L-Histidyl hydrazide, also known as Histidine hydrazide, is a scavenger of 4-hydroxy-2-nonenal. Histidyl hydrazide is effective in reducing brain damage and improving functional outcome in a mouse model of focal ischemic stroke. also protected cultured rat primary neurons against death induced by HNE, chemical hypoxia, glucose deprivation, and combined oxygen and glucose deprivation. Histidine hydrazide prevented neuronal apoptosis as indicated by decreased production of cleaved caspase-3 protein.