Antimalarial Activity of Tanzanian Plants and their Active Constituents: The Genus Uvaria ¹

Abstract

Petroleum ether, dichloromethane, and methanol extracts of leaves, stem, and root bark of nine Uvaria species: U. dependens, U. faulknerae, U. kirkii, U. leptocladon, U. lucida ssp. lucida, Uvaria sp. (Pande), U. scheffleri, and U. tanzaniae were tested for their in vitro activity against the multidrug resistant Kl strain of Plasmodium falciparum. The IC₅₀ values of the extracts varied between 5 and 500 µg/ml. The most active extracts were obtained from the stem and root bark of U. lucida ssp. lucida and Uvaria sp. (Pande) and the root bark of U. scheffleri, all of which had IC₅₀ values between 5 and 9 µg/ml. Among the compounds isolated, uvaretin, diuvaretin, and (8′,9′-dihydroxy)-3-farnesylindole were the most active (IC₅₀ = 3.49, 4.20, and 2.86 µg/ml, respectively).

Uvaria speciess - Annonaceae - antimalarial activity - dihydrochalcones - sesquiterpenoids