ANTIMALARIAL ACTIVITY OF CRYPTOLEPINE AND ISOCRYPTOLEPINE, ALKALOIDS ISOLATED FROM CRYPTOLEPIS-SANGUINOLENTA

Cryptolepis sanguinolenta extracts are currently used by African herba lists to cure malaria but the compounds involved in its antimalarial a ctivity have not been identified. Two alkaloids, cryptolepine and isoc ryptolepine, have been isolated from the roots of C. sanguinolenta and their antimalarial activity evaluated. Both alkaloids possess intrins ic 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 k illing with an IC50 in the range of 0.2 to 0.6 mu M compared with an I C50 of about 0.8 mu M for isocryptolepine. The antimalarial activity o f cryptolepine was confirmed in vivo on the rodent malarial parasites Plasmodium vinckei petteri and Plasmodium berghei ANKA.