Abstract: OBJECTIVE To investigate the protective effect of thymoquinone on renal ischemia reperfusion injury in rats.METHODS Sixty male SD rats were randomly divided into three groups:normal group, model group and thymoquinone group. Renal ischemia reperfusion model was established in model group and thymoquinone group, thymoquinone (40 mg·kg^-1) was injected intraperitoneally followed reperfusion in thymoquinone group. The pathological changes of the kidney were observed by HE staining. MDA, SOD, Scr and BUN content were determined; cell apoptosis index was detected by dUTP nick end labeling. The expression of caspase-3, Bax, TNF-α and IL-1β in renal tissue was detected by RT-PCR.RESULTS Model group showed renal tubular expansion, renal tubular epithelial cell necrosis, thymoquinone treatment significantly improved the above changes. Compared with normal group, apoptosis index in model group significantly decreased(P<0.05). Compared with normal group, SOD activities in model group significantly decreased(P<0.05), MDA content, Scr and BUN significantly increased(P<0.05); compared with model group, SOD activities in thymoquinone group significantly increased(P<0.05), MDA content, Scr and BUN significantly decreased(P<0.05). Compared with normal group, the mRNA expression of caspase-3, Bax, TNF-α and IL-1β were significantly increased(P<0.05). Compared with model group, the expression of caspase-3, Bax, TNF-α and IL-1β decreased in thymoquinone group(P<0.05).CONCLUSION Thymoquinone reduces the level of oxidative stress and inhibit the apoptosis and inflammation. Thus, it plays a protective role in the process of renal ischemia-reperfusion injury.