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.

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Intestinal epithelial cells are critical for nutrient absorption and defending against pathogen infection. Deoxynivalenol (Don), the most common mycotoxin, contaminates cereals and food throughout the world, causes serious damage to mammal intestinal mucosa, and appears as intestinal epithelial cell apoptosis and proliferation inhibition. Our previous study has found that milk-derived exosome ameliorates Don-induced intestinal damage, but the mechanism is still not fully understood. In this study, we demonstrated that Don downregulated the expression of miR-221/222 in intestinal epithelial cells, and exosome treatment reversed the inhibitory effect of Don on miR-221/222. Through immunofluorescence and flow cytometry analysis, we identified that miR-221/222 ameliorates Don-induced apoptosis and proliferation inhibition in intestinal epithelial cells. Through bioinformatics analyses and RNA immunoprecipitation analysis, we identified Phosphatase and tensin homolog (PTEN) is the target of miR-221/222. Through the PTEN interfering experiment, we found Don-induced apoptosis and proliferation inhibition relied on PTEN. Finally, through adenovirus to overexpress miR-221/222 in mice intestinal epithelial cells specifically, our results showed that miR-221/222 ameliorated Don-induced apoptosis and proliferation inhibition in intestinal epithelial cells by targeting PTEN. This study not only expands our understanding of how miR-221/222 and the host gene PTEN regulate intestinal epithelial cells defending against Don-induced damage, but also provides a new way to protect the development of the intestine.

Aquilaria (A.) sinensis is a medicinal plant widely grown in tropical South China. Given the abundant pruning waste of its leaves, the use of A. sinensis leaves is valuable. In this study, goats were fed a diet containing 20% A. sinensis leaves. Compared with the basal diet, feeding A. sinensis leaves to goats did not affect growth performance but considerably reduced the feeding cost. Strikingly, feeding A. sinensis leaves resulted in a significant decrease in the blood cholesterol levels (2.11 vs. 1.49 mmol/L, p = 0.01) along with a significant increase in the high-density lipoprotein levels (1.42 vs. 1.82 mmol/L, p = 0.01). There was also a tendency to lower the content of low-density lipoprotein levels in goats (0.78 vs. 0.45 mmol/L, p = 0.09). Furthermore, metabolomics analysis demonstrated that the reduction in cholesterol levels occurred in both the serum (0.387-fold change) and muscle (0.382-fold change) of goats during A. sinensis leaf feeding. The metabolic responses to feeding A. sinensis leaves suggest that the activation of lipolysis metabolism might happen in goats. These observed changes would be conducive to improving animal health and meat quality, ultimately benefiting human health.