Combined effects of dietary quercetin and resveratrol on growth performance, antioxidant capability and innate immunity of blunt snout bream (Megalobrama amblycephala)

Incorporating Lycium barbarum residue in diet boosts survival, growth, and liver health in juvenile grass carp (Ctenopharyngodon idellus)

This research elucidates the potential of Lycium barbarum residue (LBR), a by-product rich in bioactive substances, as a dietary supplement in aquaculture, especially for herbivorous fish like grass carp. In a detailed 120-day feeding trial, the impacts of varying LBR levels on juvenile grass carp were assessed, focusing on growth performance, survival rate, biochemical markers, and liver health. The study identified a 6% inclusion rate of LBR as optimal for enhancing survival and growth while mitigating hepatic lipid accumulation. Composition analysis of this diet revealed high concentrations of polysaccharides and flavonoids. Notably, the intake of LBR was found to enhance the antioxidant and immune-related enzymatic activities in the liver. Furthermore, it contributed to a reduction in hepatic fat deposition by decreasing the levels of triglycerides (TG) and total cholesterol (T-CHO) both in the liver and serum. Transcriptomic analysis of the liver highlighted LBR's substantial influence on lipid metabolism pathways, including the PPAR signaling pathway, primary bile acid biosynthesis, cholesterol metabolism, bile secretion, fat digestion and absorption, fatty acid degradation and fatty acid biosynthesis. Further, the expression level of genes pinpointed significant downregulation of fasn and dgat2, alongside upregulation of genes like pparda, cpt1b, cpt1ab and abca1b, in response to LBR supplementation. Overall, the findings present LBR as a promising enhancer of growth and survival in grass carp, with significant benefits in promoting fat metabolism and liver health, offering valuable insights for aquacultural nutrition strategies.

The combined analysis of transcriptomics and metabolomics reveals the mechanisms by which dietary quercetin regulates growth and immunity in Penaeus vannamei

As a potent antioxidant, the flavonoid compound quercetin (QUE) has been widely used in the farming of aquatic animals. However, there are fewer reports of the beneficial effects, especially in improving immunity of Penaeus vannamei by QUE. The aim of this study was to investigate the effects of dietary QUE on growth, apoptosis, antioxidant and immunity of P. vannamei. It also explored the potential mechanisms of QUE in improving the growth and immunity of P. vannamei. P. vannamei were fed diets with QUE for 60 days. The results revealed that QUE (0.5 or 1.0 g/kg) ameliorated the growth, and the expressions of genes related to apoptosis, antioxidant, and immunity. The differentially expressed genes (DEGs) and differential metabolites (DMs) obtained through transcriptomics and metabolomics, respectively, enriched in pathways related to nutritional metabolism such as lipid metabolism, amino acid metabolism, and carbohydrate metabolism. After QUE addition, especially at 0.5 g/kg, DEGs were enriched into the functions of response to stimulus and antioxidant activity, and the pathways of HIF-1 signaling pathway, C-type lectin receptor signaling pathway, Toll-like receptor signaling pathway, and FoxO signaling pathway. In conclusion, dietary QUE can ameliorate growth, apoptosis, antioxidant and immunity of P. vannamei, the appropriate addition amount was 0.5 g/kg rather than 1.0 g/kg. Regulations of QUE on nutrient metabolism and immune-related pathways, and bioactive metabolites, were important factors for improving the aforementioned abilities in P. vannamei.

Novel protective aspects of dietary polyphenols against pesticidal toxicity and its prospective application in rice-fish mode: A Review

The rice fish system represents an innovative and sustainable approach to integrated farming, combining rice cultivation with fish rearing in the same ecosystem. However, one of the major challenges in this system is the pesticidal pollution resulting from various sources, which poses risks to fish health and overall ecosystem balance. In recent years, dietary polyphenols have emerged as promising bioactive compounds with potential chemo-preventive and therapeutic properties. These polyphenols, derived from various plant sources, have shown great potential in reducing the toxicity of pesticides and improving the health of fish within the rice fish system. This review aims to explore the novel aspects of using dietary polyphenols to mitigate pesticidal toxicity and enhance fish health in the rice fish system. It provides comprehensive insights into the mechanisms of action of dietary polyphenols and their beneficial effects on fish health, including antioxidant, anti-inflammatory, and detoxification properties. Furthermore, the review discusses the potential application methods of dietary polyphenols, such as direct supplementation in fish diets or through incorporation into the rice fields. By understanding the interplay between dietary polyphenols and pesticides in the rice fish system, researchers can develop innovative and sustainable strategies to promote fish health, minimize pesticide impacts, and ensure the long-term viability of this integrated farming approach. The information presented in this review will be valuable for scientists, aqua-culturists, and policymakers aiming to implement eco-friendly and health-enhancing practices in the rice fish system.

