Quercetin- Inhibits glutamate release and is found in onion (highest in red onion), raw chili peppers, asparagus, kale, berries, plums, peppers, broccoli, sophora japonica leaf/flowers “These results suggest that quercetin inhibits glutamate release from rat cortical synaptosomes and this effect is linked to a decrease in presynaptic voltage-dependent Ca(2+) entry and to the suppression of PKC and PKA activity.” https://www.ncbi.nlm.nih.gov/pubmed/23933436 Protective effects of onion-derived quercetin on glutamate-mediated hippocampal neuronal cell death “This is the first report on the detailed mechanisms of the protective effect of quercetin on HT22 cells. Onion extract and quercetin may be useful for preventing [...]