Grape seed proanthocyanidin extract ameliorates hepatic lipid accumulation and inflammation in grass carp (Ctenopharyngodon idella)

Proanthocyanidins mitigate the toxic effects in loach (Misgurnus anguillicaudatus) exposed to phenanthrene via Nrf2/NF-κB signaling pathway

Phenanthrene (PHE) is a typical polycyclic aromatic hydrocarbon compound that is ubiquitous in the environment and accumulates in aquatic products, thereby posing a risk to food safety. Oligomeric proanthocyanidins (OPC) is widely distributed powerful antioxidants with potent antioxidant and anti-inflammatory properties. This study aimed to evaluate the alleviating effects of dietary OPC on oxidative stress, inflammatory suppression, and tissue damage caused by PHE exposure in loach (Misgurnus anguillicaudatus). In the study, loach was continuously exposed to 2.36 mg/L PHE for 28 days, after which they were fed a basal diet supplemented with 0, 200, 400, or 800 mg/kg OPC. The results displayed that PHE exposure resulted in significantly increased levels of liver health parameters (AST, ALT, COR, LDH, and ADA) compared to the control group (P < 0.05). The PHE-exposed fish showed the lowest levels of antioxidant enzymes (CAT, SOD, GSH, GST, GSH-Px, and GR) and the greatest levels of oxidative stress parameters (ROS and MDA). PHE exposure resulted in down-regulation of nrf2, ho-1, gsh-px, gst, and nqo-1, and up-regulation of keap-1 gene expressions in loach (P < 0.05). Moreover, PHE-induced decreased the levels of immunity indicators (CRP, MPO, C3, C4, IgM, and LYS). An up-regulation of pro-inflammatory genes (nf-κb, il-1β, il-8, il-6, il-12, and tnf-α) and a down-regulation of anti-inflammatory gene il-10 were the consequences of the PHE exposure. In addition, tissues showed histopathological alterations including vacuolization (liver), displaced nuclei (liver), atrophy (gills), glomerular congestion (kidney), and inflammatory cell infiltration (spleen) caused by PHE. Notably, dietary supplementation of OPC augmented immuno-antioxidant parameters, including their key genes, reduced oxidative stress and immunosuppression, and ameliorated tissue damage compared to fish exposed to PHE. In summary, supplementation with 400 mg/kg OPC in the diets could effectively alleviate the oxidative damage and inflammatory response induced by PHE exposure in loach through the Nrf2/NF-κB signaling pathway and enhance the defense ability against toxic substances of loach.

Exploring beneficial effects of phytobiotics in marine shrimp farming: A review

Marine shrimp farming, mainly Penaeus monodon and Litopenaeus vannamei, is an important component of the aquaculture industry. Marine shrimp farming helps produce a protein source for humans, provides job opportunities, and generates lucrative profits for investors. Intensification farming practices can lead to poor water quality, stress, and malnutrition among the farmed marine shrimp, resulting in disease outbreaks and poor production, impeding the development of marine shrimp farming. Antibiotics are the common short-term solution to treat diseases in marine shrimp farming. Moreover, the negative impacts of using antibiotics on public health and the environment erode consumer confidence in aquaculture products. Recently, research on using phytobiotics as a prophylactic agent in aquaculture has become a hot topic. Various phytobiotics have been explored to reveal their beneficial effects on aquaculture species. In this review paper, the sources and modes of action of phytobiotics are presented. The roles of phytobiotics in improving growth performance, increasing antioxidant capacity, enhancing the immune system, stimulating disease resistance, and mitigating stress due to abiotic factors in marine shrimp culture are recapitulated and discussed.

