Dietary Sodium Butyrate Supplementation Alleviates High-Fat Diet-Induced Liver Injury by Activating Nrf2 in Common Carp (Cyprinus carpio)

To evaluate the effects of sodium butyrate (NaBT) supplementation in high-fat diets on the growth performance and liver health of common carp (Cyprinus carpio), we formulated three isonitrogenous diets: the control diet (5.8% crude lipid, Control diet), the high-fat diet (10.8% crude lipid, HF diet), and the NaBT diet (10.8 % crude lipid and 0.1% NaBT, NaBT diet). Each diet was assigned to triplicate tanks (100 L) with 24 fish (14.52 & PLUSMN;0.08 g) in each tank. Experimental fish were fed twice daily for 8 weeks. The results showed that fish growth performance was not affected by experimental diets. Fish at HF group demonstrated higher content of triacylglyceride (TG) and total cholesterol (TCHO) in the liver. In addition, diet HF significantly increased hepatic oxidative stress by increasing malondialdehyde (MDA) content, decreasing activity levels of antioxidant enzymes and contents of reduced glutathione (GSH). Furthermoure, diet HF significantly decreased the mRNA expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1), and simultaneously increased the mRNA expression of tumor necrosis factor & alpha; (TNF-& alpha;), interleukin-10 (IL-10), and IL-6 in liver of common carp compared to control diet (P<0.05). However, diet NaBT significantly improved fish liver health by decreasing contents of TCHO and MDA, down-regulating mRNA expression of pro-inflammatory cytokines (e.g., TNF-& alpha;, IL-10 and IL-6), increasing the activity levels of antioxidant enzymes, and upregulating the mRNA expression of Nrf2 and HO-1 in the liver (P<0.05). In conclusion, dietary NaBT supplementation could ameliorate the detrimental effects of high-fat diets on liver health by activating Nrf2 in common carp.