Investigation on Antimalarial Activity of Rhizome of Zingiber cassumunar Roxb. (Meik-tha-lin-oot)

This research aims to investigate the antimalarial activity of rhizome of Zingiber cassumunar Roxb. (Meik-tha-lin-oot). The preliminary phytochemical investigation revealed the presence of a-amino acids, carbohydrates, glycosides, organic acids, phenolic compounds, reducing sugars, saponins, starch and terpenoids. The various crude extracts such as PE (7.11%), 95% EtOH (3.44%), EtOAc (1.64%) and H2O (1.44%) extracts were prepared by successive solvent extraction method. Curcumin (orange amorphous crystal, 0.00317% yield, M.pt=183ºC) was isolated from EtOAc crude extract by using thin layer and column hromatographic separation techniques and identified by comparing with UV and FTIR spectral data of the standard curcumin. In vitro antimalarial activities of curcumin, ethanol and watery extracts were screened by using the reported method. The ethanol and watery extracts had no antimalarial activity (EC50 values=398.07 µg/ml and 501.00 µg/ml) whereas the isolated compound, curcumin was found to inhibit the growth of Plasmodium falciparum (EC50=101.74 µg/ml). On the other hand, the isolated compound, curcumin exhibited the moderate antimalarial activity and may be used as a potential compound to be tested for newer antimalarial agent.