Evaluation of Antioxidant Function of Palygorskite and Its Derivatives In Vitro and for Broilers

This study aimed to investigate the antioxidant properties of natural palygorskite (N-pal), bundle-dissociated palygorskite (D-pal), and zinc-bearing palygorskite (Zn-pal), as well as their effects on the antioxidant capacity of broilers. Palygorskite (Pal) and its derivatives exhibited hydrogen peroxide (H₂O₂) decomposition and hydroxyl radical (·OH) scavenging abilities, with D-pal and Zn-pal demonstrating superior performance. A total of 320 one-day-old Arbor Acres broilers were randomly divided into 4 groups: control, N-pal, D-pal and Zn-pal groups. The corn-soybean meal basal diet was supplemented with N-pal (10 g/kg), D-pal (5 g/kg) and Zn-pal (1 g/kg) for the respective treatment groups. The trial lasted for 42 days. At 21 days, D-pal and Zn-pal groups significantly increased average body weight and average daily weight gain while reducing the feed-to-gain ratio (p < 0.05). Both reactive oxygen species (ROS) and malondialdehyde (MDA) levels in liver of broilers were significantly reduced, and glutathione peroxidase 1 (GPX1) gene expression was upregulated at 21 days (p < 0.05). N-pal and D-pal groups enhanced superoxide dismutase (SOD) and catalase (CAT) activities in the duodenum (21d); D-pal group increased SOD activity in the ileum (42d); all Pal groups decreased ileal jejunal mucosal ROS (21d) and MDA (42d) (p < 0.05). At 42 days, Pal supplementation downregulated oxidative stress (N-pal), oxidoreductase activity (D-pal), and H₂O₂ response (Zn-pal) pathways in jejunal mucosa. N-pal and D-pal groups upregulated ileal mucosal nuclear factor-erythroid 2-related factor-2 (Nrf2), heme oxygenase-1 (HO-1), and superoxide dismutase 1 expression, while Zn-pal group increased HO-1 expression (21d). D-pal and Zn-pal groups enhanced jejunal mucosal Nrf2 and HO-1 expression (21d). Pal improved the antioxidant capacity in broilers by activating the Nrf2-mediated pathway, upregulating antioxidant-related gene expression, particularly at 21 days. Both D-pal and Zn-pal demonstrated potent antioxidant efficacy, and they can improve growth performance by enhancing the animal's antioxidant capacity.