Comparative Erythrocyte Glutathione S-Transferase Activity Profile of Non-Malarious Guinea Pigs (Cavia tschudii) Administered Pyrimethamine/Sulfadoxine and Artemether/Lumefantrine Combination Therapies

Abstract

Background: Cellular level of enzyme activity can serve as a reliable biomarker in the event of environmental/chemical insults. Objectives: The present study investigated time-dependent alterations of erythrocyte glutathione S-transferase (Ery-GST) activity of non-malarious guinea pigs (Cavia tschudii) administered with pyrimethamine/sulfadoxine and artemether/lumefantrine combination therapies. Materials and Methods: Eighteen guinea pigs were divided into three groups of six, composed of the control (C1) and two test groups- T1: pyrimethamine/sulfadoxine treated group and T2: artemether/lumefantrine treated group. Accordingly, single dose intra-peritoneal injections equivalents of mixture of pyrimethamine = 3.7 mg/kg bw and sulfadoxine = 0.7 mg/kg bw was administered to T1, whereas a mixture of artemether = 0.3 mg/kg bw and lumefantrine = 1.8 mg/kg bw was administered to T2. The animals were not fed for 16 hours prior to treatment and blood samples were drawn at time intervals of three, six, nine and 24 hours and measured for GST activity using spectrophotometric methods. Results: The Ery-GST activity of group C1 (C1GST) within 0 ≤ t ≤ 24 hours was fairly constant and did not exhibit significant alterations (P > 0.05); whereas the Ery-GST activity profile of the test groups (T1 and T2) were biphasic. Ery-GST activity of group T1 (T1GST) varied with a range of 5.04 ± 0.98 to 5.60 ± 0.59 IU/gHb with peak enzyme activity at t = 0. At t = 9 hours, T2GST activity was not significantly different (P > 0.05) from T1GST activity. Conclusions: The Ery-GST activity profile indicated perturbation of erythrocyte physiochemistry, which could be of relevance from toxicological and therapeutic standpoints.