VITARAL COMBINATION PRODUCT CAPSULE

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

• Glaucoma
• Epilepsy
• Altitude sickness
• Metabolic alkalosis
• Congestive heart failure
• Idiopathic intracranial hypertension

Dosage

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

Adults: Refer to the BNF for specific dosing information.

Mechanism of action

Acetazolamide inhibits the enzyme carbonic anhydrase, which catalyzes the reversible hydration of carbon dioxide to bicarbonate and protons. This inhibition leads to decreased bicarbonate reabsorption in the kidneys, resulting in increased bicarbonate and water excretion, and consequently, a mild diuretic effect. The reduction in bicarbonate levels also affects acid-base balance, which can be useful in treating metabolic alkalosis.

Pharmacodynamics

By inhibiting carbonic anhydrase, acetazolamide affects the bicarbonate buffering system, leading to metabolic acidosis, which can increase respiratory drive and improve gas exchange. This mechanism is particularly useful in conditions like altitude sickness where hypoxia is prevalent. Acetazolamide also reduces intraocular pressure, making it effective in glaucoma management.

Pharmacokinetics

Acetazolamide is well absorbed from the gastrointestinal tract, with peak plasma concentrations occurring within 1-3 hours after oral administration. It has a volume of distribution of 0.5-1 L/kg and is primarily eliminated through the kidneys. The half-life of acetazolamide is approximately 10 hours, but this can vary based on renal function. It is important to monitor renal function in patients taking this medication due to its renal clearance pathway.

Interactions

• acetazolamide+methenamine: Severe (decreases efficacy)
• acetazolamide+antiepileptics: Unknown (increases risk of overheating and dehydration)
• acetazolamide+zonisamide: Unknown (increases risk of overheating and dehydration)
• acetazolamide+lithium: Unknown (affects concentration)

Indications

• General wellness support
• Anti-inflammatory effects
• Antioxidant activity
• Digestive aid
• Support for immune function

Dosage

Children: Paediatric dosing should be determined based on the specific extract and its intended use. Consultation with a healthcare provider is recommended for accurate dosing.

Adults: Dosage varies widely depending on the specific extract and formulation. It is essential to follow the manufacturer's instructions or consult a healthcare professional for appropriate dosing.

Mechanism of action

The mechanism of action of herbal extracts can vary significantly based on their constituents. Commonly, they exert their effects through multiple pathways including modulation of neurotransmitter systems, interference with inflammatory processes, or direct antioxidant activity. Some extracts may activate certain receptors or inhibit enzymes related to disease processes.

Pharmacodynamics

The pharmacodynamics of extracts is complex due to the presence of multiple active compounds which can have synergistic or antagonistic effects. These compounds may influence cellular signaling pathways, alter gene expression, or modulate immune response. The overall pharmacological profile is determined by the specific composition of the extract, its concentration, and the biological target it interacts with.

Pharmacokinetics

The pharmacokinetics of extracts involves absorption, distribution, metabolism, and excretion of the active compounds. Generally, herbal extracts are absorbed in the gastrointestinal tract, with bioavailability influenced by factors such as formulation, the presence of food, and individual metabolic differences. Compounds may undergo hepatic metabolism, and elimination can occur through urine or feces, depending on their chemical nature.

Pregnancy

Consult a healthcare professional before use, as the safety of the extract during pregnancy has not been established.

Breast-feeding

Consult a healthcare professional before use, as the safety of the extract during breastfeeding has not been established.

Storage

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

Indications

• Fatigue
• Stress management
• Cognitive enhancement
• Immune support
• General well-being

Dosage

Children: Refer to specific product guidelines, as dosing in children should be determined by a healthcare professional.

Adults: Refer to specific product guidelines, as dosing can vary based on formulation and intended use.

Mechanism of action

Ginseng is thought to exert its effects through several mechanisms, including modulation of the hypothalamic-pituitary-adrenal (HPA) axis, enhancement of antioxidant activity, and regulation of neurotransmitter levels. Ginsenosides, the active compounds in ginseng, may influence cellular signaling pathways, promote neuroprotection, and enhance immune responses.

Pharmacodynamics

The pharmacodynamic effects of ginseng are attributed primarily to its active constituents, ginsenosides, which interact with various receptors and enzymes in the body. These interactions can lead to increased energy metabolism, improved cognitive function, enhanced physical performance, and modulation of the immune system. Ginseng may also exhibit adaptogenic properties, helping the body to maintain homeostasis under stress.

Pharmacokinetics

Ginsenosides undergo extensive metabolism in the body, primarily by the liver. Bioavailability can vary significantly based on the specific ginsenoside and the method of administration. Ginseng is usually administered orally, with effects typically observed within several hours after ingestion. The elimination half-life of ginsenosides can vary based on the specific compound and individual metabolism, with some studies suggesting that effects may persist for several hours to days.

