Department of Physiology, Federal University of Sergipe, São Cristóvão, Sergipe, Brazil.
Phytomedicine. 2013 May 15;20(7):615-21. doi: 10.1016/j.phymed.2013.01.015. Epub 2013 Feb 28.
Medicinal plants are one of the most important sources of drugs used in the pharmaceutical industry. Among traditional medicinal plants, Lippia gracilis Schauer (Verbenaceae) had been used for several medicinal purposes in Brazilian northeastern. In this study, leaf essential oil (EO) of L. gracilis was prepared using hydrodistillation. Followed by GC-MS analysis, its composition was characterized by the presence of thymol (55.50%), as major constituent. The effects of EO on cell proliferation and apoptosis induction were investigated in HepG2 cells. Furthermore, mice bearing Sarcoma 180 tumor cells were used to confirm its in vivo effectiveness. EO and its constituents (thymol, p-cymene, γ-terpinene and myrcene) displayed cytotoxicity to different tumor cell lines. EO treatment caused G1 arrest in HepG2 cells accompanied by the induction of DNA fragmentation without affecting cell membrane integrity. Cell morphology consistent with apoptosis and a remarkable activation of caspase-3 were also observed, suggesting induction of caspase-dependent apoptotic cell death. In vivo antitumor study showed tumor growth inhibition rates of 38.5-41.9%. In conclusion, the tested essential oil of L. gracilis leaves, which has thymol as its major constituent, possesses significant in vitro and in vivo antitumor activity. These data suggest that leaf essential oil of L. gracilis is a potential medicinal resource.
药用植物是制药工业中使用的药物的最重要来源之一。在传统药用植物中，巴西东北部的 Lippia gracilis Schauer（马鞭草科）被用于多种药用目的。在这项研究中，使用水蒸馏法从 L. gracilis 的叶子中提取精油（EO）。通过 GC-MS 分析，其特征在于存在主要成分百里酚（55.50％）。研究了 EO 对 HepG2 细胞增殖和细胞凋亡诱导的影响。此外，还使用携带 Sarcoma 180 肿瘤细胞的小鼠来确认其体内功效。EO 及其成分（百里酚、对伞花烃、γ-萜品烯和月桂烯）对不同的肿瘤细胞系表现出细胞毒性。EO 处理导致 HepG2 细胞 G1 期停滞，同时伴随着 DNA 片段化的诱导，而不影响细胞膜完整性。还观察到与细胞凋亡一致的细胞形态和 caspase-3 的显著激活，表明诱导 caspase 依赖性细胞凋亡。体内抗肿瘤研究表明肿瘤生长抑制率为 38.5-41.9％。总之，测试的 L. gracilis 叶子精油，其主要成分是百里酚，具有显著的体外和体内抗肿瘤活性。这些数据表明，L. gracilis 的叶子精油是一种有潜力的药用资源。
