A novel KEAP1 inhibitor, tiliroside, activates NRF2 to protect against acetaminophen-induced oxidative stress and acute liver injury.

Background: Acetaminophen-induced acute liver injury (AILI) is one of the common causes of abrupt liver failure in numerous nations. Several previous studies revealed that tiliroside, a glycoside flavonoid, exerts neuroprotective and renal protective effects. However, whether it has hepatoprotective effects is not known. The objective of this research is to examine whether tiliroside can protect against AILI.

Methods: AILI mouse and cell models were performed to evaluate the protective effects of tiliroside. Molecular docking, cellular thermal shift assay, immunoprecipitation, and RNA-seq were performed to analyze the possible mechanisms of tiliroside.

Results: In vivo, tiliroside attenuated AILI in mice significantly, as evidenced by lower ALT and AST levels. Molecular docking, cellular thermal shift assay, and RNA-seq analysis revealed that tiliroside promoted the activation of nuclear factor erythroid 2-related factor 2 (NRF2) and the expression of its downstream genes through disruption of the NRF2-KEAP1 protein-protein interaction to inhibit KEAP1-mediated ubiquitination and degradation of NRF2, thereby inhibiting oxidative stress in the livers of AILI mice. Furthermore, hepatocyte-specific knockout of NRF2 greatly attenuated the hepatic-protective effects of tiliroside in mice. In vitro, tiliroside protected against acetaminophen-induced oxidative stress on cultured hepatocytes through activation of NRF2. In addition, NRF2 knockout markedly blunted the protection effects of tiliroside, suggesting that NRF2 mediates the hepatic-protective effects of tiliroside.

Conclusions: Our study demonstrated that tiliroside could protect against AILI by activating the KEAP1/NRF2 pathway, which primarily inhibits the processing of oxidative stress and cell death. Our results suggest that tiliroside could serve as a potential agent for the clinical treatment of AILI.