Integration of transcriptomics and metabolomics profiling reveals the metabolic pathways affected in dictamnine-induced hepatotoxicity in mice.

Dictamnine (DTN), a major furoquinoline alkoloid from Dictamni Cortex, was reported to induce hepatotoxicity. However, the underlying mechanism is unclear. In the present study, integrated transcriptomic and metabolomics analysis of mouse liver was performed in combination with serum biochemical and histopathological evaluation to investigate the potential mechanism. The results suggested that 640 mg/kg DTN significantly increased serum alanine transaminase and aspartate transaminase levels and induced serious cellular degeneration, with no changes occurring with 4 mg/kg DTN. Integrated analysis suggested that the metabolism of xenobiotics by cytochrome P450, drug metabolism-other enzymes, bile secretion and glutathione metabolism were the major metabolic pathways involved in DTN-induced hepatotoxicity. Notably, 640 mg/kg DTN exposure increased hepatic GSH, GSH peroxidase, superoxide dismutase and malondialdehyde, and decreased ROS, together with altered expression of Idh2 and Nedd9. Representative genes, including Mup12, Lipc, NTCP, MRP3, MRP4, CYP2E1, CYP2D9 and UGT1A9, in altered pathways were verified through PCR and Western blot. Collectively, the combined strategy of transcriptomics and metabolomics profiling could facilitate a better understanding for the discovery of metabolic pathways and that oxidative damage, ABC transporters and lipid metabolism might be the mechanisms linked to DTN-induced hepatotoxicity in mice. SIGNIFICANCE: Dictamnine (DTN) was reported to induce hepatotoxicity. Nevertheless, the underlying mechanism is unknown. This study is the first to utilize integrated transcriptomics and metabolomics in combination with general toxicity evaluation to characterize the potential molecular mechanism in DTN-induced hepatotoxicity in mice. We found that acute exposure to higher dose of DTN induced hepatocellular liver injury with more changes in biochemical parameters, genes and metabolites. Gene expression and metabolite profiles were more sensitive than general toxicity studies for detecting earlier hepatotoxicity. Integrated analysis suggested that oxidative damage, ABC transporters and lipid metabolism were closely correlated with DTN-induced hepatotoxicity. Overall, our results provide insights into the mechanism responsible for DTN-induced hepatotoxicity.