Antimalarial Activity of Cryptolepine and Isocryptolepine, Alkaloids Isolated fromCryptolepis sanguinolenta

Abstract

Cryptolepis sanguinolenta extracts are currently used by African herbalists to cure malaria but the compounds involved in its antimalarial activity have not been identified. Two alkaloids, cryptolepine and isocryptolepine, have been isolated from the roots of C. sanguinolenta and their antimalarial activity evaluated. Both alkaloids possess intrinsic inhibitory activity against the human malaria parasite, Plasmodium falciparum in vitro, whatever the chloroquine-resistance status of the strains used. Cryptolepine was slightly more efficient for parasite killing with an IC50 in the range of 0.2 to 0.6 μMSC compared with an IC50 of about 0.8 μMSC for isocryptolepine. The antimalarial activity of cryptolepine was confirmed in vivo on the rodent malarial parasites Plasmodium vinckei petteri and Plasmodium berghei ANKA.