Abstract: Objective　To investigate the protective effect and mechanism of asiaticoside (AC) on renal ischemia-reperfusion injury (RIRI) by regulating SIRT1-FOXO3-PINK1-Parkin pathway mediated mitochondrial autophagy. Methods　Fifty male SD rats were divided into the sham-operation group (Sham group), the model group, the AC group, the AC+SIRT1 inhibitor (EX-527) group and the EX-527 group by random number table method, with 10 rats in each group. RIRI model was constructed. The AC group was given AC suspension 80 mg/(kg·d) by intragastric administration for 4 weeks before modeling. The AC+EX-527 group was intraperitoneally injected with 1% DMSO solution containing EX-527 (5 mg/kg) 3 days before modeling, and intraperitoneally injected once 20 min before intraoperative reperfusion. The remaining treatments were the same as the AC group. The Ex-527 group was intraperitoneally injected with the same amount of 1% DMSO solution containing EX-527 80 mg/(kg·d). Serum creatinine (Scr) and blood urea nitrogen (BUN) levels were detected 24 h after modeling. Pathological changes and scores of renal tissues were observed by HE staining. Western blot assay was used to detect SIRT1, FOXO3, PINK1, Parkin pathway proteins, autophagy related Beclin1, LC3A/B-Ⅰ, LC3A/B-Ⅱ protein levels. The value of (LC3A/B-Ⅱ)/(LC3A/B-Ⅰ) was calculated. ATP content was detected by ultraviolet spectrophotometry. The changes of mitochondrial membrane potential were detected by JC staining. Results　Compared with the Sham group, the levels of Scr and BUN were increased, pathological damage occurred in renal tissue, expression levels of pathways and autophagy related proteins were increased, ATP content was decreased, and mitochondrial membrane potential level was decreased in the model group (P＜0.05). Compared with the model group, the levels of Scr and BUN were significantly decreased, the pathological damage of kidney tissue was alleviated, the expression levels of pathways and autophagy related proteins increased, ATP content and mitochondrial membrane potential were also increased in the AC group (P＜0.05). Compared with the AC group, the Scr and BUN levels were increased, the histopathological damage was aggravated, the expression levels of pathways and autophagy related proteins were decreased, ATP content was decreased, and the mitochondrial membrane potential level was decreased in the AC+EX-527 group and the EX-527 group (P＜0.05). Conclusion　AC can improve mitochondrial function of renal cells, inhibit apoptosis and protect RIRI by up regulating the expression levels of SIRT1-FOXO3-PINK1-Parkin signaling pathway proteins and promoting mitochondrial autophagy.

Key words: reperfusion injury, kidney, autophagy-related proteins, mitochondrial autophagy, SIRT1-FOXO3-PINK1-Parkin pathway, asiaticoside