Effects of dietary resveratrol supplementation on hepatic and serum pro-/anti-inflammatory activity in juvenile GIFT tilapia, Oreochromis niloticus

Effect of Polystyrene Microplastics on the Antioxidant System and Immune Response in GIFT (Oreochromis niloticus)

Recent studies have revealed a significant presence of microplastics (MPs) in freshwater ecosystems, raising concerns about their potential negative impacts on the growth and development of freshwater organisms. The present study was conducted to examine the effects of chronic sub-lethal doses of polystyrene microsphere MPs on the oxidative status (ROS, SOD) and the immune response (IL-1ß, TNF-α) of genetically improved farmed tilapia (a kind of tilapia hereafter referred to as GIFT). GIFT juveniles (5.1 ± 0.2 g) were exposed to different concentrations of substances. The experimental groups were as follows: group A (control, no exposure), group B (exposed to a concentration of 75 nm), group C (exposed to a concentration of 7.5 μm), group D (exposed to a concentration of 750 μm), group E (exposed to a combination of 75 nm, 7.5 μm, and 750 μm), and group F (exposed to a combination of 75 nm and Chlorella). The ROS contents in the brain and gills were significantly decreased in group F, while a significant increase was observed in group D following a 14-day exposure. SOD activities in the intestine showed an elevation in group F, as did those in the brain and gills in group D, while the SOD levels in the gills generally decreased over time in groups B and F. Notably, the highest ROS and SOD were observed in the brain of group D, whereas the lowest were in the intestines at the same concentration. The activity of IL-1β in the liver was significantly up-regulated in all of the exposure groups. IL-1β was significantly up-regulated in the brain of group B and in the gills of group D. Similarly, TNF-α was significantly up-regulated in the brain of groups B/D/E, in the liver of groups B/C/D, in the intestine of group B, and in the gills of group D. Notably, the highest levels of IL-1β and TNF-α activities were recorded in the brain, while the lowest were recorded in the intestine of group D. Overall, this study revealed that GIFT's immune response and antioxidant system can be affected by MPs.

Effects of methomyl on the intestinal microbiome and hepatic transcriptome of tilapia, and the modifying effects of mint co-culture

Methomyl (MET) is an oxime carbamate insecticide that can contaminate aquatic systems resulting in toxicological effects. It can harm some fish species possibly through the anti-oxidative, phagosome pathway. Mint is one of the most widely herbal plants exhibiting antioxidant activities. In this study, we investigated the impact of MET on the antioxidant system of Oreochromis niloticus in presence of mint as a floating bed. Results revealed that the superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase, and glutathione S-transferase significantly decreased and the GSH content significantly increased in the intestine. The hepatic peroxisome proliferator-activated receptor (PPAR) signalling pathway, carbon metabolism, renal phosphoinositide 3-kinase (PI3K)-Akt, mitogen-activated protein kinase (MAPK) signalling pathway, and phagosomes were significantly affected. Upon long-term exposure, circadian rhythm and phagosomes were enriched in the liver and kidney. However, mint increased the enriched pathways of Toll-like receptor, PPAR, p53, NF-kappa B, MAPK, oestrogen, and B cell receptor signalling pathways. MET with different concentrations destroyed the balance of gut microbiota, mint decreased Verrucomicrobia and Akkermansia for the maintenance resulted from MET. Cetobacterium had a positive impact on total nitrogen (TN), chemical oxygen demand (CODMn), and glutathione reductase (GR), while Akkermansia had a positive impact on feed conversion ratio (FCR), SOD and CAT, and the abundance of both decreased due to MET exposure. High mint density removed more concentrations of nitrogen and phosphorus in the tilapia cultivation wastewater. Therefore, planting with mint can alleviate the toxicological effects produced by MET, shape the intestinal microbiota, and strengthen the connection between water quality and the metabolic parameters.

Resveratrol attenuated fatty acid synthesis through MAPK-PPAR pathway in red tilapia

High-fat (HF) diets have been shown to cause hepatic impairment in fish species, but the mode of action, especially the pathways involved, has not yet been determined. In this study, the effects of resveratrol (RES) supplementation on the hepatic structure and fat metabolism of red tilapia (Oreochromis niloticus) were determined. Based on transcriptome and proteomics results, RES was found to promote fatty acid β-oxidation in the blood, liver, and liver cells associated with apoptosis and the MAPK/PPAR signaling pathway. RES supplementation was found to alter the expression of genes related to apoptosis and fatty acid pathways like blood itga6a and armc5 which were upregulated and downregulated respectively by high-fat feeding while ggh and ensonig00000008711 increased and decreased, respectively, with RES addition. Relative to the PPAR signaling pathway, fabp10a and acbd7 showed a reverse U-shaped tendency, both in different treatments and at different times. Proteomics results demonstrated that MAPK/PPAR, carbon/glyoxylate, dicarboxylate/glycine serine, and threonine/drug-other enzymes/beta-alanine metabolism pathways in the RES group were significantly affected, and Fasn and Acox1 decreased and increased, respectively, with RES addition. Seven subgroups were obtained using scRNA-seq, and enrichment analysis showed that the PPAR signaling pathway was upregulated with RES supplementation. RES significantly increased the expression of the marked genes (pck1) ensonig00000037711, fbp10a, granulin, hbe1, and zgc:136461, which are liver cell-specific genes. In conclusion, RES resulted in significantly enriched DGEs associated with fat metabolism and synthesis via the MAPK-PPAR signaling pathway.