Adverse effects

• Insomnia
• Headache
• Gastrointestinal disturbances
• Nervousness
• Hypertension
• Allergic reactions

Interactions

• May interact with anticoagulants (e.g., warfarin)
• May enhance the effects of caffeine
• May affect insulin levels and blood sugar control
• Potential interaction with immunosuppressants

Precautions

• Use with caution in patients with hypertension
• May cause sleep disturbances; avoid use before bedtime
• Should be used cautiously in patients with diabetes
• Consult a healthcare provider before use in individuals with autoimmune conditions

Pregnancy

Limited data available. Generally not recommended due to potential hormonal effects.

Breast-feeding

Limited data available. Consult a healthcare provider before use.

Storage

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

Formulations

• Dried root
• Powdered extract
• Capsules
• Tinctures
• Teas

Mechanism of action

Excessive palmitoylcarnitine formation and exhausted L-carnitine stores lead to energy depletion, which, along with attenuated acetylcholine synthesis and oxidative stress, are main mechanisms behind palmitate-induced neuronal loss. High levels of palmitate exposure are suggested to contribute to diabetic neuropathy and gastrointestinal dysregulation. Additionally, palmitate negatively regulates acetyl-CoA carboxylase, thereby preventing further palmitate generation.

Pharmacodynamics

Palmitate is the first fatty acid generated during lipogenesis and serves as a precursor for the synthesis of longer fatty acids. The presence of palmitate inhibits acetyl-CoA carboxylase, reducing the conversion of acetyl-ACP to malonyl-ACP, which subsequently decreases the synthesis of new palmitate. This feedback mechanism is crucial for maintaining lipid homeostasis within the body.

Pharmacokinetics

Palmitate is absorbed from dietary sources and can also be synthesized endogenously in the liver and adipose tissue. Once in circulation, it is transported via chylomicrons or albumin. The metabolism of palmitate occurs primarily in the mitochondria through fatty acid oxidation, generating acetyl-CoA, which can enter the citric acid cycle for energy production. The overall kinetics of palmitate are influenced by dietary intake, metabolic demand, and hormonal regulation.

Pregnancy

Palmitate is classified as a category C drug. Animal reproduction studies have not been conducted, and there are no adequate and well-controlled studies in pregnant women. It should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

There are no data on the excretion of palmitate in human milk. Caution should be exercised when administering to nursing mothers.

Storage

Store at room temperature, away from light and moisture. Keep the container tightly closed.

Formulations

• Palmitate 500 mg softgel
• Palmitate 1000 mg softgel

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

• Vitamin E deficiency
• Prevention of oxidative stress-related conditions
• Support for immune function
• Potential adjunctive therapy in chronic diseases such as coronary heart disease and cancer

Dosage

Adults: Refer to

Mechanism of action

The precise mechanisms of vitamin E's actions are not fully understood; however, it is known to act as an antioxidant by preventing free radical reactions with cell membranes. One key mechanism involves the termination of lipid peroxidation, where vitamin E interacts with unstable lipid radicals to produce stable lipids and a relatively stable vitamin E radical. This radical can be regenerated back to its active form through reactions with ascorbate or glutathione. Additionally, vitamin E may modulate inflammatory responses and is linked to cancer prevention through its effects on NF-kappaB signaling pathways.

Pharmacodynamics

Vitamin E functions primarily as an antioxidant, protecting cells against oxidative stress and inflammatory processes. It helps to mitigate the damaging effects of reactive oxygen species (ROS) and is vital in maintaining the integrity of cell membranes. Vitamin E deficiency can lead to various health issues, including impaired immune function and increased susceptibility to chronic diseases such as coronary heart disease and certain cancers. It also plays a role in safeguarding other fat-soluble vitamins from oxidative degradation.

Pharmacokinetics

Tocopheryl is absorbed through the intestinal tract and is typically transported in the bloodstream by lipoproteins. The bioavailability of vitamin E can be influenced by dietary fat intake, as it is fat-soluble. Once absorbed, tocopheryl is stored in the liver and adipose tissues. The metabolism of vitamin E involves conversion to various metabolites, which can be excreted in urine and bile. The half-life of alpha-tocopherol in the body can vary, but it is generally several hours to days, depending on individual factors and dietary intake.

Adverse effects

• Nausea
• Diarrhea
• Abdominal cramps
• Fatigue
• Headache

Interactions

• May enhance the effects of anticoagulants, increasing the risk of bleeding
• May interact with statins, potentially increasing risk of muscle disorders
• May reduce the effectiveness of certain chemotherapy agents

Precautions

• Use with caution in individuals with a history of bleeding disorders
• Monitor prothrombin time in patients on anticoagulants
• Consult healthcare provider before use in pregnant or breastfeeding women

Pregnancy

Vitamin E is generally considered safe during pregnancy when used in recommended amounts, but high doses should be avoided as they may pose risks.

Breast-feeding

Vitamin E is excreted in breast milk; consult a healthcare provider before supplementation while breastfeeding.

