RECOVERY OF THE HEPATIC CARCINOGEN-METABOLIZING CAPACITY IN SCHISTOSOME-INFECTED MICE AFTER TREATMENT WITH THE ANTISCHISTOSOMAL PRAZIQUANTEL

The influence of Schistosoma mansoni infection on the capacity of the carcinogen-metabolizing enzymes was investigated prior to and after tr eatment of the infected male mice with praziquantel, an anti-schistoso mal agent. The drug was administered in a daily dose of 60 mg/kg body weight for three days before decapitation at various infection interva ls. After 20 and 30 days post-infection the hepatic content of cytochr ome P-450 and cytochrome b-5 and the activity of aryl hydrocarbon hydr oxylase were markedly increased. However, the constitutive levels of t he above mentioned enzymes were significantly decreased at 45, 60 and 75 days post-infection. Treatment of the infected mice with praziquant el for three days, however, recovered the changes in these activities at each individual time point. Praziquantel showed no effect on either of the studied enzymes when administered alone except for that of NAD PH-cytochrome C reductase activity which exhibited significant increas e. The activity of NADPH-cytochrome C reductase gave inconsistent resu lts after treatment of the infected animals with praziquantel. It is c oncluded that praziquantel can be considered as a safe and useful drug for the chemotherapy of schistosomiasis and it possessed a recovery f or the activities of the drug-metabolizing enzyme.