Solasonine alleviates high glucose‐induced podocyte injury through increasing Nrf2‐medicated inhibition of NLRP3 activation

The worldwide high prevalence of diabetic nephropathy is one of the common causes of renal failure in diabetic patients. Hyperglycemia‐caused podocyte injury is considered as a major contributor to diabetic kidney disease, accompanied by a chronic inflammatory condition. Pyroptosis, a characterized inflammatory form of programmed cell death, is believed to be involved in the pathogenesis of diabetic nephropathy. Solasonine (SS) is a natural alkaloid and received attention as a potential anticancer agent. However, its protective effect against hyperglycemia‐caused podocyte injury remains to be determined. Our study found that SS alleviates cell apoptosis, and reduces pyroptosis and oxidative damage in high glucose (HG)‐treated MPC5 podocytes. Pro‐inflammatory cytokines, including interleukin (IL)‐1β and IL‐18, and caspase‐1 activity were markedly suppressed by SS in HG‐treated MPC5 podocytes. SS also reduced HG‐induced oxidative damage in MPC5 podocytes. Nrf2 expression was activated by SS in vitro under a HG condition. In addition, Nrf2 silencing attenuated the protective effect of SS against apoptosis, pro‐inflammatory cytokines release, caspase‐1 activity, and oxidative damage in MPC5 podocytes under a HG condition. Taken together, our findings revealed for the first time that SS alleviated high glucose‐induced podocyte apoptosis, pyroptosis, and oxidative damage via regulating the Nrf2/NLRP3 signaling pathway. Our results indicate that SS has the potential as a therapeutic agent for podocyte injury in diabetic nephropathy.