Purification of Phenolic Compounds from Camellia polyodonta Flower: Composition Analysis, Antioxidant Property, and Hypolipidemic Activity In Vitro and In Vivo

Camellia polyodonta flowers are rich sources of phenolics and less attention has been paid to their potential biological activity. This study aims to explore the crude extracts and resulting purified fractions (CPFP-I, II, III, and IV) through compositional analysis and antioxidant and hypolipidemic activities in vitro and in vivo. Among four fractions, CPFP-II contained the highest total phenolic content and flavonoid content, while CPFP-III exhibited the greatest total proanthocyanidin content. Among the 14 phenolic compounds, CPFP-II displayed the highest content of procyanidin B2, B4, and C1, whereas CPFP-III contained the highest amount of 1,2,3,6-tetragalloylglucose. The DPPH, ABTS, and FRAP assessments demonstrated a consistent trend: CPFP-II > CPFP-III > CPFP-I > CPFP-IV. In vivo experiments showed that that all four fractions significantly reduced lipid levels in hyperlipidemic C. elegans (p < 0.05), with CPFP-II exhibiting the most potent effect. Furthermore, CPFP-II effectively bound to bile acids and inhibited the enzymatic activity of pancreatic lipase in vitro. Consequently, CPFP-II should be prioritized as a promising fraction for further exploration and should provide substantial support for the feasibility of the C. polyodonta flower as a natural alternative.

Effects of grape seed procyanidins on the lipid metabolism of growing-finishing pigs based on transcriptomics and metabolomics analyses

This study investigated how lipid metabolism in the longissimus thoracis is influenced by the diet supplemented with grape seed procyanidins (GSPs) in growing-finishing pigs. Forty-eight crossbred pigs were randomly assigned to four groups, each receiving a basal diet, or basal diet added with 150, 200, and 250 mg/kg GSPs. Transcriptomics and metabolomics were employed to explore differential gene and metabolite regulation. The expression of key lipid metabolism-related genes was tested via qRT-PCR, and the lipid and fatty acid composition of the longissimus thoracis were determined. Dietary GSPs at different concentrations upregulated lipoprotein lipase (LPL), which is involved in lipolysis, and significantly increased the mRNA expression levels of carnitine palmitoyltransferase-1B (CPT1B) and cluster of differentiation 36 (CD36), implicated in transmembrane transport of fatty acids. Dietary supplementation of GSPs at 200 or 250 mg/kg markedly reduced total cholesterol and triglyceride content in longissimus thoracis. Dietary GSPs significantly decreased the contents of low-density lipoprotein cholesterol and saturated fatty acids, while increasing unsaturated fatty acids. In conclusion, GSPs may regulate lipid metabolism, reducing cholesterol level, and improving fatty acid composition in the longissimus thoracis of growing-finishing pigs. Our findings provide evidence for the beneficial effects of GSPs as pig feed additives for improving lipid composition.

Use of grape by-products in aquaculture: New frontiers for a circular economy application

Grape by-products have already been used in cosmetics, food industries, but also animal feed industry, especially monogastrics and in aquaculture. Grape by-products have been studied for a long time and their principal activities are antimicrobial and antioxidant. Concerning aquaculture, the great demand and necessity to replace animal sources with vegetable ones, has placed grape by-products as possible new phytonutrients with beneficial properties. The purpose of this review is to describe the use of grape by-products in aquaculture, during the last decade, concerning their effects on: 1) gut health and welfare status; 2) growth performances; 3) quality of fillets and flesh during the rearing cycle and shelf-life products. Although other studies highlighted that the high supplementation of grape by-products could negatively affect fish health and growth, due to antinutritional factors (tannins), grape by-products are proven to be valuable phytonutrients that can be incorporated into fish feed to enhance growth and health during rearing conditions. Even in fish products, their utilization has proven to elongate the properties and shelf-life of fillets and minces. Further studies to evaluate the possible integrations or replacements with grape by-products in fish feed in order to evaluate their effectiveness in aquaculture from a sustainable circular economy perspective will be desirable to enhance the use of these products.

