Graduate Institute of Chinese Medicine, China Medical University, Taichung, Taiwan.
Mutat Res. 2011 Dec 24;726(2):234-41. doi: 10.1016/j.mrgentox.2011.09.014. Epub 2011 Oct 1.
Safrole-2',3'-oxide (SAFO) is a reactive electrophilic metabolite of the hepatocarcinogen safrole, the main component of sassafras oil. Safrole occurs naturally in a variety of spices and herbs, including the commonly used Chinese medicine Xi xin (Asari Radix et Rhizoma) and Dong quai (Angelica sinensis). SAFO is the most mutagenic metabolite of safrole tested in the Ames test. However, little or no data are available on the genotoxicity of SAFO in mammalian systems. In this study, we investigated the cytotoxicity and genotoxicity of SAFO in human HepG2 cells and male FVB mice. Using MTT assay, SAFO exhibited a dose- and time-dependent cytotoxic effect in HepG2 cells with TC(50) values of 361.9μM and 193.2μM after 24 and 48h exposure, respectively. In addition, treatment with SAFO at doses of 125μM and higher for 24h in HepG2 cells resulted in a 5.1-79.6-fold increase in mean Comet tail moment by the alkaline Comet assay and a 2.6-7.8-fold increase in the frequency of micronucleated binucleated cells by the cytokinesis-block micronucleus assay. Furthermore, repeated intraperitoneal administration of SAFO (15, 30, 45, and 60mg/kg) to mice every other day for a total of twelve doses caused a significant dose-dependent increase in mean Comet tail moment in peripheral blood leukocytes (13.3-43.4-fold) and in the frequency of micronucleated reticulocytes (1.5-5.8-fold). Repeated administration of SAFO (60mg/kg) to mice caused liver lesions manifested as a rim of ballooning degeneration of hepatocytes immediately surrounding the central vein. Our data clearly demonstrate that SAFO significantly induced cytotoxicity, DNA strand breaks, micronuclei formation both in human cells in vitro and in mice. More studies are needed to explore the role SAFO plays in safrole-induced genotoxicity.
黄樟素 2',3'- 氧化物（SAFO）是一种肝致癌物黄樟素的反应性亲电代谢物，是黄樟油的主要成分。黄樟素天然存在于各种香料和草药中，包括常用的中药细辛（Asari Radix et Rhizoma）和当归（Angelica sinensis）。SAFO 是在 Ames 试验中测试的黄樟素最具致突变性的代谢物。然而，关于 SAFO 在哺乳动物系统中的遗传毒性，几乎没有或没有数据。在这项研究中，我们研究了 SAFO 在人 HepG2 细胞和雄性 FVB 小鼠中的细胞毒性和遗传毒性。使用 MTT 测定法，SAFO 在 HepG2 细胞中表现出剂量和时间依赖性细胞毒性作用，暴露 24 和 48 小时后的 TC（50）值分别为 361.9μM 和 193.2μM。此外，SAFO 在 HepG2 细胞中以 125μM 及更高剂量处理 24 小时，导致碱性彗星试验中的平均彗星尾巴瞬间增加 5.1-79.6 倍，细胞分裂阻断微核试验中的双核细胞微核频率增加 2.6-7.8 倍。此外，SAFO（15、30、45 和 60mg/kg）每隔一天腹腔内重复给药，共 12 次，导致外周血白细胞中的平均彗星尾巴瞬间（13.3-43.4 倍）和网织红细胞微核频率（1.5-5.8 倍）显著剂量依赖性增加。SAFO（60mg/kg）重复给药导致小鼠肝脏病变，表现为中央静脉周围肝细胞的气球样变性。我们的数据清楚地表明，SAFO 显著诱导了细胞毒性、DNA 链断裂、人细胞体外和小鼠体内的微核形成。需要进一步研究来探讨 SAFO 在黄樟素诱导的遗传毒性中的作用。
