New insights into evodiamine attenuates IPEC-J2 cells pyroptosis induced by T-2 toxin - Activating Keap1-Nrf2/NF-κB signaling pathway through binding with Keap1.

T-2 toxin (T-2) is a highly toxic mycotoxin with a molecular weight of 466.52 g/mol. Evodiamine (EV), an alkaloid component of Evodia, has anti-inflammation and antioxidant properties. As a receptor of oxidative stress, Keap1 with a molecular weight of 70 kDa, is a molecular switch that controls the Nrf2 signaling pathway. In this paper, the effect of EV on Keap1-Nrf2/NF-κB pathway was investigated. Based on our research outcomes, it was observed that T-2 exposure substantially increased IPEC-J2 cells intracellular ROS levels and MDA accumulation, decreased SOD and CAT activities, disrupted intestinal tight junction (ZO-1, occludin, and claudin-1), and up-regulated pyroptosis-related protein (ASC, NLRP3, caspase-1, GSDMD, IL-1β, and IL-18). Additionally, EV could bind well with Keap1, the separating it from Nrf2, promoting Nrf2 into the nucleus, enhanced antioxidant enzyme activities, reduced the production of ROS, down-regulated NF-κB expression, alleviated T-2-induced pyroptosis, and restored tight junction protein expression. However, after treatment with the Nrf2 inhibitor ML385, ML385 reversed the protective effect of EV on IPEC-J2 cells. Collectively, EV can activate the Keap1-Nrf2/NF-κB signaling pathway via binding to Keap1, exert anti-inflammatory and antioxidant effects, inhibit the pyroptosis of IPEC-J2 cells triggered by T-2, and retore intestinal barrier function.