Effects of dietary berberine on growth performance, lipid metabolism, antioxidant capacity and lipometabolism-related genes expression of AMPK signaling pathway in juvenile black carp (Mylopharyngodon piceus) fed high-fat diets
Authors: Ming Jian-Hua , Wang Ting , Wang Ting-Hui , Ye Jin-Yun , Zhang Yi-Xiang , Yang Xia , Shao Xian-Ping , Ding Zhong-Ying 
Published: September 2022

Abstract
This study aimed to investigate the effects of high-fat diet (HFD) berberine supplementation on growth, lipid metabolism, antioxidant capacity and lipometabolism-related genes expression of AMPK signaling pathway in juvenile black carp (Mylopharyngodon piceus). five hundred and forty healthy fish (4.04 ± 0.01 g) were randomly distributed into six groups, and fed six experimental diets: normal-fat diet (NFD, 5% fat), HFD (15% fat), and four HFDs supplemented with graded levels of berberine for 60 days, respectively. The results showed that, compared with fish fed NFD, HFD had no effects on the growth performance of fish except for reducing the survival rate, whereas HFD caused extensive lipid accumulation, oxidative stress injury and hepatic abnormalities. However, compared with the HFD group, Fish fed HFD supplemented with berberine at 98.26 or 196.21 mg/kg significantly improved the growth performance, increased serum high density lipoprotein-cholesterol (HDL-C) content, the activities of hepatic lipid metabolizing enzymes of hepatic lipase (HL), lipoprotein lipase (LPL), total lipase (TL), malate dehydrogenase (MDH) and hormone-sensitive lipase (HSL), liver antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) activities, and liver total antioxidant capacity (T-AOC) and reduced-glutathione (GSH) levels, and up-regulated the mRNA expression levels of adenosine-activated protein kinase (AMPK) subunits and lipolysis genes such as peroxisome proliferator-activated receptor alpha (PPARα), carnitine palmitoyltransferases 1 (CPT-1), acyl-coenzyme A oxidase (ACOX) and HSL (P < 0.05); meanwhile, significantly reduced the crude lipid contents in liver and whole-body of fish, alleviated hepatic histopathological changes, decreased serum lipid contents including triglyceride (TG), total cholesterol (TC), non-esterified fatty acid (NEFA) and low density lipoprotein-cholesterol (LDL-C), and activities of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and liver fatty acid synthase (FAS) and malondialdehyde (MDA) levels, and down-regulated the mRNA expression levels of lipogenesis genes such as sterol regulatory element-binding protein 1 (SREBP-1), acetyl-CoA carboxylase 1 (ACC1), glycerol-3-phosphate acyltransferase (GPAT), FAS and PPARγ, and lipid transporter genes such as fatty acid transport protein (FATP), fatty acids binding protein (FABP) and fatty acid translocase (FAT/CD36) (P < 0.05). Thus, HFD supplemented with an appropriate berberine (98.26 mg/kg or 196.21 mg/kg) could improve growth of juvenile black carp, promote lipid metabolism, enhance antioxidant capacity and reduce excessive lipid deposition of fish. The lipid-lowering mechanism of berberine might be mediated by activating AMPK signaling pathway, up-regulating lipolysis genes expression, and down-regulating lipogenesis and transport genes expression.