these anti-oxidant proteins has been implicated in the reduction of atherosclerosis by preventing the oxidation of low density lipoprotein. Selenium supplementation is also being investigated in the prevention of cancer and has been suggested to be beneficial to immune function. Converging data from epidemiological, ecological, and clinical studies have shown that selenium (Se) can decrease the risk for some types of human cancers. Induction of apoptosis is considered an important cellular event that can account for the cancer preventive effects of Se. Prior to occurrence of apoptosis, Se compounds alter the expression and/or activities of signaling molecules, mitochondria-associated factors, transcriptional factors, tumor suppressor genes, and cellular reduced glutathione. Mechanistic studies have demonstrated that the methylselenol metabolite pool has many desirable attributes of chemoprevention, whereas the hydrogen selenide pool with excess of selenoprotein synthesis can lead to DNA single-strand breaks. To elucidate the effects of Se on cytotoxic events, it should be remembered that the chemical forms and the dose of Se, and the experimental system used, are determinants of its biological activities. This mini-review focuses on elucidation of the molecular mechanisms of cancer prevention by Se with the apoptotic approach. /Selenium/ Selenium status can also influence thyroid hormone function via the deiodinase enzymes. Selenium is a critical component of the deiodinase enzymes, including iodothyronine 5'-deiodinases, which convert the prohormone thyroxine (T4) to the active circulating form, triiodothyronine (T3). Selenium is also a component of GPX, the main enzyme responsible for protecting thyroid cells against oxidative damage. GPX is involved in the detoxification of hydrogen peroxide, which is produced in the thyroid during the conversion of T4 to T3. /Selenium/ Selenium readily substitutes for sulfur in biomolecules and in many biochemical reactions, especially when the concentration of selenium is high and the concentration of sulfur is low in the organism. Inactivation of the sulfhydryl enzymes necessary for oxidative reactions in cellular respiration, through effects on mitochondrial and microsomal electron transport, might contribute to acute selenium toxicity. Selenium may have a role in hepatic heme metabolism that is related to GPX or lipid peroxidation. Selenocysteine is specifically found in some proteins (e.g., glutathione peroxidase); selenomethionine appears to randomly substitute for methionine in protein synthesis. This appears to be an additional mechanism for intermediate- or chronic-duration toxicity. Skin, hair, and nail damage are significant indicators of chronic selenium overexposure. The mechanism causing these integumentary effects is unclear, but could be related to the high selenium concentrations in these tissues as a consequence of the substitution of selenium for sulfur in certain amino acids, including the disulfide bridges that pr

Pharmacodynamics

Selenium is incorporated into many different selenoproteins which serve various functions throughout the body.

Mechanism of action

It is thought that the mechanism of action of thiamine on endothelial cells is related to a reduction in intracellular protein glycation by redirecting the glycolytic flux. Thiamine is mainly the transport form of the vitamin, while the active forms are phosphorylated thiamine derivatives. Natural derivatives of thiamine phosphate, such as thiamine monophosphate (ThMP), thiamine diphosphate (ThDP), also sometimes called thiamine pyrophosphate (TPP), thiamine triphosphate (ThTP), and thiamine triphosphate (AThTP), that act as coenzymes in addition to their each unique biological functions. Metabolic control analysis predicts that stimulators of transketolase enzyme synthesis such as thiamin (vitamin B-1) support a high rate of nucleic acid ribose synthesis necessary for tumor cell survival, chemotherapy resistance, and proliferation. Metabolic control analysis also predicts that transketolase inhibitor drugs will have the opposite effect on tumor cells. This may have important implications in the nutrition and future treatment of patients with cancer.

