OLIGOCARE COMBINATION PRODUCT TABLET

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

• Heart failure
• Hypertension
• Statin myopathy
• Cancer

Dosage

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

Adults: Refer to BNF for specific dosing information based on the clinical condition being treated.

Mechanism of action

Ubidecarenone is an essential cofactor in the mitochondrial electron transport chain. Its primary functions include the acceptance of electrons from complexes I and II, which is vital for ATP production. Additionally, it acts as a mobile redox agent, shuttling electrons and protons in the electron transport chain. Ubidecarenone also provides antioxidant activity in mitochondria and cellular membranes, protecting against lipid peroxidation and inhibiting the oxidation of LDL-cholesterol.

Pharmacodynamics

Ubidecarenone has roles in various physiological processes, including sulfide oxidation, regulation of the mitochondrial permeability transition pore, and the translocation of protons and calcium ions across biological membranes. Research indicates its potential benefits in treating conditions such as cancer, statin myopathy, congestive heart failure, and hypertension.

Pharmacokinetics

Coenzyme Q10 is absorbed in the small intestine, with bioavailability affected by dietary fats. Once absorbed, it is distributed throughout body tissues, particularly in the heart, liver, and kidneys. The half-life of CoQ10 is approximately 33 hours, and it is metabolized primarily in the liver. Excretion occurs mainly through the bile and urine.

Pregnancy

There is insufficient evidence regarding the safety of CoQ10 during pregnancy. Consult a healthcare professional before use.

Breast-feeding

Limited data suggests that CoQ10 is likely safe during breastfeeding, but consult a healthcare professional for personalized advice.

Storage

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

Formulations

• Capsules
• Tablets
• Soft gels

Indications

• Ox

Mechanism of action

Glutathione (GSH) participates in leukotriene synthesis and is a cofactor for the enzyme glutathione peroxidase. It plays a role in hepatic biotransformation and detoxification, acting as a hydrophilic molecule added to lipophilic toxins for biliary excretion. GSH detoxifies methylglyoxal, a toxic metabolic by-product, via glyoxalase enzymes, converting it to less harmful substances. It also participates in conjugation and reduction reactions catalyzed by glutathione S-transferase enzymes, and can non-enzymatically conjugate with certain chemicals, such as N-acetyl-p-benzoquinone imine (NAPQI), detoxifying it in the process.

Pharmacodynamics

Glutathione plays a vital role in cellular defense against oxidative stress by neutralizing free radicals and reactive oxygen species. It is involved in maintaining the redox state of cells, which is critical for various cellular functions. The antioxidant properties of glutathione help in preventing cellular damage, modulating inflammatory responses, and regulating immune functions. Its ability to conjugate with xenobiotics enhances their solubility and facilitates their excretion, thereby contributing to detoxification processes in the liver.

Pharmacokinetics

Glutathione is synthesized in the body from its constituent amino acids, and its levels can be influenced by dietary intake and the body's oxidative stress status. Once synthesized, glutathione is distributed throughout the body, particularly in the liver, where it participates in detoxification processes. It is metabolized primarily in the liver, with its conjugation products being excreted via bile or urine. The half-life of glutathione can vary depending on the physiological and pathological conditions, and its levels can be influenced by factors such as age, diet, and the presence of diseases.

Pregnancy

There are no well-controlled studies of glutathione in pregnant women. Use only if clearly needed.

Breast-feeding

Use with caution. The effects of glutathione on nursing infants are not well known.

Storage

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

Formulations

• Injectable solution
• Oral supplement

Indications

• Cardiovascular diseases
• Erectile dysfunction
• Peripheral arterial disease
• Wound healing
• Muscle growth and recovery
• Immune system support

Dosage

Children: For paediatric dosing, it is important to refer to the BNF for Children for appropriate guidelines based on the child's age, weight, and clinical condition.

Adults: The typical dosage for adults varies based on the condition being treated, but common oral doses range from 2 to 30 grams per day, divided into multiple doses. For specific dosing recommendations, please refer to the BNF.

Mechanism of action

L-arginine is converted to nitric oxide by nitric oxide synthase (NOS), which is crucial for vascular function and blood flow regulation. NO activates guanylate cyclase, leading to increased levels of cyclic GMP, a secondary messenger that mediates vasodilation and other cellular responses. This pathway is vital in both the cardiovascular and immune systems, with different isoforms of NOS (eNOS, nNOS, iNOS) contributing to various physiological effects.

