AIM To investigate the improving effects of epigallocatechin gallate (EGCG) on rat kidney injury induced by cisplatin and its mechanism of action.METHODS Fifty male SD rats (10 rats/group) were randomly divided into blank control group,kidney injury group,EGCG low-,middle-and high-dose (25,50 and 100 mg/kg) groups.The kidney injury group and the drug administration group were treated with 7.5 mg/kg cisplatin by intraperitoneal injection to build the kidney injury model,and the blank control group was intraperitoneally injected with normal saline.After fourteen days of administration,the general condition and morphological changes of kidney tissue by HE staining were observed;BUN,Cr,Cys-c contents in serum,and IL-18,KIM-1 contents in urine were detected by ELISA;MDA,GSH and T-SOD contents in renal cortex were determined by kit;Western blot method was used to determine the contents of Nrf2 protein in renal contex cytoplasm and nucleus,and the expression level of HO-1 protein.RESULTS EGCG intervention could improve the pathological structural changes of rat kidney injury induced by cisplatin,decrease kidney index,and decrease serum Cr,Cys-c contents and urine IL-18,KIM-1 contents.Moreover,renal cortex MDA concentration decreased,and renal cortex GSH concentration,T-SOD activity increased.At the same time,renal cortex cytoplasm Nrf2 content reduced,but nucleus Nrf2 and total cell HO-1 contents increased.CONCLUSION EGCG plays a role in the improvement of rat kidney injury induced by cisplatin through the activation of Nrf2/HO-1 signal pathway.