Effects of dietary ginkgo biloba leaf extract on growth performance, plasma biochemical parameters, fish composition, immune responses, liver histology, and immune and apoptosis-related genes expression of hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀) fed high lipid diets

Effects of dietary powdered Ficus deltoidea on the growth and health performance of African catfish, Clarias gariepinus production

Intensive aquaculture causes a decline in the health status of fish, resulting in an increased disease incidence. To counteract this, feed additives have been utilized to improve the growth performance and health of aquaculture species. This work specifically investigates the impact of powdered Ficus deltoidea (FD) on various parameters related to growth, blood parameters, liver and intestine morphology, body proximate analysis, digestive enzymes, antioxidant capacity, and disease resistance to motile Aeromonad Septicemia (MAS) caused by Aeromonas hydrophila infection in African catfish, Clarias gariepinus. Four formulated diets were prepared: T1 (0% FD), T2 (0.5% FD), T3 (0.75% FD), and T4 (1% FD). After 8 weeks, the African catfish's growth performance fed with the T2 diet exhibited a substantial improvement (p < 0.05), along with a remarkably lower (p < 0.05) feed conversion ratio (FCR) when compared to the other treatment groups. Blood parameter analysis revealed notably higher (p < 0.05) levels of white blood cell (WBC), lymphocytosis (LYM), hemoglobin (HGB), albumin (ALB), globulin (GLOB), as well as total protein (TP) in the T2 diet group. While all treatment groups displayed normal intestinal morphology, liver deterioration was observed in groups supplemented with higher FD. The T2 diet group recorded the highest villus length, width, and crypt depth. Protease and lipase levels were also notably improved in the T2 diet group compared to other treatment groups. Additionally, catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD) were remarkably elevated in all FD diet groups than in the control group. The expression of immune-related genes, including transforming growth factor beta 1, heat shock protein 90, nuclear factor kappa-B gene, and lysozyme G, was upregulated in all treatments. Overall, the results of this study indicate that incorporating dietary FD at 0.5% concentration in the diet of African catfish may enhance their productivity in intensive farming.

Effect of Amorphous Halomonas-PHB on Growth, Body Composition, Immune-Related Gene Expression and Vibrio anguillarum Resistance of Hybrid Grouper (Epinephelus fuscoguttatus ♀ × E. lanceolatu ♂) Juveniles

Poly-β-hydroxybutyrate (PHB) is a bacterial metabolite produced by bacteria such as Halomonas sp. that serves as a carbon and energy storage compound for bacteria under nutrient-limited conditions. Two experiments were conducted to investigate the effects of dietary supplementation with Halomonas-PHB on hybrid grouper (Epinephelus fuscoguttatus ♀ × E. lanceolatu ♂). In experiment I, juvenile groupers were fed basal diets supplemented with 3% Halomonas-PHB (3% HM-PHB) containing 1.4% PHB and 3% Halomonas (3% HM) without PHB, as well as a control diet, for seven weeks. The results showed no significant difference in survival rate, weight gain, and crude fat content between the 3% HM-PHB group and the control group; however, the crude protein of the 3% HM-PHB group was significantly lower than that of the control group. Furthermore, supplementation with 3% HM-PHB increased the fatty acids content in fish muscles, including long-chain unsaturated fatty acids C18:1n9, EPA, and DHA. In experiment II, groupers were fed a basal diet supplemented with 6.5% Halomonas-PHB (6.5% HM-PHB) containing 3% PHB and 6.5% Halomonas (6.5% HM) containing no PHB, as well as a basal diet (Control). After seven weeks of rearing, the fish were challenged with Vibrio anguillarum for 48 h. Although no significant difference in survival rate and growth was observed among different groups, the dietary supplement of 6.5% Halomonas-PHB improved the survival rate of V. anguillarum challenged grouper and significantly increased the gene expressions of catalase (CAT) and superoxide dismutase (SOD) in blood, interleukin 1 (IL1) and interleukin 10 (IL10) in the liver, spleen, head kidney, and blood (p < 0.05). In conclusion, dietary supplementation of Halomonas-PHB had no significantly positive effect on fish growth performance but increased the content of fatty acids, including long-chain unsaturated fatty acids C18:1n9, EPA, and DHA in fish muscle; it also improved the V. anguillarum resistance, possibly through increasing immune-related gene expression in different tissues and organs. Our findings offer compelling evidence that Halomonas-PHB can be utilized as a feed additive in intensive grouper farming to enhance the groupers' resistance to Vibrio.

Effects of Dietary Fish Oil Supplementation on the Growth, Proximate Composition, and Liver Health of Chinese Stripe-Necked Turtle (Mauremys sinensis)

Dietary lipids provide energy for animals and can also be converted into other nutrients (such as non-essential amino acids), which play a role in saving protein. The Chinese stripe-necked turtle is a protected and endangered species that has been bred in captivity; however, basic data on lipid requirements remain unavailable. In this study, 360 Mauremys sinensis (body weight of 65.32 ± 0.15 g) were randomly divided into six groups with three replicates per group; the turtles were fed experimental diets supplemented with various levels of fish oil (i.e., 1% (control group, CG), 3.5% (HF-1), 6% (HF-2), 8.5% (HF-3), 11% (HF-4), and 13.5% (HF-5)) for 10 weeks. The results showed that compared with CG, increasing the fish oil level promoted the growth performance of turtles, and the HF-3 group achieved the best effect. The HF-4 group showed the highest increases in the hepatosomatic index and viscerosomatic index. In addition, increased lipid levels also increased the crude lipid content and reduced the crude protein content in muscle tissue. Oil red O staining showed that the liver lipid content increased with the level of supplemented fish oil, which is consistent with the results of the hepatosomatic index. Compared with CG, triglyceride, total cholesterol, and low-density lipoprotein cholesterol increased significantly in both the liver and serum when fish oil levels exceeded 8.5% (p < 0.05), while high-density lipoprotein cholesterol decreased significantly. Aspartate transaminase and cerealthirdtransaminase levels in serum increased significantly when fish oil levels exceeded 8.5% (p < 0.05). Moreover, the activities of antioxidant enzymes (GSH-Px, SOD, T-AOC, and CAT) and MDA showed similar results, indicating that high fish oil levels (8.5-13.5%) caused liver tissue damage in M. sinensis. Increased fish oil levels significantly upregulated the expression levels of cytokines (IFN-γ, TNF-α, TGF-β1, IL-10, and IL-12) (p < 0.05), downregulated the expression levels of antioxidant enzyme-related genes (cat, mn-sod, and gsh-px), and increased apoptosis of liver cells. Supplementation of the diet with 3.5-6% fish oil improved the growth performance of M. sinensis, and the turtles maintained a beneficial immune status. The results provide a scientific basis for optimizing the commercial feed formula of M. sinensis.

Host Gut-Derived Probiotic, Exiguobacterium acetylicum G1-33, Improves Growth, Immunity, and Resistance to Vibrio harveyi in Hybrid Grouper (Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂)

Several exogenous probiotics are applicable in fish culture; however, challenges in isolation and verification have hindered the full utilization of numerous host probiotics. Therefore, this study aimed to apply the host probiotic Exiguobacterium acetylicum G1-33 to hybrid grouper (Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂) cultures and explore its mechanism of action. In total, 360 hybrid grouper were divided into four groups, which were fed the following for 60 days: three received commercial feed with varying concentrations of E. acetylicum G1-33 (106, 108, and 1010 CFU/g), while a control group received commercial feed. The results showed that supplementation with 106 and 108 CFU/g of E. acetylicum G1-33 enhanced gut morphology, upregulated growth-related genes (ghr1, igf-2, s6k1, tor), and promoted growth, with supplementation with 108 CFU/g resulting in the most notable enhancement. However, supplementation with 1010 CFU/g inhibited growth, possibly because of changes in intestinal morphology. Additionally, supplementation with E. acetylicum G1-33 upregulated the expression of immune-related genes (c3, myd88, Cu/Zn-sod, tlr3, and tnf2) in the liver and head kidney but led to an increase in malondialdehyde content, as well as a decrease in alkaline phosphatase and acid phosphatase activities, in the liver and serum, indicating increased oxidative stress. Moreover, supplementation with 106 and 108 CFU/g E. acetylicum G1-33 enhanced the widespread expression of immune-related genes in the head kidney and liver, respectively, and improved resistance to Vibrio harveyi, whereas supplementation with 1010 CFU/g weakened this resistance. In conclusion, E. acetylicum G1-33, particularly at 108 CFU/g, emerged as an effective probiotic, optimizing growth performance and immunity in hybrid grouper. This research is pioneering in its application of E. acetylicum in mariculture, potentially broadening the range of probiotic strategies in aquaculture.

Effect of dietary Lagnaria breviflora leaves extract on the growth performance, haematological, antioxidative and immune responses of African catfish (Clarias gariepinus) juveniles

The effects of dietary Lagnaria breviflora leaves extract (LBLE) on the growth performance, feed utilisation and haematological parameters of juveniles African catfish, Clarias gariepinus (mean = 8.45 ± 0.6 g) raised in a flow water (mean temperature 26.7°C, mean pH 7.52, mean dissolved oxygen 6.05 mg/L) were assessed in this study. Diets (400 g/kg crude protein; 4631.5 kcal/kg gross energy) supplemented with LBLE at levels of 0 (control), 0.5, 1.0, 1.5 or 2.0 g/kg diet were served to fish in triplicates (each replicate has 20 fish) until they appeared satiated for 12 weeks. Then, they were challenged with Aeromonas hydrophila infection for further 2 weeks. Fish served dietary LBLE had considerable higher weight gain (64.76 g) and specific growth rate (765.5% g/day) than the fish group fed with the control diet with a reduced feed conversion ratio (1.45) (p < 0.05). Compared to fish fed with the control diet, the villi height (146.30 µm) and width (284.35 µm) of the intestines increased greatly in a dose (LBLE in diets) dependent order. Similarly, dietary LBLE increased (p < 0.05) the packed cell volume (46.11%) and haemoglobin (17.03 g/dL), whereas 1.5 g of LBLE increased the counts of white blood cells. Glutathione S-transferase (769.43 U/mg protein), glutathione peroxidase (84.14 U/mg protein) and superoxide dismutase (433.15 U/mg protein) activities were significantly higher (p < 0.05) in fish fed with diets supplemented with LBLE compared to the control one. Additionally, dietary LBLE increased phagocytic and lysozyme activities and protected C. gariepinus against bacterial infections where the lowest death was observed in the fish fed on the diet containing 1.5 g LBLE/kg feed. These findings showed that the fish fed with LBLE/kg diet improved their immune system, antioxidant and growth performance in addition to providing protection from A. hydrophila infection with the optimum dose of 1.80 g/kg diet.

