Objective To investigate the protective effect of sevoflurane postconditioning against cerebral ischemia/reperfusion (I/R) injury in rats and its mechanism of action. Methods A total of 80 specific pathogen-free healthy adult male Sprague-Dawley rats were selected and randomly divided into sham-operation group (S group), cerebral I/R group (I/R group), cerebral I/R+sevoflurane postconditioning group (ISP group), and cerebral I/R+sevoflurane postconditioning+nuclear factor ery-throid 2-related factor 2 (Nrf2) inhibitor group (ISPB group), with 20 rats in each group. All rats except those in the S group were used to establish a rat model of cerebral I/R injury using the suture method for occlusion of the middle cerebral artery for 2 h, followed by reperfusion for 24 h, and for the rats in the S group, threading was performed below the middle cerebral artery without ligation. The rats in the ISP group were given inhalation of 3% sevoflurane immediately after reperfusion for 30 min, and those in the ISPB group were given intraperitoneal injection of the Nrf2 inhibitor brusatol (2 mg/kg) at 30 min before ischemia in addition to the treatment in the ISP group. After successful modeling, neurological deficit score was used to eval-uate the degree of neurological impairment. Left ventricular blood samples and pathological sections of brain tissue were obtained, and 2,3,5-triphenyltetrazolium chloride staining was used to determine the percentage of cerebral infarct volume; enzyme-linked immunosorbent assay was used to measure the serum levels of inflammatory factors (interleukin-1β [IL-1β] and tumor necrosis factor-α [TNF-α]) and oxidative stress-related factors (malondialdehyde [MDA] and superoxide dismutase [SOD]); Western blotting was used to mea-sure the expression of apoptosis-related proteins (B-cell lymphoma-2 [Bcl-2], Bcl-2 related x [Bax], and Caspase-3) and Nrf2 signaling pathway-related proteins (Nrf2 and heme oxygenase-1 [HO-1]) in brain tissue; immunofluorescence assay was used to measure the expression of Nrf2 inside and outside the nucleus of brain tissue cells. Results Compared with the I/R group, the ISP group had significant reductions in neurological deficit score, the percentage of cerebral infarct volume, the serum levels of IL-1β, TNF-α, and MDA, and the levels of Bax and Caspase-3 in brain tissue (t=5.76-18.39,P
