Influence of Schistosoma mansoni infection on carcinogen-metabolizing capacities and in vitro aflatoxin B₁ metabolism in human liver

It is well known that schistosomal infection and food contamination with aflatoxins caused marked histopathological changes in human liver. This study demonstrates the influence of Schistosoma mansoni infection on the capacity of drug-metabolizing enzymes and in vitro aflatoxin B₁ metabolism in human liver. Clinical data showed an increase in alkaline phosphatase, alanine and aspartate aminotransferase by 82, 74 and 100%, respectively. The activity of NADPH cytochrome C reductase and cytochrome P-450 content were significantly decreased in the liver of schistosomal patients by 70 and 52% respectively. The cytochrome b-5 content was also decreased by 61%. Aflatoxin B₁ tris- diol could not be detected using the microsomal fractions of the schistosomal group relative to the control group. The content of aflatoxin Q₁ metabolite produced by microsomal fractions of schistosomal patients increased by 308%. There was no difference in the formation of aflatoxin M₁ between the two groups. These observations indicate that Schistosoma mansoni infection might potentiate the deleterious effects of environmental carcinogens.