Danshen (Salvia miltiorrhiza Buge)–Gegen (Pueraria lobata (Willd.) Ohwi) Herb Pair Inhibits Ferroptosis After Ischemia–Reperfusion Injury Involving the Nrf2/System xc-/GPX4 Axis

Background:Danshen–Gegen is a classic herb pair in traditional Chinese medicine, which has been used to treat cardiovascular and cerebrovascular diseases. Ischemic stroke (IS) is a prevalent cerebrovascular condition; ferroptosis is one of the contributing factors driving the progression of IS. This study aims to determine the underlying mechanism and examine if Danshen–Gegen (DG) extract may prevent cerebral ischemia–reperfusion injury by preventing ferroptosis.Methods:The comprehensive compositional characterization of DG was analyzed by ultra-high-performance liquid chromatography coupled with hybrid quadrupole-orbitrap high-resolution mass spectrometry (UPLC-Q-orbitrap MS). The experiments were conducted in middle cerebral artery occlusion/reperfusion (MCAO/R) rats and oxygen-glucose deprivation/re-oxygenation (OGD/R) cells. The neuroprotective effects of DG on IS were assessed by examining rat survival rates, infarct volume, behavioral scores, and cerebral water content. Then, we tested the accumulation of Fe2+and lipid peroxidation products such as reactive oxygen species (ROS), glutathione (GSH), malondialdehyde (MDA), myeloperoxidase (MPO), and 4-hydroxynonenal (4-HNE) in rats and cells. The expression of nuclear factor erythroid-derived 2-like 2 (Nrf2), Solute Carrier Family 7 Member 11 (-xCT), Glutathione peroxidase 4 (GPX4), Cyclooxygenase-2 (COX-2), Transferrin Receptor 1 (TFR1), and Long-chain-fatty-acid–CoA ligase 4 (ACSL4) was also assessed in vivo and in vitro.Results:UPLC-Q-orbitrap MS analysis was performed to characterize the chemical profile of DG, and a total of 33 chemical constituents were successfully identified. DG significantly alleviated the ischemic damage to brain tissue, reduced infarct volume, and improved neurological dysfunction. The content of Fe2+and lipid peroxidation products was markedly decreased. Furthermore, DG could restore the expression of Nrf2, -xCT, and GPX4 with the inhibition of COX-2, TFR1, and ACSL4, thus achieving a suppressive effect on ferroptosis.Conclusions:The regulatory influence of DG via the Nrf2/System xc-/GPX4 axis may play a crucial role in alleviating ferroptosis and enhancing recovery from cerebral ischemia injury.