Tuberculosis is one of the top causes of death among curable infectious diseases; it is an airborne infectious disease that killed 1.1 million people worldwide in 2010. Anti-tuberculosis drug-induced liver injury is the primary cause of drug-induced liver injury (DILI). Rifampicin is one of the most common anti-tuberculosis therapies and has well-known hepatotoxicity. To understand the mechanism of rifampicin-induced liver injury, we performed a global proteomic analysis of liver proteins by LC-MS/MS in a mouse model after the oral administration of 177 and 442.5 mg/kg rifampicin (LD10 and LD25) for 14 days. Based on the biochemical parameters in the plasma after rifampicin treatment, the hepatotoxic effect of rifampicin in the mouse liver was defined as a mixed liver injury. In the present study, we identified 1101 proteins and quantified 1038 proteins. A total of 29 and 40 proteins were up-regulated and 27 and 118 proteins were down-regulated in response to 177 and 442.5 mg/kg rifampicin, respectively. Furthermore, we performed Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses to characterize the mechanism of rifampicin-induced hepatotoxicity. In the molecular function category, glutathione transferase activity was up-regulated and proteins related to arachidonic acid metabolism were down-regulated. In the KEGG pathway enrichment-based clustering analysis, the peroxisome proliferator-activated receptor-γ (PPARγ) signaling pathway, cytochrome P450, glutathione metabolism, chemical carcinogenesis, and related proteins increased dose-dependently in rifampicin-treated livers. Taken together, this study showed in-depth molecular mechanism of rifampicin-induced liver injury by comparative toxicoproteomics approach.

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Ginseng (Panax ginseng Meyer) is a popular traditional herbal medicine used worldwide. Patients often take ginseng preparations with other medicines where the ginseng dose could exceed the recommended dose during long‐term administration. However, ginseng–drug interactions at high doses of ginseng are poorly understood. This study showed the possibility of herb–drug interactions between the Korean red ginseng (KRG) extract and cytochrome P450 (CYP) substrates in higher administration in mice. The CYP activities were determined in vivo after oral administration of KRG extract doses of 0.5, 1.0, and 2.0 g/kg for 2 or 4 weeks by monitoring the concentration of five CYP substrates/metabolites in the blood. The area under the curve for OH‐midazolam/midazolam catalysed by CYP3A was increased significantly by the administration of 2.0 g/kg KRG extract for 2 and 4 weeks. CYP3A‐catalysed midazolam 1ʹ‐hydroxylation also increased significantly in a dose‐ and time‐dependent manner in the S9 fraction of mouse liver which was not related to induction by transcription. Whereas CYP2D‐catalysed dextromethorphan O‐deethylation decreased in a dose‐ and time‐dependent manner in vivo. In conclusion, interactions were observed between KRG extract and CYP2D and CYP3A substrates at subchronic–high doses of KRG administration in mice.

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Cocktail substrates are useful in investigating drug-drug interactions (DDI) that can rapidly identify the cytochrome P450 (CYP) isoforms that interact with test drugs. In this study, we developed and validated five probe drugs for CYP1A, CYP2B, CYP2C, CYP2D, and CYP3A using LC-MS/MS to determine CYP activities in mice. The five probe substrates were caffeine (2 mg/kg), bupropion (30 mg/kg), omeprazole (4 mg/kg), dextromethorphan (40 mg/kg), and midazolam (2 mg/kg) for CYP1A, CYP2B, CYP2C, CYP2D, and CYP3A, respectively. The cocktail substrates were orally administered to male 5-week-old ICR mice over 0-240 min. The analytical method was validated; it showed high selectivity, linearity, and acceptable accuracy. We confirmed the lack of interaction of this cocktail in the control state (no effect of CYP inducer or inhibitor) and suggested AUC (metabolite/substrate) as a unit to evaluate DDI in vivo. In addition, the cocktail assay was applied for the determination of pharmacokinetic parameters against phenobarbital as a selective CYP2B inducer and ketoconazole as a strong CYP3A inhibitor. The concentration of cocktail substrates and the LC-MS/MS method were optimized. In conclusion, we developed a simultaneous and comprehensive analysis system for predicting potential DDI in mice.