Screening of the antimalarial activity of plants of the Cucurbitaceae family

Crude ethanolic extracts (CEEs) from two species of Cucurbitaceae, Cucurbita maxima and Momordica charantia (commonly called "abóbora moranga" and "melão de São Caetano", respectively) were assayed for antimalarial activity by the 4-d suppressive test. The CEE of dry C. maxima seeds showed strong antimalarial activity following oral administration (250 and 500 mg/kg), reducing by 50% the levels of parasitemia in Plasmodium berghei-infected mice. Treatment of normal animals with 500 mg/kg of the extract three days before intravenous injection of P. berghei caused a significant 30% reduction in parasitemic levels. No effect was observed when the animals were treated with the CEE only on the day of inoculation. Oral administration of the CEE of dry M. charantia leaves administered orally was ineffective up to 500 mg/kg in lowering the parasitemic levels of malarious mice.