Dietary effects of microalga Tetraselmis suecica on growth, antioxidant-immune activity, inflammation cytokines, and resistance of Nile tilapia fingerlings to Aeromonas sobria infection

The dietary effects of the green microalga Tetraselmis suecica (TS) on the growth, digestive enzymes, immune and antioxidant responses, genes expression, and disease resistance of Nile tilapia (Oreochromis niloticus) fingerlings were investigated. This microalga was mixed with the diet' ingredients at doses of 0.0 (the control), 5, 10, 15, and 20 g/kg diet and then fed to fish daily for 84 days. After the feeding trial, fish were experimentally challenged with Aeromonas sobria, infection and fish mortalities were recorded for another 10 days. Dietary TS significantly (p < 0.05) enhanced growth, digestive enzymes activities, and blood proteins, particularly at the level of 15 g/kg diet. Feeding the fish on 15 TS/kg feed exhibited highest mRNA expressions of GH and IGF-1 genes as well as SOD, CAT, and GPx genes compared to other TS groups. Moreover, highest levels of hepatic antioxidant and immune indices were found in the treatment of 15 g TS/kg feed. Significant downregulation of IL-1β and IL-8 genes expression and significant upregulation of IL-10 gene expression were observed in TS-fed fish, principally in fish groups fed on 15-20 g TS/kg feed. Conversely, hepatic malondialdehyde levels, blood glucose, and the activities of transaminases (ALT and AST) were significantly (p < 0.05) decreased in fish fed with 15-20 g TS/kg diet. Serum bactericidal activity against A. sobria was significantly higher in TS-fed fish groups, and its highest levels were found in treatments of 15-20 g/kg diet. Of interest, the survival rates of fish groups fed diets with 10-20 g TS/kg feed were higher after the challenge with A. sobria infection than the control group. Accordingly, we can conclude that supplementing fish diets with a 15 g TS/kg diet enhanced the growth, antioxidant and immune activities, and resistance of Nile tilapia fingerlings to possible A. sobria infection.

Resveratrol impacts on aquatic animals: a review

Aquaculture has intensified tremendously with the increasing demand for protein sources as the global population grows. However, this industry is plagued with major challenges such as poor growth performance, the lack of a proper environment, and immune system impairment, thus creating stress for the aquaculture species and risking disease outbreaks. Currently, prophylactics such as antibiotics, vaccines, prebiotics, probiotics, and phytobiotics are utilized to minimize the negative impacts of high-density farming. One of the promising prophylactic agents incorporated in fish feed is resveratrol, a commercial phytophenol derived via the methanol extraction method. Recent studies have revealed many beneficial effects of resveratrol in aquatic animals. Therefore, this review discusses and summarizes the roles of resveratrol in improving growth performance, flesh quality, immune system, antioxidant capacity, disease resistance, stress mitigation, and potential combination with other prophylactic agents for aquatic animals.

Role of Phytobiotics in Modulating Transcriptomic Profile in Carps: A Mini-Review

Carp is a key aquaculture species worldwide. The intensification of carp farming, aimed at meeting the high demand for protein sources for human consumption, has resulted in adverse effects such as poor water quality, increased stress, and disease outbreaks. While antibiotics have been utilized to mitigate these issues, their use poses risks to both public health and the environment. As a result, alternative and more sustainable practices have been adopted to manage the health of farmed carp, including the use of probiotics, prebiotics, phytobiotics, and vaccines to prevent disease outbreaks. Phytobiotics, being both cost-effective and abundant, have gained widespread acceptance. They offer various benefits in carp farming, such as improved growth performance, enhanced immune system, increased antioxidant capacity, stress alleviation from abiotic factors, and enhanced disease resistance. Currently, a focal point of research involves employing molecular approaches to assess the impacts of phytobiotics in aquatic animals. Gene expression, the process by which genetic information encoded is translated into function, along with transcription profiling, serves as a crucial tool for detecting changes in gene expression within cells. These changes provide valuable insights into the growth rate, immune system, and flesh quality of aquatic animals. This review delves into the positive impacts of phytobiotics on immune responses, growth, antioxidant capabilities, and flesh quality, all discerned through gene expression changes in carp species. Furthermore, this paper explores existing research gaps and outlines future prospects for the utilization of phytobiotics in aquaculture.

