title: CYP3A-mediated apoptosis of dauricine in cultured human bronchial epithelial cells and in lungs of CD-1 mice.
abstract: Dauricine is the major bioactive component isolated from the root of Menispermum dauricum DC and has shown promising pharmacologic activities with a great potential for clinical use. Recently, we found that intraperitoneal exposure of dauricine produced selective pulmonary injury in mice. A quinone methide metabolite of dauricine was identified and is suggested to be associated with the pulmonary toxicity of dauricine. The present study evaluated the apoptotic effect of dauricine in cultured cells and mice, determined the change in cellular glutathione (GSH) contents after exposure to dauricine, investigated the role of GSH depletion in dauricine-induced cytotoxicity and apoptosis, and examined the role of CYP3A in dauricine-induced GSH depletion and apoptosis. Dauricine was found to induce apoptosis in NL-20 cells. Additionally, intraperitoneal administration of dauricine caused GSH depletion and apoptosis in lungs of mice. Treatment with ketoconazole, an inhibitor of CYP3A, reversed cellular GSH depletion in lungs of mice given dauricine and showed protective effect on dauricine-induced apoptosis in lungs of mice. This indicates that metabolic activation is involved in dauricine-induced GSH-depletion, cytotoxicity and apoptosis. The glutathione depletor L-buthionine sulfoximine showed potentiating effect on cytotoxicity and apoptosis induced by dauricine. We propose that dauricine is metabolized to a quinone methide intermediate which depletes cellular GSH, and the depletion of GSH may trigger and/or intensify the cytotoxicity and apoptosis induced by dauricine.
authors.affiliation: Center for Developmental Therapeutics, Seattle Children's Research Institute, Division of Gastroenterology and Hepatology, Department of Pediatrics, University of Washington, Seattle, WA 98101, USA.
authors.forename: Hua
authors.initials: H
authors.lastname: Jin
authors.forename: Shuijie
authors.initials: S
authors.lastname: Shen
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Chen
authors.forename: Dafang
authors.initials: D
authors.lastname: Zhong
authors.forename: Jiang
authors.initials: J
authors.lastname: Zheng
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D044182:Benzylisoquinolines / Q000633:toxicity*; D015153:Blotting, Western; D001980:Bronchi / Q000166:cytology* / Q000187:drug effects; D019328:Buthionine Sulfoximine / Q000494:pharmacology; D053148:Caspase 3 / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D051544:Cytochrome P-450 CYP3A / Q000502:physiology*; D065692:Cytochrome P-450 CYP3A Inhibitors; D045304:Cytochromes c / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004847:Epithelial Cells / Q000187:drug effects*; D005434:Flow Cytometry; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D020287:In Situ Nick-End Labeling; D007654:Ketoconazole / Q000494:pharmacology; D008168:Lung / Q000166:cytology* / Q000187:drug effects; D008297:Male; D051379:Mice; D044005:Tetrahydroisoquinolines / Q000633:toxicity*; D051025:bcl-Associated Death Protein / Q000378:metabolism
chemical_list: D044182:Benzylisoquinolines; D065692:Cytochrome P-450 CYP3A Inhibitors; D004791:Enzyme Inhibitors; D044005:Tetrahydroisoquinolines; D051025:bcl-Associated Death Protein; D019328:Buthionine Sulfoximine; C035934:dauricine; D045304:Cytochromes c; D051544:Cytochrome P-450 CYP3A; D053148:Caspase 3; D005978:Glutathione; D007654:Ketoconazole