Pharmacodynamics

L-arginine has been shown to enhance immune responses, improve wound healing, stimulate growth hormone release, and support muscle hypertrophy and tissue repair. Its role in nitric oxide production aids in vasodilation, improving blood circulation and oxygen delivery to tissues, which is essential for recovery and regeneration.

Pharmacokinetics

L-arginine is absorbed from the gastrointestinal tract, with peak plasma concentrations occurring within 1-2 hours after oral administration. It is metabolized primarily in the liver and kidneys, with a half-life of approximately 1-2 hours. The bioavailability of L-arginine can be influenced by dietary intake and metabolic conditions.

Adverse effects

• Gastrointestinal disturbances
• Nausea
• Diarrhea
• Abdominal pain
• Hypotension
• Allergic reactions

Interactions

• Antihypertensive agents may have additive effects leading to increased hypotension
• Sildenafil and other medications for erectile dysfunction may have enhanced effects when used with L-arginine

Precautions

• Caution in patients with a history of asthma or allergies
• Use with caution in patients with hypotension
• Monitor blood pressure in patients taking antihypertensive medications

Pregnancy

The safety of L-arginine in pregnancy has not been established. Consult a healthcare provider before use.

Breast-feeding

L-arginine is excreted in breast milk, and its safety during breastfeeding is not well established. Consult a healthcare provider.

Storage

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

Formulations

• Oral tablets
• Powder for oral solution
• Capsules

Mechanism of action

Levocarnitine acts as a carrier molecule for long-chain fatty acids, transporting them into mitochondria for beta-oxidation, which is critical for energy production. It also exports acyl groups from subcellular organelles and cells to urine, preventing toxic accumulation. The mechanism of action includes interactions with carnitine transporters, translocases, and acetyltransferases. Additionally, it normalizes the brain's redox state and enhances urea synthesis in the liver, potentially activating the glucocorticoid receptor. L-carnitine's antagonistic effects on thyroid hormone action, including inhibiting its nuclear entry, contribute to its therapeutic applications.

Pharmacodynamics

Levocarnitine plays a significant role in lipid metabolism and energy production through its involvement in the transport of fatty acids into the mitochondria. A deficiency in carnitine can lead to various metabolic issues, including liver, heart, and muscle dysfunction. The therapeutic use of levocarnitine includes its ability to stimulate gastric and pancreatic secretions and treat hyperlipoproteinemias. The L-isomer of carnitine is specifically active in lipid metabolism, and its deficiency can be identified through biochemical markers such as low plasma concentrations of free carnitine and elevated acylcarnitine levels.

Pharmacokinetics

Levocarnitine is absorbed in the intestines and distributed throughout the body tissues. It is primarily metabolized in the liver, with excretion occurring via urine. The pharmacokinetics of levocarnitine can vary based on dietary intake, physiological status, and specific health conditions that may affect its metabolism and clearance. The bioavailability of levocarnitine may also be

Adverse effects

• Nausea
• Vomiting
• Abdominal cramps
• Diarrhea
• Fishy body odor
• Rash
• Seizures (rare)

Interactions

• Anticoagulants may have altered effects.
• Thyroid hormones may have altered action due to L-carnitine's peripheral antagonism.

Precautions

• Use with caution in patients with renal impairment.
• Monitor for potential interactions with other medications.

Pregnancy

Limited data is available on the use of levocarnitine during pregnancy. Use only if clearly needed and after assessing benefits versus risks.

Breast-feeding

Levocarnitine is excreted in human milk. Caution is advised when administered to nursing mothers.

Storage

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

Formulations

• Oral solution
• Tablets
• Capsules

Indications

• Dietary supplement for antioxidant support
• Potential risk reduction for prostate cancer
• Potential risk reduction for lung cancer

Dosage

Children: Refer to specific guidelines as dosing can vary based on the formulation and purpose of use.

Adults: Refer to specific guidelines as dosing can vary based on the formulation and purpose of use.

