The Effect of Dietary Quercetin on the Glutathione Redox System and Small Intestinal Functionality of Weaned Piglets

Bioinformatics and Network Pharmacology Explore the Role of Immune Cells in the Occurrence of Anti-Vascular Endothelial Growth Factor (VEGF) Resistance in Patients with Neovascular Age-Related Macular Degeneration(nAMD) and the Application of Complementary Medicine Treatment

PURPOSE

This study explores the immune cells' role in anti-VEGF resistance in nAMD patients, and the potential of Zi-Yin-Jiang-Huo-Tang (ZYJHT), a Traditional Chinese Medicine formula, as complementary therapy.

METHODS

Aqueous humor proteomics data from 10 nAMD patients with anti-VEGF resistance and 10 nAMD patients without anti-VEGF resistance were analyzed, investigating immune cells's role in anti-VEGF resistance and its underlying mechanism. Network pharmacology methods are employed to analyze the active ingredients in ZYJHT that contribute to therapeutic effects and their mechanisms. Real-time PCR (polymerase chain reaction) was used to detect changes in the expression of SOD1 (superoxide dismutase 1) after treatment with compounds targeting SOD1 in ARPE-19 cells.

RESULTS

nAMD patients with anti-VEGF resistance showed enhancement of biological processes linked to the positive regulation of immune function, along with decreased cellular resistance to oxidative stress. Infiltration of B cells memory, plasma cells, CD8+and γδ-T cells were higher in nAMD patients with anti-VEGF resistance. SOD1 was identified as a hub gene in the occurrence of anti-VEGF resistance and a core therapeutic target of ZYJHT, negatively correlated with B and T cell infiltration. Compounds diosgenin, naringenin, and liquiritin in ZYJHT can bind to SOD1 and upregulating SOD1 expression in ARPE-19 cells.

Advance in the pharmacological effects of quercetin in modulating oxidative stress and inflammation related disorders

Numerous pharmacological effects of quercetin have been illustrated, including antiinflammation, antioxidation, and anticancer properties. In recent years, the antioxidant activity of quercetin has been extensively reported, in particular, its impacts on glutathione, enzyme activity, signaling transduction pathways, and reactive oxygen species (ROS). Quercetin has also been demonstrated to exert a striking antiinflammatory effect mainly by inhibiting the production of cytokines, reducing the expression of cyclooxygenase and lipoxygenase, and preserving the integrity of mast cells. By regulating oxidative stress and inflammation, which are regarded as two critical processes involved in the defense and regular physiological operation of biological systems, quercetin has been validated to be effective in treating a variety of disorders. Symptoms of these reactions have been linked to degenerative processes and metabolic disorders, including metabolic syndrome, cardiovascular, neurodegeneration, cancer, and nonalcoholic fatty liver disease. Despite that evidence demonstrates that antioxidants are employed to prevent excessive oxidative and inflammatory processes, there are still concerns regarding the expense, accessibility, and side effects of agents. Notably, natural products, especially those derived from plants, are widely accessible, affordable, and generally safe. In this review, the antioxidant and antiinflammatory abilities of the active ingredient quercetin and its application in oxidative stress-related disorders have been outlined in detail.

Recent Advances in Potential Health Benefits of Quercetin

Quercetin, a flavonoid found in fruits and vegetables, has been a part of human diets for centuries. Its numerous health benefits, including antioxidant, antimicrobial, anti-inflammatory, antiviral, and anticancer properties, have been extensively studied. Its strong antioxidant properties enable it to scavenge free radicals, reduce oxidative stress, and protect against cellular damage. Quercetin's anti-inflammatory properties involve inhibiting the production of inflammatory cytokines and enzymes, making it a potential therapeutic agent for various inflammatory conditions. It also exhibits anticancer effects by inhibiting cancer cell proliferation and inducing apoptosis. Finally, quercetin has cardiovascular benefits such as lowering blood pressure, reducing cholesterol levels, and improving endothelial function, making it a promising candidate for preventing and treating cardiovascular diseases. This review provides an overview of the chemical structure, biological activities, and bioavailability of quercetin, as well as the different delivery systems available for quercetin. Incorporating quercetin-rich foods into the diet or taking quercetin supplements may be beneficial for maintaining good health and preventing chronic diseases. As research progresses, the future perspectives of quercetin appear promising, with potential applications in nutraceuticals, pharmaceuticals, and functional foods to promote overall well-being and disease prevention. However, further studies are needed to elucidate its mechanisms of action, optimize its bioavailability, and assess its long-term safety for widespread utilization.