Optimal dietary lipid levels alleviated adverse effects of high temperature on growth, lipid metabolism, antioxidant and immune responses in juvenile turbot (Scophthalmus maximus L.)

Fish physiological health is often negatively impacted by high-temperature environments and there are few studies on how dietary lipids affect fish growth and physiology when exposed to heat stress. The main objective of this research was to examine the impact of dietary lipid levels on growth and physiological status of juvenile turbot (Scophthalmus maximus L.) and determine if dietary lipid concentration could alleviate the possible adverse effects of heat stress. Five diets containing 6.81%, 9.35%, 12.03%, 14.74%, and 17.08% lipid, respectively, were formulated and fed to turbot (initial weight 5.13 ± 0.02 g) under high-temperature conditions (24.0-25.0 °C). Meanwhile, the diet with 12.03% lipid (considered by prior work to be an optimal dietary lipid level) was fed to turbot of the same size at normal temperature. Results suggested that, among the different dietary lipid levels under high-temperature conditions, fish fed the optimal lipid (12.03%) exhibited better growth compared to non-optimal lipid groups, as evidenced by higher weight gain and specific growth rate. Simultaneously, the optimal lipid diet may better maintain lipid homeostasis, as attested by lower liver and serum lipid, along with higher liver mRNA levels of lipolysis-related genes (pgc1α, lipin1, pparα, lpl and hl) and lower levels of synthesis-related genes (lxr, fas, scd1, pparγ, dgat1 and dgat2). Also, the optimal lipid diet might mitigate oxidative damage by improving antioxidant enzyme activity, decreasing malondialdehyde levels, and up-regulating oxidation-related genes (sod1, sod2, cat, gpx and ho-1). Furthermore, the optimal lipid may enhance fish immunity, as suggested by the decrease in serum glutamic-oxalacetic/pyruvic transaminase activities, down-regulation of pro-inflammatory genes and up-regulation of anti-inflammation genes. Correspondingly, the optimal lipid level suppressed MAPK signaling pathway via decreased phosphorylation levels of p38, JNK and ERK proteins in liver. In summary, the optimal dietary lipid level facilitated better growth and physiological status in turbot under thermal stress.

Karyotypic changes and diversification time in Epinephelidae groupers (Perciformes). Implications on reproductive isolation

Groupers (Epinephelidae and Serranidae) have attracted special attention to fish farming, and their species offer good opportunities for successful hybridizations. Cytogenetic data allow a better understanding of the role of karyotypic diversification in the acquisition of post-zygotic reproductive isolation (RI). Thus, chromosomal analyses were performed on E. striatus (Caribbean Sea), E. coioides and E. tauvina (Indo-Pacific Region), using standard procedures and mapping of six repetitive DNA classes by the in situ hybridization. The three species have 2n=48 chromosomes. The karyotypes of E. coioides and E. striatus are composed only of acrocentric chromosomes (FN=48), while E. tauvina has 8 submetacentric chromosomes (FN=56). Heterochromatin has a preferential centromeric distribution, and the microsatellite repeats are dispersed throughout the chromosomes of all species. The 18S and 5S rDNA sites are unique but show a colocalization arrangement in E. tauvina and E. striatus. The chromosomal organization suggests that the three species still maintain a significant amount of syntenic regions. The range of the karyotype divergence and the RI levels showed low, but goes turn proportionally greater in relation to the divergence time between the parental species. The slow acquisition of postzygotic RI is consistent with the high karyotype homogeneity presented by Epinephelidae family.

Effects of Ocimum basilicum essential oil and ginger extract on serum biochemistry, oxidative stress and gill tissue damage of pearl gentian grouper during simulated live transport

This study explored the effects of the essential oil of Ocimum basilicum (EOOB) and ginger extract (GE) during the transportation of pearl gentian grouper from water quality, serum biochemistry, oxidative stress, meat flavor, and gill tissue morphology. Fish (450 ± 50 g) were allocated to the following 5 treatments: control group (fish transported in water only), 5 mg/LEOOB, 10 mg/LEOOB, 3 mg/LGE, and 6 mg/LGE and transported in insulation boxes (66 × 51 × 37.8 cm) for 72 h. Samples were taken at 0, 12, 36, 60, and 72 h immediately after transport. It was found that 10 mg/LEOOB and 6 mg/LGE could reduce the levels of total ammonia nitrogen (TAN), dissolved oxygen (DO), water pH, serum glucose (GLU), cortisol (COR), liver superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), and glutathione peroxidase (GPX), increase the activities of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH), as well as significantly increase the total free amino acid (TFAA) content in muscle compared to the control group (P < 0.05). In addition, by observing the microstructure of gill tissue, it was found that compared with untreated grouper, the morphological damage of gill tissue in EOOB and GE treatment was alleviated. These results indicated that adding appropriate amounts of EOOB and GE to transport water could improve the water quality, relieve stress, and lower energy metabolism of grouper during transport. The results of this research will help to improve the survival rate of grouper after transportation and decrease economic losses to fishery.

Effects of Dietary Bile Acids on Growth Performance, Lipid Deposition, and Intestinal Health of Rice Field Eel (Monopterus albus) Fed with High-Lipid Diets

The purpose of this trial was to study the positive effects of bile acids (BAs) on growth performance and intestinal health of rice field eel fed with high-lipid diets (HLDs). Rice field eels (initial weight 17.00 ± 0.10 g) were divided into four groups, each group containing four repetitions and feeding with different isonitrogenous diet: control diet containing 7% lipid content, HLDs containing the lipid content increased to 13%, HLDs supplementing with 0.025% BAs and 0.05% BAs, respectively. After 8 weeks, compared control group, the fish fed HLDs had no significant effect on weight gain rate and specific growth rate (P > 0.05), but increased the lipid deposition in tissues and intestinal lipase activity, and damaged to intestinal oxidative stress, inflammatory response, physical barrier, and structural integrity (P < 0.05). Dietary BAs significantly increased weight gain rate and specific growth rate in fish fed with HL diets (P < 0.05) and reduced feed conversation rate (P < 0.05). Further, the eels fed with BAs reduced the total lipid content in liver, muscle, and whole body (P < 0.05). Dietary BAs decreased the activity of intestinal lipase (P < 0.05). Meanwhile, BAs supplemented in HLDs improved intestinal antioxidant capacity through increasing the activities of T-SOD (total superoxide dismutase), GSH-PX (glutathione peroxidase), CAT (catalase), T-AOC (total antioxidant capacity), whereas reducing MDA (malondialdehyde) content (P < 0.05). Moreover, dietary BAs regulated the mRNA expression related to inflammatory response, oxidative stress, and physical barrier in intestine, such as tnf-α, il-8, tlr-8, il-10, nrf2, keap1, claudin12, and claudin15 (P < 0.05). Dietary BAs supplementation also enhanced the intestinal structural integrity characterized by increased fold height and lamina propria width (P < 0.05). This study showed that dietary BAs supplemented in HLDs (13% lipid) could increase the growth performance of rice field eel, reduce lipid deposition in tissues and whole body, and enhance intestinal health.

Ginkgo biloba Extract Drives Gut Flora and Microbial Metabolism Variation in a Mouse Model of Alzheimer's Disease

Alzheimer's disease (AD) is a complex neurodegenerative disease. Numerous investigations have demonstrated that medications that regulate the "brain-gut" axis can ameliorate disease symptoms of AD. Studies have shown that Ginkgo biloba extract (EGb) is involved in intestinal metabolism to meet the goal of illness treatment. EGb is currently utilized extensively in the clinical prevention and treatment of cardiovascular and cerebrovascular diseases. However, the regulatory effect of EGb on intestinal flora and its metabolites in AD pathology remains largely speculative. In this study, the Morris water maze test showed a significant improvement of spatial memory in the AD mouse model (APP/PS1 mice) after EGb treatment. We next confirmed the positive effects of EGb on the gut flora and metabolites of APP/PS1 mice and further showed that EGb treatment reshaped the disturbed gut microbiome, in particular by reducing the Firmicutes/Bacteroides ratio and increasing the abundance of Bacteroidetes, Uroviricota, Streptophyta, and Spirochaetes. Meanwhile, a non-targeted metabolomics analysis showed that EGb treatment significantly reversed the dysfunction of the microbial metabolic phenotype by altering Limosilactobacillus and Parvibacte, with 300 differential metabolites modulated (131 up-regulated, 169 down-regulated). Our findings highlight the significant regulatory impact of EGb on intestinal microflora and microbial metabolism in AD mice models and provide a potential therapeutic strategy for AD.

Lycopene Alleviates the Adverse Effects of Feeding High-Lipid Diets to Hybrid Grouper (♀Epinephelus fuscoguttatus ×♂E. lanceolatus)

It has been found that high-lipid diets (HLDs) disrupt lipid metabolism in fish, leading to an excessive accumulation of lipids in various tissues of the fish body. The objective of this study was to investigate if the inclusion of lycopene (LCP) in an HLD may mitigate the adverse consequences of excessive dietary lipid intake in hybrid grouper (♀ Epinephelus fuscoguttatus × ♂ E. lanceolatus). The experimental design incorporated a control group (L0), which was administered a diet consisting of 42% protein and 16% lipid. The diets for groups L1, L2, and L3 were developed by augmenting the control diet with 100, 200, and 400 mg/kg LCP, respectively. The duration of the trial spanned a period of 42 days. The results of the study showed that the weight gain rate (WGR) and protein efficiency ratio (PER) of the three LCP treatment groups (L1, L2, and L3) tended to increase and then decrease, with a significant increase in WGR and PER in L2 (P  < 0.05). Visceral somatic index and hepatic somatic index tended to decrease and then increase in all treatment groups, with a significant decrease in L2 (P  < 0.05). In serum dietary LCP significantly reduced triglyceride (TG), total cholesterol (TC), and low-density lipoprotein (LDL) content and significantly increased high-density lipoprotein (HDL) content (P  < 0.05). In the liver, dietary LCP reduced TC, TG, and very LDL levels and improved lipoprotein lipase, hepatic lipase, fatty acid (FA) synthetase, and acetyl-CoA carboxylase activities. The number and area of hepatic lipid droplets decreased significantly with increasing LCP content. In the liver, the addition of appropriate levels of LCP significantly upregulated lipoprotein lipase (lpl) and peroxisome proliferator-activated receptor α (pparα). In summary, dietary LCP improves growth and reduces lipid deposition in the liver of hybrid grouper by increasing lipolytic metabolism and decreasing FA synthesis. Under the experimental conditions, the fitted curve analysis showed that the recommended LCP additions to the high lipid diet for juvenile hybrid grouper were 200-300 mg/kg.

