Resveratrol (3,4′,5-trihy- droxystilbene), a natural phytoalexin polyphenol, exhibits anti-oxidant, anti-inflammatory, and anti-carcinogenic properties. This phytoalexin is well-absorbed and rapidly and extensively metabolized in the body. Inflammation is an adaptive response, which could be triggered by various danger signals, such as invasion by microorganisms or tissue injury. In this review, the anti-inflammatory activity and the mechanism of resveratrol modulates the inflammatory response are examined. Multiple experimental studies that illustrate regulatory mechanisms and the immunomodulatory function of resveratrol both in vivo and in vitro. The data acquired from those studies are discussed.

Background: Weaning is one of the major factors that cause stress and intestinal disease in piglets. Protocatechuic acid (PCA) is an active plant phenolic acid which exists in Chinese herb, Duzhong (Eucommia ulmoidesOliver), and is also considered as the main bioactive metabolite of polyphenol against oxidative stress and inflammation. This study aimed to investigate the effect of PCA on growth performance, intestinal barrier function, and gut microbiota in a weaned piglet model challenged with lipopolysaccharide (LPS).Methods: Thirty-six piglets (Pig Improvement Company line 337 × C48, 28 d of age, 8.87 kg ± 0.11 kg BW) were randomly allocated into 3 treatments and fed with a basal diet (CTL), a diet added 50 mg/kg of aureomycin (AUR), or a diet supplemented with 4000 mg/kg of PCA, respectively. The piglets were challenged with LPS (10 μg/kg BW) on d 14 and d 21 by intraperitoneal injection during the 21-d experiment. Animals (n = 6 from each group) were sacrificed after being anesthetized by sodium pentobarbital at 2 h after the last injection of LPS. The serum was collected for antioxidant indices and inflammatory cytokines analysis, the ileum was harvested for detecting mRNA and protein levels of tight junction proteins by PCR and immunohistochemical staining, and the cecum chyme was collected for intestinal flora analysis using 16S rRNA gene sequencing.Results: Dietary supplementation of PCA or AUR significantly increased the expression of tight junction proteins including ZO-1 and claudin-1 in intestinal mucosa, and decreased the serum levels of thiobarbituric acid reactive substances (TBARS) and IL-6, as compared with CTL group. In addition, PCA also decreased the serum levels of IL-2 and TNF-α (P < 0.05). Analysis of gut microbiota indicated that PCA increased the Firmicutes/Bacteroidetes ratio (P < 0.05). Spearman’s correlation analysis at the genus level revealed that PCA reduced the relative abundance ofPrevotella9,Prevotella2,Holdemanella, andRuminococcus torquesgroup (P < 0.05), and increased the relative abundance ofRoseburiaandDesulfovibrio(P < 0.05), whereas AUR had no significant effect on these bacteria.Conclusions: These results demonstrated that both PCA and AUR had protective effect on oxidative stress, inflammation and intestinal barrier function in piglets challenged with LPS, and PCA potentially exerted the protective function by modulating intestinal flora in a way different from AUR.Holdemanella:

Heat stress is a non-specific physiological response of the body when exposed to high ambient temperatures, which can break the balance of body redox and result in oxidative stress that affects growth performance as well as the health of poultry species. Polyphenols have attracted much attention in recent years due to their antioxidant ability and thus, can be an effective attenuator of heat stress. In this paper, the potential mechanisms underlying the inhibitory effect of polyphenols on heat stress in poultry has been reviewed to provide a reference and ideas for future studies related to polyphenols and poultry production.

Ruminant production, especially in the tropics and developing countries suffers a setback when compared with the temperate and developed countries, which is attributable to the kinds of available feed resources in the region of production. In the tropics, ruminants are restricted to grazing on low-quality forages, crop residues and agro-industrial by-products with very little or no concentrate diets, which adversely affect the animals in exhibiting their full production potential. Considering this fact, there is an increasing interest in improving the digestibility of these feed resources. In recent years, researchers have explored several methods to enhance the functions of rumen microflora, improve digestion and fermentation processes, as well as increase bioavailability and utilization of nutrients through feed supplementation. This review aims to explore the positive effects of supplementation of ruminant diets with probiotics or botanical extracts and their metabolites on the productivity of the animals. Moreover, the functions of these non-pathogenic and non-toxic live microorganisms (probiotics) and plant biologically active compounds (botanical extract) are explored because of the ban on non-therapeutic use of antibiotics as growth promoters coupled with the critical preference of consumers to high quality and safe animal products. It has been reported that these alternative supplemental products have a beneficial impact on both animal health and productivity, which is affecting stabilization of rumen environment, inhibition of pathogenic bacteria proliferation in gastro-intestinal tract, modulation of immune response, increase in fibre degradation and fermentation, nutrients availability and utilization, animal growth performance and milk production, among others. However, long-term in vivo studies are still required to determine the synergetic effects of these 2 safe supplemental products.

