Determination of reduced glutathione in treated and untreated P. falciparum.

The GSH content was determined after 5 hours incubation of the asynchronized FcM29 strain of Plasmodium falciparum without drug addition (control) or with IC75 of BSO, IC75 of ellagic acid concentration or in combination of both drugs.The glutathione contents of the controls were normalized to 100%. The GSH levels show percentages of treated parasites with reference to these basic GSH levels. Unsynchronized infected erythrocytes (15% parasitemia) were incubated for 5 hours. For this short-term incubation, we decided to apply concentrations of the respective drugs that led to 75% growth reduction in the 48 h growth inhibition assay and subsequently determined their glutathione content. IC75 values of both ellagic acid and BSO were 1.3 and 224.91 µMol respectively. The drugs were tested alone and in combination. The means ± SEM from three independent determinations are shown.**p