Integrated Metabolome and Transcriptome Analyses Reveal the Efficacy of Steroidal Saponins for Glucose and Lipid Metabolism in Hybrid Grouper (♀Epinephelus fuscoguttatus × ♂Epinephelus lanceolatu) Fed Higher-Lipid Diets

An analysis of the extent of the effect of steroidal saponin addition on glucose and lipid metabolism in hybrid grouper liver was performed at the transcriptomic and metabolomic levels. Feeds (52% crude protein, 14% crude lipid) were prepared containing 0% (S0), 0.1% (S0.1), and 0.2% (S0.2) steroidal saponins. After eight weeks of feeding trial, compared to the S0 group, the activities of serum albumin, alanine aminotransferase, and aspartate transaminase were significantly lower and the activities of lysozyme, acid phosphatase, and alkaline phosphatase were significantly higher in the S0.1 group (p < 0.05). The superoxide dismutase, catalase, and glutathione peroxidase activities in the livers of the S0.1 group were significantly higher than those of the S0 group, while the malondialdehyde content was significantly lower than that of the S0 group (p < 0.05). There were forty-two differentially expressed genes and thirty-two differential metabolites associated with glucose and lipid metabolism enriched using KEGG and GO. In the S0 group, the expression of prostaglandin-endoperoxide synthase 1, prostaglandin E synthase 1, and thromboxane-2 synthase mRNA was significantly higher than in the S0.1 group (p < 0.05). The expression levels of genes in the S0 group were significantly higher than those in the S0.1 group (p < 0.05), including for glycogen synthase kinase, glucose-6-phosphatase catalytic subunit 2, fructose-1,6-bisphosphatase, phosphoenolpyruvate carboxykinase, glucose transporter 4, and malate dehydrogenase. The expression of mRNA such as fatty acid synthase, acetyl-CoA carboxylase, and sterol regulatory element-binding protein 1 was significantly lower in the S0.1 group than in the S0 group, while the expression of carnitine acyltransferase 1, acyl-CoA synthetase, and acyl-CoA dehydrogenase genes was significantly higher in the S0 group (p < 0.05). In summary, glycogen synthesis, gluconeogenesis, and the arachidonic acid metabolism pathway were inhibited by 0.1% steroidal saponins, and glycogenolysis, glycolysis, the tricarboxylic acid cycle, and the fatty acid β-oxidation pathway were activated. This study aims to provide a reference for the formulation of grouper feeds with a higher crude-lipid level.

The Role of Algae Extract (Ulva lactuca and Solieria chordalis) in Fishmeal Substitution in Gibel Carp (Carrassius auratus gibeilo)

The function of algae extract (AE) in fishmeal (FM) substitution with plant proteins in the diets of Gibel carp (Carrassius auratus gibeilo) was investigated during a 56-day trial. Diets 1 and 2 contained 10% FM, Diets 3 and 4 contained 5% FM, and Diet 5 and 6 contained 0% FM. In contrast, Diets 2, 4, and 6 were supplemented with 0.2% AE. The results showed that FM reduction inhibited growth performance, while AE supplementation alleviated growth inhibition. FM reduction significantly decreased the crude protein levels of the whole body, while the contents of whole-body lipids were significantly decreased with AE supplementation. There were no significant changes in ALB, ALP, ALT, AST, TP, GLU, GLU, and TC in plasma. FM reduction with AE supplementation mitigated the decrease in antioxidant capacity by heightening the activity of antioxidant enzymes and related gene expressions, which mitigated the decrease in immune capacity by affecting the expression of inflammatory factors. In summary, AE supplementation could alleviate the negative effects of FM reduction in Gibel carp.

Ginkgo biloba extract alleviates fatty liver hemorrhagic syndrome in laying hens via reshaping gut microbiota

BACKGROUND

Ginkgo biloba extract (GBE) is evidenced to be effective in the prevention and alleviation of metabolic disorders, including obesity, diabetes and fatty liver disease. However, the role of GBE in alleviating fatty liver hemorrhagic syndrome (FLHS) in laying hens and the underlying mechanisms remain to be elucidated. Here, we investigated the effects of GBE on relieving FLHS with an emphasis on the modulatory role of GBE in chicken gut microbiota.

RESULTS

The results showed that GBE treatment ameliorated biochemical blood indicators in high-fat diet (HFD)-induced FLHS laying hen model by decreasing the levels of TG, TC, ALT and ALP. The lipid accumulation and pathological score of liver were also relieved after GBE treatment. Moreover, GBE treatment enhanced the antioxidant activity of liver and serum by increasing GSH, SOD, T-AOC, GSH-PX and reducing MDA, and downregulated the expression of genes related to lipid synthesis (FAS, LXRα, GPAT1, PPARγ and ChREBP1) and inflammatory cytokines (TNF-α, IL-6, TLR4 and NF-κB) in the liver. Microbial profiling analysis revealed that GBE treatment reshaped the HFD-perturbed gut microbiota, particularly elevated the abundance of Megasphaera in the cecum. Meanwhile, targeted metabolomic analysis of SCFAs revealed that GBE treatment significantly promoted the production of total SCFAs, acetate and propionate, which were positively correlated with the GBE-enriched gut microbiota. Finally, we confirmed that the GBE-altered gut microbiota was sufficient to alleviate FLHS by fecal microbiota transplantation (FMT).

CONCLUSIONS

We provided evidence that GBE alleviated FLHS in HFD-induced laying hens through reshaping the composition of gut microbiota. Our findings shed light on mechanism underlying the anti-FLHS efficacy of GBE and lay foundations for future use of GBE as additive to prevent and control FLHS in laying hen industry.

Hepatic, Muscle and Intestinal Oxidative Status and Plasmatic Parameters of Greater Amberjack (Seriola dumerili, Risso, 1810) Fed Diets with Fish Oil Replacement and Probiotic Addition

The present study was conducted to investigate the effects of dietary fish oil replacement with a mixture of vegetable oils and probiotic supplementation on plasma biochemical parameters, oxidative stress, and antioxidant ability of Seriola dumerili. Specimens with an initial weight of 175 g were used. Four feeds were formulated with 0% (FO-100), 75% (FO-25), and 100% (FO-0 and FO-0+ with the addition of Lactobacillus probiotics) substitution of fish oil with a mixture of linseed, sunflower, and palm oils. After 109 days, no significant differences were observed in the activity of antioxidant enzymes in the liver, foregut, and hindgut, only glucose-6-phosphate dehydrogenase activity in the liver was higher in the fish fed the FO-100 diet than in those fed the FO-0 diet. No significant differences were observed in the total, reduced, and oxidized glutathione and the oxidative stress index in the liver. In addition, lipid peroxidation in the liver and red muscle values were higher in the fish fed the FO-100 diet than in the fish fed the FO-0+ diet, however, the foregut of the fish fed the FO-100 diet presented lower values than that of the fish fed the FO replacement diet, with and without probiotics. There were significant differences in cholesterol levels in the FO-100 group; they were significantly higher than those observed with the fish diets without fish oil. To sum up, fish oil can be replaced by up to 25% with vegetable oils in diets for Seriola dumerili juveniles, but total fish oil substitution is not feasible because it causes poor survival. The inclusion of probiotics in the FO-0+ diet had no effects on the parameters measured.

Effects of dietary Euphorbia heterophylla extract on the growth performance, physiological, antioxidative and immune responses of Clarias gariepinus juveniles

Effects of dietary Euphorbia heterophylla extract (EH) on growth performance, feed utilization and haemato-biochemical parameters in African catfish, Clarias gariepinus, juveniles were evaluated in this study. Diets fortified with EH at 0 (control), 0.5, 1.0, 1.5 or 2.0 g/kg were fed to the fish to apparent satiation for 84 days before challenging it with Aeromonas hydrophila. The weight gain, specific growth rate and protein efficiency ratio of fish fed EH-supplemented diets were significantly higher but lower feed conversion ratio (p < 0.05) than the control group. The villi height and width at the proximal, mid and the distal of the guts rose significantly with the increasing levels of EH from 0.5 to 1.5 g than the fish fed basal diet. Dietary EH enhanced (p < 0.05) the packed cell volume and haemoglobin, whereas 1.5 g EH boosted white blood cell, in relation to their counterpart in the control group. There were significant increase in the activities of glutathione-S-transferase, glutathione peroxidase and superoxide dismutase (p < 0.05) in the fish that were fed diets supplemented with EH than the control. Dietary EH also enhanced phagocytic activities, lysozyme activities and relative survival (RS) of C. gariepinus than the control group, with the highest RS obtained in fish that were fed diet containing EH at 1.5 g/kg level. These results revealed that the fish fed 1.5 g/kg dietary EH promoted growth performance, antioxidant and immune profiles, as well as protection against A. hydrophila infection.

Effects of Dietary Steroid Saponins on Growth Performance, Serum and Liver Glucose, Lipid Metabolism and Immune Molecules of Hybrid Groupers (♀Epinephelus fuscoguttatus × ♂Epinephelus lanceolatu) Fed High-Lipid Diets

High-lipid diets are attributed to excessive lipid deposition and metabolic disturbances in fish. The aim of this experiment was to investigate the effects of steroidal saponins on growth performance, immune molecules and metabolism of glucose and lipids in hybrid groupers (initial weight 22.71 ± 0.12 g) fed high-lipid diets. steroidal saponins (0%, 0.1% and 0.2%) were added to the basal diet (crude lipid, 14%) to produce three experimental diets, designated S0, S0.1 and S0.2, respectively. After an 8-week feeding trial, no significant differences were found between the S0 and S0.1 groups in percent weight gain, specific growth rate, feed conversion ratio, protein efficiency ratio and protein deposition rate (p > 0.05). All those in the S0.2 group were significantly decreased (p < 0.05). Compared to the S0 group, fish in the S0.1 group had lower contents of serum triglyceride and low-density lipoprotein cholesterol and higher high-density lipoprotein cholesterol and glucose (p < 0.05). The activities of superoxide dismutase, catalase and glutathione peroxidase were significantly higher, and malondialdehyde contents were significantly lower in the S0.1 group than in the S0 group (p < 0.05). Hepatic triglyceride, total cholesterol and glycogen were significantly lower in the S0.1 group than in the S0 group (p < 0.05). Activities of lipoprotein lipase, total lipase, glucokinase and pyruvate kinase, and gene expression of lipoprotein lipase, triglyceride lipase and glucokinase, were significantly higher in the S0.1 group than in the S0 group. Interleukin-10 mRNA expression in the S0.1 group was significantly higher than that in the S0 group, while the expression of interleukin-6 and tumor necrosis factor-α genes were significantly lower than those in the S0 group. In summary, adding 0.1% steroidal saponins to a high-lipid diet not only promoted lipolysis in fish livers, but also activated glycolysis pathways, thus enhancing the utilization of the dietary energy of the groupers, as well as supporting the fish's nonspecial immune-defense mechanism.

