Ezetimibe ketone protects against renal ischemia-reperfusion injury and attenuates oxidative stress via activation of the Nrf2/HO-1 signaling pathway.

Recently, ezetimibe (EZM) has been suggested to be a potent Nrf2 activator that is important for preventing oxidative stress. Interestingly, we found that its metabolite ezetimibe ketone (EZM-K) also has antioxidant effects. Thus, we investigated the role of EZM-K in preventing renal ischemia‒reperfusion injury (RIRI). Cultured NRK-52E cells were subjected to simulated IR with or without EZM-K. Rats were used to simulate in vivo experiments. EZM-K alleviated HO-induced apoptosis and reactive oxygen species (ROS) and upregulated Nrf2 and HO-1 levels in NRK-52E cells. A HO-1 and a Nrf2 inhibitor reversed the protective effects of EZM-K. In the rat RIRI model, pretreatment with EZM-K activated the Nrf2/HO-1 signaling pathway, suppressed tubular injury and inflammation, and improved renal function. EZM-K significantly prevented renal injury caused by ischemia‒reperfusion via the Nrf2/HO-1 signaling axis both in vivo and in vitro. The other metabolite of EZM, ezetimibe glucuronide (EZM-G) had no protective effects against ROS in RIRI. EZM-G also had no antioxidant effects and could not activate Nrf2/HO-1 signal pathway. Our findings also indicated the therapeutic potential of EZM-K in preventing RIRI.