INTERACTION OF BERBAMINE AND CHLOROQUINE OR ARTEMISININ AGAINST CHLOROQUINE-SENSITIVE AND CHLOROQUINE-RESISTANT PLASMODIUM-FALCIPARUM IN-VITRO

Antimalarial activity of berbamine (BB), alone or in combination with chloroquine (CQ) or artemisinin (qinghaosu, QHS), was studied using CQ-sensitive and -resistant strains of Plasmodium falciparum in vitro. BB was found to have antimalarial effects with IC50 values of 603 and 359 nM, respectively, for the drug-sensitive and -resistant strains of P. falciparum, indicating that BB exhibited some selective antimalarial activity against the drug-resistant parasite. Its antimalarial efficacy and selectivity appeared to be less than that of tetrandrine (TT), however, when BB was combined with CQ, an antagonistic interaction was found against the CQ-sensitive parasite, while a potentiating antimalarial action was observed with the CQ-resistant parasite. When BB was tested in combination with QHS, a complex interaction was found-one was additive for the CQ-sensitive parasite and the other was potentiating for the CQ-resistant parasite. The above data suggested that the BB combination with either CQ or QHS is a promising candidate for an antimalarial remedy to treat at least CQ-resistant falciparum parasites which cause malaria. (C) 1993 Wiley-Liss, Inc.