Protective effects of resveratrol against high ambient temperature‐induced spleen dysplasia in broilers through modulating splenic redox status and apoptosis

BACKGROUND: Resveratrol has been shown to prevent high ambient temperature (HT)‐induced spleen dysplasia, but the mechanisms of action are not clear. This study aims to examine the hypothesis that HT‐induced spleen dysplasia may be associated with HT‐induced oxidative stress and apoptosis, and resveratrol may activate the nuclear factor erythroid 2‐related factor 2 (Nrf2) signaling pathway, thus reducing oxidative stress and apoptosis. RESULTS: Results showed that HT caused spleen dysplasia in broilers, reflecting the lower relative weight of the spleen (P < 0.05). Compared with birds in a normal ambient temperature group, birds in the HT group exhibited higher (P < 0.05) malondialdehyde (MDA), protein carbonyl (PC), 8‐hydroxydeoxyguanosine (8‐OHdG) and Bcl‐2 associated X protein (Bax) content, higher Bax, caspase‐3 and caspase‐9 mRNA levels, and caspase‐3 and caspase‐9 activity, and a higher Bax/B‐cell lympoma/leukemia‐2 (Bcl‐2) ratio, but they exhibited lower (P < 0.05) glutathione (GSH) and Bcl‐2 content, and lower Nrf2, glutathione peroxidase (Gpx), MnSOD, heme oxygenase 1, glutathione reductase (GR) and Bcl‐2 mRNA levels, and lower total antioxidant capacity (T‐AOC), T‐SOD and catalase and maganese superoixide dismutase (CAT) activity, indicating HT‐induced oxidative stress and apoptosis. Compared with birds in the HT group, birds in the HT + Res group exhibited higher (P < 0.05) GSH and Bcl‐2 content, higher Nrf2, CAT, MnSOD, GR and Bcl‐2 mRNA levels, and higher T‐AOC, T‐SOD and CAT activity, but lower (P < 0.05) MDA content, and Bax and caspase‐3 mRNA levels, lower caspase‐3 and caspase‐9 activities, and Bax/Bcl‐2 ratio, indicating that resveratrol activated the Nrf2 signaling pathway and decreased apoptosis in the spleen. CONCLUSION: Resveratrol was effective in ameliorating HT‐induced spleen dysplasia in broilers through the activation of the Nrf2 signaling pathway, thereby decreasing apoptosis, suggesting that resveratrol may offer a potential nutritional strategy to protect against some HT‐induced detriments. © 2018 Society of Chemical Industry