Storage

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

Formulations

• Capsules
• Soft gels
• Liquid formulations
• Tablets

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

... Excessive palmitoylcarnitine formation and exhausted L-carnitine stores leading to energy depletion, attenuated acetylcholine synthesis and oxidative stress to be main mechanisms behind PA-induced neuronal loss.High PA exposure is suggested to be a factor in causing diabetic neuropathy and gastrointestinal dysregulation. ... First phase insulin release response was lost in these islets. FFAs slightly increased the insulin output of normal fresh pancreas beta-cells. However, chronic exposure to FFAs resulted in loss of first phase insulin release and blunted insulin secretion response to various levels of D-glucose stimulation.

Pharmacodynamics

Palmitic acid is the first fatty acid produced during lipogenesis (fatty acid synthesis) and from which longer fatty acids can be produced. Palmitate negatively feeds back on acetyl-CoA carboxylase (ACC) which is responsible for converting acetyl-ACP to malonyl-ACP on the growing acyl chain, thus preventing further palmitate generation

Mechanism of action

The mechanism of action for most of vitamin E's effects are still unknown. Vitamin E is an antioxidant, preventing free radical reactions with cell membranes. Though in some cases vitamin E has been shown to have pro-oxidant activity. One mechanism of vitamin E's antioxidant effect is in the termination of lipid peroxidation. Vitamin E reacts with unstable lipid radicals, producing stable lipids and a relatively stable vitamin E radical. The vitamin E radical is then reduced back to stable vitamin E by reaction with ascorbate or glutathione. Cancer development and progression are closely associated with inflammation. NF-kappaB (nuclear factor kappaB) provides a mechanistic link between inflammation and cancer, and is a major factor controlling the ability of malignant cells to resist tumor surveillance mechanisms. NF-kappaB might also regulate tumor angiogenesis and invasiveness and the signalling pathways that mediate its activation provide attractive targets for new chemopreventive and chemotherapeutic approaches. ROS (reactive oxygen species) initiate inflammation by up-regulation of pro-inflammatory cytokines and therefore antioxidants provide a major defence against inflammation. alpha-Tocopherol is a lipid-soluble antioxidant. In addition to decreasing lipid peroxidation, alpha-tocopherol may exert intracellular effects. Hence, the aim of this study was to test the effect of alpha-tocopherol supplementation in cancer prevention via suppression of NF-kappaB-mediated pro-inflammatory cytokines. alpha-Tocopherol treatment significantly down-regulates expression, synthesis as well as secretion of pro-inflammatory cytokine IL-6 (interleukin-6) in cancerous mice. It also suppresses NF-kappaB binding to IL-6 promoter in liver leading to decreased secretion of IL-6 in serum. The regulation of the signalling pathway by alpha-tocopherol is found apart from its antioxidant capacity to reduce lipid peroxidation. Thus, the present study provides evidence for the hypothesis that besides the powerful free radical scavenging effects, alpha-tocopherol has genomic effects in down-regulation of pro-inflammatory cytokine and cancer prevention via the NF-kappaB-dependent pathway. Mitocans are drugs selectively killing cancer cells by destabilizing mitochondria and many induce apoptosis via generation of reactive oxygen species (ROS). However, the molecular events by which ROS production leads to apoptosis has not been clearly defined. In this study with the mitocan alpha-tocopheryl succinate (alpha-TOS) the role of the Bcl-2 family proteins in the mechanism of malignant cell apoptosis has been determined. Exposure of several different cancer cell lines to alpha-TOS increased expression of the Noxa protein, but none of the other proteins of the Bcl-2 family, an event that was independent of the cellular p53 status. alpha-TOS caused a profound conformational change in the pro-apoptotic protein, Bak, involving oligomerization in all cell types, and this also applied to the Bax protein, but only in non-small cell lung cancer cells. Immunoprecipitation studies indicated that alpha-TOS activates the two BH1-3 proteins, Bak or Bax, to form high molecular weight complexes in the mitochondria. RNAi knockdown revealed that Noxa and Bak are required for alpha-TOS-induced apoptosis, and the role of Bak was confirmed using Bak- and/or Bax-deficient cells. We conclude that the major events induced by alpha-TOS in cancer cells downstream of ROS production leading to mitochondrial apoptosis involve the Noxa-Bak axis. It is proposed that this represents a common mechanism for mitochondrial destabilization activated by a variety of mitocans that induce accumulation of ROS in the early phases of apoptosis. /alpha-Tocopheryl succinate/

Pharmacodynamics

Vitamin E is a collective term used to describe 8 separate fat soluble antioxidants, most commonly alpha-tocopherol. Vitamin E acts to protect cells against the effects of free radicals, which are potentially damaging by-products of the body's metabolism. Vitamin E deficiency is seen in persons with abetalipoproteinemia, premature, very low birth weight infants (birth weights less than 1500 grams, or 3½ pounds), cystic fibrosis, and cholestasis and severe liver disease. Preliminary research suggests vitamin E may help prevent or delay coronary heart disease and protect against the damaging effects of free radicals, which may contribute to the development of chronic diseases such as cancer. It also protects other fat-soluble vitamins (A and B group vitamins) from destruction by oxygen. Low levels of vitamin E have been linked to increased incidence of breast and colon cancer.