Evaluation of the antiplasmodial and cytotoxicity potentials of husk fiber extracts from Cocos nucifera, a medicinal plant used in Nigeria to treat human malaria.

Nigeria is an African country where transmission of malaria occurs all year round and where most inhabitants use plants as remedies against parasitic diseases, including malaria. Some of such medicinal plants have their antimalarial efficacies already demonstrated experimentally, active compounds isolated and the mechanism of drug action suggested. Decoction of Cocos nucifera husk is used in the middle belt region of Nigeria as an antimalarial remedy. In our current studies, we tested extracts from husks of four varieties of C. nucifera, all collected in Brazil, where the plant fruit is popularly named 'coco'. The husks of coco mestiço, amarelo, anão and gigante collected in the Northeast of Brazil were used to prepare extracts at the Chemistry Department, Federal University of Alagoas (UFAL), which were then tested for their antiplasmodial activities, cytotoxicities and hemolytic activities in vitro. Only the hexane extract of coco mestiço was active against the blood forms of Plasmodium falciparum human malaria parasite maintained in continuous culture. Most extracts presented selectivity indices of <10, while hexane extract of coco mestiço had a selectivity index of 35, meaning that the extract is not toxic. The isolation of the active compounds from coco mestiço husks has not yet been done.