Abstract
This study investigates the effect of Licochalcone A (Lico-A), a flavonoid from licorice roots known for its anti-inflammatory, anti-cancer, and antioxidant properties, on NMDA-induced neurotoxicity in primary cultured rat hippocampal neurons. The study measured cell survival following NMDA and Lico-A exposure, revealing that Lico-A at a 2.5 μg/ml significantly improved cell viability, countering the detrimental effects of NMDA. The study also analyzed synaptic changes by examining both postsynaptic density 95 (PSD95) and synaptophysin-targeted imaging, showing that Lico-A treatment resulted in a significant increase in synaptic puncta, contrasting with the reduction observed under NMDA exposure. Furthermore, levels of phosphorylated mixed lineage kinase domain-like pseudokinase (P-MLKL) and phosphorylated receptor-interacting serine/threonine-protein kinase 3 (P-RIP3), key necroptosis regulators, were measured using Western blotting. The results showed an increase in P-MLKL and P-RIP3 in neurons exposed to NMDA, which was reduced following Lico-A treatment. The response of astrocyte and microglia was also evaluated by immunostaining for glial fibrillary acidic protein (GFAP), ionized calcium-binding adaptor molecule 1 (IBA-1) and tumor necrosis factor alpha (TNF-α). These markers exhibited heightened expression in the NMDA group, which was substantially reduced by Lico-A treatment. These findings suggest that Lico-A has neuroprotective effects against NMDA-induced neurotoxicity, potentially contributing to synaptic preservation, inhibition of neuronal necroptosis, and modulation of glial activation. Therefore, Lico-A shows promise as a neuroprotective agent for conditions associated with NMDA-related neurotoxicity.