Pharmacodynamics

Thiamine is a vitamin with antioxidant, erythropoietic, cognition-and mood-modulatory, antiatherosclerotic, putative ergogenic, and detoxification activities. Thiamine has been found to protect against lead-induced lipid peroxidation in rat liver and kidney. Thiamine deficiency results in selective neuronal death in animal models. The neuronal death is associated with increased free radical production, suggesting that oxidative stress may play an important early role in brain damage associated with thiamine deficiency. Thiamine plays a key role in intracellular glucose metabolism and it is thought that thiamine inhibits the effect of glucose and insulin on arterial smooth muscle cell proliferation. Inhibition of endothelial cell proliferation may also promote atherosclerosis. Endothelial cells in culture have been found to have a decreased proliferative rate and delayed migration in response to hyperglycemic conditions. Thiamine has been shown to inhibit this effect of glucose on endothelial cells.

Mechanism of action

Chromium is an essential nutrient involved in the metabolism of glucose, insulin and blood lipids. Its role in potentiating insulin signalling cascades has been implicated in several studies. Chromium upregulates insulin-stimulated insulin signal transduction via affecting effector molecules downstream of the insulin receptor (IR). IR-mediated signalling pathway involves phoshorylation of multiple intracellular domains and protein kinases, and downstream effector molecules. Upon activation by ligands, intracellular β-subunit of IR autophosphorylates and activates tyrosine kinase domain of the IR, followed by activation and phosphorylation of regulatory proteins and downstream signalling effectors including phosphatidylinositol 2-kinase (PI3K). PI3K activates further downstream reaction cascades to activate protein kinase B (Akt) to ultimately promote translocation of glucose transporter-4 (Glut4)-vesicles from the cytoplasm to the cell surface and regulate glucose uptake. Chromium enhances the kinase activity of insulin receptor β and increases the activity of downstream effectors, pI3-kinase and Akt. Under insulin-resistant conditions, chromium also promotes GLUT-4 transporter translocation that is independent of activity of IR, IRS-1, PI3-kinase, or Akt; chromium mediates cholesterol efflux from the membranes via increasing fluidity of the membrane by decreasing the membrane cholesterol and upregulation of sterol regulatory element-binding protein. As a result, intracellular GLUT-4 transporters are stimulated to translocate from intracellular to the plasma membrane, leading to enhanced glucose uptake in muscle cells. Chromium attenuates the activity of PTP-1B _in vitro,_ which is a negative regulator of insulin signaling. It also alleviates ER stress that is observed to be elevated the suppression of insulin signaling. ER stress is thought to activate c-Jun N-terminal kinase (JNK), which subsequently induces serine phosphorylation of IRS and aberration of insulin signalling. Transient upregulation of AMPK by chromium also leads to increased glucose uptake. While the toxicity of metals and metalloids, like arsenic, cadmium, mercury, lead and chromium, is undisputed, the underlying molecular mechanisms are not entirely clear. General consensus holds that proteins are the prime targets; heavy metals interfere with the physiological activity of specific, particularly susceptible proteins, either by forming a complex with functional side chain groups or by displacing essential metal ions in metalloproteins. Recent studies have revealed an additional mode of metal action targeted at proteins in a non-native state; certain heavy metals and metalloids have been found to inhibit the in vitro refolding of chemically denatured proteins, to interfere with protein folding in vivo and to cause aggregation of nascent proteins in living cells. Apparently, unfolded proteins with motile backbone and side chains are considerably more prone to engage in stable, pluridentate metal complexes than native proteins with their well-defined 3D structure. By interfering with the folding process, heavy metal ions and metalloids profoundly affect protein homeostasis and cell viability. This review describes how heavy metals impede protein folding and promote protein aggregation, how cells regulate quality control systems to protect themselves from metal toxicity and how metals might contribute to protein misfolding disorders.

Pharmacodynamics

Trivalent chromium is part of glucose tolerance factor, an essential activator of insulin-mediated reactions. Chromium helps to maintain normal glucose metabolism and peripheral nerve function. Chromium increases insulin binding to cells, increases insulin receptor density and activates insulin receptor kinase leading to enhanced insulin sensitivity. In chromium deficiency, intravenous administration of chromium resulted in normalization of the glucose tolerance curve from the diabetic-like curve typical of chromium deficiency.

