Ginsenoside Rd alleviates early brain injury by inhibiting ferroptosis through cGAS/STING/DHODH pathway after subarachnoid hemorrhage

Ferroptosis, a recently identified form of regulated cell death, is characterized by lipid peroxidation and iron accumulation, plays a critical role in early brain injury after subarachnoid hemorrhage. Ginsenoside Rd, an active compound isolated from ginseng, is known for its neuroprotective properties. However, its influence on SAH-induced ferroptosis remains unclear. In this study, we constructed an SAH model using intravascular perforation in vivo and treated HT22 cells with oxyhemoglobin to simulate the condition in vitro. We observed significant changes in ferroptosis markers, including GPX4 and ACSL4, following SAH. Administration of ginsenoside Rd to both rats and HT22 cells effectively inhibited neuronal ferroptosis induced by SAH, alleviating neurological deficits and cognitive dysfunction in rats. Notably, the neuroprotective properties of ginsenoside Rd were countered by the STING pathway agonist 2'3'-cGAMP. Experiments conducted in vitro and in vivo illustrated that the impacts of ginsenoside Rd were counteracted by the BQR inhibitor. Our findings suggest that ginsenoside Rd mitigates EBI after SAH by suppressing neuronal ferroptosis through the cGAS/STING pathway while upregulating DHODH levels. These outcomes emphasize the potential of ginsenoside Rd as a therapeutic candidate for subarachnoid hemorrhage.