Tissue Lipid Profiles of Rainbow Trout, Oncorhynchus mykiss, Cultivated under Environmental Variables on a Diet Supplemented with Dihydroquercetin and Arabinogalactan

Reared rainbow trout are vulnerable to environmental stressors, in particular seasonal water warming, which affects fish welfare and growth and induces a temperature response, which involves modifications in tissue lipid profiles. Dietary supplements of plant origin, including the studied mix of a flavonoid, dihydroquercetin and a polysaccharide, arabinogalactan (25 and 50 mg per 1 kg of feed, respectively), extracted from larch wood waste, were shown to facilitate stress tolerance in fish and also to be beneficial for the safety of natural ecosystems and the sustainability of aquaculture production. This four-month feeding trial aimed to determine the effects of the supplement on liver and muscle lipid accumulation and the composition in rainbow trout reared under environmental variables. During periods of environmental optimum for trout, a consistent increase in energy lipid stores, particularly triacylglycerols (2.18 vs. 1.49-fold over a growing season), and an overall increase in lipid saturation due to lower levels of PUFAs, such as eicosapentaenoic (20:5n-3), docosahexaenoic (22:6n-3) and arachidonic (20:4n-6) acids, were observed in both control and supplement-fed fish, respectively. However, in fish stressed by an increase in ambient temperature, dietary supplementation with dihydroquercetin and arabinogalactan reduced mortality (3.65 in control vs. 2.88% in supplement-fed fish, p < 0.05) and alleviated the high-temperature-induced inhibition of lipid accumulation. It also stabilised the membrane phospholipid ratio and moderated the fatty acid composition of fish muscle and liver, resulting in higher levels of n-3 PUFAs and their precursors. Thus, the natural compounds tested are beneficial in accelerating fish tolerance to environmental stressors, reducing mortality and thermal response, and moderately improving fillet quality attributes by increasing the protein/lipid ratio and the abundance of fatty acids essential for human nutrition.

Prospects of new targeted nanotherapy combining liponiosomes with berberine to combat colorectal cancer development: An in vivo experimental model

Colorectal cancer (CRC) is one of the most identified and deadly malignancies worldwide. It presents a serious challenge due to its quick growth, which finally culminates in severe malignancy. It is critical to improve the efficacy of berberine (BR) as an anticancer agent to overcome its limited bioavailability. Implementation of a novel, effective nanocarrier system of liponiosomes for BR (LipoNio.BR) can support mechanistic actions associated with its anti-CRC role. Following CRC induction in rats using 1,2 Dimethylhydrazine (40 mg DMH/kg/week), the potency and mechanistic actions of LipoNio.BR were assessed by evaluating the lesion severity and molecular mechanisms controlling oxidative stress, apoptosis, autophagy, and inflammatory responses, and conducting histopathological and immunohistochemistry examinations of colonic tissues. The results indicated that the severity of clinical signs comprising weight gain loss, increased diarrhea and rectal bleeding, and reduced survivability were greatly restored in the LipoNio.BR-treated group. LipoNio.BR remarkably reduced CRC development compared to FBR (free berberine), as it induced apoptosis via upregulating apoptotic genes (Bax and caspase3, increased up to 7.89 and 6.25-fold, respectively) and downregulating the anti-apoptotic gene Bcl-2 by 2.25-fold. LipoNio.BR mitigated the oxidative stress associated with CRC and maintained redox homeostasis. Notably, the excessive inflammatory response associated with CRC was prominently reduced following administration of LipoNio.BR [which decreased iterleukin (IL-B, IL-6), tumor necrosis factor-alpha (TNF-α), cyclooxygenase-2 (COX2), inducible nitric oxide synthase (iNOS), proliferating cell nuclear antigen (PCNA), follistatin, and activin BA (beta-A) expression]. LipoNio.BR modulated the expression of nuclear factor kappa B (NF-κB) and mammalian target of rapamycin (mTOR), which impacted tumor vascularity (decreased Vascular endothelial growth factor (VEGF) expression by 2.36-fold). The severity of the histopathological alterations in the colonic tissues, including the development of neoplastic epithelium and the invasion of some neoplastic masses, was greatly reduced in the LipoNio.BR group compared to the FBR-(free berberine) administrated group. Following CRC induction, immunohistochemical staining revealed that the overexpression of cyclin and COX-2 in colonic tissues were suppressed in the LipoNio.BR group. Taken together, these findings suggest that LipoNio.BR has a potential role in reducing CRC progression to a greater extent compared to free BR and could be considered a promising and potent therapy against CRC.

