Unraveling the mechanism of tripterygium glycosides tablets-induced liver injury and the protective role of total glucosides of peony from immune-metabolic dysregulation to multi-cellular cascade.

Tripterygium glycosides tablets (TGT) are effective against autoimmune diseases but cause significant drug-induced liver injury (DILI) that limits clinical use. While TGT disrupts hepatic iron-lipid homeostasis and co-administration with Total Glucosides of Peony (TGP) mitigates its toxicity, the multi-cellular mechanisms remain unclear. In the current study, using integrative single-cell RNA sequencing and pathological validation in controlled mouse models (TGT vs.Con and TGT + TGP vs. TGT.) we elucidated a pathogenic iron-lipid axis driving hepatotoxicity via cellular cascades. TGT initiated Kupffer cell M1 polarization, releasing pro-inflammatory cytokines (TNF-α and IL-1β) that recruited neutrophils and induced NETosis-mediated oxidative stress. Concurrently, hepatic endothelial cells developed iron overload with increased Hamp and decreased Slc40a1, alongside inflammatory damage, while hepatocytes exhibited fatty acid metabolic dysfunction and lipid peroxidation, collectively propagating adipocyte hyperplasia and perilipin-2-driven lipid accumulation. Critically, TGP rescued toxicity by reversing Kupffer cell M1-to-M2 polarization with decreased iNOS and increased CD206, suppressing NET formation with decreased Ly6G and CitH3, alleviating iron deposition with reduced Prussian blue staining, and normalizing lipid metabolism with decreased oil red O staining and perilipin-2. This study identifies the iron-lipid axis as the central driver of TGT-induced liver injury, which is mediated by a sequential multi-cellular cascade involving Kupffer cells, neutrophils, endothelial cells, hepatocytes, and adipocytes. These findings position TGP as a multi-target detoxification agent that mechanistically disrupts this axis and establishes a cellular hierarchy blueprint for metabolic toxicity intervention, supporting its potential as a rescue strategy for precision medicine and detoxification screening.