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

Abstract

Background: Wenqingyin (WQY) is a classic traditional Chinese medicine formula used to treat various inflammatory diseases. However, its protective activity against ferroptosis in the pathogenesis of sepsis-induced liver injury and underlying mechanisms remain unclear.

Purpose: This study aimed to determine the therapeutic efficacy and potential mechanism of action of WQY in sepsis-induced liver injury both in vivo and in vitro.

Methods: In vivo: Lipopolysaccharide was intraperitoneally injected into nuclear factor erythroid 2-related factor 2 (Nrf2) knockout (Nrf2^-/-) and wild-type mice to construct a septic liver injury mouse model. Experimental mice were intraperitoneally injected with ferroptosis-1 and intragastrically administered WQY. In vitro: LO2 hepatocytes were stimulated with erastin to activate ferroptosis and later treated with varying concentrations of WQY and an Nrf2 inhibitor (ML385). Pathological damage was evaluated following hematoxylin and eosin staining. Lipid peroxidation levels were assessed using malondialdehyde, superoxide dismutase, and glutathione, as well as reactive oxygen species fluorescent probes. JC-1 staining was performed to evaluate the mitochondrial membrane potential damage. Quantitative reverse transcription polymerase chain reaction and western blot assay were performed to detect the related gene and protein levels. The levels of inflammatory factors were measured using Enzyme-Linked Immunosorbent Assay kits.

Results: In vivo, sepsis-induced liver injury activated ferroptosis in mouse liver tissue. Fer-1 and WQY attenuated septic liver injury, which was associated with increased Nrf2 expression. Deletion of the Nrf2 gene led to aggravation of septic liver injury. The effect of WQY on the attenuation of septic liver injury was partially abolished by the knockdown of Nrf2. In vitro, erastin-induced ferroptosis resulted in decreased hepatocyte viability, lipid peroxidation, and mitochondrial membrane potential damage. WQY protected hepatocytes from erastin-induced ferroptosis by activating Nrf2. The attenuation effect of ferroptosis in hepatocytes by WQY was partially abolished by the inhibition of Nrf2.

Conclusion: Ferroptosis has a critical role in the development of sepsis-mediated liver injury. Inhibition of ferroptosis is a possible novel treatment strategy for alleviating septic liver injury. WQY attenuates sepsis-mediated liver injury by suppressing ferroptosis in hepatocytes, which is related to its ability to activate Nrf2.

Keywords: Nrf2, Sepsis-induced liver injury, Ferroptosis, Lipid peroxidation; Wenqingyin.