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.

Quercetin Application for Common Carp (Cyprinus carpio): I. Effects on Growth Performance, Humoral Immunity, Antioxidant Status, Immune-Related Genes, and Resistance against Heat Stress

This study was done to evaluate the effect of different quercetin levels on growth performance, immune responses, antioxidant status, serum biochemical factors, and high-temperature stress responses in common carp (Cyprinus carpio). A total number of 216 common carp with an average weight of 27.21 ± 53 g were divided into 12 tanks (four treatments × three replications) and fed 0 mg/kg quercetin (T0), 200 mg/kg quercetin (T1), 400 mg/kg quercetin (T2), and 600 mg/kg quercetin (T3) for 60 days. There were significant differences in growth performance, and the highest final body weight (FBW), weight gain (WG), specific growth rate (SGR), and feed intake (FI) were observed in T2 and T3 (P < 0.05). Different quercetin levels significantly increased complement pathway activity (ACH50) and lysozyme activity both before and after heat stress (P < 0.05). Catalase (CAT), glutathione peroxidase (GPx), and malondialdehyde (MDA) were significantly increased in fish exposed to heat stress, but fish fed with a supplemented diet with quercetin showed the lowest levels both before and after heat stress (P < 0.05). Superoxide dismutase (SOD) levels were significantly enhanced in fish fed diets supplemented with quercetin in both phases (P < 0.05). Different quercetin levels led to a significant decrease in alanine aminotransferase (ALT) and aspartate aminotransferase (AST) before and after the challenging test (P < 0.05). Glucose and cortisol levels were significantly higher in the control group compared to the other treatments in both phases (P < 0.05). The expression of glutathione peroxidase (GPx) and lysozyme was markedly upregulated in fish fed with quercetin-supplemented diets (P < 0.05). No marked effects were observed for growth hormone (GR) and interleukin-8 (IL8) (P > 0.05). In conclusion, dietary quercetin supplementations (400-600 mg/kg quercetin) improved growth performance, immunity, and antioxidant status and increased tolerance to heat stress.

Role of Dietary Polyphenols in the Activity and Expression of Nitric Oxide Synthases: A Review

Nitric oxide (NO) plays several key roles in the functionality of an organism, and it is usually released in numerous organs and tissues. There are mainly three isoforms of the enzyme that produce NO starting from the metabolism of arginine, namely endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS), and neuronal nitric oxide synthase (nNOS). The expression and activity of these isoforms depends on the activation/deactivation of different signaling pathways at an intracellular level following different physiological and pathological stimuli. Compounds of natural origin such as polyphenols, which are obtainable through diet, have been widely studied in recent years in in vivo and in vitro investigations for their ability to induce or inhibit NO release, depending on the tissue. In this review, we aim to disclose the scientific evidence relating to the activity of the main dietary polyphenols in the modulation of the intracellular pathways involved in the expression and/or functionality of the NOS isoforms.

Resveratrol Modulates the Redox Response and Bile Acid Metabolism to Maintain the Cholesterol Homeostasis in Fish Megalobrama amblycephala Offered a High-Carbohydrate Diet

This study aimed to characterize the effects of resveratrol on the redox balance, cholesterol homeostasis and bile acid metabolism of Megalobrama amblycephala offered a high-carbohydrate diet. Fish (35.0 ± 0.15 g) were fed four diets including one control diet (32% nitrogen-free extract), one high-carbohydrate diet (45% nitrogen-free extract, HC), and the HC diet supplemented with different levels (0.04%, HCR1; 0.08%, HCR2) of resveratrol for 12 weeks. The HC diet-induced redox imbalance is characterized by increased MDA content and decreased T-SOD and CAT activities in the liver. Resveratrol attenuated this by up-regulating the transcription of Cu/Zn-sod, and increasing the activities of T-SOD, CAT, and GPX. The HC diet enhanced the cholesterol synthesis, but decreased the bile acid synthesis via up-regulating both hmgcr and acat2, and down-regulating cyp7a1, thus resulting in excessive cholesterol accumulation. Resveratrol supplement decreased cholesterol synthesis, and increased cholesterol uptake in the liver by down-regulating both hmgcr and acat2, and up-regulating ldlr. It also increased bile acid synthesis and biliary excretion by up-regulating cyp7a1, and down-regulating mrp2, oatp1, and oatp4 in the hindgut, thereby decreasing cholesterol accumulation. In conclusion, resveratrol improves the cholesterol homeostasis of Megalobrama amblycephala fed a high-carbohydrate diet by modulating the redox response and bile acid metabolism.