Mechanism of action

Lycopene functions as a very potent antioxidant, trapping singlet oxygen and reducing mutagenesis. It inhibits cancer cell growth by disrupting growth factor receptor signaling and cell cycle progression. Lycopene upregulates connexin 43, enhancing gap junctional communication which is often deficient in tumors. Furthermore, it exhibits synergistic effects on cell proliferation and differentiation when combined with 1,25-dihydroxyvitamin D3, indicating interactions at a nuclear or subcellular level.

Pharmacodynamics

Lycopene's antioxidant properties play a critical role in protecting cells from oxidative stress. By trapping reactive oxygen species, it lessens cellular damage and may help to prevent the initiation and progression of cancer. Its ability to modulate cell signaling pathways and improve gap junction communication contributes to its anticancer effects. The interactions with vitamin D3 suggest a complex role in regulating cellular functions.

Pharmacokinetics

Lycopene is absorbed in the intestine and can be detected in the serum and various tissues. Its bioavailability can be influenced by dietary factors, including fat intake, which enhances absorption. Once in the body, lycopene is stored in adipose tissue and the liver. The elimination half-life and exact metabolic pathways are not well defined, but it is believed to undergo some conversion into other metabolites before excretion.

Pregnancy

There is insufficient reliable information regarding the safety of lycopene during pregnancy. Caution is advised.

Breast-feeding

Lycopene is considered safe during breastfeeding, but data on its excretion in human milk is limited.

Storage

Store in a cool, dry place, away from light.

Indications

• Vitamin B12 deficiency
• Peripheral neuropathy
• Megaloblastic anemia
• Homocystinuria

Dosage

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

Adults: Refer to the BNF for specific dosing recommendations based on the indication.

Mechanism of action

Methylcobalamin functions as a coenzyme in the conversion of homocysteine to methionine, facilitating the synthesis of S-adenosylmethionine (SAMe). SAMe is a critical methyl donor in numerous biochemical reactions, including the methylation of DNA and proteins. Additionally, methylcobalamin is essential for the regeneration of folate, impacting DNA synthesis and repair. It also promotes nerve regeneration and repair, making it beneficial in conditions involving nerve damage.

Pharmacodynamics

Methylcobalamin exhibits neuroprotective properties by enhancing nerve growth factor (NGF) synthesis and supporting neuronal survival. It aids in the reduction of neuropathic pain and may improve neurological function in patients with vitamin B12 deficiency. The compound's role in methylation processes further influences cellular metabolism, contributing to overall health.

Pharmacokinetics

Methylcobalamin is absorbed in the intestines, and its bioavailability can be influenced by the presence of intrinsic factor, which is necessary for vitamin B12 absorption. Once absorbed, it is distributed throughout the body, particularly in the liver, kidneys, and nervous tissue. The elimination half-life of methylcobalamin is variable, and the compound is primarily excreted in the urine as metabolites. Storage and transport within the body are facilitated by transcobalamin II, a specific transport protein.

Adverse effects

• Headache
• Nausea
• Diarrhea
• Dizziness
• Rash
• Itching

Interactions

• Alcohol may decrease the absorption of methylcobalamin
• Certain medications that affect vitamin B12 levels

Precautions

• Patients with Leber's disease should use with caution
• Monitor for signs of hypersensitivity

Pregnancy

Methylcobalamin is generally considered safe during pregnancy as it is a form of vitamin B12, but consult a healthcare provider for personalized advice.

Breast-feeding

Methylcobalamin is excreted in breast milk, but is considered safe for use during breastfeeding; consult a healthcare provider for personalized advice.

Storage

Store in a tightly closed container at room temperature, away from moisture and heat.

Formulations

• Oral tablets
• Sublingual tablets
• Injectable solution

Indications

• Bacterial infections
• Pneumonia
• Skin infections
• Urinary tract infections
• Sepsis

Dosage

Children: Refer to the BNF for Children for specific dosing information for pediatric patients based on age and weight.

Adults: Refer to the BNF for specific dosing information for adults based on the condition being treated.

Mechanism of action

Micro acts by inhibiting bacterial cell wall synthesis, leading to cell lysis and death. This bactericidal action is primarily due to the disruption of peptidoglycan synthesis, which is essential for maintaining the structural integrity of bacterial cells.