Dietary Chlorella vulgaris effectively alleviates oxidative stress, immunosuppression, and enhances the resistance to Streptococcus agalactiae infection in cadmium-intoxicated Nile tilapia fingerlings

Aquatic pollutants, including cadmium (Cd), cause oxidative stress on aquatic animals. The use of probiotics, including microalgae as a feed additive to alleviate the toxic impacts of heavy metals, is a much more interesting point. Hence, the current study investigated the oxidative stress and immunosuppression in Nile tilapia (Oreochromis niloticus) fingerlings caused by Cd toxicity as well as the preventive function of dietary Chlorella vulgaris against Cd toxicity. Accordingly, fish were fed on 0.0 (control), 5, and 15 g/kg diet of Chlorella up to satiation thrice a day, along with being exposed to 0.0 or 2.5 mg Cd/L for 60 days. Following the experimental procedure, fish from each group were intraperitoneally injected with Streptococcus agalactiae, and their survivability was observed for further ten days. Chlorella-supplemented diets meaningfully (P < 0.05) boosted the antioxidative capability of fish, which was evidenced by higher activities of hepatic superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione-S-transferase (GST) as well as higher levels of reduced glutathione (GSH) along with significant reductions in hepatic malondialdehyde levels. Moreover, the innate immunity indices [phagocytic activity (PA), respiratory burst activity (RBA), and alternative complement activity (ACH50)] were significantly higher in Chlorella-fed fish, particularly in the group of 15 g/kg diet. Additionally, serum of Chlorella-fed fish showed potent bactericidal activities against S. agalactiae, particularly at the treatment of a 15 g/kg diet. Feeding Chlorella diets to Nile tilapia fingerlings upregulated SOD, CAT, and GPx genes expression alongside the down-regulation of IL-1β, IL-8, IL-10, TNF-α, and HSP70 genes expression. Conversely, Cd toxicity caused oxidative stress and suppressed the fish's innate immunity with upregulation of the expression of IL-1β, IL-8, IL-10, TNF-α, and HSP70 genes. Feeding Cd-exposed fish on Chlorella-containing diets attenuated these adverse effects. The current research revealed that supplementing feeds with the treatment of 15 g/kg diet of C. vulgaris supports the antioxidant-immune responses and alleviates the Cd toxicity effects on Nile tilapia fingerlings.

Transcriptome analysis of the response of four immune related organs of tilapia (Oreochromis niloticus) to the addition of resveratrol in feed

Resveratrol (RES) has been found to have immunological enhancement effects on Oreochromis niloticus. In O. nilocticus, the liver, spleen and kidney act as immune target tissues, while intestine works for nutrition sensing organ. In the present study, we determined RES administration on these immune tissues transcriptomic response in genetically improved farmed tilapia (GIFT), and further analyzed the relationship between transcriptomic response and intestinal microbiota. As results, hepatic hemosiderin and intestinal goblet cells significantly increased with RES addition. Kyoto encyclopedia of genes and genomes (KEGG) pathways associated with herpes simplex virus 1 infection, calcium signaling pathway, cell adhesion molecules, apoptosis, and mitogen-activated protein kinase (MAPK)/peroxisome proliferators-activated receptors (PPAR) signaling pathways were enriched. In particular, the differentially enriched genes (DEGs) associated pathways were present in different sampling tissues, times, and comparisons, interestingly, the PPAR signaling pathway was enriched with increasing time of RES addition. The assembled DEGs presented verified expression in the kidney, liver, spleen, and intestine tissues, and fabp6 was highly expressed in the intestine. Serial DEGs of fatty acid-binding proteins (fabp7, fabp7a, fabp10a) decreased in the liver and kidney, and fabp6 significantly increased in the spleen. With time, the pathways of energy metabolism, glycan biosynthesis, and metabolism decreased and increased in the intestinal metagenome. Some Candidatus branches significantly increased (C. cerribacteria and C. harrisonbacteria) and while others decreased (C. glodbacteria, etc.), whereas C. verstraetearchaeota fluctuated with RES addition. slc27a6 and dbi were negatively correlated with bacteria involved in the lipid, energy, and carbohydrate metabolism pathways. The present study suggests that RES supplementation affected lipid metabolism in immune-related organs may be related to the PPAR signaling pathway.

Effects of two host-associated probiotics Bacillus mojavensis B191 and Bacillus subtilis MRS11 on growth performance, intestinal morphology, expression of immune-related genes and disease resistance of Nile tilapia (Oreochromis niloticus) against Streptococcusiniae