The protective effects of quercetin on the physiological responses in malathion-exposed common carp, Cyprinus carpio

This study aimed to evaluate the protective effects of quercetin on the biochemical parameters, immunity, and growth performance in malathion-exposed common carp, Cyprinus carpio. The methods six experimental groups, including the control group, fish exposed to concentrations of 1.04 and 2.08 mg/l malathion, fish supplemented with quercetin (200 mg/kg diet), and fish treated with quercetin + malathion for 21 days, were considered for the experiment. After the feeding period, in results the activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione S-transferase (GST) were significantly decreased in the hepatocyte, while malondialdehyde (MDA) content increased in response to malathion. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities and glucose, cortisol, and urea levels significantly increased after exposure to malathion. Exposure of fish to malathion-induced decreases in protease, lysozyme, and alternative complement (ACH50) activities and total immunoglobulin (total Ig) in the mucosa. Changes in other parameters were different depending on malathion concentrations. The supplementation of fish with quercetin had no ameliorating effect on the malathion-related alternations of mucosal lysozyme and protease activities. However, quercetin ameliorated the depressing effects of malathion on biochemical and immunological parameters. Changes in the growth performance and hematological parameters indicated the toxic effect of malathion. In conclusion, quercetin could efficiently reduce the toxic effects of malathion on the biochemical, immune, and hematological parameters of the common carp.

Ameliorative Effect of Quercetin against Abamectin-Induced Hemato-Biochemical Alterations and Hepatorenal Oxidative Damage in Nile Tilapia, Oreochromis niloticus

Abamectin (ABM) is a common agricultural pesticide and veterinary anthelmintic drug. It can discharge from the sites of application to aquatic systems via surface run-off or spray drift, causing harmful effects to aquatic organisms. The present study investigated the protective effect of dietary quercetin supplementation on hemato-biochemical parameters and hepato-renal oxidative stress biomarkers in Nile tilapia (Oreochromis niloticus) exposed to a sublethal dose of ABM. Fish were allocated into six equal groups. The first group was kept as a control group. The second and third groups (Q₄₀₀, and Q₈₀₀) were fed diets supplemented with two quercetin levels (400 and 800 mg/kg diet), respectively. The fourth group (ABM) was intoxicated with 20.73 µg/L of ABM. The fifth and sixth groups (ABM + Q₄₀₀, and ABM + Q₈₀₀) were fed diet supplemented with two quercetin levels (400 and 800 mg/kg diet) and simultaneously intoxicated with ABM for 60 days. The results showed that ABM significantly decreased RBCs, hemoglobin content, hematocrit, total protein, albumin levels, and acetylcholinesterase activity activities compared to the control. Meanwhile, ABM significantly increased white blood cells, glucose, total lipids, cholesterol, and alanine and aspartate aminotransferase activities. Liver and kidney levels of lipid peroxidation was significantly increased, while hepato-renal antioxidant biomarkers (reduced glutathione, super oxide dismutase, catalase, and total antioxidant capacity) were significantly decreased upon ABM exposure. On the other hand, quercetin dietary supplementation improved the hemato-biochemical alterations and alleviated oxidative stress induced by ABM exposure. Fish supplemented with quercetin at a level of 800 mg/kg diet showed better alleviating effects against ABM compared to 400 mg/kg diet. Based on these study findings, we suggest that quercetin dietary supplementation (800 mg/kg) offered direct protection against ABM-induced physiological disturbance and oxidative stress 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.

Modulatory role of dietary curcumin and resveratrol on growth performance, serum immunity responses, mucus enzymes activity, antioxidant capacity and serum and mucus biochemicals in the common carp, Cyprinus carpio exposed to abamectin

