Schistogram changes after administration of antischistosomal drugs in mice at the early phase of Schistosoma mansoni infection

Abstract

Mice infected with Schistosoma mansoni were treated with oxamniquine, praziquantel, artesunate at the pre-patent phase, aiming at observing schistogram alterations. Half of the animals were perfused five days post-treatment for counting and classification of immature worms, based on pre-established morphological criteria (schistogram); the remaining animals were evaluated 42 or 100 days after infection and perfusion of the portal-system was performed for collection and counting of adult worms and oogram. It was observed that oxamniquine and artesunate treatment administered at the pre-postural phase causes significant reduction in the number of immature and adult worms. However, there was little reduction with praziquantel when used at the dose of 400 mg/kg for treatments administered 14, 15, 21 or 23 days post-infection. Artesunate was responsible for significant alterations in development of young worms, as well as for a higher number of worms presenting intestinal damages. Immature adult worms were detected in mice treated with artesunate or oxamniquine at the pre-patent phase of infection and recovered by perfusion 100 days after infection. Schistogram proved to be a very useful tool for experimental evaluation of the activity of antischistosomal drugs and a good model to identify the most sensitive stages to drugs.

Efficacy of Praziquantel Loaded Chitosan Nanoparticles Against Both Adult and Schistosomula Stages of Schistosoma Mansoni

“…PZQ treatment did not cause any significant reduction of schistosomula count when compared to positive control group. This agreed with Vimieiro et al (2013) who found that PZQ administered at the day 14 p.i. caused only little reduction of immature S. mansoni worms.…”

Effects of Callistemon citrinus aqueous extract on prepatent and patent infections with Schistosoma mansoni in experimentally infected mice

“…These results are supported by a number of studies on other anti-schistosomal therapeutic agents. When juvenile S. mansoni worms are treated early, they fail to produce eggs due to the inhibitory effect of anti-schistosomals on their sexual maturation, causing atrophy of their testes and ovaries, hence confirming the advantage of early treatment (Hamza et al , 2012; Vimieiro et al, 2013). In context, several studies have demonstrated that immature worms are less susceptible to PZQ (Botros et al , 2005; Grandière-Pérez et al ., 2006; Vimieiro et al , 2013).…”

“…Vimieiro et al (2013) described efficient treatment of schistosomiasis during the initial phase of infection as an important challenge. An ideal treatment would inhibit egg production and consequently granuloma formation, which is the main cause of the pathology of this disease (Coelho et al , 2009).…”