Qi-Shen-Tang alleviates retinitis pigmentosa by inhibiting ferroptotic features via the NRF2/GPX4 signaling pathway

Ferroptosis has been observed during retinal photoreceptor cell death, suggesting that it plays a role in retinitis pigmentosa (RP) pathogenesis. Qi-Shen-Tang (QST) is a combination of two traditional Chinese medicines used for the treatment of ophthalmic diseases; however, its mechanism of action in RP and ferroptosis remains unclear. Therefore, this study aimed to explore the effect and potential molecular mechanisms of QST on RP. QST significantly improved tissue morphology and function of the retina in the RP model mice. A significant increase in retinal blood flow and normalization of the fundus structure were observed in mice in the treatment group. After QST treatment, the level of iron and the production of malondialdehyde decreased significantly; the levels of superoxide dismutase and glutathione increased significantly; and the protein expression of glutathione peroxidase 4 (GPX4), glutathione synthetase, solute carrier family 7 member 11, and nuclear factor erythroid 2-related factor 2 (NRF2) increased significantly. The molecular docking results demonstrated potential interactions between the small molecules of QST and the key proteins of NRF2/GPX4 signaling pathway. Our results indicate that QST may inhibit ferroptosis by inhibiting the NRF2/GPX4 signaling pathway, thereby reducing RP-induced damage to retinal tissue.