In this study, we investigate the potentials of dietary curcumin and resveratrol on blood biochemistry, immune responses and resistance to the toxicity of the pesticide, abamectin. 540 common carps (30.78 ± 0.17 g) were randomly distributed into 18 tanks (30 fish per tank), as six experimental groups (T1: non-supplemented and on-exposed fish, T2: 300 mg/kg curcumin, T3: 300 mg/kg resveratrol, T4: 12.5% LC₅₀ of abamectin, T5: 300 mg/kg curcumin +12.5% LC₅₀ of abamectin, T6: 300 mg/kg resveratrol + 12.5% LC₅₀ of abamectin). Use of 300 mg/kg resveratrol in the diet of non-abamectin exposed fish improved the growth performance (P < 0.05), while such effects were not observed for curcumin (P > 0.05). There were no differences in the final weight (FW), feed conversion ratio (FCR) and weight gain (WG) between control and fish of the treatments, resveratrol + abamectin and curcumin + abamectin (P < 0.05). The immune components in blood [lysozyme, complement activity, Total immunoglobulin (total Ig), protease, myeloperoxidase (MPO), nitro-blue-tetrazolium (NBT), peroxidase, albumin] and mucus [acid phosphatase (ACP), alkaline phosphatase (ALP), esterase, antiprotease)] and antioxidant enzymes [(superoxide dismutase (SOD), glutathione peroxidase (GPx)] exhibited various change patterns compared to the control group, however, these components were almost all higher in fish supplemented with curcumin and resveratrol in an abamectin-free medium than in control and other groups (P < 0.05). In most cases, the levels of immune and antioxidant components in the control did not show significant difference with the treatments, resveratrol + abamectin and curcumin + abamectin (P > 0.05). Abamectin induced oxidative stress in fish, as the malondialdehyde (MDA) levels significantly increased in the exposed fish compared to non-exposed groups (P < 0.05). It appears that neither curcumin nor resveratrol were as effective in preventing oxidative stress, because MDA levels were higher in exposed fish (abamectin, curcumin + abamectin, resveratrol + abamectin) than in control and non-exposed individuals (P < 0.05). Curcumin and resveratrol also showed protective effects on liver, since the levels of liver metabolic enzymes [aspartate transaminase (AST), ALP, lactate dehydrogenase (LDH)] were lower in the supplemented fish in a abamectin-free medium than in control (P < 0.05). Curcumin and resveratrol also mitigated the stress responses in the exposed fish, as cortisol and glucose levels showed significant decreases in the supplemented fish (P < 0.05). In conclusion, this study revealed that abamectin can depress the growth and immunity in the common carp. Although, both resveratrol and curcumin were mitigated the toxic effects of abamectin, it seems that resveratrol be more effective than curcumin.

In vitro effects of Eucommia ulmoides and its active components on the growth, lipid metabolism and collagen metabolism of grass carp (Ctenopharyngodon idellus) hepatocyte and intramuscular fibroblast

Two experiments were conducted to investigate the in vitro effects of Eucommia ulmoides (E. ulmoides) and its active components on the growth, lipid metabolism and collagen metabolism of grass carp's (Ctenopharyngodon idellus) hepatocytes and intramuscular fibroblasts. In experiments 1 and 2 (Expt. 1, 2), hepatocytes and intramuscular fibroblasts were treated with 2.5, 5, 10, 20, 40 and 80 μg ml^-1 of Eucommia bark extract (EBE), Eucommia leaf extract (ELE), pinoresinol diglucoside (PDG), chlorogenic acid (CGA), quercetin (QC) and aucubin (AU) for 24 h, respectively, then the cell growth, lipid and collagen metabolism-related gene expressions were evaluated. The results showed that the cell proliferation rate of hepatocytes and intramuscular fibroblasts was significantly improved by the supplementation of EBE, ELE, CGA, QC and AU. Moreover, triglyceride concentration of hepatocytes was significantly decreased by the EBE, ELE, CGA and QC supplementations compared to the control. Meanwhile, EBE, ELE, CGA, QC and AU supplementations significantly upregulated the relative gene expressions of insulin-like growth factor-1 (igf1), protein kinase B (akt), target of rapamycin (tor) and eukaryotic initiation factor 4E binding protein 1 (4ebp1) in hepatocytes, and ribosomal protein S6 kinase 1 (s6k1) transcription was significantly activated by ELE, CGA and QC supplementations. Nonetheless, phosphatidylinositol 3-kinase (pi3k) was unaffected by any of the supplements. In addition, the mRNA expressions of genes associated with lipid metabolism (peroxisome proliferator activated receptor α pparα, carnitine palmitoyltransferase 1 cpt1, adipose triglyceride lipase atgl, hormone-sensitive lipase hsl, peroxisome proliferator activated receptor γ pparγ) were significantly upregulated by EBE, ELE, CGA and QC. In intramuscular fibroblasts, the EBE, ELE, CGA, QC and AU supplementations significantly increased in vitro hydroxyproline concentrations, promoted the relative expressions of transforming growth factor-β1 (tgfβ1), connective tissue growth factor (ctgf), collagen type I alpha 1/2 chain (col1a1, col1a2), lysine oxidase (lox) and tissue inhibitor of matrix metalloproteinase-2 (timp2), and decreased matrix metalloproteinase-2 (mmp2) gene expression. Also, the gene expressions of drosophila mothers against decapentaplegic protein 2/4 (smad2, smad4) and proline hydroxylase (phd) were significantly upregulated by ELE, CGA, QC and AU supplementations. Based on the present in vitro results of grass carp, EBE, ELE, CGA, QC and AU improved the growth and lipid metabolism (except AU) in hepatocytes, and promoted the collagen deposition in intramuscular fibroblast, which is partly attributed to the signalling pathways of AKT/TOR, PPARα and TGF-β/Smads/CTGF.

