Center for Developmental Therapeutics, Seattle Children's Research Institute, Division of Gastroenterology and Hepatology, Department of Pediatrics, University of Washington, Seattle, WA 98101, USA.
Toxicol Appl Pharmacol. 2012 Jun 15;261(3):248-54. doi: 10.1016/j.taap.2012.03.025. Epub 2012 Apr 11.
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.
蝙蝠葛苏林碱是从防己科蝙蝠葛中分离得到的主要生物活性成分，具有广泛的药理活性，具有很大的临床应用潜力。最近，我们发现腹腔内暴露于蝙蝠葛苏林碱会导致小鼠肺部选择性损伤。鉴定出蝙蝠葛苏林碱的醌甲醚代谢物，并提示与蝙蝠葛苏林碱的肺毒性有关。本研究评估了蝙蝠葛苏林碱在培养细胞和小鼠中的凋亡作用，确定了暴露于蝙蝠葛苏林碱后细胞谷胱甘肽 (GSH) 含量的变化，研究了 GSH 耗竭在蝙蝠葛苏林碱诱导的细胞毒性和凋亡中的作用，并研究了 CYP3A 在蝙蝠葛苏林碱诱导的 GSH 耗竭和凋亡中的作用。发现蝙蝠葛苏林碱可诱导 NL-20 细胞凋亡。此外，腹腔内给予蝙蝠葛苏林碱可导致小鼠肺部 GSH 耗竭和凋亡。酮康唑，CYP3A 的抑制剂，可逆转腹腔内给予蝙蝠葛苏林碱的小鼠肺部细胞 GSH 耗竭，并对小鼠肺部蝙蝠葛苏林碱诱导的凋亡具有保护作用。这表明代谢激活参与了蝙蝠葛苏林碱诱导的 GSH 耗竭、细胞毒性和凋亡。谷胱甘肽耗竭剂 L-丁硫氨酸亚砜可增强蝙蝠葛苏林碱诱导的细胞毒性和凋亡作用。我们提出蝙蝠葛苏林碱被代谢为醌甲醚中间体，消耗细胞内 GSH，GSH 的耗竭可能引发和/或加剧蝙蝠葛苏林碱诱导的细胞毒性和凋亡。