Mechanism of action

Copper is absorbed from the gut via high affinity copper uptake protein and likely through low affinity copper uptake protein and natural resistance-associated macrophage protein-2. It is believed that copper is reduced to the Cu1+ form prior to transport. Once inside the enterocyte, it is bound to copper transport protein ATOX1 which shuttles the ion to copper transporting ATPase-1 on the golgi membrane which take up copper into the golgi apparatus. Once copper has been secreted by enterocytes into the systemic circulation it remain largely bound by ceruloplasmin (65-90%), albumin (18%), and alpha 2-macroglobulin (12%). Copper is an essential element in the body and is incorporated into many oxidase enzymes as a cofactor. It is also a component of zinc/copper super oxide dismutase, giving it an anti-oxidant role. Copper defiency occurs in Occipital Horn Syndrome and Menke's disease both of which are associated with impaired development of connective tissue due to the lack of copper to act as a cofactor in protein-lysine-6-oxidase. Menke's disease is also associated with progressive neurological impairment leading to death in infancy. The precise mechanisms of the effects of copper deficiency are vague due to the wide range of enzymes which use the ion as a cofactor. Copper appears to reduce the viabilty and motility of spermatozoa. This reduces the likelihood of fertilization with a copper IUD, producing copper's contraceptive effect. The exact mechanism of copper's effect on sperm are unknown. The reason for the less severe reaction when the foreign body is at a distance from the retina has been proposed to be ... that near the retina & its blood vessels there is greater oxygen tension than at a distance, which causes metallic copper to oxidize to toxic copper compounds more rapidly close to or in contact with the retina than at a distance. Furthermore, the abscess formation that is characteristic of copper undergoing oxidation close to the retina & choroiod can be attributed to attraction of polymorphonuclear leukocytes from these nearby vascular tissues, which become heavily infiltrated. Liquefaction & disorganization of the vitreous body has been explained on the basis of copper catalysis of oxidation of ascorbic acid, leading to depolymerization of the hyaluronic acid of the vitreous humor. Changes in protein & hexosamine content have also been related to decrease in viscosity of the vitreous humor. Increased content of amino acids in the vitreous humor has been consistent with proteolysis of the vitreous body, but decreased concentration in the aqueous humor has suggested suppression of secretion of amino acids by the ciliary body under the influence of copper.

Pharmacodynamics

Copper is incorporated into many enzymes throughout the body as an essential part of their function. Copper ions are known to reduce fertility when released from copper-containing IUDs.