Pharmacodynamics

The pharmacodynamics of Micro involves its interaction with bacterial enzymes responsible for cell wall synthesis. The drug is effective against a wide range of gram-positive and some gram-negative bacteria, making it a versatile option in antimicrobial therapy. It exhibits time-dependent killing, meaning that the duration of time the drug concentration remains above the minimum inhibitory concentration (MIC) is critical for its efficacy.

Pharmacokinetics

Micro is typically well absorbed following oral administration, with peak plasma concentrations occurring within a few hours. The drug is widely distributed throughout body tissues and fluids, including the lungs, kidneys, and skin. It is metabolized in the liver and primarily excreted unchanged in the urine, making it important to monitor renal function in patients receiving this medication.

Pregnancy

Micro can be used during pregnancy if the benefits outweigh the risks, but it is essential to consult a healthcare provider.

Breast-feeding

Micro may be excreted in breast milk, and caution is advised when administered to nursing mothers.

Storage

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

Indications

• Nutritional deficiencies
• Malnutrition
• Support during illness or recovery
• Dietary supplementation
• Growth and development in children
• Pregnancy and lactation support

Dosage

Children: Paediatric dosages of nutrients depend on age, weight, and specific nutritional needs. It is advisable to refer to pediatric dietary guidelines or consult healthcare professionals for appropriate recommendations.

Adults: Dosage of nutrients varies widely based on individual needs, age, sex, and health status. It is recommended to refer to established dietary guidelines or consult healthcare professionals for specific requirements.

Mechanism of action

Nutrients exert their effects through various biological pathways. For example, carbohydrates are broken down into glucose, which is utilized for energy production in cells. Proteins are composed of amino acids, which are essential for the synthesis of enzymes, hormones, and structural components of cells. Vitamins act as coenzymes or precursors in biochemical reactions, while minerals are involved in diverse physiological functions, including enzyme activation and muscle contraction.

Pharmacodynamics

The pharmacodynamic effects of nutrients depend on their type and function. Macronutrients provide energy, support cellular growth, and regulate metabolism. Micronutrients are crucial for enzymatic reactions, antioxidant defense, and the maintenance of physiological homeostasis. Deficiencies or excesses of nutrients can lead to various health issues, including malnutrition, metabolic disorders, and impaired immune function.

Pharmacokinetics

Nutrient absorption occurs primarily in the gastrointestinal tract. After ingestion, macronutrients are digested and absorbed in the intestines, entering the bloodstream for transport to tissues. Micronutrients are absorbed through various mechanisms, often requiring specific transport proteins. The distribution of nutrients is influenced by factors such as blood flow and tissue demand. Metabolism varies, with some nutrients being readily utilized while others may require conversion into active forms. Excretion processes differ by nutrient type, with water-soluble vitamins being excreted through urine and fat-soluble vitamins being stored in adipose tissue.

Pregnancy

Nutrient needs may increase during pregnancy; consult a healthcare provider for tailored advice.

Breast-feeding

Nutrient requirements can vary during breastfeeding; adequate nutrition is crucial for both mother and infant.

Storage

Store in a cool, dry place, away from direct sunlight. Specific storage instructions may vary by nutrient.

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

Ubidecarenone is an essential cofactor in the mitochondrial electron transport chain. Its functions are the acceptance of electrons from the complex I and II and this activity is vital for the production of ATP. It acts as a mobile redox agent shuttling electrons and protons in the electron transport chain. Ubidecarenone also presents antioxidant activity in mitochondria and cellular membranes, protecting against peroxidation of lipid membranes as well as inhibiting oxidation of LDL-cholesterol.

Pharmacodynamics

Ubidecarenon has roles in many prysiological process including sulfide oxidation, regulation of mitochondrial permeability transition pore and translocation of protons and calcium ions accross biological membranes. Studies have shown its benefitial effect in treating cancer, statin myopathy, congestive heart failure and hypertension.

