The positive effects of dietary arginine on juvenile hybrid snakehead (Channa maculata♀×Channa argus♂) fed high-carbohydrate diets: Liver inflammation antioxidant response, and glucose metabolism

Abstract

The aim of this study was to investigate the effects of arginine supplementation on liver morphology, antioxidant capacity, inflammatory response, insulin signaling pathway and glucose metabolism in hybrid snakehead. Five experimental diets (2.31 %, 2.42 %, 2.72 %, 2.92 %, and 3.12 % arginine) were prepared by adding different levels of arginine to the basal diet containing high (27 %) level of carbohydrate. The results showed that the activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and glutathione peroxidase (GSH-Px) of fish fed with arginine diets were significantly higher than those in control group (p < 0.05), accompanied by the lower malondialdehyde (MDA) content in the same groups (p < 0.05). There were obvious mild inflammatory cell infiltration and increased perihepatic pancreatic space in control group, while the pathological state of the liver was relieved in fish fed with arginine diets. Dietary arginine supplementation resulted in significantly higher glucose metabolism-related genes glucokinase (GK), phosphoenolpyruvate carboxkinase (PEPCK), glycogen synthase (GS) and pyruvate kinase (PK) and insulin signaling pathway key genes insulin receptor subset-1 (IRS-1), protein kinase B (Akt) and phosphoenolpyruvate carboxykinase (PI3K)(p < 0.05). Immune-related genes transforming growth factor β (TGF-β), heat shock protein 70 (HSP70) and heat shock protein 90 (HSP90) were significantly higher in the arginine supplemented diet than in the control group (p < 0.05). Immune-related genes interleukin-8 (IL8), interleukin-1β (IL1β) and tissue tumor necrosis factor-α (TNF-α) in fish fed with arginine diets were significantly lower than those in control group (p < 0.05). In conclusion, dietary arginine can alleviate the adverse effects of high carbohydrate diet on hybrid snakeheads by improving glucose metabolism and enhancing antioxidant, anti-inflammatory and non-specific immune functions.