The aim of this study was to explore the mechanism underlying the protective effects of resveratrol against Aflatoxin B1-induced ileum injury in ducks. A corn–soybean meal-basal diet and two test diets (500 mg/kg resveratrol +0.2 mg Aflatoxin B1/kg, 0.2 mg AFB1/kg) were used in a 10-wk design trial (n = 15 ducks/group). These results showed that the toxicity of Aflatoxin B1 significantly reduced the antioxidant capacity of duck ileum and induced inflammation, oxidative stress, mitochondrial dysfunction and DNA damage in ducks. The expression of genes, including CYP1A2, CYP2A6, and CYP3A4, at the mRNA level was significantly upregulated (p < 0.05) by AFB1. The level of Nrf2 was suppressed (p < 0.05) and the mRNA and protein level of NF-κB was activated (p < 0.05) in the AFB1 group. However, supplementation with 500 mg/kg dietary resveratrol in Aflatoxin B1-induced ducks significantly ameliorated these alterations and decreased the mRNA expression of CYP1A1 and CYP1A2 (p < 0.05) and the production of AFB1-DNA adducts (p < 0.05). The results proved that resveratrol alleviated ileum injury induced by AFB1, decreased the production of AFB1-DNA adducts by downregulating the expression of CYP1A1 and CYP1A2, and reduced DNA damage and oxidative stress via the Nrf2/ Keap1 and NF-κB/NLRP3 signaling pathways.

BACKGROUND Lipopolysaccharides (LPS) are the main pathogenic substances in Gram‐negative bacteria. The aim of this study was to investigate the preventive effects of dietary curcumin (CUR) on LPS toxicity in the duck ileum. The duck diet was supplemented with CUR (0.5 g kg−1) for 28 days, while the birds were injected with LPS (0.5 mg kg−1 body weight per injection, administered as seven injections in the last week of the experimental period). RESULTS LPS significantly decreased the ileal villus‐to‐crypt ratio in the non‐supplemented CUR group. Dietary CUR alleviated LPS‐induced morphological damage to the ileum. Moreover, dietary CUR alleviated oxidative stress by increasing the levels of total superoxide dismutase (T‐SOD) (P < 0.05) and glutathione S‐transferase (GST) (P < 0.05) and decreasing the production of malonic dialdehyde (MDA) (P < 0.05) in control ducks and LPS‐challenged ducks. Dietary CUR significantly inhibited the LPS‐induced massive production of inflammatory factors (IL‐1β, IL‐6, and TNF‐α) (P < 0.05). CUR induced the inhibition of TLR4 and activation of Nrf2 to reduce the expression of inflammation‐related genes (TLR4, NF‐κB, IKK, TXNIP, NLRP3, caspase‐1, IL‐1β, IL‐6, and TNF‐α). Moreover, dietary CUR ameliorated the decrease in claudin‐1 and occludin expression (P < 0.05) and improved ZO‐1 expression in the duck ileum (P < 0.05). CONCLUSION In conclusion, dietary CUR has beneficial effects on LPS‐induced ileal damage, oxidative damage, and inflammatory response by inhibiting the TLR/NF‐κB and activating the Nrf2 signaling pathways in ducks. This study provides valuable information regarding the therapeutic uses of CUR in duck ileitis. © 2022 Society of Chemical Industry.