Mechanism of action

Biotin is necessary for the proper functioning of enzymes that transport carboxyl units and fix carbon dioxide, and is required for various metabolic functions, including gluconeogenesis, lipogenesis, fatty acid biosynthesis, propionate metabolism, and catabolism of branched-chain amino acids. In human tissues biotin is a cofactor for the enzymatic carboxylation of four substrates: pyruvate, acetyl coenzyme A (CoA), propionyl CoA, and beta-methylcrotonyl CoA. As such, it plays an important role in both carbohydrate and fat metabolism. Carbon dioxide fixation occurs in a two-step reaction, the first involving binding of carbon dioxide to the biotin moiety of the holoenzyme, and the second involving transfer of the biotin-bound carbon dioxide to an appropriate acceptor. Biotin functions in carbon dioxide fixation reactions in intermediate metabolism, transferring the carboxyl group to acceptor molecules. It acts similarly in decarboxylation reactions. Biotin is essential in human metabolism for its part in the previously described enzymatic steps, in catalyzing deamination of amino acids, and in oleic acid synthesis. Biotin is a cofactor for the enzymatic carboxylation of pyruvate, acetyl coenzyme A (CoA), propionyl CoA, and beta-methylcrotonyl CoA, and, therefore, plays an important role in carbohydrate and fat metabolism. Protein folding in the endoplasmic reticulum (ER) depends on Ca2+; uptake of Ca2+ into the ER is mediated by sarco/endoplasmic reticulum Ca2+-ATPase 3 (SERCA3). The 5'-flanking region of the SERCA3 gene (ATP2A3) contains numerous binding sites for the transcription factors Sp1 and Sp3. Biotin affects the nuclear abundance of Sp1 and Sp3, which may act as transcriptional activators or repressors. Here we determined whether biotin affects the expression of the SERCA3 gene and, thus, protein folding in human lymphoid cells. Jurkat cells were cultured in media containing 0.025 nmol/L biotin (denoted "deficient") or 10 nmol/L biotin ("supplemented"). The transcriptional activity of the full-length human SERCA3 promoter was 50% lower in biotin-supplemented cells compared to biotin-deficient cells. Biotin-dependent repressors bind to elements located 731 to 1312 bp upstream from the transcription start site in the SERCA3 gene. The following suggest that low expression of SERCA3 in biotin-supplemented cells impaired folding of secretory proteins in the ER, triggering unfolded protein response: (i) sequestration of Ca2+ in the ER decreased by 14 to 24% in response to biotin supplementation; (ii) secretion of interleukin-2 into the extracellular space decreased by 75% in response to biotin supplementation; (iii) the nuclear abundance of stress-induced transcription factors increased in response to biotin supplementation; and (iv) the abundance of stress-related proteins such ubiquitin activating enzyme 1, growth arrest and DNA damage 153 gene, X-box binding protein 1 and phosphorylated eukaryotic translation initiation factor 2alpha increased in response to biotin supplementation. Collectively, this study suggests that supplements containing pharmacological doses of biotin may cause cell stress by impairing protein folding in the ER. Evidence is emerging that biotin participates in processes other than classical carboxylation reactions. Specifically, novel roles for biotin in cell signaling, gene expression, and chromatin structure have been identified in recent years. Human cells accumulate biotin by using both the sodium-dependent multivitamin transporter and monocarboxylate transporter 1. These transporters and other biotin-binding proteins partition biotin to compartments involved in biotin signaling: cytoplasm, mitochondria, and nuclei. The activity of cell signals such as biotinyl-AMP, Sp1 and Sp3, nuclear factor (NF)-kappaB, and receptor tyrosine kinases depends on biotin supply. Consistent with a role for biotin and its catabolites in modulating these cell signals, greater than 2000 biotin-dependent genes have

Pharmacodynamics

Biotin is a water-soluble B-complex vitamin which is composed of an ureido ring fused with a tetrahydrothiophene ring, which attaches a valeric acid substituent at one of its carbon atoms. Biotin is used in cell growth, the production of fatty acids, metabolism of fats, and amino acids. It plays a role in the Kreb cycle, which is the process in which energy is released from food. Biotin not only assists in various metabolic chemical conversions, but also helps with the transfer of carbon dioxide. Biotin is also helpful in maintaining a steady blood sugar level. Biotin is often recommended for strengthening hair and nails. Consequenty, it is found in many cosmetic and health products for the hair and skin. Biotin deficiency is a rare nutritional disorder caused by a deficiency of biotin. Initial symptoms of biotin deficiency include: Dry skin, Seborrheic dermatitis, Fungal infections, rashes including erythematous periorofacial macular rash, fine and brittle hair, and hair loss or total alopecia. If left untreated, neurological symptoms can develop, including mild depression, which may progress to profound lassitude and, eventually, to somnolence; changes in mental status, generalized muscular pains (myalgias), hyperesthesias and paresthesias. The treatment for biotin deficiency is to simply start taking some biotin supplements. A lack of biotin in infants will lead to a condition called seborrheic dermatitis or "cradle cap". Biotin deficiencies are extremely rare in adults but if it does occur, it will lead to anemia, depression, hair loss, high blood sugar levels, muscle pain, nausea, loss of appetite and inflamed mucous membranes.