Growth-promoting and immunostimulatory effects of phytobiotics as dietary supplements for Pangasianodon hypophthalmus fingerlings

A 56-day feeding experiment was designed to evaluate the impacts of five herbal extracts, namely Ginkgo biloba (GB), Moringa oleifera (MR), Myristica fragrans (NM), Silybum marianum (MT), and Astragalus membranaceus (AT) on growth, serum immune indices, and ammonia-N stress resistance of Pangasianodon hypophthalmus fingerlings. Fish were fed on a diet with no herbal additives (reference or CNT), and several plant extracts-based diets were supplied with two inclusion doses of each extract (1.0 and 2.0 g/kg). After the end of the feeding, fish in all groups were exposed to acute ammonia stress, mortalities were recorded every 2 h for a duration of 10 h, and then survival percent was assessed. Results showed that growth was upgraded significantly in groups fed plant extracts-based diets compared to the CNT group. Serum proteins (albumin and total protein), lysozyme, complement C3, bactericidal, and myeloperoxidase activities were increased significantly in groups fed plant extracts-based diets in relation to the CNT group. The total immunoglobulin levels were increased significantly only in fish groups fed GB, MT, and NM-based diets. Post-exposure to acute ammonia stress, the Kaplan-Meier survival curve presented significantly higher survival of fish groups that fed plant extracts-enriched diets than those fed the CNT diet. The aforementioned results suggest that using herbal extracts as feed supplements can beneficially enhance the growth, the immunity of P. hypophthalmus fingerlings and may increase their tolerance in the face of extrinsic stressors. These findings may pave the way for the potential and regular application of herbal extracts in diets of P. hypophthalmus at their early life stages to raise their immunity and maintain aquaculture sustainability.

Impacts of supplemental Ginkgo biloba oil on broilers' growth, blood indices, intestinal and hepatic morphology and expression of growth-related genes

The current work examined the impact of Ginkgo biloba oil (GBO) on growth performance, some biochemical parameters, intestinal and hepatic morphology, economic efficiency and expression of some growth-related genes in broiler chickens. A total of 135 chicks (Cobb 500) were allotted into three groups with 3 replications (15 birds/replicate). The experimental groups included: G1 (control), G2 and G3 were supplemented with GBO in the drinking water (0.25 and 0.5 cm/L), respectively. The GBO was added to the drinking water only for 3 successive weeks. Compared to the other groups, supplementation with 0.25 cm/L GBO significantly (P ≤ 0.05) increased final body weight, overall weight gain, feed intake and water consumption. When 0.25 cm GBO/L was added, that group significantly differed in intestinal villus length (P ≤ 0.05). Birds received 0.25 cm GBO/L had significantly greater blood total albumin and total protein concentrations (P ≤ 0.05), while birds given 0.5 cm GBO/L had higher serum cholesterol and LDL concentrations (P ≤ 0.05). The cost parameters were significantly higher (P ≤ 0.05) in the 0.25 cm GBO/L supplemented group, which exhibited higher total return and net profit. The addition of 0.25 cm GBO/L resulted in higher expression of antioxidant enzymes and insulin-like growth factor while inhibiting the expression of Myostatin in muscles (P < 0.05) compared to the control and those received 0.5 cm GBO/L. In conclusion, broiler chickens that received 0.25 cm GBO/L for 3 consecutive days per week had better performance, intestinal morphology, profitability, and antioxidant status than the control birds.

Effects of chlorogenic acid on growth, metabolism, antioxidation, immunity, and intestinal flora of crucian carp (Carassius auratus)

In recent years, with the harm caused by the abuse of antibiotics and the increasing demand for green and healthy food, people gradually began to look for antibiotic alternatives for aquaculture. As a Chinese herbal medicine, leaf extract chlorogenic acid (CGA) of Eucommia ulmoides Oliver can improve animal immunity and antioxidant capacity and can improve animal production performance. In this study, crucian carp (Carassius auratus) was fed with complete feed containing 200 mg/kg CGA for 60 days to evaluate the antioxidant, immuno-enhancement, and regulation of intestinal microbial activities of CGA. In comparison to the control, the growth performance indexes of CGA-added fish were significantly increased, including final body weight, weight gain rate, and specific growth rate (P < 0.01), while the feed conversion rate was significantly decreased (P < 0.01). Intestinal digestive enzyme activity significantly increased (P < 0.01); the contents of triglyceride in the liver (P < 0.01) and muscle (P > 0.05) decreased; and the expression of lipid metabolism-related genes in the liver was promoted. Additionally, the non-specific immune enzyme activities of intestinal and liver tissues were increased, but the expression level of the adenylate-activated protein kinase gene involved in energy metabolism was not affected. The antioxidant capacity of intestinal, muscle, and liver tissues was improved. Otherwise, CGA enhanced the relative abundance of intestinal microbes, Fusobacteria and Firmicutes and degraded the relative abundance of Proteobacteria. In general, our data showed that supplementation with CGA in dietary had a positive effect on Carassius auratus growth, immunity, and balance of the bacteria in the intestine. Our findings suggest that it is of great significance to develop and use CGA as a natural non-toxic compound in green and eco-friendly feed additives.

Effects of dietary Ginkgo biloba leaf extract on growth performance, immunity and environmental stress tolerance of Penaeus vannamei

Ginkgo biloba leaf extract (GBE) has been extensively used in the treatment of diseases due to its anti-inflammatory, antioxidant, and immunomodulatory effects. In aquaculture, GBE is widely used as a feed additive, which is important to enhance the immunity of aquatic animals. The current study evaluated the effects of adding GBE to the diet of Penaeus vannamei (P. vannamei) under intensive aquaculture. The GBE0 (control group), GBE1, GBE2, and GBE4 groups were fed a commercial feed supplemented with 0.0, 1.0, 2.0, and 4.0 g/kg GBE for 21 days, respectively. The results showed that dietary GBE could alleviate hepatopancreas tissue damage and improve the survival rate of shrimp, and dietary 2 g/kg GBE could significantly increase the total hemocyte count (THC), the hemocyanin content, the antioxidant gene's expression, and the activity of their encoded enzymes in P. vannamei. Furthermore, transcriptome data revealed that immunity-related genes were upregulated in the GBE2 group compared with the GBE0 group after 21 days of culture. Drug metabolism-cytochrome P450, sphingolipid metabolism, linoleic acid metabolism, glycerolipid metabolism, fat digestion and protein digestion and absorption pathways were significantly enriched, according to KEGG results. Surprisingly, all of the above KEGG-enriched pathways were significantly upregulated. These findings demonstrated that supplementing P. vannamei with 2 g/kg GBE improved its environmental adaptability by improving immunity, lipid metabolism, and detoxification. In this study, a comprehensive evaluation of the effects of dietary GBE on the intensive aquaculture of P. vannamei was conducted to provide a reference for the healthy culture of P. vannamei.

Effects of dietary Hyssop, Hyssopus officinalis, extract on physiological and antioxidant responses of rainbow trout, Oncorhynchus mykiss, juveniles to thermal stress

The present study aimed at assessing the effects of dietary Hyssop, Hyssopus officinalis, extract on rainbow trout, Oncorhynchus mykiss, responses to thermal stress. The juveniles (69.8 ± 0.38 g) were stocked in 12 through-flow tanks at a density of 12 fish per tank. Methanolic extract of Hyssop (HME) was added to diet at 0, 100, 250, and 500 mg/kg and the fish were fed (3% of biomass) over a 70-d period: 62 d at 13.3 ± 0.08°C and 7 d at 21–22°C. At the end of the trial, the plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), triiodothyronine (T3), thyroxin (T4), cortisol, glucose, lactate, total antioxidant capacity (TAC), ascorbate, and the gill glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST), and malondialdehyde (MDA). The results showed that HME had no significant effects on fish growth performance, survival, and feed efficiency. Dietary 250 mg/kg HME significantly decreased plasma ALT activity (P &lt; 0.001), but showed no significant effects on plasma AST) (P = 0.106) activity, T3 (P = 0.992), and T4 (P = 0.070) levels. Thermal stress significantly (P &lt; 0.001) increased plasma ALT and AST activities, but lowered plasma T3 and T4 levels. Dietary HME and thermal stress had interaction effects on plasma cortisol (P &lt; 0.001), glucose (P = 0.007), lactate (P = 0.010), LDH (P = 0.005), TAC (P = 0.038), ascorbate (P &lt; 0.001), and the gill GPx (P = 0.001), GR (P &lt; 0.001), GST (P &lt; 0.001), and MDA (P = 0.001). Thermal stress significantly increased plasma cortisol, glucose, lactate, and LDH, the gill GPX, GR, and GST, but dietary HME supplementation significantly reduced such elevations, particularly at 250 mg/kg level. Dietary HME significantly increased plasma TAC before the thermal stress and mitigated the stress-induced decreased in TAC, particularly at 250 mg/kg level. Dietary HME significantly decreased the gill MDA before and after the thermal stress, and lowest MDA was observed in 250 mg/kg HME level. Based on the present results, 250 mg/kg HME is recommended as suitable dose to improve antioxidative responses and hepatoprotection in rainbow trout under heat stress.

An accidental discovery of mannan-oligosaccharide's protection effect against air exposure and its potential mechanism in hybrid grouper (Epinephelus lanceolatus ♂ × Epinephelus fuscoguttatus ♀)

The original objective was to explore the potential benefiting effects of three prebiotics in hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀). Therefore, three experimental diets (basal diet + 1% fructooligosaccharide, Diet F; basal diet + 1% inulin, Diet I; basal diet + 0.3% mannan-oligosaccharide, Diet M) and one basal diet (Diet C) were prepared and a feeding trial was conducted. However, at the end of the fourth week into the feeding experiment, a water-leaking accident occurred and fishes of all groups went through an unexpected air exposure event. Surprisingly, different prebiotic-supplemented groups showed significantly different air exposure tolerance: the mortality of M group was significantly lower (P ≤ 0.05) than all the other groups. Examination of antioxidant, non-specific immunity, and stress parameters revealed that comparing to control group, M group showed significantly increased catalase (CAT), acid phosphatase (ACP), and alkaline phosphatase (AKP) activities, decreased superoxide dismutase (SOD) activity, and similar cortisol level (P ≤ 0.05). Real-time PCR experiment revealed that M group significantly increased the expression of CAT, glutathione peroxidase (GPx), and manganese superoxide dismutase (MnSOD) genes in head kidney (P ≤ 0.05). Overall, M exhibited the best anti-air exposure/antioxidative stress effects among the three prebiotics and could be considered a promising feed additive to relieve air exposure/oxidative stress in hybrid grouper culture.