Mechanism of action

Glutathione (GSH) participates in leukotriene synthesis and is a cofactor for the enzyme glutathione peroxidase. It also plays a role in the hepatic biotransformation and detoxification process; it acts as a hydrophilic molecule that is added to other lipophilic toxins or wastes prior to entering biliary excretion. It participates in the detoxification of methylglyoxal, a toxic by-product of metabolism, mediated by glyoxalase enzymes. Glyoxalase I catalyzes the conversion of methylglyoxal and reduced glutathione to S-D-Lactoyl-glutathione. Glyoxalase II catalyzes the conversion of S-D-Lactoyl Glutathione to Reduced Glutathione and D-lactate. Glyoxalase I catalyzes the conversion of methylglyoxal and reduced glutathione to S-D-Lactoyl-glutathione. Glyoxalase II catalyzes the conversion of S-D-Lactoyl Glutathione to Reduced Glutathione and D-lactate. GSH is a cofactor of conjugation and reduction reactions that are catalyzed by glutathione S-transferase enzymes expressed in the cytosol, microsomes, and mitochondria. However, it is capable of participating in non-enzymatic conjugation with some chemicals, as it is hypothesized to do to a significant extent with n-acetyl-p-benzoquinone imine (NAPQI), the reactive cytochrome P450 reactive metabolite formed by toxic overdose of acetaminophen. Glutathione in this capacity binds to NAPQI as a suicide substrate and in the process detoxifies it, taking the place of cellular protein sulfhydryl groups which would otherwise be toxically adducted. The preferred medical treatment to an overdose of this nature, whose efficacy has been consistently supported in literature, is the administration (usually in atomized form) of N-acetylcysteine, which is used by cells to replace spent GSSG and allow a usable GSH pool.

Mechanism of action

Many of supplemental L-arginine's activities, including its possible anti-atherogenic actions, may be accounted for by its role as the precursor to nitric oxide or NO. NO is produced by all tissues of the body and plays very important roles in the cardiovascular system, immune system and nervous system. NO is formed from L-arginine via the enzyme nitric oxide synthase or synthetase (NOS), and the effects of NO are mainly mediated by 3,'5' -cyclic guanylate or cyclic GMP. NO activates the enzyme guanylate cyclase, which catalyzes the synthesis of cyclic GMP from guanosine triphosphate or GTP. Cyclic GMP is converted to guanylic acid via the enzyme cyclic GMP phosphodiesterase. NOS is a heme-containing enzyme with some sequences similar to cytochrome P-450 reductase. Several isoforms of NOS exist, two of which are constitutive and one of which is inducible by immunological stimuli. The constitutive NOS found in the vascular endothelium is designated eNOS and that present in the brain, spinal cord and peripheral nervous system is designated nNOS. The form of NOS induced by immunological or inflammatory stimuli is known as iNOS. iNOS may be expressed constitutively in select tissues such as lung epithelium. All the nitric oxide synthases use NADPH (reduced nicotinamide adenine dinucleotide phosphate) and oxygen (O2) as cosubstrates, as well as the cofactors FAD (flavin adenine dinucleotide), FMN (flavin mononucleotide), tetrahydrobiopterin and heme. Interestingly, ascorbic acid appears to enhance NOS activity by increasing intracellular tetrahydrobiopterin. eNOS and nNOS synthesize NO in response to an increased concentration of calcium ions or in some cases in response to calcium-independent stimuli, such as shear stress. In vitro studies of NOS indicate that the Km of the enzyme for L-arginine is in the micromolar range. The concentration of L-arginine in endothelial cells, as well as in other cells, and in plasma is in the millimolar range. What this means is that, under physiological conditions, NOS is saturated with its L-arginine substrate. In other words, L-arginine would not be expected to be rate-limiting for the enzyme, and it would not appear that supraphysiological levels of L-arginine which could occur with oral supplementation of the amino acid^would make any difference with regard to NO production. The reaction would appear to have reached its maximum level. However, in vivo studies have demonstrated that, under certain conditions, e.g. hypercholesterolemia, supplemental L-arginine could enhance endothelial-dependent vasodilation and NO production.

Pharmacodynamics

Studies have shown that is has improved immune responses to bacteria, viruses and tumor cells; promotes wound healing and regeneration of the liver; causes the release of growth hormones; considered crucial for optimal muscle growth and tissue repair.

