FOREVER F15 INNER PACK TABLETS/PACKETS

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

• 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

• Constipation
• Irritable bowel syndrome (IBS)
• Gastrointestinal discomfort
• As a dietary fiber supplement

Dosage

Children: Refer to specific product labeling and guidelines, as doses may vary based on formulation and intended use.

Adults: Refer to specific product labeling and guidelines, as doses may vary based on formulation and intended use.

Mechanism of action

Acacia acts primarily as a soluble dietary fiber. It is thought to benefit gut health by promoting the growth of beneficial bacteria, thus acting as a prebiotic. Its mucilage content may also contribute to its soothing effects on the gastrointestinal tract.

Pharmacodynamics

The pharmacodynamics of acacia involve its ability to modify gut flora and increase stool bulk. It can enhance the water-holding capacity of stool, facilitating smoother bowel movements. Additionally, its demulcent properties may help coat the mucosal lining of the gastrointestinal tract, providing relief from irritation.

Pharmacokinetics

Acacia is not digested in the stomach and small intestine, but it is fermented by colonic bacteria in the large intestine. Its components are absorbed as short-chain fatty acids, contributing to the overall health of the gut microbiome. The onset of action for acacia's effects on bowel habits can vary depending on individual digestive health and dietary factors.

Adverse effects

• Gastrointestinal discomfort
• Nausea
• Diarrhea
• Allergic reactions in sensitive individuals

Precautions

• Should be used with caution in individuals with known allergies to plant-derived substances
• Patients with gastrointestinal disorders should consult a healthcare professional before use

Pregnancy

Generally considered safe for use during pregnancy, but consultation with a healthcare provider is recommended.

Breast-feeding

Considered safe during breastfeeding; however, it is advisable to consult a healthcare professional.

Storage

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

Formulations

• Powder
• Granules
• Capsules
• Liquid extracts

Indications

• Energy source
• Dietary fiber supplement
• Source of vitamins and minerals
• Antioxidant support

Dosage

Children: Corn can be introduced to children as part of a balanced diet. There is no specific paediatric dosage; it should be given according to age-appropriate dietary guidelines.

Adults: Corn can be consumed in various forms as part of a balanced diet. There is no specific adult dosage; intake should be based on dietary preferences and nutritional needs.

Mechanism of action

The primary component of corn is starch, which is a polysaccharide composed of glucose units. Upon ingestion, starch is broken down into glucose by enzymes such as amylase in the digestive system. The glucose is then absorbed into the bloodstream, providing energy to cells throughout the body. Corn also contains antioxidants such as lutein and zeaxanthin, which may help protect against oxidative stress and support eye health.

Pharmacodynamics

Corn is mainly metabolized for energy due to its high carbohydrate content. The dietary fiber in corn aids in digestion and promotes satiety. Additionally, the presence of vitamins and minerals contributes to overall health, supporting various bodily functions including immune response and bone health. The antioxidants in corn may help reduce inflammation and lower the risk of chronic diseases.

Pharmacokinetics

The digestion and absorption of corn depend on its form (whole kernel, cornmeal, corn syrup, etc.). Generally, carbohydrates are digested and absorbed relatively quickly, with glucose appearing in the bloodstream shortly after consumption. The fiber content can slow digestion and help maintain stable blood sugar levels. The bioavailability of nutrients from corn can vary based on processing methods, such as cooking or milling.

Pregnancy

Corn is generally considered safe during pregnancy. It provides essential nutrients such as fiber, vitamins, and minerals, but should be consumed in moderation as part of a balanced diet.

Breast-feeding

Corn is safe for consumption while breastfeeding. It can provide important nutrients, but it's advisable to monitor for any allergic reactions in infants.

Storage

Store corn in a cool, dry place. Fresh corn should be kept in the refrigerator and consumed within a few days for optimal freshness.

Formulations

• Fresh corn
• Canned corn
• Frozen corn
• Cornmeal
• Corn syrup
• Corn oil

Indications

• Nutritional supplementation
• Energy source in enteral feeding
• Thickening agent in food formulations

Dosage

Children: Refer to specific product guidelines for dosing instructions.

Adults: Refer to specific product guidelines for dosing instructions.

Mechanism of action

Dextrin is metabolized in the body primarily through enzymatic hydrolysis, where enzymes such as amylase break down dextrin into glucose units. This process occurs mainly in the digestive system, where dextrin serves as a source of energy. The glucose produced can then enter glycolytic pathways, contributing to energy production.

