Thailand Center of Excellence in Drug Discovery and Development (TCEDDD), Thammasat University, Rangsit Campus, Rangsit, Pathumtani, 12121, Thailand.
Parasitol Res. 2013 Apr;112(4):1475-81. doi: 10.1007/s00436-013-3294-6. Epub 2013 Jan 23.
Malaria is one of the world's leading killer infectious diseases with high incidence and morbidity. The problem of multidrug-resistant Plasmodium falciparum has been aggravating particularly in Southeast Asia. Therefore, development of new potential antimalarial drugs is urgently required. The present study aimed to investigate antimalarial activities of a total of 27 medicinal plants and 5 herbal formulations used in Thai traditional medicine against chloroquine-resistant (K1) and chloroquine-sensitive (3D7) P. falciparum clones. Antimalarial activity of the ethanolic extracts of all plants/herbal formulations against K1 and 3D7 P. falciparum clones was assessed using SYBR Green I-based assay. All plants were initially screened at the concentration of 50 μg/ml to select the candidate plants that inhibited malaria growth by ≥50%. Each candidate plant was further assessed for the IC50 value (concentration that inhibits malaria growth by 50%) to select the potential plants. Selectivity index (SI) of each extract was determined from the IC50 ratio obtained from human renal epithelial cell and K1 or 3D7 P. falciparum clone. The ethanolic extracts from 19 medicinal plants/herbal formulation exhibited promising activity against both K1 and 3D7 clones of P. falciparum with survival of less than 50% at the concentration of 50 μg/ml. Among these, the extracts from the eight medicinal plants (Plumbago indica Linn., Garcinia mangostana Linn., Dracaena loureiri Gagnep., Dioscorea membranacea Pierre., Artemisia annua Linn., Piper chaba Hunt., Myristica fragrans Houtt., Kaempferia galanga Linn.) and two herbal formulations (Benjakul Formulation 1 and Pra-Sa-Prao-Yhai Formulation) showed potent antimalarial activity with median range IC50 values of less than 10 μg/ml against K1 or 3D7 P. falciparum clone or both. All except G. mangostana Linn. and A. annua Linn. showed high selective antimalarial activity against both clones with SI>10. Further studies on antimalarial activities in an animal model including molecular mechanisms of action of the isolated active moieties are required.
疟疾是全球主要致死性传染病之一，发病率和死亡率高。特别是在东南亚，恶性疟原虫对多种药物的耐药性问题日益严重。因此，迫切需要开发新的潜在抗疟药物。本研究旨在探讨泰国传统医学中使用的 27 种药用植物和 5 种草药配方对氯喹耐药（K1）和氯喹敏感（3D7）恶性疟原虫克隆的抗疟活性。采用 SYBR Green I 法评估所有植物/草药配方的乙醇提取物对 K1 和 3D7 恶性疟原虫克隆的抗疟活性。所有植物均在 50μg/ml 的浓度下进行初步筛选，以选择抑制疟原虫生长≥50%的候选植物。进一步评估每个候选植物的 IC50 值（抑制疟原虫生长 50%的浓度），以选择潜在植物。从人肾上皮细胞和 K1 或 3D7 恶性疟原虫克隆获得的 IC50 比值确定每个提取物的选择性指数（SI）。19 种药用植物/草药配方的乙醇提取物对 K1 和 3D7 恶性疟原虫克隆均表现出良好的活性，在 50μg/ml 的浓度下存活率低于 50%。其中，8 种药用植物（白花丹、山竹、龙血竭、穿龙薯蓣、青蒿、胡椒、肉豆蔻、益智）和 2 种草药配方（Benjakul 配方 1 和 Pra-Sa-Prao-Yhai 配方）的提取物表现出较强的抗疟活性，对 K1 或 3D7 恶性疟原虫克隆或两者的中值 IC50 值均小于 10μg/ml。除山竹和青蒿外，所有植物对两种克隆均表现出较高的选择性抗疟活性，SI>10。需要进一步在动物模型中研究抗疟活性，包括分离的活性成分的作用机制。
