LIT CONTROL PH DOWN CAPSULES

Indications

• Hepatotoxicity prevention, particularly related to acetaminophen overdose
• Cholesterol management
• Support for hair, skin, and nail health
• Heavy metal chelation
• Kidney function support

Mechanism of action

The exact mechanism of action of L-methionine's anti-hepatotoxic activity is not fully understood. It is believed that L-methionine metabolism may counteract the depletion of hepatic glutathione caused by high doses of acetaminophen, thereby reducing oxidative stress. Additionally, L-methionine and its metabolites may exhibit free-radical scavenging activity due to the presence of sulfur, which contributes to its potential antioxidant effects. L-methionine also plays a role in protein synthesis by binding with transfer RNA (tRNA) in the cytoplasm to facilitate the translation of mRNA into proteins.

Pharmacodynamics

L-methionine serves as a primary source of sulfur, which is vital for preventing disorders affecting hair, skin, and nails. It helps lower cholesterol levels by promoting the liver's production of lecithin, reduces liver fat, and may protect the kidneys. As a natural chelating agent, it aids in the detoxification of heavy metals and influences the formation of ammonia, leading to ammonia-free urine that minimizes bladder irritation. Furthermore, it is thought to promote hair growth and exhibit antioxidant properties.

Pharmacokinetics

L-methionine is absorbed in the gastrointestinal tract and subsequently distributed throughout the body. It undergoes metabolic conversion primarily in the liver, where it is involved in various pathways, including the biosynthesis of S-adenosyl-L-methionine and the regulation of one-carbon metabolism. The elimination of L-methionine occurs through metabolic pathways and is dependent on the body's protein synthesis needs.

Adverse effects

• Gastrointestinal disturbances
• Allergic reactions
• Nausea
• Vomiting

Precautions

• Use with caution in patients with renal impairment
• Not recommended for use in patients with known hypersensitivity to methionine

Pregnancy

There is limited data on the use of L-methionine during pregnancy. Consult a healthcare provider before use.

Breast-feeding

Limited information is available. Consult a healthcare provider before use while breastfeeding.

Storage

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

Formulations

• Tablets
• Capsules
• Powder

Indications

• Phosphate deficiency
• Magnesium deficiency
• Dietary supplementation

Dosage

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

Adults: Refer to the BNF for specific dosing recommendations.

Mechanism of action

Phytin acts by binding to minerals in the gastrointestinal tract, which can enhance the bioavailability of phosphate and magnesium while reducing the absorption of certain divalent and trivalent cations. This mechanism helps to regulate mineral balance in the body.

Pharmacodynamics

Phytin is known to influence mineral metabolism, particularly the absorption and utilization of calcium and magnesium. It acts as an antinutrient by chelating minerals, which can affect their bioavailability. However, it also provides an important source of phosphorus, which is critical for various physiological functions including energy metabolism and bone health.

Pharmacokinetics

The pharmacokinetics of phytin are not extensively documented; however, it is generally believed to be poorly absorbed in the gastrointestinal tract due to its chelating properties. The absorption of phytin and its effects on mineral metabolism can vary based on dietary factors and individual physiological conditions. After ingestion, its effects on mineral levels may be observed over a period of time, as it interacts with dietary components.

Pregnancy

There is limited data on the use of phytin during pregnancy. Consult healthcare professionals for guidance on safety and potential risks.

Breast-feeding

Consult with a healthcare provider before using phytin while breastfeeding, as safety data is limited.

Storage

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

Indications

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

Dosage

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

Adults: Refer to BNF for specific adult dosing information.

Mechanism of action

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

Pharmacodynamics

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

Pharmacokinetics

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

Adverse effects

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

Precautions

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

Pregnancy

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

Breast-feeding

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

Storage

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

Formulations

• Capsules
• Tablets
• Oral solutions
• Topical preparations

Mechanism of action

The mechanism of the possible anti-hepatotoxic activity of L-methionine is not entirely clear. It is thought that metabolism of high doses of acetaminophen in the liver lead to decreased levels of hepatic glutathione and increased oxidative stress. L-methionine is a precursor to L-cysteine. L-cysteine itself may have antioxidant activity. L-cysteine is also a precursor to the antioxidant glutathione. Antioxidant activity of L-methionine and metabolites of L-methionine appear to account for its possible anti-hepatotoxic activity. Recent research suggests that methionine itself has free-radical scavenging activity by virtue of its sulfur, as well as its chelating ability. Amino acids are selected for protein synthesis by binding with transfer RNA (tRNA) in the cell cytoplasm. The information on the amino acid sequence of each individual protein is contained in the sequence of nucleotides in the messenger RNA (mRNA) molecules, which are synthesized in the nucleus from regions of DNA by the process of transcription. The mRNA molecules then interact with various tRNA molecules attached to specific amino acids in the cytoplasm to synthesize the specific protein by linking together individual amino acids; this process, known as translation, is regulated by amino acids (e.g., leucine), and hormones. Which specific proteins are expressed in any particular cell and the relative rates at which the different cellular proteins are synthesized, are determined by the relative abundances of the different mRNAs and the availability of specific tRNA-amino acid combinations, and hence by the rate of transcription and the stability of the messages. From a nutritional and metabolic point of view, it is important to recognize that protein synthesis is a continuing process that takes place in most cells of the body. In a steady state, when neither net growth nor protein loss is occurring, protein synthesis is balanced by an equal amount of protein degradation. The major consequence of inadequate protein intakes, or diets low or lacking in specific indispensable amino acids relative to other amino acids (often termed limiting amino acids), is a shift in this balance so that rates of synthesis of some body proteins decrease while protein degradation continues, thus providing an endogenous source of those amino acids most in need. /Protein synthesis/ The mechanism of intracellular protein degradation, by which protein is hydrolyzed to free amino acids, is more complex and is not as well characterized at the mechanistic level as that of synthesis. A wide variety of different enzymes that are capable of splitting peptide bonds are present in cells. However, the bulk of cellular proteolysis seems to be shared between two multienzyme systems: the lysosomal and proteasomal systems. The lysosome is a membrane-enclosed vesicle inside the cell that contains a variety of proteolytic enzymes and operates mostly at acid pH. Volumes of the cytoplasm are engulfed (autophagy) and are then subjected to the action of the protease enzymes at high concentration. This system is thought to be relatively unselective in most cases, although it can also degrade specific intracellular proteins. The system is highly regulated by hormones such as insulin and glucocorticoids, and by amino acids. The second system is the ATP-dependent ubiquitin-proteasome system, which is present in the cytoplasm. The first step is to join molecules of ubiquitin, a basic 76-amino acid peptide, to lysine residues in the target protein. Several enzymes are involved in this process, which selectively targets proteins for degradation by a second component, the proteasome. /Protein degradation/ Methionine dependence, the inability of cells to grow when the amino acid methionine is replaced in culture medium by its metabolic precursor homocysteine, is characteristic of many cancer cell lines and some tumors in situ. Most cell lines proliferate normally under these conditions. The methionine dependent t

Pharmacodynamics

L-Methionine is a principle supplier of sulfur which prevents disorders of the hair, skin and nails; helps lower cholesterol levels by increasing the liver's production of lecithin; reduces liver fat and protects the kidneys; a natural chelating agent for heavy metals; regulates the formation of ammonia and creates ammonia-free urine which reduces bladder irritation; influences hair follicles and promotes hair growth. L-methionine may protect against the toxic effects of hepatotoxins, such as acetaminophen. Methionine may have antioxidant activity.

Mechanism of action

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

Pharmacodynamics

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