Wenqingyin suppresses ferroptosis in the pathogenesis of sepsis-induced liver injury by activating the Nrf2-mediated signaling pathway

Background: Wenqingyin (WQY) is a classic traditionalChinese medicine formula used to treat various inflammatorydiseases. However, its protective activity against ferroptosis inthe pathogenesis of sepsis-induced liver injury and underlying mechanismsremain unclear.

Purpose: This study aimed to determine thetherapeutic efficacy and potential mechanism of action of WQY in sepsis-inducedliver injury both in vivo and in vitro.

Methods: In vivo: Lipopolysaccharide wasintraperitoneally injected into nuclear factor erythroid 2-related factor 2(Nrf2) knockout (Nrf2^−/−) and wild-type mice to construct a septicliver injury mouse model. Experimental mice were intraperitoneally injectedwith ferroptosis-1 and intragastrically administered WQY. In vitro:LO2 hepatocytes were stimulated with erastin to activate ferroptosis and latertreated with varying concentrations of WQY and an Nrf2 inhibitor (ML385).Pathological damage was evaluated following hematoxylin and eosin staining. Lipidperoxidation levels were assessed using malondialdehyde, superoxidedismutase, and glutathione,as well as reactiveoxygen species fluorescentprobes. JC-1 staining was performed to evaluate the mitochondrialmembrane potential damage. Quantitativereverse transcription polymerase chain reaction and westernblot assay were performed to detect the related gene and proteinlevels. The levels of inflammatory factors were measured using Enzyme-LinkedImmunosorbent Assay kits.

Results: In vivo, sepsis-induced liver injuryactivated ferroptosis in mouse liver tissue. Fer-1 and WQY attenuated septicliver injury, which was associated with increased Nrf2 expression. Deletion ofthe Nrf2 gene led to aggravation of septic liver injury. The effect of WQY onthe attenuation of septic liver injury was partially abolished by the knockdownof Nrf2. In vitro, erastin-induced ferroptosis resulted indecreased hepatocyte viability, lipid peroxidation, and mitochondrial membranepotential damage. WQY protected hepatocytes from erastin-induced ferroptosis byactivating Nrf2. The attenuation effect of ferroptosis in hepatocytes by WQYwas partially abolished by the inhibition of Nrf2.

Conclusion: Ferroptosis has a critical role in thedevelopment of sepsis-mediated liver injury. Inhibition of ferroptosis is apossible novel treatment strategy for alleviating septic liver injury. WQYattenuates sepsis-mediated liver injury by suppressing ferroptosis inhepatocytes, which is related to its ability to activate Nrf2.