Molecular characterization of the grass carp bscl2 gene and its expression response to lipid accumulation, nutritional status, insulin and glucagon

Bscl2 plays a role in lipid metabolism of mammals, however its role in teleost fish remains unclear. Using the grass carp (Ctenopharyngodon idella) as a model, the bscl2 gene was isolated from the brain and characterized. Thereafter, the tissue distribution of the gene was examined, before expression was analyzed as a function of fasting, refeeding, oral glucose administration and overfeeding. In addition, bscl2 mRNA levels were evaluated in grass carp primary hepatocytes treated with glucagon, insulin, oleic acid, and glucose. Results showed that the cloned bscl2 gene was 1341 bp, encoding 446 amino acids, and was highly expressed in the brain, heart, and gonad. Following oral glucose administration, bscl2 expression increased. Expression of bscl2 decreased in fasted fish but increased following refeeding. Overfeeding, which resulted in elevated lipid accumulation, also stimulated bscl2 expression. In primary hepatocytes, bscl2 levels were increased by glucose, oleic acid, and insulin treatments, and reduced by glucagon treatment. These data suggest that bscl2 may play an important role in nutrient metabolism in teleost fish.

Multi-Omics Analysis to Understand the Effects of Dietary Proanthocyanidins on Antioxidant Capacity, Muscle Nutrients, Lipid Metabolism, and Intestinal Microbiota in Cyprinus carpio

Proanthocyanidins (Pros), a natural polyphenolic compound found in grape seed and other plants, have received significant attention as additives in animal feed. However, the specific mechanism by which Pros affect fish health remains unclear. Therefore, the aim of this study was to investigate the potential effects of dietary Pro on common carp by evaluating biochemical parameters and multi-omics analysis. The results showed that Pro supplementation improved antioxidant capacity and the contents of polyunsaturated fatty acids (n-3 and n-6) and several bioactive compounds. Transcriptomic analysis demonstrated that dietary Pro caused an upregulation of the sphingolipid catabolic process and the lysosome pathway, while simultaneously downregulating intestinal cholesterol absorption and the PPAR signaling pathway in the intestines. Compared to the normal control (NC) group, the Pro group exhibited higher diversity in intestinal microbiota and an increased relative abundance of Cetobacterium and Pirellula. Furthermore, the Pro group had a lower Firmicutes/Bacteroidetes ratio and a decreased relative abundance of potentially pathogenic bacteria. Collectively, dietary Pro improved antioxidant ability, muscle nutrients, and the diversity and composition of intestinal microbiota. The regulation of lipid metabolism and improvement in muscle nutrients were linked with changes in the intestinal microbiota.

Selenium reduces hepatopancreas lipid accumulation of grass carp (Ctenopharyngodon idella) fed high-fat diet via lipophagy activation

It has been reported that selenium (Se) can reduce hepatopancreas lipid accumulation induced by high-fat diet. However, its mechanism is still unknown. This study aims to investigate the specific mechanisms by which Se alleviates high-fat diet-induced lipid accumulation. Grass carp were fed control diet (4.8% lipid, Con), high-fat diet (8.8% lipid, HFD) or HFD supplemented with 0.3 mg/kg nano-Se (HSe0.3) for 10 weeks. Growth performance, Se deposition, lipid accumulation, hepatic ultrastructure, and gene and protein expression levels associated with autophagy were examined. Furthermore, oleic acid (OA) was used to incubate the grass carp hepatocytes (L8824) for 24 h, and then the L8824 were incubated with sodium selenite in presence or absence of an autophagy inhibitor for 24 h. L8824 was analyzed for triglyceride concentration, immunofluorescence, and gene and protein expression levels associated with autophagy. We found that dietary nano-Se improved the growth of fish fed HFD and also decreased hepatosomatic index and intraperitoneal fat ratio of fish fed HFD (P < 0.05). HFD significantly increased hepatopancreas lipid accumulation and decreased autophagic activity (P < 0.05). Treatment of grass carp fed HFD with nano-Se decreased lipid accumulation and restored hepatic autophagy (P < 0.05). In vitro, Se (100 μM sodium selenite) obviously activated autophagy in L8824 incubated with OA, and consequently reduced the lipid accumulation induced by OA (P < 0.05). Furthermore, using pharmacological inhibition (chloroquine) of the autophagy greatly diminished the beneficial effects of Se on alleviating OA-induced lipid accumulation and increased the co-localization of lipid droplets with autophagosome (P < 0.05), which indicated that Se increased autophagic flux. In conclusion, these results suggest that Se alleviates HFD-induced hepatopancreas lipid accumulation by activating lipophagy.

