Ruscogenin protects against cisplatin-induced apoptosis, inflammation, and oxidative stress of renal tubular epithelial cells

Purpose: To determine the potential effect of ruscogenin in cisplatin-induced nephrotoxicity. Methods: Rat renal tubular epithelial cells (NRK-52E) were treated with 50 mu M cisplatin to establish an in vitro cell model of nephrotoxicity. Cytotoxicity was assessed by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, flow cytometry, and western blot. Different concentrations of ruscogenin (2.5, 5, and 10 mu M) were incubated with cisplatin-treated NRK-52E cells. Alterations in the nod-like receptor family, the pyrin domain-containing protein (NLRP3) inflammasome, toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-kappa B), and nuclear factor erythropoietin-2-related factor 2 (Nrf2)/heme oxygenase 1 (HO-1) components were determined using western blot. Flow cytometry was also used to investigate the levels of reactive oxygen species (ROS). Results: Ruscogenin significantly increased cell viability (p < 0.01) and suppressed apoptosis of NRK-52E cells (p < 0.01), attenuating cisplatin-induced cytotoxicity. The NLRP3 inflammasome was activated in cisplatin-treated NRK-52E cells with enhanced NLRP3, interleukin 1 beta, and cleaved caspase-1; however, ruscogenin significantly decreased the expression of NLRP3 inflammasome components (p < 0.01). Ruscogenin attenuated cisplatin-induced expression of TLR4, myeloid differentiation primary response 88, and NF-kappa B. Further, cisplatin induction enhanced ROS formation, with increased malondialdehyde and decreased glutathione reductase and catalase levels. Ruscogenin attenuated cisplatin-induced ROS accumulation in NRK-52E cells through up-regulation of Nrf2 and HO-1. Conclusion: Ruscogenin protects against cisplatin-induced apoptosis, inflammation, and oxidative stress in renal tubular epithelial cells via suppression of TLR4/NF-kappa B activation and promotion of Nrf2/HO-1 activation. Therefore, ruscogenin provides a potential therapeutic strategy for mitigating cisplatin-induced nephrotoxicity.