Comparative in-vitro effects of some anti-malaria drugs on human erythrocyte glutathione-s-transferase (EC. 2.5.1.18) activity

Abstract

The in-vitro effects of the anti-malaria drugs chloroquine, camoquine (amodiaquine), mefloquine (lariam), quinine, halfan (halofantrine) and fansidar (sulfadoxine + pyrimethamine), on human erythrocyte gluatathione-S-transferase (GST) activity was spectrophotometrically investigated at 37°C, pH6.5 and at milligram percent (mg%) concentrations (0.10mg%, 0.20mg%, 0.40mg%, 0.60mg %, 0.80mg% and 1.00mg%) of the drugs.

Quinine and its congeners, chloroquine, camoguine (4-amino quinoline) and mefloquine, were all observed to significantly (P<0.001) increase the activity of human erythrocyte glutathione-S-transferase in a concentration dependent manner and according to the order: chloroquine > quinine > mefloquine> camoquine. For instance at 1.00mg% concentration of the drugs, human erythrocyte GST activity was increased by 13.97, 8.98 7.98 and 6.98 folds in the presence of chloroquine, quinine, mefloquine and camoquine respectively.

Halfan (halofantrine) and fansidar (non-quinoline antimalarials) produced no significant change in the activity of human erythrocyte GST at the various concentrations tested. The activation of this enzyme by quinine and its derivatives could point to a possibility of these drugs to raise the oxidant stress of the red cells in the course of their therapeutic actions.



Key Words: Malaria, Chloroquine, Camoquine, Halfan, Quinine, Fansidar, Mefloquine, Erythrocytes, Glutathione-S-transferase.


(Global J Med Sci: 2003 2(1): 43-48)