Protective effects of Dioscorea bulbifera and Zingiber officinale mixed extracts against glutamate-induced cell death in HT22 cells

Abstract This study aimed to evaluate the neuroprotective effects of mixed extracts from Dioscorea bulbifera and Zingiber officinale (DBZO) against glutamate-induced excitotoxicity in HT-22 cells and to elucidate the associated molecular mechanisms. Neurotoxicity and protective effects were assessed using MTT and LDH assays, while cellular morphology was analyzed via microscopy. DBZO extract significantly restored axonal integrity disrupted by glutamate exposure. A DCFDA assay confirmed that DBZO reduced reactive oxygen species (ROS) generation in a concentration-dependent manner, underscoring its antioxidant capacity. Western blot analysis demonstrated that DBZO markedly decreased glutamate-induced neuronal death at 0.25 and 0.5 mg/mL. The observed neuroprotection was associated with the inhibition of the MAPK signaling cascade and the downregulation of apoptotic markers, including Caspase-3 and PARP. Moreover, DBZO activated the PI3K/Akt/mTOR survival pathway, enhancing neuronal viability. It also boosted antioxidant defenses by modulating Keap1 and NQO1 expression, thereby reducing oxidative damage. Collectively, these findings suggest that DBZO confers neuroprotection by regulating oxidative stress and apoptosis through NRf2/NQO-1 signaling. Due to its strong antioxidant and antiapoptotic properties. Graphical Abstract