Feeding restriction alleviates high carbohydrate diet-induced oxidative stress and inflammation of Megalobrama amblycephala by activating the AMPK-SIRT1 pathway

This study investigated the effects of restricted feeding on the growth performance, oxidative stress and inflammation of Megalobrama amblycephala fed high-carbohydrate (HC) diets. Fish (46.94 +/- 0.04 g) were randomly assigned to four groups containing the satiation of a control diet (30% carbohydrate) and three satiate levels (100% (HC1), 80% (HC2) and 60% (HC3)) of the HC diets (43% carbohydrate) for 8 weeks. Results showed that HCl diet remarkably decreased final weight (FW), weight gain rate (WGR), specific growth rate (SGR), feed conversion ratio (FCR), hepatic activities of total anti-oxidation capacity (T-AOC), superoxide dismutase (SOD) and catalase (CAT), the AMP/ATP ratio, the p-AMPK alpha/t-AMPK alpha ratio, sirtuin-1 (SIRT1) protein expression and hepatic transcriptions of AMPK alpha 2, SIRT1, nuclear factor erythroid 2-related factor 2 (Nrf2), catalase (CAT), manganese superoxide dismutase (Mn-SOD), glutathione peroxidase 1 (GPx1) and interleukin10 (IL 10) compared to the control group, whereas the opposite was true for protein efficiency ratio (PER), nitrogen retention efficiency (NRE), energy retention efficiency (ERE), plasma glucose levels, alanine transaminase (AST) and aspartate aminotransferase (ALT) activities, hepatic contents of malondialdehyde (MDA), tumour necrosis factor alpha (TNF alpha) and interleukin 1 beta (IL 1 beta), ATP and AMP contents and hepatic transcriptions of kelch-like ECH associating protein 1 (Keap1), I kappa B kinase alpha (IKK alpha), nuclear factor kappa B (NF-kappa B), TNF alpha, IL 1 beta, interleukin 6 (IL 6) and transforming growth factor beta (TGF beta). As for the HC groups, fish fed the HC2 diet obtained relatively high values of SGR, PER, NRE, ERE, hepatic activities of T-AOC, SOD and CAT, the AMP/ATP ratio, the p-AMPK alpha/t-AMPK alpha ratio, SIRT1 protein expression and hepatic transcriptions of AMPK alpha 2, Nrf2, CAT, copper/zinc superoxide dismutase (Cu/Zn-SOD), Mn-SOD, GPx1, glutathione S-transferase (GST) and interleukin10 (IL 10), while the opposite was true for hepatic content of IL 6 and transcription of IKK alpha. Overall, an 80% satiation improved the growth performance and alleviated the oxidative stress and inflammation of blunt snout bream fed HC diets via the activation of the AMPK-SIRT1 pathway and the up-regulation of the activities and transcriptions of Nrf2-modulated antioxidant enzymes coupled with the depression of the levels and transcriptions of the NF-kappa B-mediated pro-inflammatory cytokines.