Oryzativol A from the roots of Zea mays L. alleviates NMDA-induced excitotoxic injury and improves cell survival by targeting S100A4.

Excitotoxic neuronal injury is a common pathological mechanism underlying various central nervous system disorders, yet effective therapeutic interventions remain limited. Natural products are important sources of neuroprotective agents. This study aimed to investigate the antiexcitotoxic potential of polyphenolic compounds derived from maize roots (Zea mays L.) and to elucidate the underlying molecular mechanisms. Using a bioactivity-guided isolation strategy, 15 polyphenolic compounds were isolated from maize roots and systematically evaluated for their protective effects against NMDA-induced excitotoxicity in SH-SY5Y cells. Among them, Compound 15 (oryzativol A) exhibited the strongest activity, dose-dependently reversing the NMDA-induced reduction in cell viability, apoptosis, and calcium overload. Through proteomic analysis combined with CETSA, DARTS, molecular docking, molecular dynamics simulations, and ITC assays, S100A4 was identified as the direct target of oryzativol A, with an equilibrium dissociation constant (KD) of 3.2 μM. Mechanistic studies revealed that the knockdown of S100A4 expression significantly attenuated the protective effects of oryzativol A on cell viability, apoptosis, calcium overload, and calcium signaling. In conclusion, this study identified oryzativol A as a novel S100A4-targeting agent with potent antiexcitotoxic activity, established S100A4 as a druggable target for excitotoxicity-related disorders, and provided a solid foundation for the further development of oryzativol A as a promising lead compound.