Micro-Executor of Natural Products in Metabolic Diseases

Obesity, diabetes, and cardiovascular diseases are the major chronic metabolic diseases that threaten human health. In order to combat these epidemics, there remains a desperate need for effective, safe, and easily available therapeutic strategies. Recently, the development of natural product research has provided new methods and options for these diseases. Numerous studies have demonstrated that microRNAs (miRNAs) are key regulators of metabolic diseases, and natural products can improve lipid and glucose metabolism disorders and cardiovascular diseases by regulating the expression of miRNAs. In this review, we present the recent advances involving the associations between miRNAs and natural products and the current evidence showing the positive effects of miRNAs for natural product treatment in metabolic diseases. We also encourage further research to address the relationship between miRNAs and natural products under physiological and pathological conditions, thus leading to stronger support for drug development from natural products in the future.

Tackling the Future Pandemics: Broad-Spectrum Antiviral Agents (BSAAs) Based on A-Type Proanthocyanidins

A-type proanthocyanidins (PAC-As) are plant-derived natural polyphenols that occur as oligomers or polymers of flavan-3-ol monomers, such as (+)-catechin and (-)-epicatechin, connected through an unusual double A linkage. PAC-As are present in leaves, seeds, flowers, bark, and fruits of many plants, and are thought to exert protective natural roles against microbial pathogens, insects, and herbivores. Consequently, when tested in isolation, PAC-As have shown several biological effects, through antioxidant, antibacterial, immunomodulatory, and antiviral activities. PAC-As have been observed in fact to inhibit replication of many different human viruses, and both enveloped and non-enveloped DNA and RNA viruses proved sensible to their inhibitory effect. Mechanistic studies revealed that PAC-As cause reduction of infectivity of viral particles they come in contact with, as a result of their propensity to interact with virion surface capsid proteins or envelope glycoproteins essential for viral attachment and entry. As viral infections and new virus outbreaks are a major public health concern, development of effective Broad-Spectrum Antiviral Agents (BSAAs) that can be rapidly deployable even against future emerging viruses is an urgent priority. This review summarizes the antiviral activities and mechanism of action of PAC-As, and their potential to be deployed as BSAAs against present and future viral infections.

Dietary effect of grape seed proanthocyanidin extract on growth performance, serum biochemical parameters, skin mucosal immune response, and antioxidant capacity in goldfish (Carassius auratus)

A trial was conducted to evaluate the effect of dietary grape seed proanthocyanidin extract (GSPE) on gold fish, Carassius auratus. In this regard, GSPE was added to a basal diet at four levels including 0, 200, 400, and 600 mg/kg to produce four experimental diets including control, GSPE200, GSPE400, and GSPE600. Three hundred and sixty goldfish (3.75 ± 0.1 g) were stocked in twelve 100 L rectangular tanks (30 fish per tank) and fed with the experimental diets three times a day for nine weeks. During the experimental trial, water temperature was 26.7–28.5ºC. The weight gain and specific growth rate in the fish fed with GSPE supplemented diets were higher than the control, meanwhile feed conversion ratio value in these groups decreased compared to the control. Fish fed GSPE-supplemented diets had lower fillet lipid (10-19%), but higher protein levels (7–15%) compared to the control. The levels of serum triglyceride, alanine aminotransferase and aspartate aminotransferase in the fish fed GSPE-supplemented diets were decreased compared to the control group. The highest and lowest levels of serum glucose, and ALP were in the fish fed with control and GSPE600 diets, respectively. The skin mucusal lysozyme activity (24–38%) and protein level (70–96%) were higher in fish fed GSPE-supplemented diets than the control. The highest, and lowest liver antioxidant enzymes including superoxide dismutase, catalase, and gluthatione peroxidase were observed in in GSPE 600, and control groups, respectively. The findings of the present study indicated that supplementing 400 mg/kg GSPE in diet can improve growth and health condition in goldfish.

