HERBALIFE NUTRITION NITEWORKS POWDER

Indications

• Antioxidant supplementation
• Prevention of vitamin E deficiency
• Support for cardiovascular health
• Skin protection from oxidative stress

Dosage

Children: Refer to specific guidelines for appropriate dosing based on indication and clinical context.

Adults: Refer to specific guidelines for appropriate dosing based on indication and clinical context.

Mechanism of action

Vitamin E exerts its antioxidant effects by scavenging free radicals and preventing the propagation of lipid peroxidation. It protects cell membranes by integrating into the lipid bilayer, where it can neutralize reactive oxygen species and stabilize cellular structures. This action helps maintain the integrity of cells and tissues against oxidative stress.

Pharmacodynamics

The pharmacodynamic properties of allrac-alpha-tocopheryl are primarily attributed to its role as an antioxidant. It exhibits anti-inflammatory effects and has been shown to influence immune function. Additionally, it may play a role in cardiovascular health by preventing the oxidation of low-density lipoprotein (LDL) cholesterol, thus reducing the risk of atherosclerosis.

Pharmacokinetics

Allrac-alpha-tocopheryl is absorbed in the intestine, especially in the presence of dietary fats. It is transported in the bloodstream bound to lipoproteins and is stored primarily in adipose tissue and the liver. The elimination half-life varies, but the vitamin is mainly excreted in the bile and urine. Its bioavailability can be affected by several factors, including dietary fat intake, absorption disorders, and the presence of other nutrients.

Adverse effects

• Nausea
• Diarrhea
• Fatigue
• Headache
• Rash

Interactions

• Anticoagulants may increase the risk of bleeding when used with allracalphatocopheryl
• Cholesterol-lowering medications may interact with the absorption of vitamin E
• Certain chemotherapy drugs may have altered effects when combined with antioxidants like allracalphatocopheryl

Precautions

• Use with caution in patients with a history of bleeding disorders
• Monitor blood glucose levels in diabetic patients
• Caution advised in patients on anticoagulant therapy

Pregnancy

Allracalphatocopheryl is classified as a Category C drug. Its use during pregnancy should be based on a risk-benefit assessment.

Breast-feeding

Vitamin E is excreted in human milk. Caution is advised when administering to nursing mothers.

Storage

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

Formulations

• Soft gelatin capsules
• Oil solutions
• Tablets

Indications

• Prevention and treatment of scurvy
• Nutritional supplementation in vitamin C deficiency
• Adjunct therapy in the management of certain infections
• Support for immune function
• Antioxidant therapy

Dosage

Children: For children, refer to the BNF for Children for specific dosing recommendations based on age and indication.

Adults: For adults, the typical oral dose of ascorbate is 500 mg to 1000 mg daily, depending on the indication and individual needs. Higher doses may be used under medical supervision.

Mechanism of action

Ascorbate acts primarily as an antioxidant by donating electrons to free radicals, thus neutralizing them and preventing oxidative stress. It plays a critical role in the hydroxylation of proline and lysine residues in collagen, which is essential for maintaining connective tissue integrity. Additionally, ascorbate is involved in the biosynthesis of catecholamines and various other metabolic pathways.

Pharmacodynamics

Ascorbate exhibits a range of biological effects, including enhancing immune response, reducing inflammation, and promoting wound healing. Its antioxidant properties help protect cells from oxidative damage, while its role in collagen synthesis is crucial for tissue repair and maintenance. Ascorbate also assists in the regeneration of other antioxidants, such as Vitamin E.

Pharmacokinetics

Ascorbate is readily absorbed in the gastrointestinal tract, with absorption efficiency decreasing at higher doses. It is distributed throughout body fluids and tissues, particularly in leukocytes, adrenal glands, and the brain. The renal clearance of ascorbate is dose-dependent, with excess amounts being excreted in urine. The half-life of ascorbate in plasma is approximately 16 to 24 days, although it can vary based on overall body stores and dietary intake.

Pregnancy

Ascorbate is generally considered safe during pregnancy, but high doses should be avoided unless prescribed by a healthcare professional.

Breast-feeding

Ascorbate is excreted in breast milk; however, it is generally considered safe for breastfeeding mothers when taken in recommended doses.