Effects of high fat in the diet on growth, antioxidant, immunity and fat deposition of Macrobrachium rosenbergii post-larvae

Lipids are essential nutrients for organisms, and high-fat feeds for shrimp may cause oxidative stress. This study evaluated the effects of feeding high fat in the diet on the growth, antioxidant, immunity, and liver fat accumulation of Macrobrachium rosenbergii post-larvae. Five groups with an initial body weight of 0.0084 ± 0.001 g were fed five isonitrogenous and isoenergetic diets (47.01% crude protein and 18.40 kJ/g gross energy) containing 8%, 10%, 12%, 14% and 16% (named L8, L10, L12, L14 and L16) lipid for 8 weeks, respectively. The results showed that the weight gain rate (WGR) and specific growth rate (SGR) of L8 group were significantly higher than those of L10, L12, L14 and L16 group (P < 0.05), and the feed coefficient (FCR) of L8 group was significantly lower than that of other groups (P < 0.05). With the increase of dietary fat level, the content of MDA and the activity of SOD increased significantly, and the activities of T-AOC and CAT decreased significantly (P < 0.05). H&E staining clearly revealed the occurrence of hepatocyte swelling, hepatocyte vacuolization and nucleus displacement to the peripheral cell vacuolization in the L16 group, and hepatic lipid accumulation was further observed in the L14 and L16 group by Oil red O staining. In addition, high-fat diet significantly upregulated the expression of Dorsal, Relish and IκBα mRNA, and also upregulated the expression of fat synthesis-related genes FAS, ACC, DGAT and fat transport-related gene FABP (P < 0.05), and significantly downregulated the expression of fat metabolism-related genes AMPK and CPT-1 (P < 0.05) compared to that of the L8 group. In conclusion, this study showed that feeding a high-fat diet could induce oxidative stress, inhibit growth performance, alter antioxidant capacity, cause hepatic fat deposition and affect the immune system of M. rosenbergii post-larvae.

Subacute toxicity studies of meals prepared from genetically modified potato overexpressing the StDREB1 or the VvWRKY2 transcription factor in rats

BACKGROUND

Potato tubers from genetically modified plants overexpressing the StDREB1 or the VvWRKY2 transcription factors that exhibited improved tolerance to salt and resistance to Fusarium solani infection were characterized and evaluated for safety in a 30 day rat feeding study. Male Wistar rats were split into four groups and provided with a diet composed of 33% (w/w) of either one of the two genetically modified potatoes (GMPs), 33% of the commercial Spunta variety (Sp), or a control group fed with the basal rats' diet. The influence of the GMPs on rat behavior and overall health parameters was evaluated and compared with that of commercial potato (i.e. the Sp group) and control diet.

RESULTS

Small differences were noticed in the chemical composition of the different tubers, but all the diets were adjusted to an identical caloric level. Results showed no sign of toxic or detrimental effects on the rats' overall health as a result of these diets. The rats fed with the GMPs meal showed hematological and biochemical compositions of the plasma comparable to the control groups. No histopathological damage nor any structural disorganization, severe congestion, or acute inflammation were noticed in the rats' tissues.

CONCLUSION

Under these study conditions, the GMP diets did not induce any apparent or significant adverse effects on rats after 30 days of dietary administration in comparison with rats fed diets with the corresponding non-transgenic diet and the standard diet group. These two GMPs were therefore considered to be as safe as their commercial comparator. © 2022 Society of Chemical Industry.

Impacts of tea polyphenols on growth, antioxidant capacity and immunity in juvenile hybrid grouper (Epinephelus fuscoguttatus ♀ × E. lanceolatus ♂) fed high-lipid diets

The experiment aimed to investigate the alteration of tea polyphenols (TP) in growth and immunity for hybrid grouper (Epinephelus fuscoguttatus ♀ × E. lanceolatus ♂) fed high-lipid diets. Six concentrations of TP (0, 0.01, 0.02, 0.04, 0.08, 0.16%, named TP1 (basic diet control), TP2, TP3, TP4, TP5, TP6) were supplied in isonitrogenous (51%) and isolipidic (16.7%) experimental diets. These diets were fed to the juvenile grouper (8.68 ± 0.22 g) for 8 weeks. The results showed that dietary TP significantly increased the weight gain rate and specific growth rate (P < 0.05), compared with the control group. The protein efficiency ratio in TP4 group was significantly higher than that of the control group (P < 0.05). TP supplement in high-lipid diets increased antioxidant capacity in the serum (CAT, GSH-Px, T-AOC) and liver (SOD, CAT, GSH-Px, T-AOC). Additionally, dietary TP decreased oxidative stress (ROS, MDA) and improved immunity (ACP, AKP, LYS, IgM) in the liver. The histology of hepatic tissue indicated that dietary TP alleviated pathological symptoms caused by high-lipid diets. Compared with the control group, appropriate dietary TP significantly up-regulated expression of sod, cat, gsh-px, nrf2, keap1, hsp70, hsp90, myd88, tnfα and down-regulated expression of tlr22, il8, il1β, il10 in the liver (P < 0.05). In the head kidney, expression of myd88, il1β, tnfα and il6 were significantly up-regulated and expression of tlr22 and il10 were significantly down-regulated by dietary TP (P < 0.05). After the challenge of Vibrio harveyi, survival rate in higher doses of TP group (TP4 ∼ TP6) was evidently higher, compared with the control group. In conclusion, TP supplement in high-lipid diets improved antioxidant capacity and enhanced immunity of grouper. We speculate that TP may play the role of an immunostimulant, enhancing immunity and disease resistance by cytokine-medicated immune responses. Based on the second-order regression, 0.092-0.106% tea polyphenols were recommended in juvenile grouper high-lipid diets.

The positive effects of dietary inositol on juvenile hybrid grouper (♀ Epinephelus fuscoguttatus × ♂ E. lanceolatu) fed high-lipid diets: Growthperformance, antioxidant capacity and immunity

The objective of the present research was to assess the influence of inositol supplementation on growth performance, histological morphology of liver, immunity and expression of immune-related genes in juvenile hybrid grouper (♀ Epinephelus fuscoguttatus × ♂ E. lanceolatu). Hybrid grouper (initial weight 6.76 ± 0.34 g) were fed isonitrogenous and isolipidic diets (16%) with various inositol levels of 0.17 g/kg (J1, the control group), 0.62 g/kg (J2), 1.03 g/kg (J3), 1.78 g/kg (J4), 3.43 g/kg (J5), 6.59 g/kg (J6), respectively. The growth experiment lasted for 8 weeks. The results indicated that dietary inositol had a significant promoting effect on final mean body weight of the J5 and J6 groups and specific growth rate (SGR) of the J3, J4, J5 and J6 groups (P < 0.05). In the serum, superoxide dismutase (SOD) of the J4 group became significantly active compared with that of the control group (P < 0.05), while aspartate transaminase (AST), alanine transaminase (ALT) and alkaline phosphatase (AKP) activities in the inositol-treated groups showed distinctly decreased compared with those of the control group (P < 0.05). In the liver, dietary inositol could significantly increase the activities of SOD, catalase (CAT), lysozyme (LYZ) and the contents of total antioxidative capacity (T-AOC) and immunoglobulin M (IgM) (P < 0.05), and distinctly reduce the content of malondialdehyde (MDA) as well as reactive oxygen species (ROS) (P < 0.05). Compared with the control group, the damaged histological morphology of the liver was relieved and even returned to normal after an inositol increase (0.4-3.2 g/kg). In the liver, the remarkable up-regulation of SOD, CAT, glutathione peroxidase (GPX), heat shock protein70 (HSP70) and heat shock protein90 (HSP90) expression levels were stimulated by supply of inositol, while interleukin 6 (IL6), interleukin 8 (IL8) and transforming growth factor β (TGF-β) expression levels were down-regulated by supply of inositol. In head kidney, the mRNA of toll-like receptor 22 (TLR22), myeloid differentiation factor 88 (MyD88) and interleukin 1β (IL1β) expression levels were significantly down-regulated (P < 0.05), which could further lead to remarkable down-regulation of IL6 and tumor necrosis factor α (TNF-α) expression (P < 0.05). These results indicated that high-lipid diets with supply of inositol promoted growth, increased the antioxidant capacity, and suppressed the inflammation of the liver and head kidney by inhibiting the expression of pro-inflammation factors (IL6, IL8, TGF-β and TNF-α). In conclusion, these results indicated that dietary inositol promoted growth, improved antioxidant capacity and immunity of hybrid grouper fed high-lipid diets. Based on SGR, broken-line regression analysis showed that 1.66 g/kg inositol supply was recommended in high-lipid diets of juvenile grouper.

Bio-active components in medicinal plants: A mechanistic review of their effects on fish growth and physiological parameters

World population is increasing at a tremendous rate so is the demand for animal-based protein. Aquaculture is a promising industry that has the potential to supply high quality protein for mankind with minimum environmental impact. In the past decade, aquaculture practices have been shifting from extensive to intensive culture. To achieve maximum production per unit area, high stocking densities are maintained in intensive aquaculture. If not managed properly, this may lead to stress in fish. Fish under stress condition show decreased growth, suppressed appetite, weakened immunity and increased susceptibility to infections. Chemicals, vaccines and antibiotics are used for the treatment of diseased fish. Use of synthetic chemicals, vaccines and antibiotics is not sustainable because pathogens develop resistance against them and they have high residues. Moreover, certain chemicals used for the treatment of fish diseases are not safe for humans therefore, are banned in some countries. Plant parts and their extracts are used in traditional medicines to cure many diseases and to improve health of mankind. In aquaculture industry, use of plants and their derivatives in fish feed to improve health status of fish is increasing. Several plants improve growth and overall health status of fish, some provide protection against pathogens by improving the immune system while others increase appetite by direct action on neuro-endocrine axis of fish. This review provides an in depth and up to date information about use of medicinal plants and their derivatives to improve growth and physiological status of fish and their possible mechanism of action.

