Malaria parasites adapt to the oxidative stress during their erythrocytic stages with the help of vital thioredoxin redox system and glutathione redox system. Glutathione reductase and thioredoxin reductase are important enzymes of these redox systems that help parasites to maintain an adequate intracellular redox environment. In the present study, activities of glutathione reductase and thioredoxin reductase were investigated in normal and Plasmodium berghei-infected mice red blood cells and their fractions. Activities of glutathione reductase and thioredoxin reductase in P. berghei-infected host erythrocytes were found to be higher than those in normal host cells. These enzymes were mainly confined to the cytosolic part of cell-free P. berghei. Full characterization and understanding of these enzymes may promise advances in chemotherapy of malaria.
Animals ; Antioxidants/*isolation & purification/*metabolism ; Cell Fractionation ; Cytosol/enzymology ; Erythrocytes/parasitology ; Glutathione Reductase/*isolation & purification/*metabolism ; Mice ; Plasmodium berghei/*enzymology ; Thioredoxin-Disulfide Reductase/*isolation & purification/*metabolism

OBJECTIVETo study the effects of Angelica sinensis Polysaccharides (ASP) on the hepatic drug metabolism enzymes activities in normal mice and those prednisolone (PSL)-induced liver injury.

METHODThe activities of phase II enzymes (GSH-related enzymes) and cytochrome P450 enzymes were measured by biochemical method.

RESULTASP increased the activities of glutathione S-transferase in liver microsomes and mitochondria. The cytochrome P450 content, NADPH-cytochrome c reductase, aminopyrine N-demethylase, and aniline hydroxylase activities in liver microsomes were also increased. PSL significantly increased serum ALT levels, and decreased the liver mitochondrial glutathione content. At the same time, other enzymes activities were all increased. When mice were treated with ASP 2.0 g.kg-1, the PSL-induced changes on cytochrome P450 enzymes, glutathione S-transferase, and GSH content were restored.

CONCLUSIONASP can modulate the activities of drug metabolism enzymes.

Aminopyrine N-Demethylase ; metabolism ; Angelica sinensis ; chemistry ; Aniline Hydroxylase ; metabolism ; Animals ; Chemical and Drug Induced Liver Injury ; enzymology ; etiology ; Cytochrome P-450 Enzyme System ; metabolism ; Glutathione Transferase ; metabolism ; Male ; Mice ; Microsomes, Liver ; enzymology ; Mitochondria, Liver ; enzymology ; NADPH-Ferrihemoprotein Reductase ; metabolism ; Plants, Medicinal ; chemistry ; Polysaccharides ; isolation & purification ; pharmacology ; Prednisolone