Pyridoxamine

Pyridoxamine is a water-soluble form of vitamin B6 and one of the three natural vitamers of the vitamin, the others being pyridoxine and pyridoxal. In humans, pyridoxamine can be converted to the active coenzyme pyridoxal 5'-phosphate (PLP) through cellular processes that involve phosphorylation and the action of pyridoxine 5'-phosphate oxidase on related phosphorylated forms. As PLP-dependent coenzyme, the vitamers participate in a wide range of reactions related to amino acid metabolism, neurotransmitter synthesis, and other essential processes.

Beyond its role as a cofactor, pyridoxamine has attracted interest for its non-enzymatic properties. It can act as a nucleophilic scavenger of reactive carbonyl compounds and form stable adducts with glyoxal and methylglyoxal, thereby reducing the formation of advanced glycation end-products (AGEs) and potentially mitigating oxidative stress. This antiglycation activity has been studied in the context of diabetic and AGE-related tissue damage.

Clinical research on pyridoxamine has focused on diabetic complications and AGE-related pathology. While some animal studies and early human trials suggested potential protective effects, results in humans have been mixed and no approved therapeutic indication exists to date. Pyridoxamine is not widely used as a medication and is typically considered in the context of dietary intake of the broader vitamin B6 group.

Dietary sources include meat, fish, poultry, fortified cereals, and some fruits and vegetables. Adults generally require about 1.3 mg/day of total vitamin B6, with slightly higher recommendations for older individuals. Long-term high-dose supplementation of B6 vitamers can cause neuropathy, so intake should follow established guidelines.