Overview on cysteine protease inhibitors as chemotherapy for Schistosomiasis mansoni in mice and also its effect on the parasitological and immunological profile.

The present study evaluated the use of 3 types of Cysteine Protease Inhibitors (CPIs) with praziquantel (PZQ) as chemotherapy against schistosomiasis mansoni in mice. All groups were going to assessment of fluromethylketone (FMK), Vinyl Sulfone (VS) and Sodium Nitro Prussid (SNP) by measurement of parasitological, immunological and histological parameters. In our study, The ova count/gm liver or intestine on with PZQ treatment showed 99.1 and 95.2% Percent Reduction (PR), respectively compared to control group. The most effective CPI was FMK when combined with PZQ recording 99.8 and 99.6% PR for liver and intestine, respectively. Regarding to the oogram pattern, FMK, VS and SNP treatment either at 3 or 5 wk PI revealed marked decrease in the immature and mature ova counts and an increase of the dead ova percentages. The effect of CPIs was studied on the PR of Mean Granuloma Diameter (MGD) and Mean Granuloma Number (MGN) of infected treated groups compared to infected control and PZQ treated groups. FMK treatment proved to be highly was effective against S. mansoni in mice disintegrating ova and reduction in granulomatous size and numbers. The microscopic examination of liver sections of infected mice showed a large cellular granuloma with living central ova. sections of Infected mice liver treated with FMK or VS alone or combined with PZQ showed a great reduction in granuloma size as small cellular granuloma with central degenerated ova. We observed that these CPIs alone or combined with PZQ could effectively block schistosomal activity and prevented its growth and differentiation. Briefly, the best schistosomicidal effect of CPIs, that gained by drug administration orally in a dose of 50 mg kg(-1) mouse, was observed with FMK. This was followed by VS and lastly with SNP. These results gave evidence that CPIs can selectively arrest parasite replication without untoward toxicity to the host.