Screening of a library of traditional Chinese medicines to identify anti-malarial compounds and extracts

• Published in: Malaria Journal
• Main Authors: Motohiro Nonaka, Yuho Murata, Ryo Takano, Yongmei Han, Md. Hazzaz Bin Kabir, Kentaro Kato
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2018
• Subjects: Antimalarial drugs; Drug screening; Traditional Chinese medicine; Plasmodium falciparum; Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic
• Online Access: https://doi.org/10.1186/s12936-018-2392-4; https://doaj.org/article/0c28a0b7f076422982fda379c5acb7f8

Abstract Background Malaria is a major infectious disease in the world. In 2015, approximately 212 million people were infected and 429,000 people were killed by this disease. Plasmodium falciparum, which causes falciparum malaria, is becoming resistant to artemisinin (ART) in Southeast Asia; therefore, new anti-malarial drugs are urgently needed. Some excellent anti-malarial drugs, such as quinine or ART, were originally obtained from natural plants. Hence, the authors screened a natural product library comprising traditional Chinese medicines (TCMs) to identify compounds/extracts with anti-malarial effects. Methods The authors performed three assays: a malaria growth inhibition assay (GIA), a cytotoxicity assay, and a malaria stage-specific GIA. The malaria GIA revealed the anti-malarial ability and half-maximal inhibitory concentrations (IC50) of the natural products, whereas the malaria stage-specific GIA revealed the point in the malaria life cycle where the products exerted their anti-malarial effects. The toxicity of the products to the host cells was evaluated with the cytotoxicity assay. Results Four natural compounds (berberine chloride, coptisine chloride, palmatine chloride, and dehydrocorydaline nitrate) showed strong anti-malarial effects (IC50 < 50 nM), and low cytotoxicity (cell viability > 90%) using P. falciparum 3D7 strain. Two natural extracts (Phellodendri cortex and Coptidis rhizoma) also showed strong antiplasmodial effects (IC50 < 1 µg/ml), and low cytotoxicity (cell viability > 80%). These natural products also demonstrated anti-malarial capability during the trophozoite and schizont stages of the malaria life cycle. Conclusions The authors identified four compounds (berberine chloride, coptisine chloride, palmatine chloride, and dehydrocorydaline nitrate) and two extracts (Phellodendri cortex and Coptidis rhizoma) with anti-malarial activity, neither of which had previously been described. The IC50 values of the compounds were comparable to that of chloroquine and better ...