Plant-Derived Polyphenols as Nrf2 Activators to Counteract Oxidative Stress and Intestinal Toxicity Induced by Deoxynivalenol in Swine: An Emerging Research Direction

The contamination of deoxynivalenol (DON) in feed is a global problem, which seriously threatens the productivity efficiency and welfare of farm animals and the food security of humans. Pig is the most sensitive species to DON, and is readily exposed to DON through its grain-enriched diet. The intestine serves as the first biological barrier to ingested mycotoxin, and is, therefore, the first target of DON. In the past decade, a growing amount of attention has been paid to plant-derived polyphenols as functional compounds against DON-induced oxidative stress and intestinal toxicity in pigs. In this review, we systematically updated the latest research progress in plant polyphenols detoxifying DON-induced intestinal toxicity in swine. We also discussed the potential underlying mechanism of action of polyphenols as Nrf2 activators in protecting against DON-induced enterotoxicity of swine. The output of this update points out an emerging research direction, as polyphenols have great potential to be developed as feed additives for swine to counteract DON-induced oxidative stress and intestinal toxicity.

Drenching Bovine Colostrum, Quercetin or Fructo-Oligosaccharides Has No Effect on Health or Survival of Low Birth Weight Piglets

The introduction of hyperprolific sows has resulted in more low birth weight (LBW) piglets, accompanied by higher mortality. A possible strategy to enhance the resilience and survival of LBW piglets is oral supplementation (drenching) of bioactive substances. This study evaluated the supplementation of bovine colostrum, short-chain fructo-oligosaccharides (scFOS) or quercetin that were dissolved separately in a milk replacer. The study was divided into two sub-experiments. First, the milk replacer was compared with a sham drenched group. Secondly, each dissolved compound was compared with the milk replacer. The LBW piglets, defined as weighing between (mean litter birth weight -1*SD) and (mean litter birth weight -2.5*SD), were randomly allocated to the different treatments and drenched once a day for seven days. On day 1, 3, 9, 24 and 38, piglets were weighed and scored for skin lesions. Blood samples were collected on day 9 and 38 and analyzed to determine glucose, non-esterified fatty acids, urea, immunoglobulin G, insulin-like growth factor 1, and a standard blood panel test. There was no difference between sham drenched piglets and piglets that were drenched with milk replacer regarding any of the parameters. No effect was observed between the milk replacer group and any of the bioactive compounds either, except a higher mortality within the scFOS group. In conclusion, this study showed that drenching the evaluated bioactive compounds, in the used dosages, did not improve LBW piglets' resilience or survival and more research is required to determine the effect of scFOS on small piglets.

Supplementation with Exogenous Catalase from Penicillium notatum in the Diet Ameliorates Lipopolysaccharide-Induced Intestinal Oxidative Damage through Affecting Intestinal Antioxidant Capacity and Microbiota in Weaned Pigs

The present study aimed to explore the protective effects of exogenous catalase (CAT) from microorganisms against lipopolysaccharide (LPS)-induced intestinal injury and its molecular mechanism in weaned pigs. Fifty-four weaned pigs (21 days of age) were randomly allocated to CON, LPS, and LPS+CAT groups. The pigs in CON and LPS groups were fed a basal diet, whereas the pigs in LPS+CAT group fed the basal diet with 2,000 mg/kg CAT supplementation for 35 days. On day 36, six pigs were selected from each group, and LPS and LPS+CAT groups were administered with LPS (50 μg/kg body weight). Meanwhile, CON group was injected with an equivalent amount of sterile saline. Results showed that LPS administration damaged intestinal mucosa morphology and barrier. However, CAT supplementation alleviated the deleterious effects caused by LPS challenge through enhancing intestinal antioxidant capacity which was benefited to decrease proinflammatory cytokines concentrations and suppress enterocyte apoptosis. Besides, LPS-induced gut microbiota dysbiosis was significantly shifted by CAT through decreasing mainly Streptococcus and Escherichia-Shigella. Our study suggested that dietary supplemented with 2,000 mg/kg catalase was conducive to improve intestinal development and protect against LPS-induced intestinal mucosa injury via enhancing intestinal antioxidant capacity and altering microbiota composition in weaned pigs.

