Exploration for Traditional Antimalarial Medicinal Plants in Central Africa

在这个项目中，我们小组访问了刚果民主共和国，寻找和收集传统上用于治疗疟疾的药用植物。在金沙萨大学教授Kubata博士和给当地人开药用植物处方的当地治疗师的帮助下，我们收集了18种抗疟疾药用植物。首先，我们评估了对疟疾寄生虫的体外生长抑制活性。结果表明，15种药用植物对恶性疟原虫的增殖有较强的抑制作用。接下来，我们利用感染柏氏疟原虫的小鼠来评估体内抗疟效果。结果表明，三种药用植物，大戟，酸膜心，Morinda morindoides，显示出有吸引力的体内效力，而没有显示任何细胞毒性。此外，在生物测定指导下，对三种植物的MeOH提取物进行分离，分离出黄酮醇单糖苷、黄酮- c -糖苷和苯基丙烷缀合环烯醚萜类化合物作为主要活性成分。值得注意的是，这三种活性成分在化学结构上与已知的抗疟药有很大不同。此外，这三种活性原理对一种耐药菌株均显示出抗疟活性。

In this project, our group visited the Democratic Republic of Congo in order to search and collect medicinal plants used for malaria therapy traditionally. With the assistance of Dr. Kubata, a Professor of Kinshasa University and local healers who prescribe medicinal plants to local people we could collect 18 kinds of antimalarial medicinal plants. In the first instance, we evaluated for in vitro growth inhibitory activity on malaria parasites. As a result of our evaluation, 15 kinds of medicinal plants were shown to inhibit proliferation of Plasmodium falciparum potently. Next, We assessed in vivo antimalarial efficacy by use of P. berghei infected mice. In consequence, the three medicinal plants, Euphorbia hirta, Hymenocardia acida, Morinda morindoides, were revealed to exhibit attractive in vivo potency without showing any cytotoxicity. Furthermore, bioassay-guided separation of the MeOH extracts of the three plants resulted in the isolation of flavonol monoglycosides, flavonoid-C-glycosides, and phenyl propanoid conjugated iridoids as responsible active principles. It should be noteworthy that the three active principles are fairly different from known antimalarial drugs in terms of their chemical structures. In addition, all of the three active principles showed antimalarial activity against a drug resistance strain.