Ferulic acid (FA) and vanillic acid (VA) are considered as major phenolic metabolites of cyanidin 3-glucoside, a polyphenol that widely exists in plants that possess a protective effect against oxidative stress and inflammation in our previous study. This study aimed to investigate the effect of FA and VA on inflammation, gut barrier function, and growth performance in a weaned piglet model challenged with lipopolysaccharide (LPS). Thirty-six piglets (PIC 337 × C48, 28 d of age) were randomly allocated into 3 treatments with 6 replicate pens (2 piglets per pen). They were fed with a basal diet or a diet containing 4,000 mg/kg of FA or VA. Dietary supplementation of VA significantly increased average daily gain (ADG) (P < 0.05). Both FA and VA decreased serum levels of thiobarbituric acid reactive substances (TBARS), interlukin (IL)-1β, IL-2, IL-6, and tumor necrosis factor (TNF)-α (P < 0.05), and enhanced the expression of tight junction protein oclaudin (P < 0.05). Analysis of gut microbiota indicated that both FA and VA increased the Firmicutes/Bacteroidetes ratio alongside reducing the relative abundance of the Prevotellaceae family including Prevotella 9 and Prevotella 2 genera, but enriched the Lachoiraceaea family including the Lachnospiraceae FCS020 group (P < 0.05). Moreover, VA reduced the relative abundance of Prevotella 7 and Prevotella 1 but enriched Lachnospira, Eubacterium eligens group, and Eubacterium xylanophilum group (P < 0.05), while FA showed a limited effect on these genera. The results demonstrated that both VA and FA could alleviate inflammation and oxidative stress, but only VA has a significant positive effect on the growth performance of LPS-challenged piglets potentially through modulating gut microbiota.

The aim of this study was to investigate whether supplementation with resveratrol could alleviate intestinal injuries and to explore how resveratrol regulates heat shock protein (HSP)70, HSP90, nuclear factor kappa B (NF-κB) and epidermal growth factor (EGF) expression in the jejunal mucosa of black-boned chickens under circular heat stress. A total of 300 black-boned chicks of 42-d-old were randomly assigned to five treatment groups. The positive control chickens were kept in a normal-temperature (NT, 24 ± 2 °C) chamber and fed with a basal diet. The other four groups were kept in a circular high-temperature (HT, 37 ± 2 °C) chamber for 8 h and fed a basal diet supplemented with 0, 200, 400, or 600 mg per kg of resveratrol for 15 days. The results showed that the heat-stress responses damaged the villus structures of the jejunum and ileum, resulting in shortened intestinal villi, deepened crypts, and a reduced villus height to crypt depth (V/C) ratio and decreased the numbers of goblet cells and lymphocytes. Heat stress also caused increased mRNA and protein expression of HSP70, HSP90 and NF-κB, and reduced EGF in the jejunal mucosa. Dietary supplementation with 400 mg per kg of resveratrol improved the villus morphology, increased the numbers of goblet cells and lymphocytes, attenuated the mRNA overexpression of HSP70, HSP90 and NF-κB on the 6^th, 10^th and 15^th day of heat stress (P < 0.05), and activated the expression of EGF (P < 0.05) in the jejunal mucosa. Resveratrol reduced protein expression of HSP70, HSP90 and NF-κB in the jejunal villi after 15 days of heat stress, and increased EGF expression from the lamina propria toward the epithelial cells of the villi. These results suggest that dietary resveratrol offers a potential nutritional strategy to improve the intestinal morphology and alleviate jejunum mucosa injuries by modulating the mRNA and protein expression of HSPs, and the epithelial growth factor and transcription factor in black-boned chickens subjected to circular heat stress.