Short Communication: Erythrocyte Glutathione S-transferase Activity of Non-Malarious Male Human Volunteers Administered with Five Antimalarial Drugs

Abstract

Investigation to ascertain the potencies of five antimalarial drugs (Fansidar, Halfan, Quinine, Coartem and Chloroquine phosphate) to alter/distort non-parasitized human erythrocyte (HbAA genotype) glutathione S-transferase (GST) activity was carried out. Apparently healthy and clinically confirmed non-malarious male human volunteers enrolled for this study. The incubation of human erythrocytes with 1-chloro-2, 4-dinitrobenzene (CDNB) resulted in almost quantitative conjugation
of glutathione (GSH) to form S-(2, 4-dinitrophenyl) glutathione. The reaction formed the basis for the spectrophotometric determination of GST activity. Determination of GST activity was carried out before and after the five (5) drug treatments.The control values ranged between 3.27+0.13 iu/gHb and 3.40+0.05 iu/gHb. Generally, the erythrocyte GST activity was time dependent of the five antimalarial drugs showing biphase profile. The first phase showed decrease levels of relative GST activity within approximate time range: (0 < t < 6) hours after the drugs were administered to the volunteers. The second phase showed recovery effect of the erythrocyte GST activity from the inhibitory action of the drugs. The
results of these findings suggested the capability of these drugs to bind to the human erythrocyte GST, accompanied with raised oxidant stress of the erythrocytes.

Keywords: Glutathione S-transferase (GST) activity, erythrocytes, antimalarial drugs, humans, 1-chloro-2, 4-
dinitrobenzene (CDNB).