Therapeutic Potential of Quercetin Loaded Nanoparticles: Novel Insights in Alleviating Colitis in an Experimental DSS Induced Colitis Model

Oxidative stress is considered the main etiologic factor involved in inflammatory bowel disease (IBD). Integration of nanocarriers for natural therapeutic agents with antioxidant and anti-inflammatory potential is a novel promising candidate for curing IBD. Herein, the colonic antioxidant and anti-inflammatory effects of different concentrations of quercetin nanoparticles (QT-NPs) were evaluated using a dextran sulfate sodium (DSS)-induced colitis model. Following colitis induction, the efficacy and mechanistic actions of QT-NPs were evaluated by assessing lesion severity, molecular aids controlling oxidative stress and inflammatory response, and histopathological and immunohistochemistry examination of colonic tissues. Administration of QT-NPs, especially at higher concentrations, significantly reduced the disease activity index and values of fecal calprotectin marker compared to the colitic group. Colonic oxidant/antioxidant status (ROS, H₂O₂, MDA, SOD, CAT, GPX and TAC) was restored after treatment with higher concentrations of QT-NPs. Moreover, QT-NPs at levels of 20 mg/kg and, to a lesser extent, 15 mg/kg reduced Nrf2 and HO-1 gene expression, which was in line with decreasing the expression of iNOS and COX2 in colonic tissues. Higher concentrations of QT-NPs greatly downregulated pro-inflammatory cytokines; upregulated genes encoding occludin, MUC-2 and JAM; and restored the healthy architectures of colonic tissues. Taken together, these data suggest that QT-NPs could be a promising alternative to current IBD treatments.

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.

Interactive effects of dietary quercetin nanoparticles on growth, flesh antioxidant capacity and transcription of cytokines and Aeromonas hydrophila quorum sensing orchestrating genes in Nile tilapia (Oreochromis niloticus)

Recently, the concept of incorporating natural products into nanocarriers has been intended to promote fish growth and health via modulating their stability and bioavailability. In this concern, the potential role of reformulated quercetin into nanocarriers was examined, for the first time, on Nile tilapia's performance and immunity, flesh quality and antioxidant indices and disease resistance. Five hundred fish assigned into five experimental groups with formulated diets containing quercetin nanoparticles (QT-NPs) at levels of 0, 100, 200, 300 and 400 mg/kg were challenged with Aeromonas hydrophila (A. hydrophila) after 12 weeks feeding trial. Fish final body weight gain and feed efficiency were significantly maximized in groups enriched with 300 and 400 mg/kg of QT-NPs. Significant reduction in total saturated fatty acids and an elevation in polyunsaturated fatty acids' contents were noticed in fish fed higher QT-NPs doses. The levels of Hydrogen peroxide, reactive oxygen species and malondialdehyde, the markers of meat antioxidant capacity, were reduced by higher inclusion levels of QT-NPs. Accordingly, serum activities and transcriptional levels of GSH-Px, CAT and SOD genes were increased with elevated QT-NPs levels. Immune responses mediated by upregulation of IL-10 and TGF-β and downregulation of IL-1β, IL-8 and TNF-α mRNA levels were found to be positively affected by QT-NPs. Dietary QT-NPs downregulated the expression of ahyI and ahyR quorum sensing genes conferring protection against A. hydrophila challenge. This study concluded that supplementation of quercetin in encapsulated nanoparticles could improve its efficacy making it as a compelling approach to improve fish performance and as a promising drug candidate against A. hydrophila virulence.

