In recent years, numerous clinical trials were undertaken in order to elucidate the active principle of garlic (Allium sativum L., Alliaceae). The most prominent effect of garlic preparations is a contribution to the prevention of stroke and arteriosclerosis.
N-methyl D-aspartate receptors (NMDARs), a subclass of glutamate receptors have broad actions in neural transmission for major brain functions. Overactivation of NMDARs leading to "excitotoxicity" is the underlying mechanism of neuronal death in a number of neurological diseases, especially stroke.