Dietary Supplementation of Novel Aflatoxin Oxidase CotA Alleviates Aflatoxin B-Induced Oxidative Stress, Lipid Metabolism Disorder, and Apoptosis in the Liver of Japanese Quails.

This research explored the role of aflatoxin oxidase CotA in mitigating aflatoxin B (AFB)-induced hepatotoxicity in Japanese quails. A total of 225 female Japanese quails, aged two weeks, were randomly assigned to three dietary groups: a control diet, an AFB-contaminated diet, and an AFB-contaminated diet supplemented with aflatoxin oxidase CotA for three weeks. The results indicate that quails receiving the AFB-contaminated diet exhibited reduced body weight gain, pronounced vacuolar degeneration within hepatocytes, and inflammatory cell infiltration. Additionally, the AFB group demonstrated an increased liver index and elevated serum liver enzyme activities (ALT, AST, and ALP). Supplementation with CotA improved body weight gain and conferred protection against AFB-induced liver injury. Furthermore, the addition of CotA significantly enhanced liver antioxidant enzyme activities (T-AOC, GST, GSH-Px, POD, and CAT), reduced hepatic HO and MDA levels, and upregulated the mRNA expression levels of genes in the Nrf2 pathway in quails exposed to AFB. AFB exposure led to lipid droplet accumulation in liver tissues and elevated serum TG and LDL-C levels. However, the introduction of CotA mitigated AFB-induced alterations in lipid metabolism. Furthermore, dietary supplementation with CotA inhibited AFB-induced hepatocyte apoptosis and decreased the mRNA expression of apoptosis-related genes, including Bax, caspase-9, and caspase-3. Notably, the AFB+CotA group exhibited a significant reduction in AFB residues and AFB-DNA adducts in quail liver tissues compared to the AFB group. These findings indicate that aflatoxin oxidase CotA holds promise as a feed additive to alleviate AFB-induced hepatotoxicity.