Ethanol extract of Gastrodia elata Blume alleviates ischemic stroke by inhibiting oxidative stress and ferroptosis through the PI3K/AKT/Nrf2 pathway.

Abstract

ETHNOPHARMACOLOGICAL RELEVANCE: Gastrodia elata Blume (G. elata) is characterized by its ability to dispel wind, relieve spasms, and calm hyperactive liver yang. These effects are consistent with traditional Chinese medical (TCM) theory on therapeutic strategies for ischemic stroke (IS), particularly in alleviating neurological symptoms and promoting the recovery of cerebral circulation. However, the underlying mechanism of G. elata against IS remains to be fully elucidated. AIM OF THE STUDY: This study aimed to explore the protective effect and mechanism of G. elata ethanol extract (GEE) against IS. MATERIALS AND METHODS: HPLC and LC-MS were used for qualitative and compositional analysis of GEE. The in vivo and in vitro models of IS have been established. Network pharmacology, transcriptomics, Western blot, immunofluorescence and qRT-PCR were used to evaluate potential mechanisms. RESULTS: GEE can reduce ischemic brain injury and improve neurobehavioral performance in vivo. Meanwhile, GEE can attenuate the OGD/R-induced cell death. Importantly, combining network pharmacology, transcriptomics and experimental validation revealed that GEE can inhibit oxidative stress, inflammation, and ferroptosis to improve IS. These effects were attributed to the activation of Nrf2. ML385 and transfection of Nrf2-siRNA can reverse the neuroprotective effect of GEE. In addition, the neuroprotective effect mediated by GEE against IS injury benefits from PI3K/AKT. Notably, LY294002 reversed the antioxidant and anti-ferroptotic effects mediated by GEE after OGD/R. CONCLUSIONS: This study revealed for the first time that GEE can improve IS by regulating the PI3K/AKT pathway to activate Nrf2 and its downstream antioxidant and anti-ferroptotic effects.