2.4. In vitro antiplasmodial assay
Filter sterilized extracts (100, 50, 25, 12.5, 6.25 and 3.125 毺g/mL) were incorporated in 96 well tissue culture plate containing 200 毺L of P. falciparum culture with fresh red blood cells diluted to 2% hematocrit.
Negative control was maintained with fresh red blood cells and 2% parasitized P. falciparum diluted to 2% hematocrit, positive control was maintained with parasitized blood cells culture treated with chloroquine and artemether[13].
Parasitaemia was evaluated after 48 h by Giemsa stain and the average percentage suppression of parasitaemia was calculated by the following formula: Average % suppression of parasitaemia = Average % parasitaemia in control – Average % parasitaemia in test/ Average % parasitaemia in control 伊 100.