Mh. Alin et A. Bjorkman, CONCENTRATION AND TIME DEPENDENCY OF ARTEMISININ EFFICACY AGAINST PLASMODIUM-FALCIPARUM IN-VITRO, The American journal of tropical medicine and hygiene, 50(6), 1994, pp. 771-776
Citations number
13
Categorie Soggetti
Public, Environmental & Occupation Heath","Tropical Medicine
A chloroquine-sensitive strain of Plasmodium falciparum, F32, from Tan
zania was exposed during continuous culture to concentrations of artem
isinin, 10(-8)-10(-5) M, with exposure times ranging from 1 to 96 hr.
After drug exposure, the cultures were washed and the incubation was c
ontinued for one or two parasite cycles to assess the remaining viabil
ity of the parasites. Artemisinin at a concentration of 10(-6) M inhib
ited parasite growth by 63% within 3 hr of drug exposure. The parasite
mia then continued to decrease after removing the drug by washing the
cultures. A 95% inhibition was thus observed 48 hr later. For 100% inh
ibition, at least 12 hr of exposure to 10(-6) M artemisinin was requir
ed. The compound at a concentration of 10(-7) M inhibited growth by 86
% within 24 hr of drug exposure and by 98% 48 hours after removing the
drug. A concentration of 3 x 10(-8) M exhibited 97-100% inhibition on
ly after 72 or 96 hr of drug exposure, while 10(-8) M did not have any
appreciable effect on the growth of the parasites even after 96 hr. I
t is concluded that artemisinin at high concentrations has a significa
nt rapid in vitro effect that appears to be highly parasitocidal. The
compound appears to have a broad spectrum of action, not only schizont
ocidal as reported earlier, but also against the asexual blood stages
of P. falciparum.