Bile Acids Promote Hepatic Biotransformation and Excretion of Aflatoxin B1 in Broiler Chickens

Abstract

Aflatoxin B1 (AFB1) is a hazardous mycotoxin that often contaminates animal feed and may potentially induce severe liver damage if ingested. The liver is the primary organ responsible for AFB1 detoxification through enzyme-catalyzed xenobiotic metabolism and bile acid (BA)-associated excretion. In this study, we sought to investigate whether exogenous BA improves hepatic AFB1 detoxification to alleviate AFB1-induced liver injury in broiler chickens. Five-day-old broiler chicks were randomly assigned to three groups. CON and AFB1 received a basal diet; AFB1 + BA received a basal diet with 250 mg/kg BA for 20 days. After a 3-day pre-feed, AFB1 and AFB1 + BA were daily gavaged with 250 μg/kg BW AFB1, while CON received gavage solvent for AFB1 treatment. Dietary BA supplementation protected chickens from AFB1-induced hepatic inflammation and oxidative stress. The hepatic biotransformation of AFB1 to its metabolite AFBO was improved, with accelerated excretion to the gallbladder and cecum. Accordantly, AFB1-induced down-regulation of detoxification genes, including cytochrome P450 enzymes, glutathione S-transferases, and the bile salt export pump, was rescued by BA supplementation. Moreover, liver X receptor α, suppressed by AFB1, was enhanced in BA-treated broiler chickens. These results indicate that dietary BA supplementation improves hepatic AFB1 detoxification and excretion through LXRα-involved regulation of xenobiotic enzymes.

AFB1 Toxicity in Human Food and Animal Feed Consumption: A Review of Experimental Treatments and Preventive Measures

“…Epoxidation-2,3 of AFB1 by CYP450 causes the production of carcinogens in one possible metabolic biochemical route. To improve biotransformation, several studies explored the addition of external bile acids that proved to protect chickens from AFB1-induced liver abnormalities and increased transformation, which leads to the affirmed excretion of the gallbladder and cecum [29]. Elimination of AFB1 was improved by 64% when cell wall fractions of B. thuringiensis AMK10/1 were added, and the effects were due to the properties of the surface layer fraction of the cell wall [30].…”