Mechanism of action

Molecular iodine is known to inhibit the induction and promotion of N-methyl-n-nitrosourea-induced mammary carcinogenesis, to regress 7,12-dimethylbenz(a)anthracene-induced breast tumors in rats.It has also been shown to have beneficial effects in fibrocystic human breast disease. An acute iodide excess (above the preexisting dietary intake) transiently decreases the production of thyroid hormones in the thyroid gland; this is referred to as the acute Wolff-Chaikoff effect. In normal people, this is followed by a return to normal levels of hormone synthesis, referred to as escape from the acute Wolff-Chaikoff effect, without a significant change in circulating hormone levels. Escape is thought to be the result of down regulation of the sodium-iodide symport (NIS), the iodide transporter in the thyroid gland, resulting in a decrease in the intrathyroidal iodine and the resumption of normal hormone synthesis. An acute or chronic excess of iodide can also decrease circulating T4 and T3 levels and induce a hypothyroid state in some people who have underlying thyroid disorders. These effects are the result of a failure to escape from the acute Wolff-Chaikoff effect. Most people who experience iodine-induced hypothyroidism recover when the excess iodine intake is discontinued.

Mechanism of action

Niacin performs a number of functions in the body and so has many mechanisms, not all of which have been fully described. Niacin can decrease lipids and apolipoprotein B (apo B)-containing lipoproteins by modulating triglyceride synthesis in the liver, which degrades apo B, or by modulating lipolysis in adipose tissue. Niacin inhibits hepatocyte diacylglycerol acyltransferase-2. This action prevents the final step of triglyceride synthesis in hepatocytes, limiting available triglycerides for very low density lipoproteins (VLDL). This activity also leads to intracellular degradation of apo B and decreased production of low density lipoproteins, the catabolic product of VLDL. Niacin also inhibits a high density lipoprotein (HDL) catabolism receptor, which increases the levels and half life of HDL. Prolonged niacin treatment elicits beneficial effects on the plasma lipid and lipoprotein profile that is associated with a protective CVD risk profile. Acute niacin treatment inhibits nonesterified fatty acid release from adipocytes and stimulates prostaglandin release from skin Langerhans cells, but the acute effects diminish upon prolonged treatment, while the beneficial effects remain. To gain insight in the prolonged effects of niacin on lipid metabolism in adipocytes, we used a mouse model with a human-like lipoprotein metabolism and drug response [female APOE*3-Leiden.CETP (apoE3 Leiden cholesteryl ester transfer protein) mice] treated with and without niacin for 15 weeks. The gene expression profile of gonadal white adipose tissue (gWAT) from niacin-treated mice showed an upregulation of the "biosynthesis of unsaturated fatty acids" pathway, which was corroborated by quantitative PCR and analysis of the FA ratios in gWAT. Also, adipocytes from niacin-treated mice secreted more of the PUFA DHA ex vivo. This resulted in an increased DHA/arachidonic acid (AA) ratio in the adipocyte FA secretion profile and in plasma of niacin-treated mice. Interestingly, the DHA metabolite 19,20-dihydroxy docosapentaenoic acid (19,20-diHDPA) was increased in plasma of niacin-treated mice. Both an increased DHA/AA ratio and increased 19,20-diHDPA are indicative for an anti-inflammatory profile and may indirectly contribute to the atheroprotective lipid and lipoprotein profile associated with prolonged niacin treatment. /The study objective was/ to determine the effects of niacin on adiponectin and markers of adipose tissue inflammation in a mouse model of obesity. Male C57BL/6 mice were placed on a control or high-fat diet (HFD) and were maintained on such diets for the duration of the study. After 6 weeks on the control or high fat diets, vehicle or niacin treatments were initiated and maintained for 5 weeks. Identical studies were conducted concurrently in HCA2 (-/-) (niacin receptor(-/-)) mice. Niacin increased serum concentrations of the anti-inflammatory adipokine, adiponectin by 21% in HFD-fed wild-type mice, but had no effect on lean wild-type or lean or HFD-fed HCA2 (-/-) mice. Niacin increased adiponectin gene and protein expression in the HFD-fed wild-type mice only. The increases in adiponectin serum concentrations, gene and protein expression occurred independently of changes in expression of PPARgamma C/EBPalpha or SREBP-1c (key transcription factors known to positively regulate adiponectin gene transcription) in the adipose tissue. Further, niacin had no effect on adipose tissue expression of ERp44, Ero1-Lalpha, or DsbA-L (key ER chaperones involved in adiponectin production and secretion). However, niacin treatment attenuated HFD-induced increases in adipose tissue gene expression of MCP-1 and IL-1beta in the wild-type HFD-fed mice. Niacin also reduced the expression of the pro-inflammatory M1 macrophage marker CD11c in HFD-fed wild-type mice. Niacin treatment attenuates obesity-induced adipose tissue inflammation through increased adiponectin and anti-inflammatory cytokine expression and reduced pro-inflammatory cytokine expressio

