Yu Dan Tong Formula inhibits NLRP3 inflammasome activation by suppressing Ca²⁺ influx in treating cholestatic liver disease.

BACKGROUND

Cholestatic liver disease (CLD) is a common disorder characterized by impaired bile flow that results in liver injury and fibrosis. However, current therapeutic options for CLD are limited and ineffective. Yu Dan Tong Formula (YDTF), a formulated Traditional Chinese Medicine (TCM), has been routinely used for over 50 years at Beijing Children's Hospital for the treatment of CLD in children. We previously found that YDTF can reduce jaundice and alleviate liver injury. However, the pharmacological mechanisms underlying the effects of YDTF on CLD remain unclear.

PURPOSE: This study aimed to investigate the pharmacological mechanisms of YDTF in the treatment of CLD, with a focus on NLRP3 inflammasome activation.

METHODS

Macrophage inflammasomes were activated by classical and non-classical NLRP3 agonists, including taurochenodeoxycholic acid (TCDCA). The effects of YDTF on inflammasome activation and inflammatory responses were assessed in an lipopolysaccharide (LPS)-induced murine model of systemic inflammation in C57BL/6 mice, and the underlying mechanisms were evaluated. The effects of YDTF on NLRP3 activation and its therapeutic potential in CLD were explored using an α-naphthylisothiocyanate (ANIT)-induced CLD model in C57BL/6 mice

RESULTS

YDTF inhibited NLRP3 activation in a dose-dependent manner with broad-spectrum inhibitory effects. Mechanistically, YDTF inhibited Ca²⁺ influx, thereby inhibiting apoptosis-associated speck-like protein (ASC) oligomerization, and subsequent inflammasome assembly and activation. In the ANIT-induced CLD mouse model, YDTF effectively suppressed NLRP3 inflammasome activation and reduced the magnitude of the inflammatory response. Furthermore, YDTF alleviated abnormal liver function and resolved liver injury.

CONCLUSIONS

YDTF effectively inhibited NLRP3 activation by inhibiting Ca²⁺ influx and significantly alleviated liver injury in the ANIT-induced CLD model. The inhibition of NLRP3 activation could represent a critical pharmacological strategy for the treatment of CLD. Additionally, our results suggest that YDTF may be beneficial in treating other NLRP3 inflammasome-driven diseases.