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，以寻找和收集传统上用于治疗疟疾的药用植物。在金沙萨大学教授库巴塔博士和给当地人开药草的当地医生的帮助下，我们收集了18种抗疟疾药用植物。首先，我们评估了体外对疟疾寄生虫的生长抑制活性。评价结果表明，15种药用植物对恶性疟原虫有较强的抑制作用。接下来，我们利用感染伯氏疟原虫的小鼠评估了体内的抗疟疾效果。因此，这三种药用植物，一品红，膜心膜，巴戟天，显示出诱人的体内药效，而没有任何细胞毒性。此外，在生物测定的指导下对三种植物的甲醇提取物进行分离，得到黄酮醇单糖苷、黄酮类-C-糖苷和苯丙烷类共轭环烯醚萜作为有效成分。值得注意的是，这三种有效成分在化学结构上与已知的抗疟疾药物有很大不同。此外，所有三种活性成分都显示出对耐药菌株的抗疟疾活性。

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.