Vitamin C
Ascorbate (vitamin C) is a vital antioxidant molecule in the brain. However, it also has a number of other important functions, being a cofactor involved in several enzyme reactions, including catecholamine synthesis, collagen production, and regulation of HIF-1 alpha.
Ascorbate is transported to the brain and neurons via the sodium-dependent vitamin C transporter 2 (SVCT2), resulting in an accumulation of ascorbate in cells against a concentration gradient. Dehydroascorbic acid, the oxidized form of ascorbate, is transported via glucose transporters of the GLUT family. Once in cells, it is rapidly reduced to ascorbate.
The highest concentrations of ascorbate in the body are found in the brain and in neuroendocrine tissues such as the adrenal gland, although the brain is the organ where ascorbate is most rapidly degraded. Combined with a regional asymmetry in ascorbate distribution in different brain areas, these facts suggest an important role for ascorbate in the brain.
Ascorbate is proposed to be a neuromodulator of glutamatergic, dopaminergic, cholinergic, and GABAergic transmission and associated behaviors. Because neurodegenerative diseases are typically associated with high levels of oxidative stress, ascorbate is thought to have a potential therapeutic role in ischemic stroke, Alzheimer’s disease, Parkinson’s disease, and Huntington’s disease, the authors write.
Vitamin C Function in the Brain: Vital Role of the Ascorbate Transporter SVCT2.
