Poster Presentation First Malaria World Congress 2018

Bioassay guided isolation and identification of antimalarial compound in Clausena lansium (Lour.) Skeels leaves (#417)

Kamonlawan Chomchopbun 1 , Woon-Chien Teng 1 , Deepika Singh 1 , Wilson Chan 1 , Xue-Ming Loy 1 , Cheng-Shoong Chong 1 , ็Han-Kiat Ho 1 , Ying Lee 2 , Rossarin Suwanarusk 3 , Bruce Malcolm Russell 4 , Laurent Renia 3 , Hwee-Ling Koh 1
  1. Pharmacy, Faculty of Science, National University of Singapore, Singapore
  2. Leeward Pacific Pte Ltd, Singapore
  3. Singapore Immunology Network, Agency for Science, Technology and Research (A*STAR), Singapore
  4. Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore

Malaria is a potentially life-threatening disease, affecting millions worldwide. With the emergence and spread of multi-drug resistance, the search for new antimalarial drugs is urgent and important. Medicinal plants have been sources of antimalarial drugs including quinine and artemisinin, from Cinchona bark and Artemisia annua respectively. Clausena lansium (Lour.) Skeels (C. lansium), a Chinese herbal medicine, has been traditionally used for the treatment of malaria. However, to the best of our knowledge, there are no reports of antimalarial studies carried out on C. lansium leaves despite its traditional use in malaria.

This study aims to carry out bioassay guided fractionation of C. lansium leaves to isolate and identify potential antimalarial compounds. Extraction of the leaves was conducted using maceration and acid-base alkaloidal extraction. Column chromatography was performed and antimalarial screening was carried out using the Schizont Maturation Assay on chloroquine-sensitive (3D7) and chloroquine-resistant (Dd2) strains of Plasmodium falciparum. The isolated compound was identified using High Performance Liquid Chromatography, Gas Chromatography-Mass Spectrometry, Liquid Chromatography-Mass Spectrometry, Fourier Transformation Infra-red spectroscopy and Nuclear Magnetic Resonance spectroscopy. Anisolactone was successfully isolated and identified in C. lansium leaves. It was found to be active against both 3D7 and Dd2 strains of Plasmodium falciparum, with IC50 values of 7.27±1.25 µg/mL and 4.22±1.43 µg/mL respectively. This is the first report of the antimalarial activity of anisolactone. The presence of an antimalarial compound in C. lansium leaves provides a scientific basis for their traditional use for the treatment of malaria. The results pave the way for further development of novel antimalarial drugs in the continuous fight against malaria. This work is supported by a collaborative research grant between the National University of Singapore and Leeward Pacific Pte Ltd (R-148-000-172-592 to HLK) and graduate research scholarships (to KC and WCT).