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The study mainly aimed at the effects of dietary Senecio scandens buch-ham extract (SSBE) on the growth performance, body composition, plasma biochemical index, intestinal and liver histology and the expression of antioxidant, apoptosis and inflammatory related genes in hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀). Basal diets supplemented with SSBE (10:1) 0%, 0.05%, 0.1%, 0.2% and 0.4% were fed hybrid grouper for 8 weeks. The results showed that WGR and SGR were significantly increased in the week 2 and week 4 in Diet 0.05% group (P < 0.05). The total protein, globulin and albumin significantly increased whereas alanine aminotransferase, triglyceride and alkaline phosphate in the plasma were significantly decreased in Diet 0.1% group (P < 0.05). The villi length, width, muscle thickness and the cross-sectional area of intestine were improved in Diet 0.05% and Diet 0.1% group. The expression levels of PPAR-α and CPT-1 in the liver of hybrid grouper were significantly increased following the supplementation of SSBE (P < 0.05). The expression levels of antioxidant related genes (CAT, GPX, GR and Keap1) and anti-inflammatory factor (IL-10) in liver, head kidney and spleen of hybrid grouper decreased significantly (P < 0.05). In addition, diets supplemented with 0.05%-0.1% SSBE had a good liver-protecting effect, but it would have a detrimental effect on hepatocytes when the content exceeds 0.2%. The above results indicated that the suitable additive amount of SSBE in hybrid grouper feed was 0.05%-0.1%., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The purpose of the present study was to explore the impaired anti-bacteria ability in immune organs and immune systems of obscure puffer induced by chronic dietary phosphorus (P) deficiency. Fish were fed diets supplemented with 6 g/kg P (P6) and 0 g/kg P (P0) respectively for 15 weeks, and lower final body weight, feed intake, weight gain, whole body P content and bone P content were observed in fish fed P0 diet (P < 0.05). Then the fish were continued to feed for 3 weeks and intraperitoneal injection with PBS (P6+PBS) and Aeromonas hydrophila (A.hydrophila) (P6 + A.hydrophila and P0 + A.hydrophila), and sampled at 3, 6, 12 and 24 h. The results showed that dietary P deficiency lowered survival rate, total hemocyte count, whereas enhanced ROS production and apoptosis rate of obscure puffer compared to the 6 g/kg P supplemented group after infection. Moreover, compared to the P sufficient group, puffer fish fed P deficient diet decreased the expressions of antioxidant genes catalase (cat) and glutathione reductase (gr), immune-related genes toll-like receptor 2 (tlr-2) and anti-inflammatory factors transforming growth factor β1 (tgf-β1) and interleukin 11 (il-11) while increased pro-inflammatory cytokines tumor necrosis factor α (tnf-α), interleukin 1β (il-1β) and interleukin 8 (il-8) in head kidney post-infection. In addition, dietary P deficiency decreased the hepatic gene expressions of anti-apoptotic factor B-cell lymphoma 2 (bcl-2) and bax-inhibitor 1 (bi-1), accompanied by increasing the mRNA expressions of pro-apoptotic factor caspase 3, caspase 8 and caspase 9 compared to the P sufficient group after A.hydrophila infection. In conclusion, dietary P deficiency impaired the anti-bacteria function of the immune system as well as immune organs by increasing oxidative stress and aggravating the inflammatory response and apoptosis in obscure puffer under the A.hydrophila challenge., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Excessive lipid accumulation and chemical abuse can induce fatty liver diseases in fish, but the underlying mechanism and therapies are unknown. The present study aims to evaluate the effects of Xiaochaihu Decoction (XCHD) on the growth performance, lipid metabolism and antioxidant function of hybrid grouper in vitro and in vivo, and provide evidence as to whether it can be potentially used as a medicine for liver diseases in aquaculture. In vitro, steatosis model of hybrid grouper primary hepatocytes were incubated for 48 h in control or lipid emulsion (LE)-containing medium with or without 24 h post-treatment with XCHD. XCHD treatment reversed the LE-induced intracellular lipid accumulation, cell viability and hepatocytes morphological structure. In vivo, a total of 300 hybrid grouper with an average initial weight of 25.43 ± 0.18 g were fed diets containing five graded levels of XCHD at 150-1200 mg/kg diet for 8 weeks. After that, a challenge trial was conducted by injection of D-GalN/LPS to induce liver injury. As a result, dietary supplementation with 150-300 mg/kg XCHD diets can significant improve growth performance and