Effects of curcumin on antioxidant-related genes and caecal flora in rabbits

Abstract

This study aimed to investigate the effects of curcumin on the expression of antioxidation-related genes in the liver and jejunum and caecum microorganisms of rabbits. A total of 160 IRA rabbits with similar body weight were randomised assigned to 4 groups. The control group received a basal diet, while the experimental groups were given diets supplemented with 50, 100, and 150 g/t curcumin, respectively. The pre-test period spanned 7 days, followed by a 21-day test period. Results revealed a significant upregulation of nuclear factor erythroid-2 related factor 2 (Nrf2) mRNA in the liver and jejunum due to curcumin (p < 0.05). Additionally, curcumin supplementation markedly increased the expression of NAD(P)H: quinone oxidoreductase 1 (NQO1) mRNA in the liver and jejunum of rabbits (p < 0.05), and reduced the expression of c-Jun N-terminal kinase (JNK) mRNA in the liver (p < 0.05). The inclusion of 100 and 150 g/t curcumin enhanced caecal microbiota richness and increased the relative abundance of Lactobacillus, Lactobacillus helveticus, and Lactobacillus iners (p < 0.05). Furthermore, curcumin at 100 and 150 g/t significantly increased the relative abundance of coenzyme B biosynthesis and creatinine degradation I (p < 0.05). In conclusion, curcumin’s regulation of antioxidant performance in rabbits appears linked to JNK and Nrf2/NQO1 signalling. Curcumin modulates caecal flora, with probiotic effects mediated by Lactobacillus. Notably, Lactobacillus helveticus and Lactobacillus iners may be beneficial strains associated with curcumin. The recommended curcumin dosage in rabbit feed is 100 g/t. HIGHLIGHTS The regulation of antioxidant performance by curcumin in meat rabbits may be related to JNK and Nrf2/NQO1 signalling. Curcumin can regulate caecal flora, and its probiotic function may be mediated by Lactobacillus. Curcumin could improve the coenzyme B biosynthesis and creatinine degradation ability of caecal flora.