Pharmacodynamics

Niacin is a B vitamin used to treat vitamin deficiencies as well as hyperlipidemia, dyslipidemia, hypertriglyceridemia, and to reduce the risk of myocardial infarctions. Niacin acts to decrease levels of very low density lipoproteins and low density lipoproteins, while increasing levels of high density lipoproteins. Niacin has a wide therapeutic window with usual oral doses between 500mg and 2000mg. Patients with diabetes, renal failure, uncontrolled hypothyroidism, and elderly patients taking niacin with simvastatin or lovastatin are at increased risk of myopathy and rhabdomyolysis.

Mechanism of action

Vitamin B6 is the collective term for a group of three related compounds, pyridoxine (PN), pyridoxal (PL) and pyridoxamine (PM), and their phosphorylated derivatives, pyridoxine 5'-phosphate (PNP), pyridoxal 5'-phosphate (PLP) and pyridoxamine 5'-phosphate (PMP). Although all six of these compounds should technically be referred to as vitamin B6, the term vitamin B6 is commonly used interchangeably with just one of them, pyridoxine. Vitamin B6, principally in its biologically active coenzyme form pyridoxal 5'-phosphate, is involved in a wide range of biochemical reactions, including the metabolism of amino acids and glycogen, the synthesis of nucleic acids, hemogloblin, sphingomyelin and other sphingolipids, and the synthesis of the neurotransmitters serotonin, dopamine, norepinephrine and gamma-aminobutyric acid (GABA).

Pharmacodynamics

Vitamin B6 (pyridoxine) is a water-soluble vitamin used in the prophylaxis and treatment of vitamin B6 deficiency and peripheral neuropathy in those receiving isoniazid (isonicotinic acid hydrazide, INH). Vitamin B6 has been found to lower systolic and diastolic blood pressure in a small group of subjects with essential hypertension. Hypertension is another risk factor for atherosclerosis and coronary heart disease. Another study showed pyridoxine hydrochloride to inhibit ADP- or epinephrine-induced platelet aggregation and to lower total cholesterol levels and increase HDL-cholesterol levels, again in a small group of subjects. Vitamin B6, in the form of pyridoxal 5'-phosphate, was found to protect vascular endothelial cells in culture from injury by activated platelets. Endothelial injury and dysfunction are critical initiating events in the pathogenesis of atherosclerosis. Human studies have demonstrated that vitamin B6 deficiency affects cellular and humoral responses of the immune system. Vitamin B6 deficiency results in altered lymphocyte differentiation and maturation, reduced delayed-type hypersensitivity (DTH) responses, impaired antibody production, decreased lymphocyte proliferation and decreased interleukin (IL)-2 production, among other immunologic activities.

