Shine Neurobine Mechanism of Action

Pharmacology: (Summary of Pharmacokinetics and Pharmacodynamics): Small amounts of thiamine are well absorbed from the gastro-intestinal tract following oral administration, but the absorption of doses larger than about 5 mg is limited. It is also rapidly absorbed following intramuscular administration. It is widely distributed to most body tissues, and appears in breast milk. Within the cell thiamine is mostly present as the disphosphate. Thiamine is not stored to any appreciable extent in the body and amounts in excess of the body's requirements are excreted in the urine as unchanged thiamine or as metabolites. Pyridoxine, pyridoxal, and pyridoxamine are readily absorbed from the gastro-intestinal tract following oral administration and are converted to the active forms pyridoxal phosphate and pyridoxamine phosphate. They are stored mainly in the liver where there is oxidation to 4-pyridoxic acid and other inactive metabolites which are excreted in the urine. As the dose increases, proportionally greater amounts are excreted unchanged in the urine. Vitamin B12 substances bind to intrinsic factor; a glycoprotein secreted by the gastric mucosa, and is then actively absorbed from the gastro-intestinal tract. Absorption is impaired in patients with an absence of intrinsic factor, with a malabsorption syndrome or with disease or abnormality of the gut, or after gastrectomy. Vitamin B12 is stored in the liver, excreted in the bile, and undergoes extensive enterohepatic recycling; part of an administered dose is excreted in the urine, most of it in the first 8 hours; urinary excretion, however, accounts for only a small fraction in the reduction of total body stores acquired by dietary means. Vitamin B12 diffuses across the placenta and also appears in breast milk.
Thiamine combines with ATP to form the coenzyme, thiamine disphosphate required in carbohydrates metabolism and transketolation reactions to enable pyruvic acids to enter Krebs Citric Acid cycle.
Pyridoxine is converted in erythrocytes to pyridoxal phosphate and to a lesser extent pyridoxamine phosphate, which act as coenzymes for various metabolic functions affecting protein, carbohydrate, and lipid utilization. Pyridoxine is involved in conversion of tryptophan to niacin or serotonin, breakdown of glycogen to glucose-1-phosphate, conversion of oxalate to glycine, synthesis of gamma aminobutyric acid (GABA) within the CNS, and synthesis of heme.
Cyanocobalamin acts as a coenzyme for various metabolic function, including fat and carbohydrate metabolism and protein synthesis. It is necessary for growth, cell replication, haematopoiesis and nucleoprotein and myelin synthesis, largely due to its effects on metabolism of methionine, folic acid and malonic acid.