The intensification and diversification of production systems have increased the incidence of diseases, which are usually treated with antibiotics. However, its use should be restricted due to the increasing prevalence of antibiotic-resistant bacteria. Probiotics represent therefore an alternative environmentally friendly strategy for improving growth and disease resistance in aquaculture. Considering that host-derived probiotics may offer greater advantages than those from other environments in terms of safety and efficacy, two potential host-associated probiotic strains (Bacillus mojavensis B191 and Bacillus subtilis MRS11) were used in the present study, which were previously isolated from intestinal mucus of Nile tilapia (Oreochromis niloticus). This study was conducted to assess the effects of dietary administration of two Bacillus strains on growth performance, intestinal morphology, immunity, and disease resistance of Nile tilapia. A total of 375 fish were randomly divided into five groups in triplicate. Nile tilapia were fed a basal diet (control group) or a basal diet supplemented with Bacillus mojavensis B191 (BM) or Bacillus subtilis MRS11 (BS) spores at different concentrations of 1 × 10⁶ (BM6 and BS6, respectively) and 1 × 10⁸ (BM8 and BS8, respectively) CFU/g of feed for 60 days. Moreover, the survival rate of tilapia upon challenge with Streptococcus iniae was determined following the feeding trial. After the feeding trial, the growth performances were significantly improved in all probiotic-fed groups, with the BS8 group being the highest. Light and electron microscopy observations revealed elevated goblet cells, intestinal villus length (except BM8), microvilli length, microvilli density, and perimeter ratio increase in the intestine of all probiotic-fed groups compared with the control group. Regarding the expression analysis, HSP70 gene was only up-regulated in the BM8 group and a general trend of up-regulation of some immune-related cytokines (TGF-β, IL-10, TNF-α and IL-1β) was observed in all probiotic-fed groups. Likewise, the best protection against Streptococcus iniae was observed in the BS8 group, followed by BS6, BM6 and BM8 groups. Altogether, dietary probiotic supplementation with BS8 and BM6 may improve growth performance, intestinal morphology, immunity, and disease resistance in Nile tilapia.

Resveratrol ameliorates oxidative stress, inflammatory response and lipid metabolism in common carp (Cyprinus carpio) fed with high-fat diet

High-fat diet is regarded as crucial inducers of oxidative stress, inflammation, and metabolic imbalance. In order to investigate the ameliorative potential of resveratrol against the progression of liver injury towards steatohepatitis, common carp (Cyprinus carpio) were distributed into six experimental groups and were fed with a normal-fat diet, a high-fat diet, and supplemented with resveratrol (0.8, 1.6, 2.4, and 3.2 g/kg diet) for 8 weeks. The high-fat diet decreased the antioxidant capacities, as well as causing the inflammatory response and lipid deposition of common carp. Resveratrol induced a marked elevation in the final body weight, weight gain rate, condition factor and significant decrease in the feed conversion ratio. Moreover, dietary resveratrol showed a significant decrease in the alanine aminotransferase, aspartate aminotransferase, triglyceride and low-density lipoprotein levels, which was accompanied by an increase in high-density lipoprotein concentration in serum. A significant elevation in total superoxide dismutase, catalase, glutathione peroxidase and a decreased malondialdehyde content were observed, along with a substantial elevation in antioxidant activities were found. Additionally, fish fed with resveratrol had an up-regulation of hepatic catalase, copper, zinc superoxide dismutase, glutathione peroxidase 1a, and glutathione peroxidase 1b gene expression via Nrf2 signaling pathway. Expectedly, our results also demonstrated that resveratrol regulates hepatic lipid metabolism in fish by inhibiting the expression of hepatic lipogenesis genes (acetyl-CoA carboxylase 1, fatty acid synthase, and sterol regulatory element binding protein 1), fatty acid uptake-related genes of lipoprotein lipase, and β-oxidation-related genes via PPAR-γ signaling pathway. Furthermore, dietary resveratrol reduced inflammation, as evident by down-regulating the interleukin-1β, interleukin-6, interleukin-8, and tumor necrosis factor-α expression levels and upregulating the interleukin-10 and transforming growth factor-β2 expression levels via NF-κB signaling pathway. As a whole, our results demonstrated that resveratrol defensed the impacts against high-fat diet on the serum biochemical, hepatic antioxidants, inflammation, and lipid metabolism.

Effects of resveratrol on lipid metabolism in liver of red tilapia Oreochromis niloticus

Resveratrol (RES), as a polyphenol natural plant extract, mainly accumulates in the root of Polygonum cuspidatum, which can alleviate liver injury in mammals. Our study aims to explore the effects and potential mechanism of RES on lipid metabolism of red tilapia, and the effects of RES on liver structure, fat synthesis and metabolism of red tilapia were determined. The present study designed four groups named as 8 % fat (8%CK), 10 % fat (10 % HF), 10 % HF + RES and 10 % HF + RES + EX527 (selisistat). The liver tissues of red tilapia were collected at 3 (3 W), 6 (6 W) and 9 (9 W) weeks for parameter determination. Compared to the normal diet group, the hepatocyte of tilapia showed nuclear shift and vacuoles of different sizes when fed a high-fat diet. Meanwhile, the high-fat diet increased the contents of LDL, TC and TG significantly at 6 W, and significantly decreased the content of NAD⁺ at 9 W. Compared to the high-fat group, the nuclei of tilapia fed with RES were increased and visible, the degree of steatosis and the number of vacuoles were both reduced. At 3/6/9 W, RES significantly decreased the contents of LDL, TG and TMAO, and significantly increased the content of NAD⁺. A total of 1416 genes were up-regulated and 1928 genes were down-regulated in the group with added RES when compared to the 10 % HF group. The pathways related to lipid metabolism including PPAR signaling pathway have been enriched. Interestingly, the expressions of sirt1, pparα, fabp7 and cpt1b genes were up-regulated in RES diet group, while the expressions of pparγ, me1, scd and lpl genes were down-regulated. After the addition of an inhibitor (EX527), the above indexes showed an opposite trend when compared to the group with added RES. The overall results showed that the high-fat diet could cause fatty liver lesions in the liver of red tilapia, and RES could activate the sirt1 gene, regulate the PPARα/γ pathway and related genes, and thus regulate liver fat synthesis and metabolism leading to the alleviation of damage to liver tissue.