feed utilization (P < 0.05). Dietary XCHD down-regulated the expression of lipogenic-related genes (G6PD, DGAT2 and ME1) and up-regulated lipolysis-related genes (ATGL, PPARα and LPL) expression in the liver of hybrid grouper. Livers challenged with D-GalN/LPS exhibited extensive areas of vacuolization with the disappearance of nuclei and the loss of hepatic architecture. These pathological alterations were ameliorated by XCHD treatment. XCHD significantly down-regulated the D-GalN/LPS induced apoptosis-related genes caspase-3, caspase-9 and p53 mRNA expression and up-regulated the antioxidant-related genes CAT and MnSOD mRNA expression in dose dependent manner, respectively. XCHD potently reduced hepatic lipid accumulation and enhanced antioxidant capability in hybrid grouper and may be a potential fish-feed additive to prevent fatty liver diseases onset and progression., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

In this study, two experiments were performed to explore the effect of Radix Bupleuri extracts (RBE) on growth, lipid deposition and metabolism and immune response of hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀) using in vitro and in vivo models. In vitro, we used 2 ml/L 20% lipid emulsion (LE)-induced steatosis in hybrid grouper primary hepatocytes, then RBE (200, 400 and 800 μg/ml) was added to the hepatocytes after (post-treatment) the incubation with 20% LE (2 ml/L) in the culture medium. We found that RBE markedly increased cell viability, which were consistent with hepatocytes morphological structure examination and lipid metabolism and immune related genes study. The above result suggested that RBE has a protective effect on this model of hepatocytes damage. In vivo, five graded levels of RBE at 0, 200, 400, 800 and 1600 mg/kg diet were supplemented to a basal diet with 15% lipid levels (high lipid), and fed to a total of 300 hybrid grouper with an average initial weight of 25.58 ± 0.05 g for 8 weeks. Growth performance, liver histology, plasma biochemical parameters, and expression of genes involved in lipid metabolism and immune-related were measured. The study indicated that dietary RBE significantly improved growth performance and feed utilization and reduced hepatosomatic index. Dietary supplementation with 200-800 mg/kg RBE diets effectively decreased serum ALP, ALT, AST and LDH contents in fish. Furthermore, adipogenesis relative mRNA levels of DGAT2, G6PD, ME1 and DGKα in fish fed 200-400 mg/kg RBE diets were lower (P < 0.05) than in those fed RBE0 diets, while dietary supplementation with 200-800 mg/kg RBE diets up-regulated lipolysis-related genes (CPT1, LPL and PPARα) expression in the liver of hybrid grouper. Moreover, dietary RBE down-regulated the expression of apoptosis-related genes (caspase-9), up-regulated the expression of antioxidant genes (CAT) and immune-related genes (MHC2, IKKα and TGF-β1). Thus, our data suggest that RBE suppressed lipid accumulation and enhanced immune capability in hybrid grouper both in vitro and in vivo. These results offer new insight into RBE as a hepatoprotective in fish., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The study investigated the effects of dietary supplementation with dandelion extracts (DE) on growth performance, feed utilization, body composition, serum biochemical, liver histology, immune-related gene expression and CCl 4 resistance of hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀). A basal diet supplemented with DE at 0% (diet 0%), 0.1% (diet 0.1%), 0.2% (diet 0.2%), 0.4% (diet 0.4%) and 0.8% (diet 0.8%) were fed to hybrid grouper for 8 weeks. The results revealed that dietary DE had not a significant impact on growth performance and feed utilization (P > 0.05), but it could decrease the percent of crude lipids in whole body and increase the percent of crude protein in muscle (P < 0.05). Dietary DE increased the mRNA levels of antioxidant enzymes (catalase, glutathione peroxidase and glutathione reductase) and reduced inflammatory factor in the spleen and head-kidney of fish (P < 0.05), but reduced the expression of the liver antioxidant gene except for glutathione reductase (P < 0.05). Dietary supplementation with 0.2%-0.4% DE could effectively improve liver health. After injection of CCL 4 by 72 h, fish fed Diet0.2% and Diet0.4% showed regular hepatocyte morphology while fish fed Diet 0%, Diet 0.1% and Diet 0.8% showed hepatocyte damage. Higher survival rate and total blood cell count was observed in fish fed 0.1%-0.4% dietary DE (P < 0.05). In conclusion, DE could be used as a functional feed additive to enhance liver function of farmed fish. The best level of it should be between 0.2% and 0.4%., (Copyright © 2019. Published by Elsevier Ltd.)