Pharmacodynamics

As a carbohydrate, dextrin provides a source of energy for the body. Once ingested, dextrin is converted into glucose, which is utilized in various metabolic processes. The rate of absorption and conversion to glucose can vary depending on the specific type of dextrin and the presence of other macronutrients in the diet, influencing its impact on blood glucose levels.

Pharmacokinetics

Dextrin is rapidly hydrolyzed into glucose in the gastrointestinal tract after oral administration. The absorption of glucose occurs primarily in the small intestine, with peak blood glucose levels typically reached within 30 to 60 minutes following ingestion. The metabolism of glucose follows standard pathways, where it can be used for immediate energy or stored as glycogen in the liver and muscle tissues.

Pregnancy

Dextrin is generally considered safe during pregnancy as it is a carbohydrate derived from starch and does not exhibit harmful effects.

Breast-feeding

Dextrin is not known to adversely affect breastfeeding and is typically considered safe for nursing mothers.

Storage

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

Formulations

• Powder
• Granules
• Tablets

Indications

• Constipation
• Irritable bowel syndrome (IBS)
• Diverticulitis
• Hyperlipidemia
• Type 2 diabetes management
• Weight management

Dosage

Children: For children, the recommended daily intake of fiber varies by age and is approximately 14 grams per 1,000 calories consumed. It is advisable to refer to specific pediatric guidelines for more detailed dosing.

Adults: The general recommendation for adults is to consume 25 to 30 grams of dietary fiber daily from food sources, rather than supplements, to promote optimal health.

Mechanism of action

Fiber works primarily by adding bulk to the stool and facilitating regular bowel movements. Soluble fiber dissolves in water to form a gel-like substance, which can help to slow digestion and regulate blood sugar levels by slowing the absorption of sugar. Insoluble fiber does not dissolve in water and helps food pass more quickly through the stomach and intestines.

Pharmacodynamics

The pharmacodynamics of fiber involve its ability to enhance gastrointestinal health. Soluble fiber can lower cholesterol levels, improve glycemic control, and promote satiety, which may assist in weight management. Insoluble fiber contributes to increased stool bulk and can help prevent constipation. The fermentation of soluble fiber in the colon produces short-chain fatty acids, which have various health benefits, including anti-inflammatory effects.

Pharmacokinetics

Fiber is not absorbed in the gastrointestinal tract; thus, it has no bioavailability. It passes through the stomach and small intestine largely intact, reaching the colon where it can be fermented by gut microbiota. The rate of fermentation and the production of short-chain fatty acids can vary based on the type of fiber consumed and the individual's gut microbiome.

Adverse effects

• Bloating
• Gas
• Abdominal cramps
• Diarrhea
• Constipation

Precautions

• Increase fiber intake gradually to avoid gastrointestinal discomfort.
• Adequate fluid intake is necessary to prevent constipation.
• Caution is advised in patients with gastrointestinal disorders.

Pregnancy

Fiber is generally considered safe during pregnancy. It supports digestive health and can help alleviate constipation common in this population.

Breast-feeding

Fiber is safe during breastfeeding and can aid in postpartum digestive health.

Storage

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

Formulations

• Powder
• Capsules
• Tablets
• Granules
• Natural food sources (fruits, vegetables, whole grains)

Dosage

Children: Refer to specific product guidelines or consult with a healthcare professional.

Adults: Refer to specific product guidelines or consult with a healthcare professional.

Pregnancy

Consult a healthcare provider before use.

Breast-feeding

Consult a healthcare provider before use.

Storage

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

Indications

• Constipation
• Irritable bowel syndrome
• Gut dysbiosis
• Enhancing gut health
• Supporting immune function

Dosage

Children: Refer to specific guidelines or consult a healthcare professional as dosing can vary based on formulation and individual needs.

Adults: Refer to specific guidelines or consult a healthcare professional as dosing can vary based on formulation and individual needs.

Mechanism of action

Fructooligosaccharides exert their effects by selectively stimulating the growth and activity of beneficial gut bacteria, particularly bifidobacteria and lactobacilli. This prebiotic action helps to enhance gut health, improve digestion, and may contribute to immune function. The fermentation of FOS in the colon leads to the production of short-chain fatty acids, which can be utilized by colonocytes for energy and may play a role in maintaining colonic health.