Effects of Dietary Supplementation of Peanut Skin Proanthocyanidins on Growth Performance and Lipid Metabolism of the Juvenile American Eel (Anguilla rostrata)

As a functional feed additive, grape seed proanthocyanidin extract has received a lot of attention due to its biological activity in the health of aquatic animals, but its high cost limits the application of this feed additive in the diet of many fish species. It is thus urgent to develop a new resource of proanthocyanidin extract. We aimed to investigate the effects of dietary supplementation with peanut skin proanthocyanidins (PSPc) on growth parameters and lipid metabolism of juvenile American eel (Anguilla rostrata). Four hundred and fifty juvenile eels were randomly divided into five groups fed diets with five PSPc supplementation levels. The trial lasted for 8 weeks. Dietary PSPc supplementation significantly improved weight gain and feed utilization, and the best growth performance was found in the group fed with 900 mg/kg PSPc. PSPc supplementation significantly affected the crude protein level of whole fish and serum lipid parameters, and the best lipid-lowering effect was found in the fish fed with 900 mg/kg PSPc. Dietary PSPc supplementation increased lipolytic enzyme activities and decrease lipid synthase levels in the liver. The lipid metabolites affected by 900 mg/kg PSPc in the liver were mainly upregulated phosphatidylethanolamine in autophagy, downregulated ceramides in sphingolipid metabolism, upregulated phosphatidylcholine and phosphatidylethanolamine, downregulated 2-lysophosphatidylcholine in glycerophospholipid metabolism, and upregulated phosphatidylcholine in linoleic acid metabolism. In conclusion, an appropriate level of PSPc might effectively improve growth performance and regulate the lipid metabolism of the juvenile American eel, and 900 mg/kg PSPc is recommended in the diet of this fish species.

Solid Lipid Nanoparticles Administering Antioxidant Grape Seed-Derived Polyphenol Compounds: A Potential Application in Aquaculture

The supply of nutrients, such as antioxidant agents, to fish cells still represents a challenge in aquaculture. In this context, we investigated solid lipid nanoparticles (SLN) composed of a combination of Gelucire^® 50/13 and Precirol^® ATO5 to administer a grape seed extract (GSE) mixture containing several antioxidant compounds. The combination of the two lipids for the SLN formation resulted in colloids exhibiting mean particle sizes in the range 139–283 nm and zeta potential values in the range +25.6–43.4 mV. Raman spectra and X-ray diffraction evidenced structural differences between the free GSE and GSE-loaded SLN, leading to the conclusion that GSE alters the structure of the lipid nanocarriers. From a biological viewpoint, cell lines from gilthead seabream and European sea bass were exposed to different concentrations of GSE-SLN for 24 h. In general, at appropriate concentrations, GSE-SLN increased the viability of the fish cells. Furthermore, regarding the gene expression in those cells, the expression of antioxidant genes was upregulated, whereas the expression of hsp70 and other genes related to the cytoskeleton was downregulated. Hence, an SLN formulation containing Gelucire^® 50/13/Precirol^® ATO5 and GSE may represent a compelling platform for improving the viability and antioxidant properties of fish cells.

