Dietary geniposide supplementation alleviates hepatic lipid deposition and oxidative stress induced by high-fat diet in juvenile tiger puffer, Takifugu rubripes

Abstract

High-fat diet has a negative impact on fish health, making it crucial to implement measures to mitigate these effects. This study aimed to assess the effects of geniposide administration in a high-fat diet (HFD) on the growth performance, serum biochemical parameters, hepatic histological characteristics, and lipid metabolism of juvenile tiger puffer (Takifugu rubripes). A total of 270 fish (initial body weight: 3.69 ± 0.07 g) were randomly divided into three groups with triplicate tanks. They were hand-fed to apparent satiety for 8 weeks with control diet (10 % crude lipid, CON), high-fat diet (15 % crude lipid, HFD), and HFD with 400-mg/kg geniposide (HFDG), respectively. The results showed that no significant differences in growth performance were observed among the three groups (P > 0.05). However, the crude lipid contents of whole body and liver, serum levels of triglycerides (TG), alanine transaminase (ALT) and aspartate transaminase (AST), hepatic malonaldehyde (MDA) content and total superoxide dismutase (T-SOD) were significantly higher in HFD group than that in CON group (P < 0.05). Compared with HFD group, the HFDG group had notably lower hepatic crude lipid content, serum and hepatic TG and total cholesterol levels, serum AST levels, and hepatic T-SOD activity (P < 0.05). H&E staining revealed hepatocyte enlargement and cytoplasmic vacuolization in the HFD group, while HFD supplemented with geniposide ameliorated these conditions. Transcriptomic sequencing of fish liver tissues revealed 350 differentially expressed genes between the HFD and HFDG groups. KEGG analysis showed that these genes were enriched in lipid metabolism-related pathways, including glycerolipid metabolism, fatty acid degradation, and steroid hormone biosynthesis. Compared with HFD group, the HFDG group showed significant downregulation of genes involved in lipogenesis (dgat1, acc, fasn, chrebp, lxrα, and fabp-1) and upregulation of genes involved in lipolysis (agtl, lpl, and pparα) (P < 0.05). In conclusion, 400 mg/kg geniposide supplementation in HFD alleviated the HFD-induced hepatic lipid deposition and oxidative stress in T. rubripes by inhibiting lipogenesis and promoting lipolysis.