Succinate cytochrome c reductase in schistosomiasis: in vitro inhibition by some schistosomicidal drugs

Abstract

Enzymes in mitochondria play an important role in biological oxidation and energy production. To understand the effect of schistosomiasis on these important processes, succinate cytochrome c reductase (SCR) from control and Schistosoma-infected mice was subjected for investigation. In this article, we report that SCR from Schistosoma-infected mouse showed a significant decrease in its Vmax and Km compared to control using both cytochrome c and 2,6-dichlorophenolindophenol as substrates. Furthermore, the kinetic studies of the purified SCR in the absence and presence of the schistosomicidal drugs praziquantel and Commiphora extract reveal that both drugs have an inhibitory action on the enzyme from the control and Schistosoma-infected mice and praziquantel changes the type of inhibition of SCR towards cytochrome c from mixed type in control to a competitive one in the case of the infection.

Primary targets of the sesquiterpene lactone deoxymikanolide on Trypanosoma cruzi

“…The activity of SCR was measured in a reaction mixture (1.0 ml) containing 20 mM succinate, 0.2 mM EDTA, 0.1 M KH 2 PO 4 buffer of pH 7.4, and 50 μM DCIP (Balbaa et al, 2010). The reaction was carried out at 30°C and was started by the addition of 100 -200 μl of enzyme source (the supernatant employed to measure TryR activity).…”