Tolterodine ameliorates inflammatory response and ferroptosis against LPS in human bladder epithelial cells

Bacterial endotoxin lipopolysaccharide (LPS)-induced inflammatory response and ferroptosis play an important role in urinary tract infections. Tolterodine has been used as a urinary tract antispasmodic and anticholinergic agent. However, the effects of Tolterodine against LPS-induced insults in human bladder epithelial cells (hBECs) have not been reported before. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase release assays to determine the cell viability, reactive oxygen species (ROS) and malondialdehyde level detection were used to determine the level of oxidative stress, enzyme-linked immunosorbent assay and Western blot analysis were used to detect the protein level. In the current study, we found that Tolterodine ameliorated LPS-induced production of ROS and lipid oxidation in hBECs. Interestingly, Tolterodine inhibited the production of interleukin 6, interleukin-1β, and tumor necrosis factor α. Also, Tolterodine reduced the levels of Fe²⁺ and suppressed ferroptosis by reducing the levels of glutathione peroxidase 4, prostaglandin-endoperoxide synthase 2, and acyl-CoA synthetase long-chain family member 4 in LPS-challenged bladder epithelial cells. Mechanistically, it was shown that Tolterodine restored the nuclear factor E2-related factor 2 (Nrf2)/nuclear factor-κB signaling. Importantly, inhibition of Nrf2 with its specific inhibitor ML385 abolished the protective effects of Tolterodine in the inflammatory response and ferroptosis, suggesting that the effects of Tolterodine are mediated by Nrf2. Based on these findings, we conclude that Tolterodine might serve as a promising agent for the treatment of LPS-induced bladder inflammation.