Vitamin E amelioration of oxidative stress and low immunity induced by high-lipid diets in hybrid grouper (♀ Epinephelus fuscoguttatus × ♂ E. lanceolatu)

The experiment was conducted to investigate the effects of vitamin E (VE) on growth, oxidative stress and immunity for hybrid grouper (♀ Epinephelus fuscoguttatus × ♂ E. lanceolatu) fed high-lipid diet. Six groups of iso-protein (50.23%) and iso-lipidic high-lipid (15.36%) experimental diets were prepared by adding 0 (basic diet control), 0.01%, 0.02%, 0.03%, 0.04%, 0.05% α-tocopherol respectively in basic diet. Each treatment consisted of 3 replicates and 30 fish (10.20 ± 0.02 g) in each replicate for 8 weeks. The results showed that: 1) compared with the control group, the growth performance of grouper was not affected by the addition of VE in high-lipid diet, but the specific growth rate (SGR) in high VE dose (0.6%) group were significantly decreased compared with 0.02% and 0.03% groups. 2) Adding VE to high-lipid diet can alleviate the hepatic oxidative damage caused by high-lipid diet, and significantly improve the serum and liver antioxidant enzyme activity. 3) Compared with the control group, appropriate VE significantly increased the expression of liver anti-inflammatory factors TGF-β and IL10, and significantly decreased the expression of proinflammatory factors IL8 and IL6. In conclusion, adding appropriate amount of VE into high-lipid diet can improve antioxidant capacity and immunity of grouper, we speculated that VE may alleviate lipid peroxidation by improving antioxidant capacity to reduce the inflammatory response. In combination with the results of the current study, we recommend an additional dose of 0.02%-0.03% of α-tocopherol in this experiment under high-lipid conditions.

Assessing integrated biomarkers of triplefin fish Forsterygion capito inhabiting contaminated marine water - A multivariate approach

The presence of multiple chemicals in aquatic ecosystems makes evaluation of their real impact on the biota difficult. Integrated biomarkers are therefore needed to evaluate how these chemicals contribute to environmental degradation. The aims of the present study were to evaluate responses to and effects of marine pollution using a series of biomarkers through multivariate analyses. Transcriptional responses of cyp1a (cytochrome P450), mt (metallothionein), vtg (vitellogenin) and cyp19b (cytochrome P450 aromatase); branchial and hepatic histological alterations; and Fulton condition factors (CF) were evaluated, as well as the metals and polycyclic aromatic hydrocarbons present in Forsterygion capito in Auckland, New Zealand. Sites were selected along a contamination gradient: four highly contaminated sites and four less contaminated. Molecular responses with a higher relative expression of the mt and cyp1a genes were detected at a highly contaminated site (Panmure). Several histological lesion types were found in the livers of fish inhabiting both types of sites, but gill lesions were present primarily at highly contaminated sites. In terms of general health status, the lowest CF values were overwhelmingly found in fish from the same site (Panmure). The multivariate approach revealed that telangiectasia and hyperplasia were associated with the presence of chemicals, and these showed negative associations with the CF values, with fish from three highly contaminated sites being most affected. In conclusion, the multivariate approach helped to integrate these biological markers in this blennioid fish, thus providing a more holistic view of the complex chemical mixtures involved. Future studies should implement these analyses.

Enhancement of growth, antioxidative status, nonspecific immunity, and disease resistance in gibel carp (Carassius auratus) in response to dietary Flos populi extract

This study investigated the effects of dietary Flos populi extract (FPE) on the growth, antioxidation capability, innate immune response, and disease resistance in gibel carp. A total of 480 fish were fed with five different diets containing 0, 0.5, 1.0, 1.5, or 2.0 g kg^-1 FPE (designated as control, D0.5, D1.0, D1.5, or D2.0 groups) for 45 days. The fish were challenged with A. hydrophila after the feeding trial. Compared with the control, the feed efficiency (FE), weight gain (WG), final body weight (FBW), and specific growth rate (SGR) were significantly improved in groups D1.0 and D1.5. Dietary FPE significantly increased serum superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) activities, as well as glutathione (GSH) content. The contents of protein carbonyl (PCC) and malondialdehyde (MDA) in serum decreased significantly. Additionally, FPE supplementation in diets resulted in significant improvement in serum lysozyme (LZM) and myeloperoxidase (MPO) activities, as well as immunoglobulin M (IgM) and complement 3 (C3) concentrations. The hepatic antioxidant enzymes (CAT and SOD) activities increased, whereas content of MDA decreased in fish treated with dietary FPE than those of control both pre- and post-challenged. After 12 h-challenge, an obvious downregulation of hepatic Kelch-like-ECH-associated protein 1 (Keap1), splenic tumor necrosis factor-α (TNF-α), interleukin (IL)-8, IL-1β, and toll-like receptor 2 (TLR2) mRNA levels was observed in fish treated with dietary FPE, whereas hepatic Nrf2 transcription level was upregulated compared to the control. Furthermore, compared to group D0.5, higher relative percent survival (RPS) was observed in gibel carp fed dietary 1.0-2.0 g/kg FPE. Our results reveal that FPE supplemented diet has a stimulatory effect on antioxidant capacity and nonspecific immune response, along with improved growth performance and enhanced resistance against A. hydrophila infection in juvenile gibel carp.

Effects of dietary dandelion extract on the growth performance, serum biochemical parameters, liver histology, and immune and apoptosis-related genes expression of hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀) at different feeding period

The study explored on the effects of dietary 0.4% dandelion extract on the growth performance, serum biochemical parameters, liver histology and the expression levels of immune and apoptosis-related genes in the head kidney and spleen of hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀) at different feeding period. The results showed that the weight gain rate (WGR) of the hybrid grouper were significantly increased at the second and fourth weeks (P < 0.05), but there was no significant difference in WGR at the eighth week (P > 0.05). Compared with the control group, dietary dandelion extracts supplementation improve lipid metabolism, reduce lipid accumulation in liver and maintain normal liver histology at the second and fourth weeks. At the end of the second week, the relative expression levels of antioxidant related genes (MnSOD, GPX and GR) in the head kidney of hybrid grouper fed with dandelion extract increased significantly; at the end of week 4 and week 8, the relative expression levels of antioxidant related genes other than MnSOD did not change significantly. However, in the spleen of hybrid grouper, the expression of these antioxidant genes showed the opposite trend. At the end of the eighth week, dietary dandelion extract supplementation significantly increased the expression of inflammatory response related genes in head kidney of hybrid grouper, but showed the opposite trend in spleen. In conclusion, the short-term (2 or 4 weeks) application of 0.4% dandelion extract in feed had the effects of growth improvement, liver protection and immune stimulation on hybrid grouper due to its antioxidant and anti-inflammatory activities. The beneficial effect of dandelion extract on hybrid grouper was time-dependent, and its action time on different immune organs of hybrid grouper was not synchronous.

The effects of dietary compound plant extracts on growth performance, liver and intestine health, and immune related genes expression in hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀)

The study explored on the effect of dietary compound plant extract supplementation on the growth performance, serum biochemical indicators, liver and intestinal morphological and gene expression levels in the head kidney and spleen of the hybrid grouper (Epinephelus lanceolatus♂× Epinephelus fuscoguttatus♀). The compound plant extracts (BDG) was a mixture of Bupleurum edulis extract, dandelion extract and Ginkgo biloba extract in a ratio of 1:4:1. Basal diets supplemented with BDG at 0, 0.75, 1.5, 3 and 6 g/kg were fed hybrid grouper for 8 weeks. The results showed that dietary 0.75 and 1.5 g/kg BDG supplementation could significantly increase the WGR and SGR of hybrid grouper (P < 0.05). And dietary 0.75 g/kg BDG could also significantly decrease serum aspartate aminotransferase, glucose and lactate dehydrogenase in hybrid grouper (P < 0.05). Dietary BGD supplementation protected the integrity of liver and intestinal morphological structure, reduced the accumulation of liver fat. Dietary BDG supplementation might enhance the immunity of hybrid grouper by regulating the expression of antioxidant and inflammation-related genes in head kidney and spleen of hybrid grouper. Our study demonstrated that the growth promoting effect of Bupleurum extract, dandelion extract and Ginkgo biloba extract in the ratio of 1:4:1 as a compound feed additive was better than any of them as a feed additive alone, and the dosage was less. The optimal additive dosage of BDG was 0.75 g/kg in hybrid grouper diets.

Effects of dietary Mitracarpus scaber leaves extract on growth, physiological, antioxidants, and mucosal immune profiles of North African catfish, Clarias gariepinus, and resistance against Edwardsiella tarda infection

This study evaluated the effect of Mitracarpus scaber leaves extract (MSLE) as a dietary supplement on growth performance, physiological, antioxidants, and mucosal immune profiles of North African catfish, Clarias gariepinus, and resistance to Edwardsiella tarda infection. Four isonitrogenous diets containing 0, 2, 4, or 6 MSLE g/kg were fed to North African catfish fingerlings (n = 240; mean weight = 5.80 g) for 56 days. After the feeding trial, 10 fish from each experimental tank were intraperitoneally injected with E. tarda (ATCC 15,947; 1.0 × 10⁸ CFU/mL) while clinical signs and mortalities were observed for 14 days. The results show that North African catfish fed dietary MSLE had better growth performance, physiological antioxidants, and mucosal immune profiles than when fed a control diet. The best growth, physiological, antioxidant, and mucosal immune response profiles were noticed in the fish fed diet containing 6 MSLE g/kg. Furthermore, fish fed 6 MSLE g/kg diet had a higher survival rate after E. tarda infection. These results indicated that supplementation of MSLE at 6 g/kg improves growth, physiological, antioxidant, and mucosal immune profiles, and promotes resistance of North African catfish.

The Potential Application of Chinese Medicine in Liver Diseases: A New Opportunity

Liver diseases have been a common challenge for people all over the world, which threatens the quality of life and safety of hundreds of millions of patients. China is a major country with liver diseases. Metabolic associated fatty liver disease, hepatitis B virus and alcoholic liver disease are the three most common liver diseases in our country, and the number of patients with liver cancer is increasing. Therefore, finding effective drugs to treat liver disease has become an urgent task. Chinese medicine (CM) has the advantages of low cost, high safety, and various biological activities, which is an important factor for the prevention and treatment of liver diseases. This review systematically summarizes the potential of CM in the treatment of liver diseases, showing that CM can alleviate liver diseases by regulating lipid metabolism, bile acid metabolism, immune function, and gut microbiota, as well as exerting anti-liver injury, anti-oxidation, and anti-hepatitis virus effects. Among them, Keap1/Nrf2, TGF-β/SMADS, p38 MAPK, NF-κB/IκBα, NF-κB-NLRP3, PI3K/Akt, TLR4-MyD88-NF-κB and IL-6/STAT3 signaling pathways are mainly involved. In conclusion, CM is very likely to be a potential candidate for liver disease treatment based on modern phytochemistry, pharmacology, and genomeproteomics, which needs more clinical trials to further clarify its importance in the treatment of liver diseases.