Effect of Methomyl on Growth, Antioxidant System of GIFT (Oreochromis niloticus), and Residue in the Presence of Water Spinach (Ipomoea aquatica Forsk)

This study was conducted to investigate the effect of methomyl (MET) on the growth and antioxidant system of GIFT (5.28 ± 0.12, n = 180) in the presence of water spinach (Ipomoea aquatica) aas a floating bed. Four treatment groups have been established, named control (0), 2, 20, and 200 μg/L MET. Results showed that at moderate temperatures such as 25°C to 30°C, tilapia's feed consumption increased and body weight improved. SOD, CAT, and GSH in the liver of GIFT indicated the significant increase under MET exposure. MET reduced the growth rate of GIFT, and water spinach reduced part of the water quality indexes in the MET (<200 μg/L) groups. Water spinach altered GIFT's hepatic oxidation system to some extent and effectively absorbed MET in water and transferred it to itself, and the degradation time was lower than the dietary standard time which termed as 15–20 days. Growing water spinach in farmed waters partially decomposes MET and prevents it from causing damage to GIFT's liver.

Effect of methomyl on water quality, growth performance and antioxidant system in liver of GIFT (Oreochromis niloticus) in the presence of peppermint (Mentha haplocalyx Briq.) as a floating bed

This study was conducted to investigate the effect of methomyl (MET) on water quality, growth and antioxidant system of genetically improved farmed tilapia (GIFT, Oreochromis niloticus) in the presence of peppermint as a floating bed. The concentration of NH3-N, NO2--N, NO3--N and TP in T3 (with 200 g wet peppermint) was significantly lower (P < 0.05) than that in T2 (100 g), T1 (50 g) and control, and the nutrient removal rates were 61.90%, 31.59%, 59.86% and 45.92% in 20 days, respectively. Juveniles GIFT (5.1 ± 0.2 g) were exposed to sub-lethal concentrations of 0.2, 2.0, 20 and 200 µg/L of MET for 45 days. After 6 weeks of a feeding trial, percentage weight gain (PWG), specific growth rate (SGR) and feed conversion ratio (FCR) were significantly decreased in 0.2, 2.0, 20 µg/L MET groups respectively and increased in the 200 µg/L MET group. Compared with the control, no significant changes in superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) were detected in the 0.2 µg/L group. The significant increase in activities of SOD, CAT and GPx was accompanied by a diminution in reduced glutathione (GSH) levels resulting with tilapia exposed to 2.0, 20, or 200 µg/L for 45 days. The highest rates observed in SOD, CAT, GPx were 157.63%, 164.05% and 167.46% of the control respectively, and the lowest inhibition rate in GSH was 66.42% of the control. Peppermint as a floating bed can alleviate the adverse effects of MET, such as growth retardation and oxidative stress.

An Overview and Therapeutic Promise of Nutraceuticals against Sports-Related Brain Injury

Sports-related traumatic brain injury (TBI) is one of the common neurological maladies experienced by athletes. Earlier the term 'punch drunk syndrome' was used in the case TBI of boxers and now this term is replaced by chronic traumatic encephalopathy (CTE). Sports-related brain injury can either be short term or long term. A common instance of brain injury encompasses subdural hematoma, concussion, cognitive dysfunction, amnesia, headache, vision issue, axonopathy, or even death if remain undiagnosed or untreated. Further, chronic TBI may lead to pathogenesis of neuroinflammation and neurodegeneration via tauopathy, formation of neurofibrillary tangles, and damage to the blood-brain barrier, microglial, and astrocyte activation. Thus, altered pathological, neurochemical, and neurometabolic attributes lead to the modulation of multiple signaling pathways and cause neurological dysfunction. Available pharmaceutical interventions are based on one drug one target hypothesis and thereby unable to cover altered multiple signaling pathways. However, in recent time's pharmacological intervention of nutrients and nutraceuticals have been explored as they exert a multifactorial mode of action and maintain over homeostasis of the body. There are various reports available showing the positive therapeutic effect of nutraceuticals in sport-related brain injury. Therefore, in the current article we have discussed the pathology, neurological consequence, sequelae, and perpetuation of sports-related brain injury. Further, we have discussed various nutraceutical supplements as well as available animal models to explore the neuroprotective effect/ upshots of these nutraceuticals in sports-related brain injury.

Transcriptome Analysis of Juvenile Tilapia (Oreochromis niloticus) Blood, Fed With Different Concentrations of Resveratrol

