Su Miaoxian, Wu Xia, Chung Hau Yin, Li Yaolan, Ye Wencai
Department of Biology, The Chinese University of Hong Kong, Hong Kong, China.
Nat Prod Commun. 2009 Aug;4(8):1025-30.
Extracts and fractions prepared from five medicinal herbs used to treat cancer in Chinese folk medicine were tested for their antiproliferative activities on five cancer cell lines using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The MTT results revealed that the ethanolic extracts possessed stronger antiproliferative activities than the corresponding aqueous ones. The bioactive fractions of the ethanolic extracts were mostly found in n-hexane and/or ethyl acetate fractions, which by TLC analysis were shown to contain terpenes and/or phenolic compounds. The ethyl acetate fraction from the ethanolic extract of Elephantopus scaber showed the highest effect with IC50 values of less than 25 microg/mL on three susceptible cell lines, namely, PC-3 (human prostate carcinoma cell), CNE (human nasopharyngeal carcinoma epithelial cell) and HL-60 (human acute promyelocytic leukemia cell). Further isolation and analysis of this fraction led to the identification of three sesquiterpene lactones, two flavonoids and five triterpenes. MTT results showed that the sesquiterpene lactones were the most effective group with IC50 values ranging from 0.9 to 7.5 microM while the flavonoids possessed moderate to strong effect with IC50 values ranging from 17.3 to 42.6 microM. However, the triterpenes displayed weak effect with IC50 values larger than 50 microM. Among the active compounds, deoxyelephantopin, a sesquiterpene lactone, exhibited the strongest effect on the PC-3, CNE and HL-60 cells, with IC50 values of 4.6, 2.6 and 0.9 microM, respectively. Flow cytometric analysis showed that treatment with deoxyelephantopin caused subG-1 population augmentation in PC-3, CNE and HL-60 cells, suggesting apoptosis was induced in these cells.
采用3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐（MTT）法，对中国民间医学中用于治疗癌症的五种草药制备的提取物和馏分进行了测试，以检测它们对五种癌细胞系的抗增殖活性。MTT结果显示，乙醇提取物比相应的水提取物具有更强的抗增殖活性。乙醇提取物的生物活性馏分大多存在于正己烷和/或乙酸乙酯馏分中，通过薄层色谱分析表明这些馏分含有萜类化合物和/或酚类化合物。地胆草乙醇提取物的乙酸乙酯馏分对三种敏感细胞系，即PC-3（人前列腺癌细胞）、CNE（人鼻咽癌上皮细胞）和HL-60（人急性早幼粒细胞白血病细胞）显示出最高的效果，IC50值小于25μg/mL。对该馏分进行进一步的分离和分析，鉴定出三种倍半萜内酯、两种黄酮类化合物和五种三萜类化合物。MTT结果表明，倍半萜内酯是最有效的一组，IC50值在0.9至7.5μM之间，而黄酮类化合物具有中等至强的效果，IC50值在17.3至42.6μM之间。然而，三萜类化合物显示出较弱的效果，IC50值大于50μM。在活性化合物中，倍半萜内酯脱氧地胆草素对PC-3、CNE和HL-60细胞表现出最强的效果，IC50值分别为4.6、2.6和0.9μM。流式细胞术分析表明，用脱氧地胆草素处理导致PC-3、CNE和HL-60细胞中subG-1期细胞群增加，表明这些细胞中诱导了凋亡。