Ginkgo biloba leaf extract improves growth, intestinal histomorphometry, immunity, antioxidant status and modulates transcription of cytokine genes in hapa-reared Oreochromis niloticus

This study was designed to evaluate the impacts of dietary supplementation with Ginkgo biloba leaf extract (GBL) on the growth, intestinal histomorphometry, immunity, antioxidant status, and expression of cytokine genes in Nile tilapia reared in the hapas. A control diet was enriched with different GBL levels (0.0, 5.0, 7.0, and 9.0 g/kg) to form 4 experimental diets and were fed to Nile tilapia for 8 weeks. The findings illustrated that dietary GBL significantly enhanced the growth and feed utilization indices compared to those reared in the control group. A dose-dependent increase of hepatic catalase, superoxide dismutase, and glutathione peroxidase activities alongside a decline of hepatic malondialdehyde levels were recorded in GBL groups compared with the control. Serum lysozyme activity, complement C3, and immunoglobulin M levels were significantly increased in GBL groups compared with the control group. Moreover, dietary GBL maintained the normal intestinal and hepatopancreatic histological structures with a significant increase of some histomorphometric measurements of proximal, middle, and distal intestinal parts of the treated fish. Interestingly, dietary GBL supplementation significantly increased the mRNA expression of interleukin-1 beta (IL-1β), IL-6, IL-10, tumor necrosis factor alpha (TNF-α) and interferon gamma (INF-γ) genes in the splenic tissues of treated fish over the control group. To conclude, it could be recommended to use GBL as a functional phytogenic feed additive to improve the growth, hepatic and intestinal health status, hepatic antioxidant status, and immunity of treated Nile tilapia. Besides, the second order polynomial regression revealed that 7.50 g GBL/kg diet is the optimal inclusion level to improve growth with no negative impacts on the overall health condition of treated Nile tilapia.

Dietary Lactobacillus casei K17 Improves Lipid Metabolism, Antioxidant Response, and Fillet Quality of Micropterus salmoides

Simple Summary

In order to find effective antioxidants to improve the fleshy degeneration and liver tissue lesions of Micropterus salmoides that were fed artificial mixed feed, Lactobacillus casei K17, which displayed a high level of antioxidant activity in vitro and in vivo was selected in this study. The results indicated that after a trial for 69 days, live bacteria (LB), live bacteria protected by skim milk powder (MB), and dead bacteria were able to improve hemal and hepatic lipid metabolism and antioxidant response, reduce reactive oxygen species production, and protect Micropterus salmoides hepatic cells from injury, while LB and MB were also able to improve fillet quality. Therefore, Lactobacillus casei K17 might be a good alternative source of improving fillet quality and liver health in Micropterus salmoides.

Abstract

We previously demonstrated that Lactobacillus casei K17, isolated from Korean kimchi, has high antioxidant levels in vitro and in vivo. However, its effect on Micropterus salmoides is unknown. In this study, we investigated the impact of L. casei K17 supplementation on the lipid metabolism, antioxidant response, liver histology, and fillet quality of M. salmoides. We randomly assigned 450 M. salmoides (33.0 ± 0.5 g) to six diet groups for 69 days. The diets were as follows: 0.85% normal saline; 10% skim milk powder; 1 × 10⁸ CFU/g live L. casei K17 (LB); 1 × 10⁸ live L. casei K17 protected by skim milk powder (MB); 1 × 10⁸ dead L. casei K17 (DB); and L. casei K17 fermentation supernatant. MB significantly improved the crude protein, total collagen, alkaline-insoluble collagen, fiber numbers, hardness, chewiness, and gumminess of M. salmoides fillets (p < 0.05). LB significantly improved crude protein and fiber numbers (p < 0.05). Furthermore, dietary supplementation with LB, MB, and DB maintained normal liver histology, preserved liver function, and increased hepatic and hemal antioxidant status by enhancing antioxidant enzyme activities. Meanwhile, the three diets also promoted lipid metabolism by increasing HDL-C effectiveness and reducing total cholesterol, triglyceride, and low-density lipoprotein cholesterol levels in serum and liver tissues, indicating that dietary supplementation with DB, LB, and MB had hypolipidemic effects on M. salmoides. MB and LB significantly improved fillet quality and LB, MB, and DB improved hemal and hepatic lipid metabolism and antioxidant response and reduced reactive oxygen species production, protecting M. salmoides hepatic cells from injury.

Impact of a Novel Nano-Protectant on the Viability of Probiotic Bacterium Lactobacillus casei K17

Probiotics are considered as desirable alternatives to antibiotics because of their beneficial effects on the safety and economy of farm animals. The protectant can ensure the viability of probiotics, which is the prerequisite of the beneficial effects. The objective of this study was to evaluate the effects of a novel nano-protectant containing trehalose, skim milk powder, phytoglycogen nanoparticles, and nano-phytoglycogen Pickering emulsions on the viability of Lactobacillus casei K17 under different conditions. The results indicated that the optimal concentration of the carbohydrate substrate was determined to be 10% skim milk powder (w/w) instead of trehalose. The combination of 10% skim milk powder (w/w), 1% phytoglycogen nanoparticles (w/w), and 10% Pickering emulsions (w/w) was selected as the optimal component of the protectant. Trilayer protectants with an optimal component had a more significant protective effect on the bacteria than that of the monolayer and bilayer protectants, or the control in feed storage, freeze-drying, and simulated gastrointestinal environment. A scanning electron microscope was used to monitor the morphological characteristics of the protectants for different layers on L. casei. In conclusion, the trilayer protectant exhibited a substantial effect on L. casei during storage and consumption, which could be used in the feed and functional food.

Role of inhibiting Chk1-p53 pathway in hepatotoxicity caused by chronic arsenic exposure from coal-burning

Arsenic is a naturally occurring environmental toxicant, chronic exposure to arsenic can cause multiorgan damage, except for typical skin lesions, liver damage is the main problem for health concern in population with arsenic poisoning. Abnormal apoptosis is closely related to liver-related diseases, and p53 is one of the important hallmark proteins in apoptosis progression. This study was to investigate whether arsenic poisoning-induced hepatocyte apoptosis and the underlying role of p53 signaling pathway. A rat model of arsenic poisoning was established by feeding corn powder for 90 days, which was baked with high arsenic coal, then were treated with Ginkgo biloba extract (GBE) for 45 days by gavage. The results showed that arsenic induced liver damage, increased hepatocyte apoptosis and elevated the expression level of Chk1 and the ratios of p-p53/p53 and Bax/Bcl-2 in liver tissues, which were significantly attenuated by GBE. Additionally, to further demonstrate the potential apoptosis-associated mechanism, L-02 cells were pre-incubated with p53 inhibitor pifithrin-α (PFTα), ataxia telangiectasia-mutated (ATM)/ataxia telangiectasia-mutated and Rad3-related (ATR) inhibitor (CGK733) or GBE, then treated with sodium arsenite (NaAsO₂) for 24 h. The results showed that GBE, PFTα or CGK733 significantly reduced arsenic-induced Chk1 expression and the ratios of p-p53/p53 and Bax/Bcl-2. In conclusion, Chk1-p53 pathway was involved in arsenic poisoning-induced hepatotoxicity, and inhibiting of Chk1-p53 pathway ameliorated hepatocyte apoptosis caused by coal-burning arsenic poisoning. The study provides a pivotal clue for understanding of the mechanism of arsenic poisoning-induced liver damage, and possible intervention strategies.

Effects of dietary terrestrial oils supplemented with L-carnitine on growth, antioxidant capacity, lipid metabolism and inflammation in large yellow croaker (Larimichthys crocea)

The present study was conducted to determine the effects of dietary terrestrial oils (TO) supplemented with L-carnitine on growth performance, biochemical and antioxidant response, lipid metabolism and inflammation in large yellow croaker (Larimichthys crocea). Three iso-nitrogenous and iso-lipidic experimental diets were formulated with FO (fish oil, the control group), 75% TO (75% FO was substituted by the oil mixture with equal amounts of soybean oil, linseed oil and pork lard) and 75% TOC (75% TO supplemented with 800 mg/kg L-carnitine), respectively. Compared to the control group, feed efficiency ratio and specific growth rate were significantly increased in fish fed diets with 75% TO and 75% TOC. Hepatic lipid content, serum triglyceride level, low-density lipoprotein-cholesterol level and the mRNA expression of pro-inflammatory genes (tnfα and ifnγ) were significantly increased in fish fed the diet with 75% TO compared to the control group. However, the supplementation of 800 mg/kg L-carnitine in the 75% TO diet repressed hepatic lipid content, serum low-density lipoprotein-cholesterol level and the mRNA expression of tnfα and ifnγ in fish compared to fish fed the diet with 75% TO. Total antioxidant capacity, the activity of superoxide dismutase, the mRNA expression of cpt-I and the activity of CPT-I were significantly increased in fish fed the diet with 75% TOC compared to 75% TO. In conclusion, these results suggested that the supplementation of 800 mg/kg L-carnitine in the diet with terrestrial oils mixture could increase growth, antioxidant capacity, fatty acid oxidation and decrease the expression of inflammatory genes in large yellow croaker.

First screening report of immune and protective effect of non-toxic Jatropha vernicosa stem bark against Vibrio parahaemolyticus in Longfin yellowtail Seriola rivoliana leukocytes

In México, the infusion of Jatropha vernicosa stem bark has been used in folk medicine for many clinical situations, but no reports were available about this particular species of Jatropha in fish of mammals. In this first screening report, the phytochemical, antioxidant profile and antimicrobial properties of aqueous J. vernicosa stem bark extract were explored against Vibrio parahaemolyticus, an opportunist fish pathogen. To evaluate the cytotoxicity and immunological effect for the possible application of aqueous J. vernicosa stem bark in aquaculture, this study assessed it by using Longfin yellowtail Seriola rivoliana leukocytes. The results showed that phytochemical composition of the J. vernicosa extract was rich in phenol, flavonoid, saponin, and coumarin compounds. The antioxidant capacity of hydroxyl radical and superoxide anion scavenging activities, iron-chelation activity and β-carotene bleaching coupled to linoleic acid showed that J. vernicosa extracts had a moderate antioxidant effect compared with synthetic antioxidants (BHT, BHA and EDTA). No adverse effects were observed on spleen leukocytes (viability > 98%). Interestingly, J. vernicosa stem bark extract has immunostimulant and antioxidant effects, increasing phagocytosis, respiratory burns activity, and nitric oxide production, as well as superoxide dismutase and catalase activities. Additionally, J. vernicosa extract increased pro-inflammatory cytokine IL-1β and suppressed anti-inflammatory IL-10 gene expression upon stimuli and V. parahaemolyticus challenge. Finally, the data confirms that J. vernicosa stem bark extract is non-cytotoxic, rich in bioactive compounds with antioxidant effects, capable of enhancing the immune system in leukocytes and with great potential to fight against opportunistic diseases, such as vibriosis in fish.

