Effects of curcumin supplementation in high-fat diet on growth performance, antioxidant capacity and lipid metabolism of spotted sea bass (Lateolabrax maculatus)

This study aimed to investigate the effects of curcumin supplementation in high-fat diets on growth performance, antioxidant capacity and lipid metabolism in spotted sea bass ( Lateolabrax maculatus ). Six experimental diets were formulated: a normal-fat diet (NF), a high-fat diet (HF), and four experimental diets derived from the HF supplemented with 0.02%, 0.04%, 0.08%, and 0.16% curcumin. A total of 450 healthy spotted sea bass, with an initial body weight of (2.00±0.16) g, were selected and randomly divided into 6 groups (3 replicates per group, 25 fish per replicate). The fish were raised in 200L tank and fed the experimental diets twice daily, over a 70-day culture period. The results showed that, compared to the NF, the HF had no significant impact on weight gain rate (WGR), specific growth rate (SGR), or feed conversion ratio (FCR) in spotted sea bass ( P >0.05). The HF increased malondialdehyde (MDA) levels in both serum and liver ( P <0.05), while reducing nuclear factor-related factor 2 ( nrf2 ) gene expression. The levels of triglyceride (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) in the serum were significantly increased ( P <0.05). The levels of TC and LDL-C in the liver were significantly increased, along with a notable rise in hepatic lipid deposition ( P <0.05). Compared to the HF, supplementing curcumin had no significant effect on WGR, SGR, or FCR in spotted sea bass ( P >0.05). However, it increased the activity of superoxide dismutase (0.04%, 0.16%) in the serum and the gene expression levels of nrf2 (0.08%, 0.16%) ( P <0.05), while reducing MDA levels in both serum and liver (0.02%-0.08%, P <0.05). Compared to the HF, curcumin significantly reduced TG levels in both serum and liver of spotted sea bass (0.04%, 0.08%, P <0.05), markedly decreased hepatic lipid deposition (0.02%-0.16%), and significantly upregulated the expression of fatty acid β-oxidation-related genes, peroxisome proliferator-activated receptor alpha ( ppar-α , 0.08%) and carnitine palmitoyltransferase I ( cpt1 , 0.16%), in the liver ( P <0.05). In summary, adding curcumin to high-fat diets can alleviate oxidative damage in spotted sea bass by enhancing antioxidant capacity and improve its lipid metabolism disorders. The optimal supplementation level of curcumin is 0.09%.