Pharmacology: Mechanism of Action: The B vitamins thiamine (B1), pyridoxine (B6) and methylcobalamin are referred as "neurotropic" vitamins because of their important functions in the nervous system and supportive role in nerve regeneration process. They play an important role in the treatment of diabetic polyneuropathy.
Vitamin B1 acts as a coenzyme in the carbohydrate metabolism, which is the main energy supply for nerve fibres.
Vitamin B6 is essential for the amino acid metabolism hence it plays a key role in neurotransmitter synthesis which is needed for signal transmission in the nervous system.
Methylcobalamin promotes myelin formation and reduced Wallerian degeneration responses. It has neuroprotective effects and is essential for the folate dependent methionine cycle. The therapeutic effect of Methylcobalamin involves upregulation of multiple neurotropic factors, namely nerve growth factor (NGF) and brain-derived neurotrophic factor which promotes nerve survival and regeneration. It also promotes remyelination and maintenance of myelin sheath.
Folates and Methylcobalamin have fundamental roles in CNS function at all ages, especially the methionine-synthase mediated conversion of homocysteine to methionine, which is essential for nucleotide synthesis and genomic and non-genomic methylation. They may have roles in the prevention of disorders of CNS development in elderly people.