Dietary Ginkgo biloba leaf extracts supplementation improved immunity and intestinal morphology, antioxidant ability and tight junction proteins mRNA expression of hybrid groupers (Epinephelus lanceolatus ♂ × Epinephelus fuscoguttatus ♀) fed high lipid diets

For many years, Ginkgo biloba has been used as a traditional Chinese medicine because of its antioxidant, anti-inflammatory and hepatoprotective effects. The present study aimed to investigate the effects of dietary Ginkgo biloba leaf extract (GBLE) supplementation on immune response, intestinal morphology, antioxidant ability and tight junction proteins mRNA expression of hybrid groupers fed high lipid diets. Basal diets supplemented with GBLE at 0, 0.50, 1.00, 2.00, 4.00 and 10.00 g/kg were fed to hybrid grouper for 8 weeks. The study showed that dietary GBLE supplementation significantly improved immune ability by increasing plasma complement 3, complement 4 and Immunoglobulin M content. Dietary supplementation of 0.50-2.00 g/kg GBLE improved intestinal morphology and increased the expression of zonula occludens 1, zonula occludens 2, zonula occludens 3, occludin and claudin 3a. Dietary supplementation of 0.50-2.00 g/kg GBLE improved antioxidant ability by increasing activities and expressions of glutathione peroxidase, catalase and glutathione reductase, suppressed inflammatory by increasing expression of interleukin 10, transforming growth factor β1 and target of rapamycin, and decreased apoptotic responses by reducing the expression of caspase 3, caspase 8 and caspase 9 in the intestine of hybrid grouper fed high lipid diets. This study indicated that dietary GBLE supplementation was clearly beneficial for intestinal health and immunity in hybrid groupers fed high lipid diets and it could be used as a functional feed additive in aquaculture to promote the application of high lipid diets.

Effects of dietary Senecio scandens buch-ham extracts on growth performance, plasma biochemical, histology and the expression of immune-related genes in hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀)

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%.

Dietary β-sitosterol regulates serum lipid level and improves immune function, antioxidant status, and intestinal morphology in broilers

This research investigated effects of dietary β-sitosterol addition at different levels on serum lipid levels, immune function, oxidative status, and intestinal morphology in broilers. One-day-old broiler chicks were allocated to 5 groups of 6 replicates. Chickens in the 5 groups were fed a basal diet supplemented with 0 (control group), 40, 60, 80, and 100 mg/kg of β-sitosterol for 42 D, respectively. β-Sitosterol linearly decreased (P < 0.05) concentrations of serum total cholesterol, jejunal tumor necrosis factor α (TNF-α), and ileal interleukin 1β (IL-1β) and mRNA relative expressions levels of jejunal TLR4 and ileal MyD88, whereas it linearly increased (P < 0.05) contents of jejunal immunoglobulin G (IgG), ileal secreted IgA and glutathione, jejunal catalase activity and Nrf2 mRNA relative expression level, villus height (VH), and VH-to-crypt depth (CD) ratio (VH:CD) in the jejunum and ileum. Linear and quadratic increases (P < 0.05) in absolute and relative spleen weight were observed by dietary β-sitosterol, whereas malondialdehyde (MDA) concentration in the jejunum and ileum followed the opposite trend (P < 0.05). Compared with the control group, dietary β-sitosterol at higher than or equal to 60 mg/kg level decreased (P < 0.05) contents of serum total cholesterol, ileal MDA, and jejunal TLR4 mRNA relative expression level, whereas it increased (P < 0.05) absolute spleen weight and ileal glutathione content. Higher than or equal to 80 mg/kg level of β-sitosterol enhanced (P < 0.05) jejunal IgG concentration, VH, catalase activity, and Nrf2 relative expression level and ileal secreted IgA content, but reduced (P < 0.05) ileal IL-1β content and MyD88 mRNA relative expression level. β-Sitosterol addition at 60 and 80 mg/kg levels increased (P < 0.05) relative spleen weight, whereas it decreased (P < 0.05) jejunal MDA accumulation. Moreover, 100 mg/kg level of β-sitosterol reduced (P < 0.05) jejunal TNF-α level, but it increased (P < 0.05) VH in the jejunum and VH:CD in the jejunum and ileum. Accordingly, dietary β-sitosterol supplementation could regulate serum cholesterol level, promote immune function, and improve intestinal oxidative status and morphology in broilers.

Dietary Ginkgo biloba leaf extract alters immune-related gene expression and disease resistance to Aeromonas hydrophila in common carp Cyprinus carpio

Ginkgo biloba leaf is widely used in traditional medicine in China. The present study aimed to illustrate the effects of dietary Ginkgo biloba leaf extract (GBLE) on growth performance and immune responses in common carp infected by Aeromonas hydrophila. Six different diets either not treated (control) or treated with 0.5, 1, 2, 5 and 10 g/kg of GBLE were designed to feed the fishes for 8 weeks. The results indicated that, compared to the control groups, 10 g/kg dietary GBLE significantly increased body growth and feed utilization. In GBLE dietary groups, red blood cell levels, white blood cells, hematocrit, hemoglobin, total protein, albumin and globulin were significantly increased relative to the control groups. Dietary supplementation with 5 g/kg GBLE increased the phagocytic ratio, and phagocytic indexes increased in the 2, 5 and 10 g/kg groups relative to the control groups. Moreover, 2, 5 and 10 g/kg GBLE diets increased O₂^- production compared to the control groups. Additionally, GBLE diets stimulated lysozyme activity (in 10 g/kg group) and inhibited bactericidal activity (in 0.5, 2, 5 and 10 g/kg group). Quantitative real-time PCR showed that IL1β, IL8, TNF-α, IL10, TGFβ, and inducible enzyme genes were prone to decrease while SAA, hepcidin and GPX1 were increased due to the GBLE diet in the intestine. In the head-kidney, the GBLE treatment decreased IL1β, IL8, TNF-α, IL10, TGFβ, INOS and arginase gene expressions, whereas SOD upregulation was found in the GBLE condition. The mRNA expressions of IL1β, IL8, TNF-α, IL10 and INOS were decreased, but SAA, hepcidin, GPX1 and SOD mRNA levels were increased in the spleen in the GBLE diet compared to the control. Additionally, diet supplemented with GBLE improved the survival rate infected with A. hydrophila. Our observations suggest that GBLE effectively enhanced growth performance, modulated immune-related gene expression. It improved survival rate of common carp after A. hydrophila infection and the optimum concentration we recommend is 10 g/kg of GBLE.

High level of dietary olive oil decreased growth, increased liver lipid deposition and induced inflammation by activating the p38 MAPK and JNK pathways in large yellow croaker (Larimichthys crocea)

A feeding experiment was conducted to determine the effects of fish oil replaced by olive oil (OO) on growth performance, serum biochemical, antioxidant capacity and inflammatory response in large yellow croaker (Larimichthys crocea). Four iso-nitrogenous and iso-lipidic diets were formulated by replacing fish oil (FO) with 0% (the control group), 33.3%, 66.7% and 100% OO. Fish fed the diet with 100% OO had the lowest growth performance among dietary treatments. However, there were no significant differences in SGR and FI among fish fed diets with 0% (the control group), 33.3% and 66.7% OO (P > 0.05). As to morphological parameters, HSI was significantly increased in fish fed the diet with 100% OO than the control group (P < 0.05). Furthermore, the lipid content of the liver in fish fed the diet with 100% OO was significantly higher than the control group (P < 0.05). Fish fed the diet with 100% OO had the highest content of C18:1n-9 among dietary treatments. Serum total triglyceride (TG), low-density lipoprotein-cholesterol (LDL-C) levels and activity of serum alanine transaminase (ALT) were significantly increased in fish fed the diet with 100% OO compared with the control group (P < 0.05). Meanwhile, dietary OO decreased the activity of superoxide dismutase (SOD) and the total antioxidant capacity (T-AOC) in fish fed diets with increasing dietary OO levels. However, the content of malondialdehyde (MDA) was significantly increased in fish fed the diet with 100% OO compared with the control group (P < 0.05). The expression of pro-inflammatory genes, COX-2, IL-1β and TNFα, were significantly increased in the liver of fish fed the diet with 100% OO compared with the control group (P < 0.05), which was probably due to the activation of p38 mitogen-activated protein kinase (p38 MAPK) pathways and Jun N-terminal kinase (JNK) as the increased protein ratio of p-p38 MAPK to p38 MAPK and p-JNK to JNK. These results suggested that high level of dietary OO decreased the growth performance and antioxidant capacity but induced inflammation via the activation of p38 MAPK and JNK pathways in large yellow croaker.

Effects of traditional Chinese medicines on immunity and culturable gut microflora to Oncorhynchus masou

The present study was conducted to evaluate the effect of dietary traditional Chinese medicines on the growth, immunity, and composition of culturable gut microflora in Oncorhynchus masou. Diets were formulated to contain no medicine (control), antitoxic decoction (A), general antiphlogistic decoction (B), or Herbae Artemisiae Capillariae decoction (C). Fish were manually fed twice daily till apparent satiation for 30 days. Compared with that in the control group, supplementation with the three kinds of Chinese herbal medicine enhanced fish growth significantly (P < 0.05). The activities of liver superoxide dismutase and glutathione peroxidase in the treatment groups were significantly higher compared with those in the control group (P < 0.05). The quantity of intestinal microflora was higher in the treatment groups compared with that in the control group. Moreover, there were some effects of dietary Chinese herbal medicine on the composition of intestinal microflora. Microflora of Pseudomonas sp., Psychrobacter sp., Microbacterium sp., Macrococcus sp., Burkholderia sp., and Arthrobacter sp. were found in the treatment groups, whereas there were none in the control group. There was a significant increase in their amounts in the treatment groups (P < 0.05). The three kinds of traditional Chinese medicines can improve the growth and immunity of Oncorhynchus masou and affect the quantity and composition of intestinal microflora.