An overview of aflatoxin B1 biotransformation and aflatoxin M1 secretion in lactating dairy cows

Abstract

Milk is considered a perfect natural food for humans and animals. However, aflatoxin B1 (AFB1) contaminating the feeds fed to lactating dairy cows can introduce aflatoxin M1 (AFM1), the main toxic metabolite of aflatoxins into the milk, consequently posing a risk to human health. As a result of AFM1 monitoring in raw milk worldwide, it is evident that high AFM1 concentrations exist in raw milk in many countries. Thus, the incidence of AFM1 in milk from dairy cows should not be underestimated. To further optimize the intervention strategies, it is necessary to better understand the metabolism of AFB1 and its biotransformation into AFM1 and the specific secretion pathways in lactating dairy cows. The metabolism of AFB1 and its biotransformation into AFM1 in lactating dairy cows are drawn in this review. Furthermore, recent data provide evidence that in the mammary tissue of lactating dairy cows, aflatoxins significantly increase the activity of a protein, ATP-binding cassette super-family G member 2 (ABCG2), an efflux transporter known to facilitate the excretion of various xenobiotics and veterinary drugs into milk. Further research should focus on identifying and understanding the factors that affect the expression of ABCG2 in the mammary gland of cows.

Discovering the Protective Effects of Resveratrol on Aflatoxin B1-Induced Toxicity: A Whole Transcriptomic Study in a Bovine Hepatocyte Cell Line

“…Conversely, the amount of highly toxic AFL increased with R concentration, thus indicating that this natural polyphenol impacts on AFB1 reduction, the reaction forming AFL in the liver [ 73 ]. Aflatoxicol can be reconverted to AFB1, thereby serving as a reservoir of AFB1 and thus prolonging the AFB1 residency time in the liver [ 74 ].…”

Luteolin Alleviates AflatoxinB1-Induced Apoptosis and Oxidative Stress in the Liver of Mice through Activation of Nrf2 Signaling Pathway

“…Aflatoxins are one of the most dangerous mycotoxins, produced mainly by Aspergillus flavus and Aspergillus parasiticus and usually found in agricultural environments and food commodities [ 1 ]. According to studies, even low levels of aflatoxins in the diet can be harmful to human health [ 2 , 3 ]. Currently, approximately 4.5 billion people are in danger of being exposed to aflatoxins, which cause 4.6–28.2% of all occurrences of hepatocellular carcinoma worldwide [ 4 , 5 ].…”

Detection of multimycotoxins in camel feed and milk samples and their comparison with the levels in cow milk

“…Aflatoxin M1 (AFM1), a hepatic metabolite of aflatoxin B1 (AFB1), is a frequently detected mycotoxin in animal milk and other body secretions (Flores‐Flores et al., 2015; Hassan, Al‐Thani, Atia, et al., 2018; Min et al., 2021). Like the parent toxin (AFB1), AFM1 is also a known carcinogen (toxicity is 10 times lower than AFB1) and is the only regulated mycotoxin in the milk.…”