Storage

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

Formulations

• {'name': 'Ascorbic Acid', 'dosage_form': 'Tablet', 'strength': 'Various strengths available'}
• {'name': 'Ascorbic Acid', 'dosage_form': 'Powder', 'strength': 'Various strengths available'}
• {'name': 'Ascorbic Acid', 'dosage_form': 'Injection', 'strength': 'Various strengths available'}

Indications

• Mild muscle pain
• Joint pain
• Minor arthritis pain
• Muscle strains
• Bruises
• Skin irritation

Dosage

Children: Refer to the BNF for Children for specific dosing information based on age and weight, as doses may vary.

Adults: Apply a thin layer to the affected area up to three times daily. Do not apply to broken skin.

Mechanism of action

The active ingredients in balm, such as menthol and camphor, produce a cooling sensation when applied to the skin. This cooling effect is thought to activate certain receptors (TRPM8) that trigger a sensation of cold, which can distract from pain. Additionally, camphor and eucalyptus oil have mild anti-inflammatory properties, which may further contribute to pain relief.

Pharmacodynamics

Balm formulations primarily exert their effects locally on the site of application. The cooling sensation induces vasodilation, which can promote blood flow and potentially aid in the healing process. The anti-inflammatory effects of certain components may reduce swelling and discomfort associated with minor injuries or inflammatory skin conditions.

Pharmacokinetics

When applied topically, the absorption of balm ingredients can vary based on formulation and skin integrity. The onset of action is typically rapid, with effects usually felt within minutes. Systemic absorption is minimal, which limits systemic side effects but may still occur if large amounts are applied or if used on broken skin. The duration of action is usually several hours, necessitating reapplication as needed.

Adverse effects

• Skin irritation
• Allergic reactions
• Contact dermatitis

Precautions

• Avoid contact with eyes and mucous membranes
• Use with caution in patients with sensitive skin
• Not recommended for use on broken skin or open wounds

Pregnancy

Consult healthcare provider before use, as safety during pregnancy has not been established.

Breast-feeding

Consult healthcare provider before use, as safety during breastfeeding has not been established.

Storage

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

Formulations

• Topical ointment
• Cream
• Gel

Indications

• Acidulant in food and beverages
• Preservative in pharmaceutical formulations
• pH adjuster in various chemical preparations

Dosage

Children: Refer to product-specific guidelines for appropriate dosing based on formulation and indication.

Adults: Refer to product-specific guidelines for appropriate dosing based on formulation and indication.

Mechanism of action

Citric acid acts by chelating metal ions, which can enhance the solubility of certain compounds and improve their bioavailability. It also contributes to the acidity of the environment, which can influence enzymatic activity and metabolic pathways, particularly in the degradation of citronellol.

Pharmacodynamics

Citric acid exhibits mild pharmacological effects primarily attributed to its role in metabolic processes. It aids in the regulation of pH levels, which can impact enzymatic reactions and biochemical pathways. The acid's chelating properties may help to reduce the toxicity of certain metal ions in biological systems.

Pharmacokinetics

Citric acid is rapidly absorbed after oral administration and is metabolized in the liver. It undergoes conversion to various metabolites in the citric acid cycle, contributing to energy production. The elimination primarily occurs through urine, with minimal accumulation in the body.

Pregnancy

Citric acid is generally regarded as safe during pregnancy when used in food amounts. However, consult a healthcare provider for advice on medicinal use.

Breast-feeding

Citric acid is considered safe during breastfeeding when consumed in food amounts. For medicinal use, consult a healthcare provider.

Storage

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

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.

Mechanism of action

Folic acid is biochemically inactive until it is converted into active forms, primarily tetrahydrofolic acid and methyltetrahydrofolate, by the enzyme dihydrofolate reductase (DHFR). These active forms are essential for maintaining normal erythropoiesis, synthesizing nucleic acids, interconverting amino acids, and generating formate. They participate in critical one-carbon transfer reactions necessary for DNA synthesis and methylation processes. Folic acid, in conjunction with vitamin B12, helps normalize elevated homocysteine levels by facilitating its remethylation to methionine, a process that is crucial for various metabolic pathways.

Pharmacodynamics

Folic acid is an essential cofactor for enzymes involved in nucleic acid synthesis and amino acid metabolism. It is particularly significant in preventing megaloblastic anemia, which arises from impaired DNA synthesis due to folate deficiency. The synthesis of thymidylate, necessary for DNA formation, is directly influenced by folate availability. Folic acid's role is especially crucial during periods of rapid cellular division, and it has protective effects against certain cancer developments. As humans cannot synthesize folic acid endogenously, adequate dietary intake is essential for maintaining normal physiological functions.

