Electroacupuncture pretreatment inhibits ferroptosis and inflammation after middle cerebral artery occlusion in rats by activating Nrf2.

Abstract

Objective: Electroacupuncture (EA) pretreatment can effectively increase the tolerance of the brain to ischemic stroke. The mechanism of ischemic tolerance induced by EA is related to Nrf2, but its specific mechanism has not been elucidated. This paper was designed to explore the effect of EA pretreatment on brain injury and the related mechanisms.

Methods: Rats were pretreated with EA before middle cerebral artery occlusion (MCAO) modeling. The symptoms of neurological deficit and the volume of cerebral infarction were measured. The levels of inflammatory factors, oxidative stress-related factors, LPO, ROS, and Fe²⁺ were evaluated by the corresponding kits. Cell apoptosis was determined through TUNEL staining. The mRNA expression of inflammatory factors was examined by RT-qPCR, and the protein expression of ferroptosis-related factors, pyroptosis-related proteins, Keap1, Nrf2, HO-1, and NQO1 by western blotting.

Results: EA pretreatment improved the symptoms of neurological deficit and reduced the volume of cerebral infarction. EA pretreatment significantly inhibited oxidative stress, inflammatory response, ferroptosis, pyroptosis, and apoptosis in brain tissues of MCAO rats. Mechanistically, EA pretreatment could activate Nrf2 expression and reduce Keap1 expression.

Conclusion: EA pretreatment reduced inflammation and oxidative stress and inhibited ferroptosis by activating Nrf2 expression, ultimately delaying the development of ischemic stroke.