Mangrove plants as a source of lead compounds for the development of new antiplasmodial drugs from South East coast of India.

Malaria is the world's leading killer among the infectious diseases. The treatment of malaria is mystified by the challenges of widespread resistance of the malaria parasites to cheap and affordable antimalarial drugs. The present study was made in an attempt to identify the in vitro antiplasmodial activity against mangrove plant parts. (Avicennia marina, Acanthus ilicifolius, Bruguiera cylindrica, Excoecaria agallocha, Rhizophora apiculata, and Rhizophora mucronata mangrove plant extracts exhibited in vitro antiplasmodial activity against Plasmodium falciparum). Of the selected mangrove plant parts, the bark extract of A. marina exhibited minimum concentration of inhibitory activities IC(50) 49.63 μg.ml(-1). The leaf extract of A. marina, the hypocotyl extract of B. cylindrica, the leaf extract of E. agallocha, the flower extract of R. mucronata, and the hypocotyl extract of R. apiculata showed IC(50) values between 50 and 100 μg.ml(-1). Statistical analysis reveals that significant antiplasmodial activity (P<0.05) was observed between the concentrations and time of exposure. The chemical injury to erythrocytes was also carried out, and it shows that there were no morphological changes in erythrocytes by the ethanolic extract of mangrove plants after 48 h of incubation. The in vitro antiplasmodial activity might be due to the presence of alkaloids, carboxylic acids, coumarins, saponins, flavonoids, xanthoproteins, tannins, phenols, sugars, resins, steroids, and proteins in the ethanolic extracts of mangrove plants. It is concluded from the present study that the ethanolic extracts of mangrove plant parts of A. marina possess lead compounds for the development of antiplasmodial drugs.