Gametocytocidal effect in vitro of cinchona alkaloids and derivatives on a Plasmodium falciparum clone
Bhasin, V.K.; Trager, W.
Acta Leidensia 55: 151-158
1987
ISSN/ISBN: 0065-1362 PMID: 3321831 Document Number: 300563
Eight compounds which are derivatives and/or mixtures of cinchona alkaloids were evaluated in vitro for their gametocytocidal activity against a P. falciparum clone HB-3. The parasites were kept for 4 days in microcultures for gametocyte development, the first 2 days under drug pressure. The percentage reduction of gametocytes in relation to control was calculated and gametocytocidal ED50 and ED90 values were estimated from semilog plots of percentage reduction against concentration of drug. Quinidine, quinine, quinidine/hydroquinidine (mixture), proved to be the most effective gametocytocidal drug, followed by hydroquinidine, quinine/hydroquinine (mixture), apoquinine, hydroquinine and epiquinine/epiquinidine sulphate. The concentration of quinine required to destroy 90% of the gametocytes in vitro was much lower than the mean plasma level reached in individuals ingesting therapeutic doses of quinine.