Oreochromis niloticus (genetically improved farmed tilapia, GIFT) often bites the root of Polygonum cuspidatum when it is used as a floating bed, and resveratrol (RES) is mainly accumulated in the root of P. cuspidatum. Blood acts as a pipeline for the fish immune system. Generating blood transcriptomic resources is crucial for understanding molecular mechanisms underlying blood immune responses. In this study, we determined the effects of RES administration on blood transcriptomic response in GIFT. With increasing RES concentration, 133 (0.025 vs. 0.05 g/kg RES), 155 (0.025 vs. 0.1 g/kg RES), and 123 (0.05 vs. 0.1 g/kg RES) genes were detected as significant differentially expressed genes (DEGs). Three and ninety-five shared significant DEGs were found to be enriched among the three (except 0.1 g/kg RES) and four groups (0, 0.025, 0.05, and 0.1 g/kg RES), respectively. To determine the relationship between mitochondrial regulation and RES supplementation, the results of RNA-Seq were analyzed and nine mitochondria-related genes (ATP synthase or mitochondrial-function-related genes) were verified. The results revealed the same expression pattern: cytochrome c isoform X2 (cox2), katanin p60 ATPase-containing subunit A1 isoform X1 (katna1), plasma membrane calcium-transporting ATPase 1-like (atp2b1) and GTP-binding protein A-like (gtpbpal) showed the highest expression in the 0.1 g/kg RES group, while NADH dehydrogenase [ubiquinone] iron-sulfur protein 2 mitochondrial (nad7), ATP synthase subunit beta, mitochondrial (atpb), ATP synthase subunit alpha, mitochondrial-like (atpal), ATP synthase subunit alpha, mitochondrial (atpa) and ATP-dependent Clp protease proteolytic subunit, mitochondrial (clpp) revealed a dose-dependent expression following RES supplementation. Blood Ca²⁺-ATPase activity, and malondialdehyde, glutathione, and ATP content were significantly increased in the 0.05 (except Ca²⁺-ATPase activity), 0.1 g/kg RES group when compared with the controls. Eighty-nine shared DGEs were mainly enriched in antigen processing and presentation, cell adhesion molecules and phagosome pathways, based on the comparison between previous reported hepatic and the present blood transcriptome. Our study demonstrated that RES supplementation might improve the resistance to metabolism dysfunction via mitochondrial energy synthesis and/or the respiratory chain (e.g., ATPase).

A Novel Promising Frontier for Human Health: The Beneficial Effects of Nutraceuticals in Cardiovascular Diseases

Cardiovascular diseases (CVDs) such as hypertension, atherosclerosis, myocardial infarction, and diabetes are a significant public health problem worldwide. Although several novel pharmacological treatments to reduce the progression of CVDs have been discovered during the last 20 years, the better way to contain the onset of CVDs remains prevention. In this regard, nutraceuticals seem to own a great potential in maintaining human health, exerting important protective cardiovascular effects. In the last years, there has been increased focus on identifying natural compounds with cardiovascular health-promoting effects and also to characterize the molecular mechanisms involved. Although many review articles have focused on the individual natural compound impact on cardiovascular diseases, the aim of this manuscript was to examine the role of the most studied nutraceuticals, such as resveratrol, cocoa, quercetin, curcumin, brassica, berberine and Spirulina platensis, on different CVDs.

Transcriptome alterations in female Daphnia (Daphnia magna) exposed to 17β-estradiol

The molecular mechanism of evaluating 17β-estradiol (E₂)-induced toxicity in female Daphnia magna has not been determined. In this study, the transcriptome of D. magna was analyzed after exposure to three different concentrations (0, 10, and 100 ng L^-1) of E₂ at 3, 6, and 12 h. The results showed 351-17,221 significantly up-regulated and 505-10,282 significantly down-regulated genes (P < 0.05). Overall, the selected largest 10,282 (10 ng L^-1vs control at 12 h) down-regulated and 17,221 (100 vs 10 ng L^-1) up-regulated genes were identified; following annotation, pathways in cancer and RNA transport were found to be enriched according to the interaction network. Among all completed comparisons, KEGG pathways related to the immune system, cancer, disease infection, and active compound metabolism were identified by short time series expression miner analysis. A different set of genes fluctuated in a "U"-shaped pattern over time and at different concentrations of E₂, whereas some genes associated with disintoxication showed a reverse "U"-shaped response as E₂ administration was increased. These results suggest that E₂ exposure caused transcriptional changes in the immune system, disintoxication, disease prevention, and the protein degradation pathway.

Resveratrol Induces Expression of Metabolic and Antioxidant Machinery and Protects Tilapia under Cold Stress

Exposures to low ambient temperature require ectothermic fish to not only adjust their metabolic machinery but also to mount protective responses against oxidative stress. In this study, we tested whether diets supplemented with resveratrol (RSV), a naturally occurring polyphenol known to stimulate metabolic and protective responses in various animals, would be beneficial to tilapia (Oreochromis mossambicus) under hypothermic challenge. Feeding tilapia with RSV-supplemented diet promoted liver expression of sirtuins and their known targets, including metabolic/antioxidative enzymes. After exposure to 15 °C cold conditions for three days, the oxygen–nitrogen (O:N) ratio was decreased in the control-diet-fed tilapia but not in their RSV-fed counterparts. Moreover, at 27 °C, RSV-fed tilapia showed significantly higher prolonged swim speed compared with controls. RSV feeding produced no significant effect on upper and bottom layer preference between the control- and RSV-treated tilapia at either 27 °C or 15 °C. Together, these findings suggest that RSV stimulates beneficial metabolic/antioxidative adjustments in teleosts and may serve as a valuable feed supplement for tropical fish exposed to cold stress during winter.

