Evaluation of pyrimethamine and mefloquine antimalarial drugs for the treatment of albino mice co-infected with toxoplasma - gondii and Schistosoma mansoni

The mainstay of this work is to elucidate the prophylactic and curative effects of using two different antimalarial drugs [Pyrimethamine+ Mefloquine] in experimental Toxoplasma gondii infection on top of chronic schistosomiasis mansoni. A group of forty Swiss albino mice chronically infected [each with 80 S. mansoni cercariae and kept for seven weeks], was used in the experiment. This group was further subdivided into three subgroups. Subgroup I: control group which is further subdivided into two smaller subgroups. Subgroup I [A]: control infected untreated animals given S. mansoni cercariae by body immersion and kept for seven weeks [the time needed for the infection to become chronic]. Subgroup I [B]: included control doubly infected untreated animals. S. mansoni infected mice were given 100 tachyzoites of T. gondii via an intraperitoneal cannula seven weeks post schistosoma mansoni infection, then sacrificed four days later. Subgroup II: prophylactic group, included chronic S. mansoni infected mice [for 7 weeks], given the oral drug combination [Pyrimethamine 25 mg/Kg body weight + Mefloquine 100 mg/ Kg body weight] single daily dose for 14 successive days before Toxoplasma infection. Subgroup III: chronic S. mansoni infected mice for 7 weeks, treated 24 hours post Toxoplasma infection with the same oral drug combination [Pyrimethamine 25 mg/Kg body weight + Mefloquine 100 mg/Kg body weight] single daily dose for 14 successive days. Sacrifice was performed two weeks post Toxoplasma infection. The efficacy of both drugs was assessed by worm and tissue egg load and oogram pattern for schistosomiasis, and animal survival, and collecting peritoneal exudates from succumbing mice, then calculation at random for the presence of Toxoplasma gondii parasites. It was found that doubly infected [chronic seven weeks old Schistosoma mansoni followed by Toxoplasma gondii infections] untreated mice died between 6 and 8 days post Toxoplasma infection, while treatment markedly prolonged the survival time of experimental animals. Again, Daraprim and Mefloquine failed to significantly reduce the total number of worms when compared to the infected untreated control group. Moreover, there was complete absence of tachyzoites in the post infection treated group, in comparison with the control infected untreated animals. These data were less conspicuous in the group treated 14 days prior to Toxoplasma infection. This study may be of value in endemic areas, where double parasitic infestation with schistosomiasis and toxoplasmosis is a common occurrence

Parasitological versus renal and hepatic stigmata after using a new chemotherapeutic agent in experimental schistosomiasis haematobium

This study aims to clarify the parasitological effect of a new antischistosomal drug: Ro 15-9268 [9-acridanone hydrazone derivative, synthesized by Hoffman La-Roche Co. Basel, Switzerland] in experimental schistosomiasis haematobium infection. It also aims to study the repercussion of using this compound on some of the major liver [ASAT and ALAT] and kidney [Serum urea, uric acid and creatinine concentrations] function tests. Forty Golden Syrian hamsters have been used in the experiment. Animals were divided into two major groups. Group I: Included infected [300 +/- 50 cercariae/ hamster] untreated control animals sacrificed at 13, 15, 17 and 19 weeks post infection respectively. Group II: infected hamsters further subdivided into three orally treated small subgroups: subgroup IIa: received Ro15-9268 [5mg/Kgb.wt.], subgroup lIb: treated with the same drug [10mg/Kgb.wt] and subgroup IIc: given oral praziquantel 150mg/kgb.wt. Sacrifice was done two days, two, four and six weeks post treatment respectively. It was found that the effect of Ro 15-9268 at the dose of 10mg/kg b.weight was superior to that of 5 mg/kg and praziquantel, with minimal worm and tissue egg load recovery especially two days and two weeks post treatment. A marked drop in the infection-induced risen liver enzymes [serum Aspartate Amino Transferase ASAT and Serum Alanine Amino transferase ALAT], was noted in the group given the 10mg/Kg drug regimen [P<0.001 from respective untreated control mice]. This drop was less salient in the other two treated groups. As regards the serum urea, it reached the lowest level with the high dose regimen at the second and six weeks post treatment respectively [P<0.05 and P<0.01 from respective infected untreated control animals]. Again, a significant drop in serum uric acid and creatinine was recorded in the group given the two dose regimens, as well as praziquantel at all the time intervalls post treatment for serum uric acid and at the 2[nd], 4[th] and sixth week post treatment for serum creatinine [P<0.001 from infected untreated control hamsters]. This drug could be used in endemic areas where resistance to praziquantel starts to be an emerging public health problem

Morbid parasitological and histopathological events in hamsters infected with intestinal amoebiasis given artesunate

This work is a trial to elucidate the parasitological and histopathological sequelae of giving the antimalarial drug [Artesunate] in experimental intestinal amoebiasis. A group of 20 hamsters were infected each by Entamoeba hisrolytica cysts orally by using an oral canula. This group was further subdivided into two main subgroups: Subgroup I constituted infected hamsters given 6000 E. histolytica cysts orally by an oral canula. then sacrificed five weeks post infection. Subgroup II: Infected hamsters given the same infective dose, then two weeks later, treated orally with Artesunate 30 mgm/ Kg body weight/ hamster/over 3 consecutive days Again sacrifice was initiated five weeks post infection. Multiple stool examinations, and histopathological examination of the caecal end of the large intestine were resorted to, in order to assess the anti-amoebic effect of the drug. It was found by mucosal scrapings of the caecum, that hamsters given Artesunate, revealed a minimal amount of Entamoeba histolytica trophozoites when compared to the control untreated animals [P< 0.001]. Histopathological study of the caecal mucosa, revealed complete resolution of the ulcerating shragged mucosal layer after treatment with Artesunate compared to the respective untreated control animals. This study may be of value in endemic areas where drug resistance to the usual antiamoebics may be commonly encountered

Effect of a novel antimalarial drug on different pathological and parasitological parameters in experimental intestinal giardiasis

Objectives the gold standard of this study, is to demonstrate the effect of the antimalarial drug Articulate in experimental intestinal Giardia lamblia infection. It aims at studying the pathological imprint of this drug on the duodenal mucosa of the studied infected hamsters

Methods: in this study, a group of fifteen Golden Syrian hamsters was used. This group was further subdivided into three small subgroups. Subgroup I: constituted control infected untreated hamsters. Infection was done by oral administration of 10,000 Giardia lamblia cysts through an esophageal tube. Subgroup II constituted infected animals, treated three weeks later with a single oral dose of Artesunate 100mg /Kgm body weight. Subgroup III included infected animals, given three weeks later two successive oral doses of Artesunate 100mg/Kgm body weight each, 24 hours appart. All animals were sacrificed two weeks post treatment. By faucal smear examination, it was noticed that the number of Giardia cysts was markedly reduced in the group given the single dose regimen. This number mostly vanished in the group given the double dose regimen when compared to the respective untreated control hamsters. Again, pathological examination of the upper third of the duodenum, revealed complete villus regeneration in the group given the double dose regimen, compared to the respective untreated control animals. This study could be of value un endemic areas where people tend to develop drug resistance to the commonly used antigiardial preparations