Tripterygium Glycosides Extract-Induced Hepatic Cholestasis: A Mechanistic Study Using a Microfluidic Liver-on-a-Chip System.

Tripterygium glycosides extract (TGE), the primary active component of tripterygium glycosides tablets, is widely used for immune-related disorders but raises significant clinical concerns regarding cholestatic drug-induced liver injury. As conventional models fail to fully recapitulate the complex pathogenesis of traditional Chinese medicine toxicity, this study aimed to elucidate the mechanisms of TGE-induced cholestatic injury using a biomimetic microfluidic liver-on-a-chip platform. The chip integrated rat precision-cut liver slices (PCLSs) and human endothelial cells (EA.hy926) to simulate the hepatic sinusoidal microenvironment. Following TGE exposure (15-135 μg/mL for 12 and 24 h), vascular barrier integrity was maintained, while liver injury markers (ALT, AST, TBA, DBIL) significantly increased in a dose- and time-dependent manner, accompanied by progressive histopathological deterioration in PCLSs. Mechanistically, TGE triggered severe oxidative stress (decreased SOD/GSH/GSH-Px and increased MDA) and upregulated pro-inflammatory cytokines (IL-4 and IL-1β). Consequently, the expression of the bile acid receptor FXR and transporters (BSEP and MRP2) was significantly downregulated. In conclusion, TGE induces cholestatic liver injury via a sequential pathway: oxidative stress initiates an immune-inflammatory response, which subsequently suppresses the FXR/BSEP/MRP2 axis. Future studies should focus on developing fully humanized liver-on-a-chip systems to further validate these mechanisms and improve clinical translational significance.