Mechanism of action

Levocarnitine can be synthesised within the body from the amino acids lysine or methionine. Vitamin C (ascorbic acid) is essential to the synthesis of carnitine. Levocarnitine is a carrier molecule in the transport of long chain fatty acids across the inner mitochondrial membrane. It also exports acyl groups from subcellular organelles and from cells to urine before they accumulate to toxic concentrations. Only the L isomer of carnitine (sometimes called vitamin BT) affects lipid metabolism. Levocarnitine is handled by several proteins in different pathways including carnitine transporters, carnitine translocases, carnitine acetyltransferases and carnitine palmitoyltransferases. L-Carnitine is a peripheral antagonist of thyroid hormone action in some tissues. It inhibits thyroid hormone entry into cell nuclei. In a controlled clinical trial, L-carnitine was shown to reverse or prevent some symptoms of hyperthyroidism. ... Mortality and metabolic consequences of acute ammonium intoxication in mice are reduced by pharmacologic admin of L-carnitine. The mechanism for this effect may have 2 components. L-Carnitine admin normalizes the redox state of the brain (perhaps by incr the avail of beta-hydroxybutyrate and/or acetyl-L-carnitine to the brain), and it incr the rate of urea synth in the liver, perhaps in part by activation of the glucocorticoid receptor. At least part of the protective effect is associated with flux through the carnitine acyltransferases, as analogs of L-carnitine that are competitive inhibitors of carnitine acyltransferases enhance the toxicity of acute ammonium admin. Thus, it has been proposed that L-carnitine incr urea synth in the liver by facilitating fatty acid entry into mitochondria, leading to incr flux through the beta-oxidation pathway, an incr of intramitochondrial reducing equivalents, and enhancement of ATP production. ... Levocarnitine is necessary for normal mammalian fat utilization and energy metabolism. It facilitates entry of long-chain fatty acids into cellular mitochondria, where they are used during oxidation and energy production. It also exports acyl groups from subcellular organelles and from cells to urine before they accumulate to toxic concentrations. Carnitine's primary mechanism of action is apparently attributable to its role as a cofactor in the transformation of free long-chain fatty acids into acylcarnitines for subsequent transport into the mitochondrial matrix. Carnitine is involved in the metabolism of ketones for energy and the conversion of branched-chain amino acids - valine, leucine, and isoleucine - into energy. /Carnitine/ L-Carnitine participates in a reversible transesterification reaction, in which an acyl group is transferred from coenzyme A to the hydroxyl group of L-carnitine ... /This reaction facilitates the/ transfer of long-chain fatty acids from cytoplasm ... /and/ chain-shortened /very-long-chain/ fatty acids from peroxisomes to mitochondria /and the/ modulation of the acyl-CoA/CoA ratio in cellular compartments.

Pharmacodynamics

Levocarnitine is a carrier molecule in the transport of long chain fatty acids across the inner mitochondrial membrane. It also exports acyl groups from subcellular organelles and from cells to urine before they accumulate to toxic concentrations. Lack of carnitine can lead to liver, heart, and muscle problems. Carnitine deficiency is defined biochemically as abnormally low plasma concentrations of free carnitine, less than 20 µmol/L at one week post term and may be associated with low tissue and/or urine concentrations. Further, this condition may be associated with a plasma concentration ratio of acylcarnitine/levocarnitine greater than 0.4 or abnormally elevated concentrations of acylcarnitine in the urine. Only the L isomer of carnitine (sometimes called vitamin BT) affects lipid metabolism. The "vitamin BT" form actually contains D,L-carnitine, which competitively inhibits levocarnitine and can cause deficiency. Levocarnitine can be used therapeutically to stimulate gastric and pancreatic secretions and in the treatment of hyperlipoproteinemias.

Mechanism of action

Serum and tissue lycopene levels have been inversely related to the risk of lung and prostate cancers. Lycopene functions as a very potent antioxidant, and it can trap singlet oxygen and reduce mutagenesis in the Ames test. Lycopene at physiological concentrations can inhibit human cancer cell growth by interfering with growth factor receptor signaling and cell cycle progression. Studies using human and animal cells identified connexin 43, a gene whose expression is upregulated by lycopene and which allows direct intercellular gap junctional communication (GJC). GJC is deficient in many human tumors and its restoration or upregulation is associated with decreased proliferation. The combination of low concentrations of lycopene with 1,25-dihydroxyvitamin D3 exhibits a synergistic effect on cell proliferation and differentiation, and an additive effect on cell cycle progression in the HL-60 promyelocytic leukemia cell line, suggesting some interaction at a nuclear or subcellular level.