Antimalarial Activity of<i>Croton macrostachyus</i>Stem Bark Extracts against<i>Plasmodium berghei In Vivo</i>

Abstract

There is an increasing need for innovative drug and prophylaxis discovery against malaria. The aim of the present study was to test <i>in vivo</i> antiplasmodial activity of <i>Croton macrostachyus</i> H. (Euphorbiaceae) stem bark extracts from Kenyan folkloric medicine. Inbred Balb/c mice were inoculated with erythrocytes parasitized with <i>Plasmodium berghei</i> (ANKA). Different doses (500, 250, and 100 mg/kg) of <i>C. macrostachyus</i> ethyl acetate, methanol, aqueous, and isobutanol extracts were administrated either after inoculation (Peters' 4-day suppressive test) or before inoculation (chemoprotective test) of the parasitized erythrocytes. All the extracts showed significant suppression of parasitemia compared to control (<i>p</i> < 0.001): for the ethyl acetate extract in the range of 58-82%, for the methanol extract in the range of 27-68%, for the aqueous extract in the range of 24-72%, and for the isobutanol extract in the range of 61-80%. Chemoprotective effect was significant (<i>p</i> < 0.001) and the suppression caused by the ethyl acetate extract was between 74 and 100%, by the methanol extract between 57 and 83%, and by the isobutanol extract between 86-92%. The study showed that it is possible to inhibit the growth of the parasites by various stem bark extracts of <i>C. macrostachyus</i> in Balb/c mice supporting the folkloric use of the plant against malaria.