Pharmacokinetics

Folic acid is absorbed in the small intestine and is then converted into its active forms within the body. The bioavailability of folic acid is influenced by factors such as food composition and the presence of certain gastrointestinal conditions. Once absorbed, it is transported in the bloodstream, mainly as 5-methyltetrahydrofolate. The distribution of folate occurs within various tissues, with significant

Adverse effects

• Allergic reactions
• Gastrointestinal disturbances
• Skin rash
• Altered sleep patterns

Interactions

• Anticonvulsants may reduce the effectiveness of folic acid
• Methotrexate may interfere with folic acid metabolism
• Trimethoprim-sulfamethoxazole can enhance the effects of folic acid deficiency

Precautions

• Monitor for signs of anemia in patients with malabsorption syndromes
• Use cautiously in patients with a history of hypersensitivity to folic acid
• Assess for vitamin B12 deficiency before initiating treatment, as folic acid can mask symptoms

Pregnancy

Folic acid is essential during pregnancy to prevent neural tube defects and support fetal development. Supplementation is recommended before conception and during the first trimester.

Breast-feeding

Folic acid passes into breast milk, and adequate maternal intake is important to ensure sufficient levels for the nursing infant.

Storage

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

Formulations

• Tablets
• Oral solutions
• Injectable forms

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

Indications

• Supplementation for enhancing exercise performance
• Support for cardiovascular health
• Potential use in managing erectile dysfunction
• Adjunctive therapy for ammonia detoxification

Dosage

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

Adults: Refer to the BNF for specific dosing recommendations. Typical doses for supplementation range from 3 to 6 grams per day, depending on the indication.

Mechanism of action

L-citrulline is converted to L-arginine by the enzyme argininosuccinate synthase. L-arginine is subsequently converted to nitric oxide (NO) by nitric oxide synthase (NOS). NO is a crucial signaling molecule in the cardiovascular and nervous systems, mediating its effects primarily through cyclic GMP. The production of cyclic GMP from guanosine triphosphate (GTP) is catalyzed by guanylate cyclase, which is activated by NO.

Pharmacodynamics

L-citrulline serves as a precursor to L-arginine, which has various biological activities including potential anti-atherogenic effects. The amino acid is involved in stimulating energy levels, immune system function, and the detoxification of ammonia. Although it is not incorporated into proteins during protein synthesis, citrulline residues are generated by peptidylarginine deiminases from arginine, contributing to the structure of several proteins.

Pharmacokinetics

L-citrulline is absorbed in the intestines and is metabolized primarily in the kidneys and liver. It does not accumulate in tissues as it is readily converted to L-arginine and subsequently to nitric oxide. The bioavailability of L-citrulline varies based on the route of administration and individual metabolic differences. Its effects are typically seen after supplementation due to its role in increasing L-arginine levels and enhancing nitric oxide production.

Adverse effects

• Gastrointestinal discomfort
• Nausea
• Diarrhea
• Abdominal cramps

Precautions

• Use with caution in patients with renal impairment
• Monitor blood pressure in patients taking antihypertensive medications

Pregnancy

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

Breast-feeding

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

Storage

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

Formulations

• Oral tablets
• Powder for oral solution

Indications

• Nutritional support in individuals with deficiencies
• Heart failure
• Cystic fibrosis
• Diabetes mellitus
• Neurological disorders

Dosage

Children: Refer to the BNF for Children for specific dosing recommendations, as pediatric doses are often weight-based and condition-specific.

Adults: Refer to the BNF for specific dosing recommendations, as doses may vary based on the condition being treated.

Mechanism of action

Dietary supplements containing taurine function by replacing missing nutrients in the body. Taurine acts as a substrate for the formation of bile salts, regulates cell volume, modulates intracellular calcium levels, and provides cytoprotection to the central nervous system.

Pharmacodynamics

Taurine supplements serve as a well-tolerated nitrogen source for nutritional support. The administration of taurine regulates plasma amino acid concentrations, nitrogen balance, weight, and serum protein levels, aiding in the improvement of overall nutritional status.

Pharmacokinetics

Taurine is absorbed through the small intestine and distributed throughout the body, with high concentrations in the heart, brain, and skeletal muscles. It is primarily metabolized in the liver and excreted via the kidneys. The bioavailability of taurine may vary based on dietary sources and individual metabolic rates.

