Dihydromyricetin attenuates aflatoxin B1-induced IEC-6 cell damage and intestinal damage in mice by activating the Nrf2/HO-1 signaling pathway and modulation of gut microbiota.

Aflatoxin B1 (AFB1) is commonly found in food and feed and has toxic effects on the gastrointestinal tract, impacting public health and livestock development. Dihydromyricetin (DHM) is a natural oxanthrone that has been proven to have significant protective effects on the intestines. This study aimed to elucidate the potential mechanism of DHM alleviating AFB1 exposure-intestinal toxicity in mice. In vitro , rat small intestinal crypt epithelial cells (IEC-6) were treated with aflatoxin B1 (0–120 μmol/L) and DHM (0–320 μmol/L). In vivo , BALB/c mice were divided into four groups: control, AFB1(200 μg/kg), DHM-L (AFB1 + DHM-100 mg/kg), and DHM-H (AFB1 + DHM-200 mg/kg), and gavaged for 30 days. The results showed that the viability of IEC-6 cells decreased with increasing mycotoxin concentration. In addition, RT-qPCR, Western blot, and immunofluorescence results showed that DHM significantly reversed AFB1-induced down-regulation of tight junction proteins, inhibition of the Nrf2/HO-1 signaling pathway, increased expression levels of Caspase-3, Bax, and inflammatory factors, and decreased Bcl-2 levels. In in vivo experiments, we also found that chorionic villus height and crypt depth, expression levels of tight junction proteins, Nrf2/HO-1 signaling pathway, Bax, Bcl-2, Caspase-3, and inflammatory factors, as well as intestinal microbiota, were significantly adversely affected in AFB1-exposed mice. However, the microbial diversity was significantly improved and enhanced by the DHM intervention. In conclusion, DHM intervention attenuated aflatoxin B1-induced intestinal injury by remodeling the gut microbiota, activating the Nrf2/HO-1 signaling pathway, strengthening the intestinal barrier, reducing apoptosis, and inhibiting the release of pro-inflammatory cytokines. • DHM attenuated intestinal mucosal injury by regulating the tight junction protein. • DHM attenuated intestinal mucosal injury by activating the Nrf2/HO-1 signaling pathway and controlling ROS content. • DHM controlled the content of Bax and Caspase-3 and up-regulated the level of Bcl-2 to prevent AFB1-induced apoptosis. • DHM effectively attenuated AFB1-induced inflammatory factor levels of IL-1β, IL-6, TNF-α, NF-kB, and p-NF-kB in the intestine. • DHM corrected AFB1-induced gut microbiota dysbiosis and enhanced microbial diversity in the gut.