The Effects of Dietary Pterostilbene on the Immune Response, Antioxidant Function, and Jejunal Structure of Broilers

This experiment was carried out to investigate the effect of pterostilbene (PTE) supplementation in feed on Arbor Acres broilers in terms of serum biochemical parameters, immune and inflammatory responses, antioxidant status, and intestinal morphological structure. For a duration of 42 days, a total of 480 1-day-old Arbor Acres broilers were randomly divided into four groups. Each group was assigned to receive either the basal diet or the basal diet supplemented with 200, 400, or 600 mg/kg of PTE. Each treatment consisted of eight replicates, with 15 chicks per replicate. In comparison with the control group, three PTE treatments significantly increased the lymphocyte transformation rate in the spleen of broilers. The automated biochemical analysis, enzyme-linked immunosorbent assay, and RT-qPCR analysis kits found that 400 mg/kg of PTE significantly increased the serum levels of complement C3, IL-4, and iNOS; reduced the serum levels of IL-6, TNF-α, and mRNA levels of the genes IL-6, IL-8, TNF-α, NLRP3, and IFN-γ; significantly improved the activities of antioxidant enzymes including CAT, GSH-Px, and T-SOD in the jejunum; and significantly reduced the MDA contents in the serum and jejunum of broilers. Nikon microscope observations and ImagePro Plus 6.0 measure results found that 400 mg/kg of PTE supplementation significantly reduced the relative length and weight of the jejunum and improved the jejunal villi structure, resulting in increased intestinal villi, deepened crypt, and an enhanced ratio of villi height to crypt depth (VH/CD). RT-qPCR and Western blot found that dietary PTE also resulted in increased mRNA levels of the genes Claudin-2, Occludin, ZO-1, and Sirt1, and decreased NF-κB protein levels in the jejunum. The results of this study demonstrated that dietary PTE improved the immune function and intestinal health of broilers by reducing inflammation and increasing the antioxidant capacity of the animals.