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.