Pregnancy

There is no sufficient evidence to confirm the safety of taurine during pregnancy. Consult a healthcare provider before use.

Breast-feeding

There is limited information available regarding the safety of taurine during breastfeeding. Consult a healthcare provider for guidance.

Storage

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

Formulations

• Taurine capsules
• Taurine powder
• Taurine tablets

Indications

• Scurvy prevention
• Digestive aid
• Immune system support
• Skin health
• Antimicrobial applications

Dosage

Children: There is no specific paediatric dosage for lemon; it can be given to children in moderate amounts as part of a balanced diet.

Adults: There is no specific adult dosage for lemon; it can be consumed in various forms such as fresh fruit, juice, or as part of food and beverages.

Mechanism of action

Lemon contains compounds such as citric acid, flavonoids, and essential oils. Citric acid may enhance the absorption of minerals and has a role in the Krebs cycle, promoting energy metabolism. Flavonoids possess antioxidant properties, which help combat oxidative stress and inflammation, while essential oils can exhibit antimicrobial and anti-inflammatory effects.

Pharmacodynamics

The pharmacodynamic effects of lemon are primarily attributed to its antioxidant properties, which help neutralize free radicals, reduce oxidative stress, and support overall health. The citric acid in lemon may also aid in alkalizing the body, improving metabolic processes, and supporting digestion.

Pharmacokinetics

The bioavailability of lemon compounds can vary based on the form of consumption (whole fruit, juice, or extract). Vitamin C is rapidly absorbed in the gastrointestinal tract and distributed throughout the body. The metabolism of flavonoids occurs primarily in the liver, and they may have a variable half-life depending on individual metabolism.

Adverse effects

• Allergic reactions in sensitive individuals
• Gastrointestinal discomfort
• Tooth enamel erosion with excessive use

Precautions

• Caution in individuals with citrus allergies
• May cause skin irritation if applied topically in concentrated forms

Pregnancy

Lemon is generally considered safe during pregnancy, but excessive intake should be avoided.

Breast-feeding

Lemon is safe during breastfeeding when consumed in normal dietary amounts.

Storage

Store in a cool, dry place. Fresh lemons should be kept in the refrigerator to maintain freshness.

Formulations

• Fresh lemon
• Lemon juice
• Lemon essential oil
• Lemon zest

Indications

• Energy supplementation for athletes
• Rapid glucose replenishment
• Rehydration solutions
• Food additive for thickening and stabilizing

Dosage

Children: Refer to specific product guidelines or consult a healthcare professional for appropriate dosing.

Adults: Refer to specific product guidelines or consult a healthcare professional for appropriate dosing.

Mechanism of action

Maltodextrin is readily metabolized by the body to glucose. Upon ingestion, it is broken down by enzymes in the digestive tract into simpler sugars, which are then absorbed into the bloodstream. This rapid conversion supports immediate energy needs, particularly during physical activity.

Pharmacodynamics

Maltodextrin primarily serves as a source of energy, particularly for athletes and individuals requiring rapid glucose replenishment. Its high glycemic index means it can quickly raise blood sugar levels, providing immediate energy. Additionally, maltodextrin can help improve hydration status and nutrient absorption when included in rehydration solutions.

Pharmacokinetics

Maltodextrin is absorbed quickly in the gastrointestinal tract, leading to a rapid increase in plasma glucose concentrations. The peak plasma glucose levels typically occur within 30 minutes to 1 hour after consumption. The metabolic pathway involves conversion to glucose, which can then be utilized by various tissues for energy or stored as glycogen in the liver and muscles.

Adverse effects

• Gastrointestinal discomfort
• Diarrhea
• Nausea
• Flatulence

Precautions

• Use with caution in individuals with diabetes due to potential impact on blood glucose levels
• Monitor for gastrointestinal symptoms in sensitive individuals

Pregnancy

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

Breast-feeding

Maltodextrin is regarded as safe during breastfeeding, though consultation with a healthcare provider is recommended.

