Antiplasmodial activities of some Ghanaian plants traditionally used for fever/malaria treatment and of some alkaloids isolated from Pleiocarpa mutica; in vivo antimalarial activity of pleiocarpine

Fourteen Ghanaian plants used in folk medicine to treat fever:malaria were screened for activity against Plasmodium falciparum (strain K1) and were te sted for general toxicity to the brine shrimp. Extracts from three of the p lants, Pleiocarpa mutica, Cleistopholis patens and Uvaria chamae were found to have significant antiplasmodial activity. The extract of U. chamae was toxic to brine shrimps. These findings lend support to the use of these pla nts in traditional medicine. Possible toxicity due to U. chamae is a cause for concern. Five known alkaloids, pleiocarpine (1), kopsinine (2), pleioca rpamine (3), eburnamine (4) and pleiomutinine (5) were isolated from the ro ots of P. mutica. This is the first report of the occurrence of (4) in P. m utica. Compound (5) was the most active against P. falciparum (IC50 = 5 muM ). Although (1) was inactive against malaria parasites in vitro, it was mod erately active against P. berghei in mice (25 mg kg(-1) daily for 4 days re duced parasitaemia by 28.5% compared to untreated controls). (C) 2001 Elsev ier Science Ireland Ltd. All rights reserved.