Abstract
The present study was designed to understand the host parasite relationships between Schistosoma mansoni and its intermediate host, Biomphalaria alexandrina snail, using flow cytometric analysis of the cell cycle: gap one stage (GO/1), synthesis stage (S-phase%), and gap two stage (G2/M); and apoptosis-regulating proteins: p53, and Bcl-2. Biomphalaria alexandrina snails were exposed individually to miracidia of Schistosoma mansoni; and classified into susceptible group (shed cercariae), resistant group (failed to shed cercariae) and control group. In susceptible snails, cell cycle analysis showed significant (p<0.01) decrease in GO/1 and G2/M phases (%) while S-phase% was significantly (p<0.01) increased as compared to both control and resistant snails. P53 protein expression (%) showed significant (p<0.01) increase while Bcl-2 levels showed significant (p<0.01) decrease as compared to both control and resistant snails. In resistant snails, cell cycle analysis showed significant (p<0.05) decrease in GO/1 phase of cell cycle (%), in addition to significant (p<0.01) decrease in S-phase% as compared to control. p53 analysis showed significant (p<0.01) increase while Bcl-2 analysis showed significant (p<0.05) decrease as compared to control. We concluded that in susceptible Biomphalaria alexandrina snails, Schistosoma mansoni infection can modify the normal progression of the cell cycle and induce an apoptotic process.