Mechanism of action

Vision:Vitamin A (all-<i>trans</i> retinol) is converted in the retina to the 11-<i>cis</i>-isomer of retinaldehyde or 11-<i>cis</i>-retinal. 11-<i>cis</i>-retinal functions in the retina in the transduction of light into the neural signals necessary for vision. 11-<i>cis</i>-retinal, while attached to opsin in rhodopsin is isomerized to all-<i>trans</i>-retinal by light. This is the event that triggers the nerve impulse to the brain which allows for the perception of light. All-<i>trans</i>-retinal is then released from opsin and reduced to all-<i>trans</i>-retinol. All-<i>trans</i>-retinol is isomerized to 11-<i>cis</i>-retinol in the dark, and then oxidized to 11-<i>cis</i>-retinal. 11-<i>cis</i>-retinal recombines with opsin to re-form rhodopsin. Night blindness or defective vision at low illumination results from a failure to re-synthesize 11-<i>cis</i> retinal rapidly. Epithelial differentiation: The role of Vitamin A in epithelial differentiation, as well as in other physiological processes, involves the binding of Vitamin A to two families of nuclear retinoid receptors (retinoic acid receptors, RARs; and retinoid-X receptors, RXRs). These receptors function as ligand-activated transcription factors that modulate gene transcription. When there is not enough Vitamin A to bind these receptors, natural cell differentiation and growth are interrupted. Topical vitamin A can reverse the impairment of wound healing seen in patients receiving corticosteroids, perhaps by restoring the normal inflammatory reaction in the wound. The possibility has been suggested that systemic vitamin A could inhibit the anti-inflammatory effect of systemic corticosteroids. Retinol arrested proliferation of cultured neuroblastoma cells at concentrations of 50 um. A correlation existed between inhibition of growth and inhibition of ornithine decarboxylase in both neuroblastoma cells and glioma cells with retinol. In rats exptl-hypervitaminosis A has been shown ... to produce severe damage of the retina, mainly in the pigment epithelium according to electron microscopy. Alcohol dehydrogenase activity was shown to disappear in the pigment epithelium and visual cells ... . /The authors/ have shown that in an experimental cell culture system consisting of carcinogen-treated 10T1/2 cells, both retinoids and all dietary carotenoids examined can reversibly inhibit neoplastic transformation in the post-initiation phase of carcinogenesis. This activity strongly correlates with their ability to increase gap junctional intercellular communication by up-regulating the expression of the gene CX43 (connexin43). Connexins comprise the structural unit of gap junctions, organelles which allow direct transfer of signals, nutrients and waste products between contacting cells. CX43 is the most widely expressed member of the gap junction family of genes, and we have demonstrated that its expression is strongly down-regulated in human cancers and in several premalignant conditions. When several human tumour cell lines were genetically engineered to conditionally express CX43 under the influence of a tetracycline promoter, their neoplastic phenotype was strongly attenuated. Specifically, induced cells were inhibited from growing in an anchorage-independent manner and, additionally, growth as xenografts in immunocompromised animals was also strongly attenuated. Growth inhibition in suspension was associated both with increased G(1) cell-cycle arrest and with increased apoptosis. /The authors/ propose a model whereby junctional communication allows the transfer of growth inhibitory signals from normal to neoplastic cells and that retinoids and carotenoids, by increasing signal transfer, act to prevent cancer.

Pharmacodynamics

Vitamin A is effective for the treatment of Vitamin A deficiency. Vitamin A refers to a group of fat-soluble substances that are structurally related to and possess the biological activity of the parent substance of the group called all-<i>trans</i> retinol or retinol. Vitamin A plays vital roles in vision, epithelial differentiation, growth, reproduction, pattern formation during embryogenesis, bone development, hematopoiesis and brain development. It is also important for the maintenance of the proper functioning of the immune system.

Mechanism of action

Tocopherol acts as a radical scavenger. It mainly acts as an antioxidant for lipid bilayers. Tocopherol's functions depend on the H-atom donating ability, location, and movement within the membrane, as well as the efficiency in the radical recycling by some cytosolic reductants such as ascorbate. Tocopherol actions are related to the trap of radicals, and it has been shown that even in the absence of substituents in the ortho-positions, tocopherol can trap more than two radicals. The type of radicals available for tocopherol are alkyl and peroxy.

Pharmacodynamics

The antioxidant effects of tocopherol can be translated into different changes at the pharmacodynamic level. In vitro studies have shown that this antioxidant activity can produce modification in protein kinase C (PKC) which will later be translated into an inhibition of cell death. Some other derivate effects are the anti-inflammatory properties of tocopherol which can be related to the modulation of cytokines or prostaglandins, prostanoids and thromboxanes.