Dietary Approaches to Attain Fish Health with Special Reference to their Immune System

Fish despite their low collocation in the vertebrate phylum possess a complete immune system. In teleost fish both innate and adaptive immune responses have been described with melanomacrophage centers (MMCs) equivalent to mammalian germinal centers. Primary lymphoid organs are represented by the thymus and kidney, while spleen and mucosa-associated lymphoid tissues act as secondary lymphoid organs. Functions of either innate immune cells (e.g., macrophages and dendritic cells) or adaptive immune cells (T and B lymphocytes) will be described in detail, even including their products, such as cytokines and antibodies. In spite of a robust immune arsenal, fish are very much exposed to infectious agents (marine bacteria, parasites, fungi, and viruses) and, consequentially, mortality is very much enhanced especially in farmed fish. In fact, in aquaculture stressful events (overcrowding), microbial infections very frequently lead to a high rate of mortality. With the aim to reduce mortality of farmed fish through the reinforcement of their immune status the current trend is to administer natural products together with the conventional feed. Then, in the second part of the present review emphasis will be placed on a series of products, such as prebiotics, probiotics and synbiotics, β-glucans, vitamins, fatty acids and polyphenols all used to feed farmed fish. With special reference to polyphenols, results of our group using red grape extracts to feed farmed European sea bass will be illustrated. In particular, determination of cytokine production at intestinal and splenic levels, areas of MMCs and development of hepatopancreas will represent the main biomarkers considered. All together, our own data and those of current literature suggests that natural product administration to farmed fish for their beneficial effects may, in part, solve the problem of fish mortality in aquaculture, enhancing their immune responses.

Transcriptome analysis of juvenile genetically improved farmed tilapia (Oreochromis niloticus) livers by dietary resveratrol supplementation

Here we used RNA-Seq to explore the transcriptomic response and specific involvement of hepatic mRNA of juvenile Oreochromis niloticus (GIFT) as a result of dietary resveratrol supplementation (0.05 g/kg RES). More than 24,513,018 clean reads were reference genome guided assembly into 23,417 unigenes. 12,596 unigenes (29.64%) were annotated to GO database. There were 5, 179 and 1526 genes significantly differentially expressed genes at 15, 30 and 45 d respectively, and 8 KEGG pathways were enriched associated with this immune response. Hyperemia and compressed hepatic sinusoid, fibrosis of liver cell and abnormal hepatic epidermal cell revealed by H&E and SEM analysis respectively. Genes related with cytokine production (il12rb2, scfr), immune system (ig8l, hlfl, cd226, prf1l), autophagy regulation (atg4b), foxo signaling (ccnb2), steroid hormone biosynthesis (cyp3a40), fatty acid metabolism (scd1), metabolism (cacna1b) have been significantly decreased, while genes associated with such pathways above (leap-2, prdx4, mb, homer1, mif, sat1, cytbc1_8) and the pathway of protein processing in endoplasmic reticulum (cne1, tram1) have been significantly increased. These findings suggested RES activated some immune and biological process-related genes to enhance GIFT's innate immunity. It also suggested high concentration addition or long-time administration may bring negative effect in tilapia liver.

Time-dependent gut microbiota analysis of juvenile Oreochromis niloticus by dietary supplementation of resveratrol

To evaluate the changes in bacterial diversity at various time points under resveratrol supplementation, we aimed to investigate the diversification of gut microbiota and the changes in total genetic diversity. We performed 16S rDNA gene sequencing at different time points (15, 30, and 45 days) to analyze the gut microbiota of tilapia. Fusobacteria, Proteobacteria, and Bacteroidetes (15 days) or Cyanobacteria (30 and 45 days) were found to be the three most abundant phyla. Cyanobacteria (15 and 30 days), Proteobacteria (15 days), Firmicutes and Chlamydiae (30 and 45 days), Planctomycetes (30 days), Bacteroidetes, Actinobacteria, and Fusobacteria (45 days) in the 0.05 g/kg RES group increased as compared to that in the controls. Proteobacteria and Cyanobacteria significantly decreased and increased at 30 and 45 days, respectively, while the reverse pattern was observed at 15 days. The Bacteroidetes:Firmicutes and Proteobacteria:Cyanobacteria ratios were significantly increased (15 and 45 days, P < 0.05) and decreased (30 days, P < 0.05). RES supplementation did not affect the richness and diversity of the gut microbiota in tilapia. Our findings may contribute to the development of strategies for the management of diseases.

Resveratrol attenuates oxidative stress and inflammatory response in turbot fed with soybean meal based diet

Adding immunopotentiators to plant protein based diets has been a feasible way to improve fish growth performance and healthy status. In this study, an 8-week trial was carried out to explore the effects of resveratrol, a natural polyphenolic compound, on growth performance, anti-oxidative capacity and immune responses in turbot fed soybean meal based diet. As the results showed, replacement 45% fish meal with soybean meal (SBM) significantly depressed the fish growth, feed utilization and the heights of villi and microvilli in distal intestine. The mRNA levels of hepatic antioxidant enzymes, including superoxide dismutase (sod), glutathione peroxidase (gsh-px) and peroxiredoxin 6 (prx 6), were highly inhibited in SBM group. The inflammation related genes in intestine were also responsive to soybean meal. Supplying resveratrol showed no effects on fish growth performance but significantly restored the intestinal morphology and improved the mRNA levels of hepatic antioxidant enzymes as well as the activity of SOD. Meanwhile, resveratrol significantly improved the mRNA levels of anti-inflammatory cytokine transforming growth factor-β and inhibited the expression of pro-inflammatory cytokines tumor necrosis factor-α (tnf-ɑ), interleukin-1β (il-1β) and interleukin-8 (il-8). The results indicate that resveratrol could attenuate the oxidative stress and inflammatory response induced by soybean meal in turbot. This study shows resveratrol is an effective immunopotentiator to carnivorous fishes fed plant protein sources.

