Department of Life & Nanopharmaceutical Science, Kyung Hee University, Seoul, South Korea; Department of Oriental Pharmaceutical Science, College of Pharmacy, Kyung Hee University, Seoul, South Korea.
Department of Life & Nanopharmaceutical Science, Kyung Hee University, Seoul, South Korea.
J Ethnopharmacol. 2015 Jul 1;169:426-34. doi: 10.1016/j.jep.2015.04.029. Epub 2015 May 1.
Eclipta prostrate L. (syn. E. alba Hassk), commonly known as False Daisy, has been used in traditional medicine in Asia to treat a variety of diseases, including cancer. Although an anti-tumor effect has been suggested for E. prostrata, the exact anti-tumor effects and underlying molecular mechanisms of its bioactive compounds are poorly understood. The aim of this study was to identify compounds with anti-cancer activity from E. prostrata and to investigate their mechanism of action.
To assess cell viability, cell cycle progression, and apoptosis, we performed MTT assays and FACS analysis using Annexin and PI staining. We also investigated reactive oxygen species (ROS) production and caspase activation using flow cytometry and Western blot analysis, respectively. Cytosolic translocation of cytochrome c was measured using an ELISA kit. Antioxidants, MAPK signaling inhibitors, NADPH oxidase inhibitors, and siRNA were used to elucidate the molecular mechanism of action of the compound.
We isolated five terthiophenes from the n-hexane fraction of E. prostrata; of these, α-terthienylmethanol possessed potent cytotoxic activity against human endometrial cancer cells (Hec1A and Ishikawa) (IC50<1μM). The growth inhibitory effect of α-terthienylmethanol was mediated by the induction of apoptosis, as shown by the accumulation of sub-G1 and apoptotic cells. In addition, α-terthienylmethanol triggered caspase activation and cytochrome c release into the cytosol in a time-dependent manner. Moreover, α-terthienylmethanol increased the intracellular level of ROS and decreased that of GSH, and the antioxidants N-acetyl-l-cysteine and catalase significantly attenuated α-terthienylmethanol-induced apoptosis. We further demonstrated that inhibition of the NADPH oxidase attenuated α-terthienylmethanol-induced cell death and ROS accumulation in endometrial cancer cells.
Overall, these results suggest that α-terthienylmethanol, a naturally occurring terthiophene isolated from E. prostrata, induces apoptosis in human endometrial cancer cells by ROS production, partially via NADPH oxidase.
ETHNOPHARMACOLOGICAL 相关性：马齿苋（Eclipta prostrate L.），俗称假雏菊，在亚洲传统医学中被用于治疗多种疾病，包括癌症。虽然已经提出马齿苋具有抗肿瘤作用，但对于其生物活性化合物的确切抗肿瘤作用和潜在分子机制知之甚少。本研究的目的是从马齿苋中鉴定具有抗癌活性的化合物，并研究其作用机制。
为了评估细胞活力、细胞周期进程和细胞凋亡，我们使用 MTT 测定法和 Annexin 和 PI 染色的 FACS 分析进行了实验。我们还分别使用流式细胞术和 Western blot 分析研究了活性氧 (ROS) 的产生和半胱天冬酶的激活。使用 ELISA 试剂盒测量细胞色素 c 的细胞质易位。使用抗氧化剂、MAPK 信号通路抑制剂、NADPH 氧化酶抑制剂和 siRNA 来阐明该化合物的作用机制。
我们从马齿苋的正己烷部分分离出五种三噻吩；其中，α-三噻吩甲醇对人子宫内膜癌细胞（Hec1A 和 Ishikawa）具有很强的细胞毒性（IC50<1μM）。α-三噻吩甲醇的生长抑制作用是通过诱导细胞凋亡介导的，这表现在亚 G1 和凋亡细胞的积累上。此外，α-三噻吩甲醇在时间依赖性方式中触发半胱天冬酶的激活和细胞色素 c 向细胞质的释放。此外，α-三噻吩甲醇增加了细胞内 ROS 的水平并降低了 GSH 的水平，抗氧化剂 N-乙酰-l-半胱氨酸和过氧化氢酶显著减弱了α-三噻吩甲醇诱导的细胞凋亡。我们进一步证明，NADPH 氧化酶的抑制减弱了α-三噻吩甲醇诱导的子宫内膜癌细胞死亡和 ROS 积累。
总的来说，这些结果表明，α-三噻吩甲醇，一种从马齿苋中分离出来的天然三噻吩，通过 ROS 产生诱导人子宫内膜癌细胞凋亡，部分通过 NADPH 氧化酶。
