Einbond L S, Negrin A, Kulakowski D M, Wu H-A, Antonetti V, Jalees F, Law W, Roller M, Redenti S, Kennelly E J, Balick M J
The Institute of Economic Botany, The New York Botanical Garden, Bronx, NY 10458, USA; Lehman College, The City University of New York, Bronx, NY 10468, USA; Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.
Lehman College, The City University of New York, Bronx, NY 10468, USA; The CUNY Graduate Center, Biology, Biochemistry and Chemistry Ph.D. Programs, The City University of New York, New York, NY 10016, USA.
Phytomedicine. 2017 Jan 15;24:1-13. doi: 10.1016/j.phymed.2016.11.002. Epub 2016 Nov 5.
Epidemiological studies indicate there is low incidence of colon cancer in the South Pacific islands, including Fiji, West Samoa, and Vanuatu. Cancer incidence has been shown to be inversely associated with kava (Piper methysticum G. Forst.) ingestion. Hypothesis/Purpose: Kava prepared traditionally will inhibit the growth of human cancer cells. This investigation entails preparation and analysis of kava extracts and study of the growth inhibitory activity of the extracts, alone and combined with hibiscus.
We will prepare kava as in Micronesia - as a water extract, high in particulate content, alone or combined with sea hibiscus (Hibiscus tiliaceus L.) - and examine the components and growth inhibitory activity.
We obtained ground kava prepared in the traditional way from lateral roots and sea hibiscus mucilage and sap from different sources in Micronesia, and prepared water extracts (unfiltered, as well as filtered, since in traditional use the kava beverage contains a high particulate content) and partitions. We used the MTT assay to determine the growth inhibitory activity of the preparations on colon and breast cancer cells and nonmalignant intestinal epithelial cells. LC-MS analysis was used to examine the components of the kava and sea hibiscus extracts and partitions.
Traditional preparations of kava inhibit the growth of breast and colon cancer cells. Among the kava preparations, the order of decreasing activity was Fiji(2), Fiji(1), Hawaii; the unfiltered preparations from Fiji were more active than the filtered. Phytochemical analysis indicated that filtering reduced most kavalactone and chalcone content. For example, for Fiji(2), the ratio of dihydromethysticin in filtered/unfiltered kava was 0.01. Thus, for the extracts from Fiji, growth inhibitory activity correlates with the content of these compounds. Unfiltered and filtered kava from Fiji(1) were more active on malignant than nonmalignant intestinal epithelial cells. Since kava is prepared in Micronesia by squeezing the extract through sea hibiscus bark, we assayed the growth inhibitory activity of combinations of kava and sea hibiscus sap and found that sea hibiscus enhanced the growth inhibitory effect of kava.
Our results show that traditional kava, alone or combined with sea hibiscus, displays activity against human cancer cells and indicate it will be worthwhile to develop and further analyze these preparations to prevent and treat colon and other cancers. Our findings suggest it is important to examine the activity of plants in the form that people consume them.
流行病学研究表明，在包括斐济、西萨摩亚和瓦努阿图在内的南太平洋岛屿，结肠癌发病率较低。研究显示癌症发病率与卡瓦（胡椒科植物卡瓦Piper methysticum G. Forst.）的摄入量呈负相关。假设/目的：传统制备的卡瓦会抑制人类癌细胞的生长。本研究需要制备和分析卡瓦提取物，并研究提取物单独以及与芙蓉花联合使用时的生长抑制活性。
我们将按照密克罗尼西亚的方法制备卡瓦——制成颗粒含量高的水提取物，单独使用或与海芙蓉（Hibiscus tiliaceus L.）联合使用——并检测其成分和生长抑制活性。
我们从密克罗尼西亚不同来源获取了以传统方式制备的磨碎的卡瓦侧根、海芙蓉黏液和汁液，制备了水提取物（未过滤的以及过滤后的，因为在传统用法中卡瓦饮料含有高颗粒成分）和分配物。我们使用MTT法测定这些制剂对结肠癌细胞、乳腺癌细胞和非恶性肠上皮细胞的生长抑制活性。采用液相色谱 - 质谱联用（LC - MS）分析来检测卡瓦和海芙蓉提取物及分配物的成分。
传统制备的卡瓦能抑制乳腺癌细胞和结肠癌细胞的生长。在卡瓦制剂中活性从高到低的顺序为：斐济（2）、斐济（1）、夏威夷；来自斐济的未过滤制剂比过滤后的更具活性。植物化学分析表明，过滤会降低大多数卡瓦内酯和查耳酮的含量。例如，对于斐济（2），过滤后的/未过滤的卡瓦中二氢醉椒素的比例为0.01。因此，对于来自斐济的提取物，生长抑制活性与这些化合物的含量相关。来自斐济（1）的未过滤和过滤后的卡瓦对恶性肠上皮细胞的活性比对非恶性肠上皮细胞的活性更强。由于在密克罗尼西亚制备卡瓦是通过将提取物挤过海芙蓉树皮，我们检测了卡瓦与海芙蓉汁液组合的生长抑制活性，发现海芙蓉增强了卡瓦的生长抑制作用。
我们的结果表明，传统卡瓦单独或与海芙蓉联合使用时，对人类癌细胞具有活性，并表明开发和进一步分析这些制剂以预防和治疗结肠癌及其他癌症是值得的。我们的研究结果表明，以人们食用的形式研究植物的活性很重要。
