Abstract: This study was conducted to explore the effects of dietary resveratrol supplementation on liver anti-oxidant capacity and anti-apoptosis of Shanma ducks under acute heat stress, and to determine the effects of resveratrol supplementation on SIRT1 signaling pathway, antioxidant enzyme system and apoptosis related genes in the liver of Shanma ducks. A total of 120 healthy female Shanma ducks with similar weight at 60 days old were randomly divided into two groups, 60 in each group. The control (C) group was fed a basic diet, and the resveratrol (RES) group was fed a basic diet supplemented with 400 mg·kg^-1 resveratrol. Animals in two groups were kept at a temperature of (24±2) ℃. After 15 days, there was no significant difference in the weight of the animals between the two groups. Then the animals in each group were randomly divided into 3 groups,20 in each group, and placed in an artificial climate room at 39 ℃ for 0, 30, and 60 min, respectively. After heat stress treatment, duck serum samples and liver tissues were collected, and the mRNA, protein level and apoptosis number of SIRT1 signal pathway and apoptosis related genes were detected using qRT-PCR, Western blot and TUNEL techniques. Biochemical method was adopted to detect the oxidation index in serum and liver. The results showed that the mRNA expression of HSP70and HSP90 in RES group was higher than those in control group. At the same time, resveratrol activated the SIRT1 pathway and increased the mRNA expressions of downstream PGC-1α and TFAM, and significantly increased the nuclear proteins expression of Nrf1 and Nrf2 under heat stress for 60 min. Resveratrol increased the levels of T-AOC in serum. Resveratrol significantly increased the levels of SOD, CAT, AIHR and decreased the content of MDA under heat stress for 60 min，and under the same heat stress condition， the T-AOC, CAT and GSH-Px in liver of RES group were higher than those of C group, while MDA content in RES group was lower than that in C group. Under the condition of acute heat stress, the number of hepatocyte apoptosis in RES group was significantly lower than that in C group, and resveratrol decreased the mRNA expression of Bax, Bak1, Bax/Bcl-2, increased the protein expression of Bcl-2, and decreased the protein expression of Bax, Caspase3, Bax/Bcl-2. In conclusion, the addition of 400 mg·kg^-1 resveratrol to the diet can activate the SIRT1 signaling pathway in duck liver, reduce the expression of pro-apoptotic genes and increase the expression of anti-apoptotic genes. Resveratrol can improve the anti-oxidant capacity and anti-apoptosis ability of duck liver, and can improve the oxidative damage of duck liver caused by acute heat stress.

Key words: resveratrol, heat stress, antioxidant, apoptosis