Storage

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

Formulations

• Powder
• Liquid

Mechanism of action

Folic acid, as it is biochemically inactive, is converted to tetrahydrofolic acid and methyltetrahydrofolate by dihydrofolate reductase (DHFR). These folic acid congeners are transported across cells by receptor-mediated endocytosis where they are needed to maintain normal erythropoiesis, synthesize purine and thymidylate nucleic acids, interconvert amino acids, methylate tRNA, and generate and use formate. Using vitamin B12 as a cofactor, folic acid can normalize high homocysteine levels by remethylation of homocysteine to methionine via methionine synthetase. Folic acid, after conversion to tetrahydrofolic acid, is necessary for normal erythropoiesis, synthesis of purine and thymidylates, metabolism of amino acids such as glycine and methionine, and the metabolism of histidine. The principal biochemical function of folates is the mediation of one-carbon transfer reactions. 5-Methyltetrahydrofolate donates a methyl group to homocystine, in the conversion of homocystine to L-methionine. ... 5,10-Methyltetrahydrofolate is regenerated from tetrahydrofolate via the enzyme serine hydroxymethyltransferase, a reaction, which in addition to producing 5,10-methyltetrahydrofolate, yields glycine. ... 5,10-methyltetrahydrofolate, supplies the one carbon group for the methylation of deoxyuridylic acid to form the DNA precursor thymidylic acid. This reaction is catalyzed by thymidylate synthase and the folate product of the reaction is dihydrofolate. Dihydrofolate is converted to tetrahydrofolate via the enzyme dihydrofolate reductase ...

Pharmacodynamics

Folic acid is a water-soluble B-complex vitamin found in foods such as liver, kidney, yeast, and leafy, green vegetables. Also known as folate or Vitamin B9, folic acid is an essential cofactor for enzymes involved in DNA and RNA synthesis. More specifically, folic acid is required by the body for the synthesis of purines, pyrimidines, and methionine before incorporation into DNA or protein. Folic acid is the precursor of tetrahydrofolic acid, which is involved as a cofactor for transformylation reactions in the biosynthesis of purines and thymidylates of nucleic acids. Impairment of thymidylate synthesis in patients with folic acid deficiency is thought to account for the defective deoxyribonucleic acid (DNA) synthesis that leads to megaloblast formation and megaloblastic and macrocytic anemias. Folic acid is particularly important during phases of rapid cell division, such as infancy, pregnancy, and erythropoiesis, and plays a protective factor in the development of cancer. As humans are unable to synthesize folic acid endogenously, diet and supplementation is necessary to prevent deficiencies. In order to function properly within the body, folic acid must first be reduced by the enzyme dihydrofolate reductase (DHFR) into the cofactors dihydrofolate (DHF) and tetrahydrofolate (THF). This important pathway, which is required for de novo synthesis of nucleic acids and amino acids, is disrupted by anti-metabolite therapies such as [DB00563] as they function as DHFR inhibitors to prevent DNA synthesis in rapidly dividing cells, and therefore prevent the formation of DHF and THF. In general, folate serum levels below 5 ng/mL indicate folate deficiency, and levels below 2 ng/mL usually result in megaloblastic anemia.

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

L-citrulline is converted to L-arginine by argininosuccinate synthase. L-arginine is in turn responsible for citrulline's therapeutic affects. Many of 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, L-arginine could enhance endothelial-dependent vasodilation and NO production.

Pharmacodynamics

A non-essential amino acid and a precursor of arginine. Citrulline supplements have been claimed to promote energy levels, stimulate the immune system and help detoxify ammonia (a cell toxin). L-citrulline is made from L-ornithine and carbamoyl phosphate in one of the central reactions in the urea cycle. It is also produced from L-arginine as a by-product of the reaction catalyzed by the enzyme NO synthase. L-citrulline, while being an amino acid, is not involved in protein synthesis and is not one of the amino acids coded for by DNA. Although citrulline cannot be incorporated in proteins during protein synthesis, several proteins are known to contain citrulline as an amino acid. These citrulline residues are generated by a family of enzymes called peptidylarginine deiminases (PADs), which convert the amino acid arginine into citrulline. Proteins that contain citrulline residues include myelin basic protein (MBP), fillagrin and several histone proteins.

Mechanism of action

The diet supplements containing taurine function by replacing the missing nutriments in the body. Taurine, as a single agent, presents different functions like substrate for formation of bile salts, cell volume regulation, modulation of intracellular calcium, cytoprotection of central nervous system, etc.

Pharmacodynamics

The diet supplements containing taurine are formulated as a well-tolerated nitrogen source for nutritional support. Administration of diet supplements regulates the level of plasma amino acid concentration, nitrogen balance, weight and serum protein concentration to reach normal values, thus improving the nutritional status.