Pharmacodynamics

Fructooligosaccharides demonstrate a significant impact on gut flora composition and overall gut health. They help to increase the population of beneficial bacteria in the intestines, which can improve gut barrier function, reduce inflammation, and enhance nutrient absorption. The production of short-chain fatty acids from FOS fermentation also has systemic effects, potentially influencing metabolic pathways and immune responses.

Pharmacokinetics

Fructooligosaccharides are not absorbed in the upper gastrointestinal tract and have minimal caloric value. They pass through the stomach and small intestine intact and reach the colon, where they are fermented by microbiota. The extent of fermentation can vary among individuals based on their gut microbiota composition. The short-chain fatty acids produced during fermentation are absorbed by colon cells and can enter the systemic circulation, affecting various physiological processes.

Adverse effects

• Gastrointestinal discomfort
• Bloating
• Flatulence
• Diarrhea
• Nausea

Precautions

• Use with caution in patients with irritable bowel syndrome or other gastrointestinal disorders.
• Monitor for excessive gastrointestinal symptoms when starting treatment.

Pregnancy

Fructooligosaccharides are generally considered safe during pregnancy, but consult a healthcare provider for individual recommendations.

Breast-feeding

Considered safe during breastfeeding, though consultation with a healthcare provider is advised.

Storage

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

Formulations

• Powder
• Granules
• Tablets

Indications

• Weight management
• Appetite suppression
• Cholesterol control

Dosage

Children: Refer to specific product guidelines as no standard paediatric dose is established.

Adults: Refer to specific product guidelines as no standard adult dose is established.

Mechanism of action

Hydroxycitric acid (HCA), the primary active compound in Garcinia, is believed to inhibit the enzyme citrate lyase, which plays a crucial role in the conversion of carbohydrates to fats. By blocking this enzyme, HCA may reduce the synthesis of fatty acids and cholesterol, thereby promoting weight loss. Additionally, HCA may increase serotonin levels in the brain, which could help reduce appetite and improve mood.

Pharmacodynamics

The pharmacodynamic effects of Garcinia are primarily associated with its ability to modulate lipid metabolism. HCA's action on citrate lyase inhibits fat storage, potentially leading to decreased body weight and fat mass. Some studies suggest that HCA may also enhance glycogen synthesis, which can provide an energy source and improve physical performance. However, the clinical significance of these effects varies, and results from studies have been inconsistent.

Pharmacokinetics

Garcinia extracts containing HCA are typically absorbed in the gastrointestinal tract after oral administration. The bioavailability of HCA can be influenced by factors such as food intake and the specific formulation of the supplement. Metabolism of HCA occurs primarily in the liver, and it is excreted in urine. The half-life of HCA has not been well established in humans, and further research is needed to fully elucidate its pharmacokinetic profile.

Adverse effects

• Gastrointestinal upset
• Headache
• Nausea
• Diarrhea
• Dry mouth

Interactions

• May interact with medications for diabetes, potentially affecting blood sugar levels
• Could interact with anticoagulants, increasing the risk of bleeding

Precautions

• Caution in patients with diabetes, as it may affect blood glucose levels
• Use with caution in individuals with a history of liver disease
• Not recommended for use in pregnant or breastfeeding women without medical advice

Pregnancy

There is insufficient data on the safety of garcinia during pregnancy. It is best avoided unless prescribed by a healthcare professional.

Breast-feeding

There is limited information on the excretion of garcinia in human milk. Caution is advised.

Storage

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

Formulations

• Capsules
• Tablets
• Powder

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

• Administration of drugs requiring solubilization
• Intravenous fluid therapy
• Oral rehydration solutions

Dosage

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

Adults: Refer to the BNF for specific dosing information.

Mechanism of action

The mechanism of action of soluble compounds typically involves their ability to dissociate in solution, allowing for increased bioavailability and enhanced pharmacological effects. In some cases, they may act as osmotic agents or facilitate the transport of drugs across biological membranes.

Pharmacodynamics

Pharmacodynamics of soluble compounds generally relates to their effects on the body, including their interaction with receptors, enzymes, or cellular pathways. The solubility enhances the distribution of the drug, leading to more predictable and effective therapeutic outcomes.

Pharmacokinetics

Pharmacokinetics involves the absorption, distribution, metabolism, and excretion of soluble compounds. Due to their solubility, these compounds are typically absorbed quickly into the bloodstream when administered orally or intravenously. They may undergo metabolism in the liver, and their elimination primarily occurs through renal pathways, depending on the specific compound and its formulation.

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

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

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

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.