Hepatic cytochrome P450s play a major role in monocrotaline-induced renal toxicity in mice
Abstract
Jun YAO, Cheng-gang LI, Li-kun GONG, Chen-chen FENG, Chun-zhu LI, Man GAO, Yang LUAN, Xin-ming QI*, Jin REN*
Center for Drug Safety Evaluation and Research, State Key Laboratory of New Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
Aim: Monocrotaline (MCT) in plants of the genus Crotalaria induces significant toxicity in multiple organs including the liver, lung and kidney. Metabolic activation of MCT is required for MCT-induced toxicity. In this study, we attempted to determine whether the toxicity of MCT in kidney was a consequence of the metabolic activation of MCT in the liver.
Methods: Liver-specific cytochrome P450 reductase-null (Null) mice, wild-type (WT) mice and CYP3A inhibitor ketoconazole-pretreated WT (KET-WT) mice were examined. The mice were injected with MCT (300, 400, or 500 mg/kg, ip), and hepatotoxicity and nephrotoxicity were examined 24 h after MCT treatment. The levels of MCT and its metabolites in the blood, liver, lung, kidney and bile were determined using LC-MS analysis.
Results: Treatment of WT mice with MCT increased the serum levels of alanine aminotransferase, hyaluronic acid, urea nitrogen and creatinine in a dose-dependent manner. Histological examination revealed that MCT (500 mg/kg) caused severe liver injury and moderate kidney injury. In contrast, these pathological abnormalities were absent in Null and KET-WT mice. After injection of MCT (400 and 500 mg/kg), the plasma, liver, kidney and lung of WT mice had significantly lower MCT levels and much higher N-oxide metabolites contents in compared with those of Null and KET-WT mice. Furthermore, WT mice had considerably higher levels of tissue-bound pyrroles and bile GSH-conjugated MCT metabolites compared with Null and KET-WT mice.
Conclusion: Cytochrome P450s in mouse liver play a major role in the metabolic activation of MCT and thus contribute to MCT-induced renal toxicity.
Keywords: monocrotaline; pyrrolizidine alkaloid; hepatic cytochrome P450s; ketoconazole; metabolic activation; hepatic toxicity; renal toxicity
This work was supported by Key Projects of National Science and Technology Pillar Program (2012ZX09301001-006 and 2012zx09302003) and the Public Service Platform Project of Shanghai Science and Technology Committee (11DZ2292500).
We thank Prof Yi-zheng WANG and Guo-yu PAN for helpful advice.
* To whom correspondence should be addressed.
E-mail xmqi@cdser.simm.ac.cn (Xin-ming QI); jren@cdser.simm.ac.cn (Jin REN)
Received 2013-04-26 Accepted 2013-09-09
Keywords:
Center for Drug Safety Evaluation and Research, State Key Laboratory of New Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
Aim: Monocrotaline (MCT) in plants of the genus Crotalaria induces significant toxicity in multiple organs including the liver, lung and kidney. Metabolic activation of MCT is required for MCT-induced toxicity. In this study, we attempted to determine whether the toxicity of MCT in kidney was a consequence of the metabolic activation of MCT in the liver.
Methods: Liver-specific cytochrome P450 reductase-null (Null) mice, wild-type (WT) mice and CYP3A inhibitor ketoconazole-pretreated WT (KET-WT) mice were examined. The mice were injected with MCT (300, 400, or 500 mg/kg, ip), and hepatotoxicity and nephrotoxicity were examined 24 h after MCT treatment. The levels of MCT and its metabolites in the blood, liver, lung, kidney and bile were determined using LC-MS analysis.
Results: Treatment of WT mice with MCT increased the serum levels of alanine aminotransferase, hyaluronic acid, urea nitrogen and creatinine in a dose-dependent manner. Histological examination revealed that MCT (500 mg/kg) caused severe liver injury and moderate kidney injury. In contrast, these pathological abnormalities were absent in Null and KET-WT mice. After injection of MCT (400 and 500 mg/kg), the plasma, liver, kidney and lung of WT mice had significantly lower MCT levels and much higher N-oxide metabolites contents in compared with those of Null and KET-WT mice. Furthermore, WT mice had considerably higher levels of tissue-bound pyrroles and bile GSH-conjugated MCT metabolites compared with Null and KET-WT mice.
Conclusion: Cytochrome P450s in mouse liver play a major role in the metabolic activation of MCT and thus contribute to MCT-induced renal toxicity.
Keywords: monocrotaline; pyrrolizidine alkaloid; hepatic cytochrome P450s; ketoconazole; metabolic activation; hepatic toxicity; renal toxicity
This work was supported by Key Projects of National Science and Technology Pillar Program (2012ZX09301001-006 and 2012zx09302003) and the Public Service Platform Project of Shanghai Science and Technology Committee (11DZ2292500).
We thank Prof Yi-zheng WANG and Guo-yu PAN for helpful advice.
* To whom correspondence should be addressed.
E-mail xmqi@cdser.simm.ac.cn (Xin-ming QI); jren@cdser.simm.ac.cn (Jin REN)
Received 2013-04-26 Accepted 2013-09-09