Procyanidins from Hawthorn (Crataegus Pinnatifida) Alleviates Lipid Metabolism Disorder via Inhibiting Insulin Resistance and Oxidative Stress, Normalizing Gut Microbiota Structure and Intestinal Barrier, Further Suppressing Hepatic Inflammation and Lipid Accumulation

Recently, lipid metabolism disorder (LMD) has been regarded as a risky factor leading to multiple diseases and affecting human health. Procyanidins have been reported to be the potential therapy for...

Grape seed proanthocyanidin extract regulates lipid metabolism of the American eel (Anguilla rostrata)

The current study was aimed to examine the effect of grape seed proanthocyanidin extract (GSPE) on regulating lipid metabolism of American eels. A total of six cement tanks of fish were randomly divided into a control group fed with a commercial diet and a GSPE group fed with a commercial diet supplemented 400 mg/kg GSPE. There were three replicates in each group. Results suggested that GSPE could decrease the levels of total cholesterol, triglycerides, and low-density lipoprotein cholesterol, and increase the high-density lipoprotein cholesterol level in serum. GSPE might regulate lipid metabolism through upregulating linoleic acid metabolism and arachidonic acid metabolism along with downregulating metabolisms of phenylalanine, tyrosine, and tryptophan biosynthesis and valine, leucine, and isoleucine biosynthesis.

Dietary Intake of Hydrolyzable Tannins and Condensed Tannins to Regulate Lipid Metabolism

Lipid metabolism disorder is a multifactor issue, which contributes to several serious health consequences, such as obesity, hyperlipidemia, atherosclerosis diabetes, non-alcoholic fatty liver etc. Tannins, applied as natural derived plant, are commonly used in the study of lipid metabolism disease with excellent safety and effectiveness, while producing less toxic and side effects. Meanwhile, recognition of the significance of dietary tannins in lipid metabolism disease prevention has increased. As suggested by existing evidence, dietary tannins can reduce lipid accumulation, block adipocyte differentiation, enhance antioxidant capacity, increase the content of short-chain fatty acids, and lower blood lipid levels, thus alleviating lipid metabolism disorder. This study is purposed to sum up and analyze plenty of documents on tannins, so as to provide the information required to assess the lipid metabolism of tannins.

Metabolism and antioxidation regulation of total flavanones from Sedum sarmentosum Bunge against high-fat diet-induced fatty liver disease in Nile tilapia (Oreochromis niloticus)

Diet-induced fatty liver is a considerable threaten to fish aquaculture due to the popularity of the high-fat diet (HFD) feeding. Our study aims to investigate the effects of flavanones from Sedum sarmentosum Bunge (FSSB) on the liver function to identify a potential treatment for HFD-induced fatty liver disease. Physiological and pathological indicators were tested in the liver of Nile tilapia (Oreochromis niloticus) and results showed parameters including lipid metabolites, redox parameters, and inflammatory factors could be adequately restored to normal level by addition of 150 mg/kg FSSB to HFD. Proteomics analysis was performed in liver tissues from tilapia with normal diet (ND), HFD, and HFD+FSSB. Totally, 51 upregulated proteins and 77 downregulated proteins were identified in HFD groups and 67 proteins of them were restored after treated with FSSB. Bioinformatics analysis showed that differentially expressed proteins (DEPs) in HFD+FSSB150 group compared with HFD group are mainly enriched in acety-CoA metabolic process, adenosine-triphosphate (ATP) biosynthetic process, lipid metabolic process, and phospholipid metabolic process. The dysregulated proteins were involved in peroxidosome proliferators-activated receptor (PPAR) signaling pathway, fat digestion and absorption, and immune system. The quantitative real-time PCR (qRT-PCR) assay further revealed that the expression of GST, PPARα, PPARγ, and multiple-inflammatory cytokines could be also reversed in HFD group under the treatment of 150 mg/kg FSSB. Our findings demonstrated FSSB is efficient for the treatment of fatty liver disease through regulation of lipid metabolism and antioxidation in Nile tilapia, providing a new treatment of non-alcoholic fatty liver disease (NAFLD) in fish aquaculture.