Group B vitamins protect murine cerebellar granule cells from glutamate/NMDA toxicity

The role of B group vitamins in preventing neuronal death against excitotoxicity was investigated. Neuronal death of cultured mouse cerebellar granule neurons (CGNs) caused by glutamate (50 microM) or NMDA (200 microM) was delayed in CGNs that had been treated with riboflavin (B2), folic acid (B9) or cynocobalamin (B12) for 18 h. Such neuroprotection by B2, B9 and B12 was in a dose- and time-dependent manner. In contrast, application of thiamin (B1), nicotinamide (B3), d-pantothenic acid (B5), pyridoxine (B6) or carnitine (BT) did not ameliorate glutamate or NMDA-mediated excitotoxicity to CGCs. These results are the first indication that certain B group vitamins are not only required for the normal brain function, but can also play a protective role against excitotoxicity to the brain.