Reshaping fecal gut microbiota composition by growing with Polygonum cuspidatum, Houttuynia cordata, and Ipomoea aquatica

We carried out sequencing of samples cultivated in floating beds with different Chinese medicinal herbs (Control, Houttuynia cordata Thunb., Polygonum cuspidatum, and a combination of H. cordata with Ipomoea aquatica Forssk.; named groups A, B, C, D, respectively) to analyze changes in the composition of gut microbiota of tilapia feces. Fusobacteria (ranging from 49.0% to 73.3%), Firmicutes (12.3%–37.8%), and Proteobacteria (5.1%–23.0%) were found to be the most dominant phyla present in all samples. The operational taxonomic units and the Ace and Chao1 indices of groups A and D were significantly higher than those of group C. Polygonum cuspidatum decreased the species richness and diversity of microbial communities in tilapia intestinal feces. The phylum WCHB1-60, order Enterobacteriales, and genus Plesiomonas significantly decreased (in group A); the species Plesiomonas shigelloides significantly decreased (in groups B and C); and the genus Leucobacter significantly increased (in group D) when compared with the control. The relative abundance of the class Verrucomicrobiae (groups B vs C) significantly decreased. In the presence of I. aquatica, the phylum Bacteroidetes significantly decreased, while the genera Leucobacter and Pelotomaculum significantly increased. The ratio of Bacteroidetes to Firmicutes was significantly higher in groups B and C relative to the controls, while it decreased significantly in group D. The algae (i.e., Anabaena and Microcystis) and beneficial pathogenic bacteria decreased in groups C and D, respectively. In addition, Enterovibrio decreased in all treatment groups. The present data demonstrate that floating bed cultivation with Chinese medicinal herbs significantly alters the gut microbiota of tilapia, which may enhance its immune activity.

Varieties of immunity activities and gut contents in tilapia with seasonal changes

We performed 16S rDNA sequencing of tilapia fecal samples to analyze changes in tilapia gut contents after cultivation of the fish in the presence of sandwich-like floating beds of Chinese medicinal herbs (5 and 10% planting-areas; 5% Polygonum cuspidatum). The interactive effects between water quality and blood and hepatic pro- and anti-inflammatory concentrations were also assessed. Our results showed that the water quality (i.e., NO₃^--N, NO₂^--N, TP removal rates) improved, and the abundance of Chloroflexi and Cyanobacteria increased. The abundance of Bacteroidetes, Verrucomicrobia, Saccharibacteria, and Actinobacteria showed both significant seasonal decreases and increases in the presence of P. cuspidatum (increases in August and decreases in July). Fish blood and hepatic IL-10 and IFN-γ levels (together with fish sampled in September) significantly increased in the P. cuspidatum group sampled in August, while those of TNF-α (10% sandwich-like, P. cuspidatum), IL-1β (P. cuspidatum), IL-8 (5% sandwich-like in September, S905S) significantly decreased. Heat shock proteins 60 and 70 levels significantly increased in the P. cuspidatum group, and complement C3 and C4 concentrations significantly increased in S905S. This study demonstrated that enhanced immunity through the regulation of pro- and anti-inflammatory proteins was sustained throughout development until harvest, particularly in fish grown with P. cuspidatum.

Lycopene and resveratrol ameliorate zinc oxide nanoparticles-induced oxidative stress in Nile tilapia, Oreochromis niloticus

Industrial products contained nano-zinc oxide (ZnONP) can gain access to the aquaculture environment causing hazardous effects on the living biota. Therefore, this work was planned to examine the ameliorative effects of dietary supplementation of lycopene (LYC) and/or resveratrol (RES) against ZnONP toxicity in Nile tilapia. Five groups with 20 fish each were used; Control, received tap water only; ZnONP group, was intoxicated with ZnONP (50 mg/L); ZnONP-LYC group, was exposed to ZnONP and LYC (500 mg/ kg of the diet); ZnONP-RES group, was exposed to ZnONP and RES (50 mg/kg of the diet); ZnONP-LYC-RES group, was exposed to ZnONP and a combination of LYC and RES. The experiment was continued for 30 days. Fish blood and tissues were then assembled for determination of liver and kidney function and oxidative stress status in liver, kidney, and gills tissue. Results revealed a considerable elevation of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), cholesterol, urea, and creatinine with a noticeable lowering of total proteins and albumin serum levels in response to ZnONP intoxication. In addition, there were significant increase in malondialdehyde (MDA) and reduction in the reduced-glutathione (GSH) levels and superoxide dismutase (SOD) and catalase (CAT) activities. However, treatment with LYC and/or RES ameliorated the ZnONP-inflicted oxidative stress which possibly attributed to their beneficial antioxidant activities.

Effects of combined therapy with resveratrol, continuous and interval exercises on apoptosis, oxidative stress, and inflammatory biomarkers in the liver of old rats with non-alcoholic fatty liver disease

CONTEXT

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder.

OBJECTIVE

Effects of combined therapy with resveratrol, interval and continuous exercises on oxidative stress, inflammation, and apoptosis in the liver of rats with NAFLD.

METHODS

NAFLD rats were organised in patient, saline, resveratrol (RSV), continuous exercise, interval exercise, continuous exercise + RSV, and interval exercise + RSV groups.

RESULTS

Resveratrol supplementation alone or in combination with interval and continuous training significantly decreased malondialdehyde and TNF-α level (p < .05), while the levels of catalase; superoxide dismutase and IL-10 were significantly increased (p < .05). Although RSV alone significantly decreased the percentage of apoptotic cells (17.12%), its combination with interval (10.74%), and continuous (14.85%) exercise training demonstrated higher anti-apoptotic activity (p < .05).