IMPORTANCE Exogenous CAT derived from microorganisms has been widely used in food, medicine, and other industries. Recent study also found that exogenous CAT supplementation could improve growth performance and antioxidant capacity of weaned pigs. However, it is still unknown that whether dietary exogenous CAT supplementation can provide a defense against the oxidative stress-induced intestinal damage in weaned pigs. Our current study suggested that dietary supplemented with 2,000 mg/kg CAT was conducive to improve intestinal development and protect against LPS-induced intestinal mucosa injury via enhancing intestinal antioxidant capacity and altering microbiota composition in weaned pigs. Moreover, this study will also assist in developing of CAT produced by microorganisms to attenuate various oxidative stress-induced injury or diseases.

Dietary Quercetin Supplementation Attenuates Diarrhea and Intestinal Damage by Regulating Gut Microbiota in Weanling Piglets

Antioxidant polyphenols from plants are potential dietary supplementation to alleviate early weaning-induced intestinal disorders in piglets. Recent evidences showed polyphenol quercetin could reshape gut microbiota when it functioned as anti-inflammation or antioxidation agents in rodent models. However, the effect of dietary quercetin supplementation on intestinal disorders and gut microbiota of weanling piglets, along with the role of gut microbiota in this effect, both remain unclear. Here, we determined the quercetin's effect on attenuating diarrhea, intestinal damage, and redox imbalance, as well as the role of gut microbiota by transferring the quercetin-treated fecal microbiota to the recipient piglets. The results showed that dietary quercetin supplementation decreased piglets' fecal scores improved intestinal damage by increasing tight junction protein occludin, villus height, and villus height/crypt depth ratio but decreased crypt depth and intestinal epithelial apoptosis (TUNEL staining). Quercetin also increased antioxidant capacity indices, including total antioxidant capacity, catalase, and glutathione/oxidized glutathione disulfide but decreased oxidative metabolite malondialdehyde in the jejunum tissue. Fecal microbiota transplantation (FMT) from quercetin-treated piglets had comparable effects on improving intestinal damage and antioxidative capacity than dietary quercetin supplementation. Further analysis of gut microbiota using 16S rDNA sequencing showed that dietary quercetin supplementation or FMT shifted the structure and increased the diversity of gut microbiota. Especially, anaerobic trait and carbohydrate metabolism functions of gut microbiota were enriched after dietary quercetin supplementation and FMT, which may owe to the increased antioxidative capacity of intestine. Quercetin increased the relative abundances of Fibrobacteres, Akkermansia muciniphila, Clostridium butyricum, Clostridium celatum, and Prevotella copri but decreased the relative abundances of Proteobacteria, Lactobacillus coleohominis, and Ruminococcus bromii. Besides, quercetin-shifted bacteria and carbohydrate metabolites short chain fatty acids were significantly related to the indices of antioxidant capacity and intestinal integrity. Overall, dietary quercetin supplementation attenuated diarrhea and intestinal damage by enhancing the antioxidant capacity and regulating gut microbial structure and metabolism in piglets.

Organic Acids Improve Growth Performance with Potential Regulation of Redox Homeostasis, Immunity, and Microflora in Intestines of Weaned Piglets

The objective of this study is to evaluate the effects of organic acids on piglet growth performance and health status. A total of 360 weanling pigs (5.3 ± 0.6 kg) were randomly allotted to 3 treatment groups with 12 replicates of 10 pigs/pen. Piglets were fed the same basal diet and given either water (control) or water plus 2.0 L/Ton organic acid (OA) blends, such as OA1 or OA2, respectively, for 7 weeks. Compared to the control, OA1 and OA2 improved growth performance and/or reduced the piglets' diarrhea rate during the various periods and improved small intestinal morphology at days 14 and/or 49. OA1 and OA2 also increased serum CAT and SOD activities and/or T-AOC and, as expected, decreased MDA concentration. Moreover, at day 14 and/or day 49, OA1 and OA2 increased the jejunal mRNA levels of host defense peptides (PBD1, PBD2, NPG1, and NPG3) and tight junction genes (claudin-1) and decreased that of cytokines (IL-1β and IL-2). Additionally, the two acidifiers regulated the abundance of several cecum bacterial genera, including Blautia, Bulleidia, Coprococcus, Dorea, Eubacterium, Subdoligranulum, and YRC2. In conclusion, both of the organic acid blends improved piglet growth performance and health status, potentially by regulating intestinal redox homeostasis, immunity, and microflora.

Influence of quercetin on the global DNA methylation pattern in pigs

The plant flavonol quercetin causes multiple health-promoting effects in human and animals.