Abstract: The objective of this study was to observe the protective effect of petroleum ether fraction of Toona sinensis Roem seeds extracts on the kidney of diabetic nephropathy (DN) rats and its preliminary mechanism.Male Wistar rats were fed up with high-fat diet for one month.DN rats were established by injecting streptozotocin at the dose of 60 mg/kg.DN rats were divided into model group,sample intervention group (5 mg/100g·d) and normal control group.After treatment for 10 weeks,the rats were sacrificed,the blood samples and the renal cortex were collected.Biochemical indicators in serum and renal index were determined. HE staining,PAS staining,PASM staining and Masson staining were applied for observing the pathological changes of the renal tissues.Changes of renal structure were observed in DN rats by transmission electron microscopy.The protein levels of TGF-β1,CTGF and collagen IV were detected.The petroleum ether fraction of T.sinensis seeds extracts can reduce blood glucose,urinary albumin,renal index,oxidative stress index,serum creatinine and urea nitrogen.The renal pathology abnormality was improved in DN rats.The protein levels of TGF-β1,collagen IV and CTGF were increased.The expressions of TGF-β1,collagen IV and CTGF were decreased.These results indicated that petroleum ether fraction of T.sinensis seeds extracts had protective effects on DN rats by inhibiting oxidative stress,protein expression of TGF-β1,collagen IV and CTGF.

Key words: petroleum ether fraction of Toona sinensis seeds extract, diabetic nephropathy, oxidative stress, immunohistochemistry