ABSTRACT
In the present work, five antigenic fractions were prepared from Biomphalaria alexandrina snails. These antigens were immunized into five different groups of mice. The effect of these antigens on the serum enzyme activity levels, namely transaminase [GOT and GPT], alkaline phosphatase [alk-phase] and 5-nucleotidase [5- Nase], was studied and compared to those of non-immunized mice. In addition, the activity levels of these enzymes were also studied in control and immunized mice 10 weeks post infestation with cercariae of the Egyptian strain Schistosoma mansoni. Significant decreases were observed in the activity levels of GOT, GPT, Alk-phase and 5-Nase in the infested immunized mice as compared to the infested non-immunized mice. These results indicated the efficiency of these antigens in reducing the damaging effect caused by parasitic infestation