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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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1-Bromopropane (1-BP) is used as a cleaning agent or adhesive solvent in the workplace. In the present study, the hepatotoxic and immunotoxic effects of 1-bromopropane and its conjugation with glutathione (GSH) were investigated in female BALB/c mice. The animals were treated orally with 200, 500 and 1000 mg kg(-1) of 1-BP in corn oil for a dose response study or treated orally with 1000 mg kg(-1) of 1-BP for 6, 12, 24 and 48 h for a time course study. The hepatic and splenic contents of GSH were significantly decreased by 1-BP in a dose-dependent manner. S-propyl GSH was identified in livers following treatment with 1-BP by liquid chromatography-electrospray ionization tandem mass spectrometry. When the production of conjugates from 1-BP was investigated in livers following oral treatment with 1000 mg kg(-1) of 1-BP for 6, 12, 24 and 48 h, the GSH conjugates were detected maximally 6 h after treatment. Treatment of mice with 1-BP increased the serum activity of alanine aminotransferase dose-dependently. The oral 1-BP treatment significantly suppressed the antibody response to a T-dependent antigen and the production of splenic intracellular IL-2 in response to Con A in a dose-dependent manner. The present results suggested that 1-BP could cause hepatotoxicity and immunotoxicity as well as depletion of GSH content due to the formation of GSH conjugates.

The hepatotoxic effects of 1-bromopropane (1-BP) and its conjugation with glutathione were investigated in male ICR mice. A single dose (1000 mg/kg, po) of 1-BP in corn oil to mice significantly increased serum activities of alanine aminotransferase and aspartate aminotransferase. Glutathione (GSH) content was dose-dependently reduced in liver homogenates 12 h after 1-BP treatment. In addition, 1-BP treatment dose-dependently increased levels of S-propyl GSH conjugate at 12 h after treatment, as measured by liquid chromatography-electrospray ionization tandem mass spectrometry. The GSH conjugate was maximally increased in liver at 6 h after 1-BP treatment (1000 mg/kg), with a parallel depletion of hepatic GSH content. Finally, 1-BP induced the production of malondialdehyde in liver. The present results suggest that 1-BP might cause hepatotoxicity, including lipid peroxidation via the depletion of GSH, due to the formation of GSH conjugates in male ICR mice.