Molecular Cloning and Characterization of Sirtuin 1 and Its Potential Regulation of Lipid Metabolism and Antioxidant Response in Largemouth Bass (Micropterus salmoides)

Sirtuin 1 (SIRT1) of largemouth bass (Micropterus salmoides) was cloned and characterized in the present study and the influence of SIRT1 activation induced by resveratrol inclusion on the expression of genes related to lipid metabolism and antioxidation was also investigated. The SIRT1 of largemouth bass, with full-length cDNA sequence of 3395bp encoding 695 amino acids, was mainly expressed in gonad, heart and liver. The analysis of multiple sequence alignment revealed that, in accordance with other species, SIRT1 of largemouth bass contained highly conserved substrate-binding site and NAD⁺ binding site. The result of subcellular localization displayed that SIRT1 of largemouth bass was mainly localized in the nucleus. The inclusion of 1.0 and 2.5‰ dietary RSV, a natural SIRT1 activator, significantly elevated the SIRT1 protein expression. Meanwhile, the phosphorylation of AKT1 and FoxO1 followed similar pattern with that of SIRT1, indicating the activation of insulin pathway, which may result in the inhibition of lipogenesis and activation of lipolysis, and reduced hepatic triglycerides content. Additionally, the activation of SIRT1 induced by dietary RSV elevated the antioxidant capacity at both transcriptional level and enzymatic level, which was probably mediated by the transcription factor Nrf2. In above, SIRT1 was suggested to be involved in improving antioxidant capacity and alleviating hepatic lipid deposition in largemouth bass.

Resveratrol inclusion alleviated high-dietary-carbohydrate-induced glycogen deposition and immune response of largemouth bass, Micropterus salmoides

Excessive hepatic glycogen accumulation commonly impairs hepatocytes function and further produces negative effects on growth and health status of carnivorous fish. A 9-week feeding trial was conducted to explore the potential regulation of resveratrol (RSV) on high-carbohydrate-induced glycogen deposition and immune response of largemouth bass. Results showed that high dietary carbohydrate (10 % inclusion of starch) led to hepatic glycogen accumulation and post-prandial hyperglycemia compared with the diet with 5 % starch, which was both alleviated with the inclusion of RSV. The use of RSV promoted the expression of sirtuin 1, which was down-regulated by high dietary carbohydrate. Meanwhile, RSV inclusion promoted the expression of genes involved in insulin pathway and glycolysis and inhibited the expression of gluconeogenesis-related genes. Additionally, high dietary carbohydrate significantly reduced lysozyme content but increased complement C4 content, which were both reversed with RSV supplementation. Meanwhile, RSV inclusion inhibited the expression of pro-inflammatory cytokines but promoted anti-inflammatory cytokines expression, compared with the high carbohydrate treatment. In conclusion, RSV inclusion was beneficial in alleviating high-dietary-carbohydrate-induced glycogen accumulation and immune response in largemouth bass.

Quercetin attenuates endocrine and metabolic responses to oxytetracycline in silver catfish (Rhamdia quelen)

This study aimed to verify whether dietary quercetin protects against the detrimental effects induced by oxytetracycline (OTC) administration in silver catfish (Rhamdia quelen). Fish were divided into different experimental groups that received OTC and/or quercetin, either during 14 or 21 days. To determine the endocrine system stress response, we have measured the brain mRNA expression levels of corticotropin-releasing hormone (crh), proopiomelanocortins (pomca and pomcb) and some of the pituitary hormones (growth hormone [gh], somatolactin [sl], and prolactin [prl]). We have also quantified the levels of cortisol as well as some metabolites (glucose, glycogen, lactate, and triglycerides) in the plasma. Moreover, the enzymatic activity of hexokinase, phosphorylase (active GPase), fructose-biphosphatase (FBP), glycerol-3-phosphate dehydrogenase, glucose-6-phosphate dehydrogenase, and glutamate dehydrogenase (GDH) and gill Na⁺/K⁺-ATPase were measured. The results demonstrated that OTC activates the silver catfish stress response by increasing the plasma cortisol and decreasing the glucose levels at 14 and 21 days. Additionally, OTC also altered the fish hepatic metabolic status as demonstrated by an increase in triglycerides levels and the enzymatic activity of both FBP and GDH after 14 days. OTC also stimulated Na⁺/K⁺-ATPase activity in the gill after 14 days and altered the hypophyseal expression of gh (at 14 and 21 days) and prl (at 14 days). The co-treatment with 1.5 g of quercetin could prevent most of the alterations caused by OTC, strongly suggesting quercetin as a beneficial compound when added to the fish diet.