CONCLUSIONS

Although resveratrol alone has an antioxidant, anti-apoptotic and anti-inflammatory properties, combined therapy with interval, and continuous training can be more effective to mitigate these abnormalities in NAFLD patients.

Effects of dietary caffeic acid supplement on antioxidant, immunological and liver gene expression responses, and resistance of Nile tilapia, Oreochromis niloticus to Aeromonas veronii

The present study investigated the effects of dietary caffeic acid on haematological, serum biochemical, non-specific immune and liver gene expression responses of Nile tilapia, Oreochromis niloticus. Five experimental groups of fish with mean weights of 89.85 ± 2.5 g were used in the study; three of them were fed with caffeic acid incorporated diets (1 g kg^-1-Caf1, 5 g kg^-1-Caf5, 10 g kg^-1-Caf10), whereas an additive free basal diet served as the control. Additionally, the fifth group was an antibiotic medicated diet (0.02 g kg^-1-AMF), prepared with the florfenicol. Dietary caffeic acid especially at 5 g kg^-1 significantly increased phagocytic index, potential killing activity, respiratory burst activity, serum myeloperoxidase activity and serum catalase activity. Furthermore, increased levels of immune expression [heat shock protein 70 (HSP70), interleukin 1, beta (IL-1β), tumor necrosis factor (TNF-α), CC-chemokine (CC1), interleukin 8 (IL-8), toll-like receptor 7 (tlr-7), interferon gamma (IFN-γ) and immunoglobulin M (IgM)] and antioxidant related genes [superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)] in the liver of fish fed with 5 g kg^-1 caffeic acid. At the end of the 20-day challenge period the survival rates were significantly higher in the Caf5 and AMF groups compared to all other treatment groups. As a result, feeding Nile tilapia with a diet containing 5 g kg^-1 caffeic acid over a period of 60 days might be adequate to improve fish immune parameters, antioxidant status, as well as survival rate against A. veronii, similar to antibiotic treatment. Thus caffeic acid can be suggested as a dietary substitute for antibiotic to prevent A. veronii in tilapia.

Gut microbiota analysis of juvenile genetically improved farmed tilapia (Oreochromis niloticus) by dietary supplementation of different resveratrol concentrations

The genetically improved farmed tilapia (GIFT, Oreochromis niloticus) is cultured widely for production of freshwater fish in China, while streptococcosis, likely related to pathogenic infections, occurs frequently in juvenile, mother, and operated GIFT. The gut microbiota plays an important role in nutrient digestibility in animals, and resveratrol (RES) has been used in feed for different freshwater fish species. Therefore, understanding changes in the tilapia gut microbiota across different concentrations of dietary RES supplementation is extremely important. The gut microbiota population in tilapia at 45 d after supplementation with different concentrations (0, 0.025, 0.05, 0.1 g/kg) of dietary RES was assessed by 16S rDNA gene sequencing. A total of 5445 operational taxonomic units were identified from all samples, and 14 phyla and 81 families were identified from all fecal samples. The bacteria of the phylum Firmicutes were significantly enriched in the 0.025 g/kg RES group when compared with the controls. Proteobacteria, Firmicutes and Cyanobacteria were the most dominant three phyla in all samples. With the increasing concentrations, the proportion of beneficial microbial taxa (Acetobacteraceae and Methylobacteriaceae) increased, whereas the proportion of harmful microbial taxa decreased, eg. Streptococcaceae except for 0.1 g/kg RES groups. RES did not affect the richness and diversity in tilapia gut microbiota. These findings provide information on the diversity and differences in GIFT gut microbiota database, and may contribute to developing strategies for management of diseases and long-term sustainability of O. niloticus culture.

Hepatic transcriptome analysis of juvenile GIFT tilapia (Oreochromis niloticus), fed diets supplemented with different concentrations of resveratrol

The GIFT (Genetically Improved Farmed Tilapia) tilapia, Oreochromis niloticus, is cultured widely for the production of freshwater fish in China. Streptococcosis, which is related to pathogenic infections, occurs frequently in juvenile and adult female GIFT individuals. Resveratrol (RES) has been used in feed to control these infections in freshwater tilapia. To address the effects of RES on tilapia, we used high-throughput RNA sequencing technology (RNA-Seq, HiSeq. 2500) to explore the global transcriptomic response and specific involvement of hepatic mRNA of juvenile O. niloticus fed with diets containing different concentrations of (0, 0.025, 0.05, and 0.1g/kg) RES. A total of > 24,513,018 clean reads were generated and then assembled into 23,244 unigenes. The unigenes were annotated by comparing them against non-redundant protein sequence (Nr), non-redundant nucleotide (Nt), Swiss-Prot, Pfam, Gene Ontology database (GO), Clusters of Orthologous Groups (COG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, and 12,578 unigenes were annotated to the GO database. A total of 1444 (0.025g/kg RES), 1526 (0.05g/kg RES), and 3135 (0.1g/kg RES) genes were detected as significant differentially expressed genes (DEGs), when compared with the controls. A total of 6 (0.025 vs 0.05g/kg RES), 19 (0.025 vs 0.1g/kg RES), and 124 (0.05 vs 0.1g/kg RES) genes were detected as significant DEGs. Six genes, including dnah7x1, sox4, fam46a, hsp90a, ddit4, and nmrk2, were associated with an immune response. These findings provide information on the innate immunity of GIFT and might contribute to the development of strategies for the effective management of diseases and long-term sustainability of O. niloticus culture.