In vitro efficacy of new synthetic benzimidazole-related compounds against Schistosoma mansoni adult worms

Objective:To evaluate the in vitro antischistosomal activity of two new synthetic benzimidazole-related compounds:NBTP-OH and NBTP-F.Methods:Schistosoma adult worms were recovered from mice infected with Schistosoma mansoni cercaria,washed and then incubated in the culture media with different concentrations of compounds NBTP-OH and NBTP-F up to 72 h.Scanning electron microscopy was conducted to report morphological changes.Results:Incubation of adult Schistosoma mansoni with 10 μg/mL of NBTP-OH for 48 h killed 81.25% of worms.The calculated LC50and LC90 72 h post-incubation were 6.8 μg/mL and 9.8 μg/mL,respectively.Exposure of worms to 10 μg/mL of NBTP-F killed89.5% of worms after 48 h,mostly males(83.3%),the LC50 and LC90 after 72 h of incubation were 4.8 μg/mL and 6.9 μg/mL,respectively.Worms incubated for 72 h with these compounds revealed swelling and deformity of oral sucker,disorganization and erosion of the tegument when examined with scanning electron microscopy.Conclusions:NBTP-OH and NBTP-F possess in vitro antischistosomal activities;however,in vivo studies should be conducted to examine their antischistosomal effects..

Laboratory diagnosis of schistosomiasis mansoni: Current status and future trends

Schistosomiasis is a neglected tropical disease that affects about 290 million patients worldwide. Children aged between 5 and 14 years represent 45.8% of the affected patients, in addition, schistosomiasis has been reported in Schistosoma-free areas, mostly because of tourism and immigration from endemic countries. Intestinal schistosomiasis caused by Schistosoma mansoni is mainly diagnosed via direct stool examination for egg detection. Immunological methods are favoured for disease monitoring and preliminary checking for communities in areas with low infection rates, and for patients with light and chronic infections where parasitological tests are negative. PCR-based diagnostic techniques are more sensitive, but expensive. Tegument proteins and miRNAs are promising markers for diagnosis of schistosomiasis. Here we review the diagnostic methods for schistosomiasis mansoni aiming to reach a standardized technique for diagnosis of early infection to help better control of the disease.

Evaluation of the in vivo effect of ivermectin on Schistosoma mansoni in experimentally-infected mice

Objective:To evaluate the effect of ivermectin on mice experimentally infected with Schistosoma mansoni.Methods:Ivermectin was given to mice 42 days p.o.in two treatment regimens:a single dose of 25 mg/kg or the same dose for two consecutive days.Results:In both regimens,there were significant reductions in female worms,hepatic tissue egg count and early immature ova,in addition to significant reductions in the count and size of hepatic granuloma.The same dose for two consecutive days resulted in significant reductions in male,total worms,and intestinal tissue egg load.In both regimens,scaning electron microscopy revealed tegumental alternations as bleb formation,erosion and necrosis more evident with the double dose.In addition,high dose showed extensive erosions of male worms with destruction of the gynaecophoric canal.In females,marked destruction of the tegumental surface was extending to both ventral and oral suckers.Conclusions:lvermnectin has promising anti--schistosomal effcts.However,further research is needed to test the effect of ivermectin on schistosomiasis especially in combination with other antischistosomal agents,to avoid any possible resistance from monotherapy.