Institut für Pharmazeutische Biologie und Phytochemie IPBP, Westfälische Wilhelms-Universität Münster, Hittorfstrasse 56, D-48149, Münster, Germany.
J Ethnopharmacol. 2010 May 4;129(1):127-30. doi: 10.1016/j.jep.2010.02.015. Epub 2010 Feb 26.
The dichloromethane extract prepared from aerial parts of Ageratum conyzoides L. (Asteraceae), a plant commonly used in folk medicine for a number of illnesses including sleeping sickness, was recently found to exhibit a prominent activity (IC(50)=0.78 microg/mL) against bloodstream forms of Trypanosoma brucei rhodesiense, the etiologic agent of East African Human Trypanosomiasis (East African Sleeping Sickness). This extract also exhibited noticeable activities against Leishmania donovani (Kala-Azar, IC(50)=3.4 microg/mL) as well as Plasmodium falciparum (Malaria tropica, IC(50)=8.0 microg/mL). In the current study, we sought for potentially active constituents of Ageratum conyzoides.
Extracts prepared with solvents of different polarity were tested for activity against the above mentioned parasites as well as against Trypanosoma cruzi (Chagas' disease) and for cytotoxicity using established protocols. The dicholoromethane extract showed the highest level of activity and was chosen for phytochemical studies aimed at the isolation of potential active constituents.
Five highly methoxylated flavonoids along with the chromene derivative encecalol methyl ether were isolated. All isolated compounds were previously reported from Ageratum conyzoides. While the chromene turned out to be inactive against the tested parasites, the flavonoids showed activity against the protozoan pathogens, some in the lower micromolar range. However, none of these isolated compounds was as active as the crude extract. This is the first report on antiprotozoal activity of this plant species and some of its constituents. The chemical principle accounting for the high activity of the crude extract, however, remains to be identified.
从菊科植物 Ageratum conyzoides L.（俗称蓝雏菊）的地上部分提取的二氯甲烷提取物，最近被发现对布氏锥虫罗得西亚株（引起东非人类锥虫病（东非昏睡病）的病原体）的血液形式具有显著的活性（IC（50）=0.78μg/mL）。该提取物对利什曼原虫（黑热病，IC（50）=3.4μg/mL）和恶性疟原虫（热带疟疾，IC（50）=8.0μg/mL）也表现出明显的活性。在本研究中，我们寻找了 potentially active constituents of Ageratum conyzoides。
使用不同极性溶剂制备的提取物根据既定方案针对上述寄生虫以及 Trypanosoma cruzi（恰加斯病）进行了活性测试和细胞毒性测试。二氯甲烷提取物显示出最高水平的活性，并被选为旨在分离潜在活性成分的植物化学研究。
分离得到了五个高度甲氧基化的黄酮类化合物和色烯衍生物 encecalol 甲基醚。所有分离出的化合物均以前从 Ageratum conyzoides 中报道过。虽然色烯对测试的寄生虫没有活性，但黄酮类化合物对原生动物病原体表现出活性，有些在较低的微摩尔范围内。然而，这些分离出的化合物都没有粗提取物那么活跃。这是首次报道该植物物种及其某些成分具有抗原生动物活性。然而，仍需确定导致粗提取物高活性的化学原理。
