Parasitological, hematological and ultrastructural study of the effect of Cox-2 inhibitor, pyocyanin pigment and praziquantel, on S. mansoni infected mice

ABSTRACT

The effect of cyclooxygenase-2 [COX-2] inhibitor, such [as meloxicam, and pyocyanin pigment of Pseudomonas aeruginosa] with and without praziquantel [PZQ] on worms, ova count, bone marrow and blood cells in 7 groups of Schistosoma mansoni infected mice was studied. The results revealed significant decrease of worm burden and ova count in all treated groups as compared to the infected untreated group, while those with combined treatment of PZQ and meloxicam or pyocyanin showed complete eradication of the worm with the highest reduction in the tissue egg load. EM showed extensive swelling and vesiculation of the tegument, completely implanted spines that overlie degenerated muscle layer were obvious in groups treated with either meloxicam or pyocyanin. Hematological study revealed significant increase [P < 0.05] of total leucocytic count of PZQ treated group while that treated with either meloxicam or pyocyanin showed significant decrease [P < 0.05], but in combination of PZQ with meloxicam or pyocyanin no significant difference as compared to the infected untreated group. The neutrophil was the main cell affected in groups treated with neither meloxicam nor pyocyanin alone with significant decrease [P < 0.05], but with significant increase [P < 0.05] in combination with PZQ as compared to the infected untreated group. Those treated with PZQ plus meloxicam showed significant increase as compared to that plus pyocyanin. Eosinophil count showed significant decrease [P < 0.05] in all treated groups as compared to the infected untreated group. Inverse correlation between serum level of sFas and peripheral neutrophil count was detected. Ultrastructural study of the bone marrow explained the results as groups treated with meloxicam revealed dissociation between nuclear and cytoplasmic development in the neutophils with cytoplasm maintaining primitive appearance despite maturation of the nucleus that is manifested by the persistent production of immature granules and the still orientation of Golgi cternae and the centriole around the nucleus. Groups treated with pyocyanin pigment revealed many abnormalities in neutophils as hypogranularity or early apoptotic morphology changes as intense pen- nuclear chromatin aggregation or nucleus fragmentation.In peripheral blood apoptotic morphology changes was detected in both groups treated with meloxicam or pyocyanin while most of cells of mice treated with PZQ were in an active state. Consequently, it is preferable to give meloxicam with PZQ for a short period of time [less side-effect] to eradicate S. mansoni worm completely but with continuous observation of the peripheral neutrophil count and function