Compound Sophorae Decoction Alleviates Ferroptosis in Colitis Rats via Activating Keap1/Nrf2/GPX4 Signaling Pathway

Compound sophorae decoction (CSD) has been extensively applied in clinic for the treatment of ulcerative colitis (UC). However, the effect and precise therapeutic mechanism have not been fully clarified. In this study, we systematically explored the protective efficacy and the underlying molecular mechanisms of CSD against UC.

The main constituents of CSD were analyzed by HPLC-MS/MS and TLC. H₂O₂-treated Caco-2 cells were employed to investigate the impact of CSD on ferroptosis and its underlying mechanism. The impacts of CSD on inflammation, oxidative stress, and ferroptosis in vitro were evaluated by ELISA, biochemical detection, or fluorescence probe. The UC model was established in rats by administering 5% DSS in the drinking water. The effects and safety of CSD on DSS-induced colitis were evaluated through daily body weight, DAI, colon length, and HE staining. In addition, cytokines (IL-1β, IL-6, TNF-α, and TGF-β) and ferroptosis-associated parameters (iNOS and PTGS2) were detected by ELISA. Antioxidant and oxidant enzyme activities (SOD, GSH, MDA, and NO) and lipid ROS in serum and colon tissue were measured by biochemical kit. Ferroptosis was determined by analysis of ferroptosis-associated proteins (Keap1, Nrf2, GPX4, and SLC7A11).

Then, 10 main active components were identified in CSD. CSD significantly attenuated DSS-induced intestinal injury and inflammation. Moreover, CSD notably decreased oxidative stress and lipid peroxidation. Mechanistically, CSD suppressed ferroptosis in DSS-induced UC and upregulated GPX4 and SLC7A11 expression through the activation of Nrf2 signaling in DSS-induced rats.

Collectively, this study demonstrated that CSD ameliorates ferroptosis in DSS-induced UC rats, with its protective effects attributed to the activation of the Keap1/Nrf2/GPX4 signaling pathway.