Related Papers
The Scientific World Journal
Study of the Activity of 3-benzyl-5-(4-chloro-arylazo)-4-thioxo-imidazolidin-2-one against Schistosomiasis Mansoni in Mice
2012 •
ELIETE CAVALCANTI DA SILVA
Antimicrobial Agents and Chemotherapy
Evaluation of the Anti-Schistosoma mansoni Activity of Thiosemicarbazones and Thiazoles
2014 •
Sheilla Oliveira
ABSTRACTSchistosomiasis is a chronic and debilitating disease caused by a trematode of the genusSchistosomaand affects over 207 million people. Chemotherapy is the only immediate recourse for minimizing the prevalence of this disease and involves predominately the administration of a single drug, praziquantel (PZQ). Although PZQ has proven efficacy, there is a recognized need to develop new drugs as schistosomicides since studies have shown that repeated use of this drug in areas of endemicity may cause a temporary reduction in susceptibility in isolates ofSchistosoma mansoni. Hydrazones, thiosemicarbazones, phthalimides, and thiazoles are thus regarded as privileged structures used for a broad spectrum of activities and are potential candidates for sources of new drug prototypes. The present study determined thein vitroschistosomicidal activity of 10 molecules containing these structures. During the assays, parameters such motility and mortality, oviposition, morphological changes ...
Parasitology Research
Experimental chemotherapy of Schistosoma mansoni with praziquantel and oxamniquine: differential effect of single or combined formulations of drugs on various strains and on both sexes of the parasite
1992 •
Italo Cesari
The susceptibility of two Venezuelan (YT and SM) and one Brazilian (BH) strain ofSchistosoma mansoni to single oral doses of praziquantel (Pz; 250 or 500 mg/kg), oxamniquine (Ox; 40, 60, or 100 mg/kg) or to low-dose combinations of both drugs (33 mg/kg Pz and 25 mg/kg Ox; 66 mg/kg Pz and 12.5 mg/kg Ox; 250 mg/kg Pz and 40 mg/kg Ox) was experimentally evaluated in mice. At lower doses of either drug, adult worms of the SM isolate were less susceptible than those of the BH and YT isolates. However, no difference in liver or intestinal egg counts (IECs) could be detected among the isolates after this treatment. At such doses, Pz was better than Ox at reducing IECs. In spite of lowered IECs, eggs continued to accumulate in the liver after Ox treatment. At higher individual doses or following treatment with low-dose combinations of both drugs, no difference in susceptibility could be detected among the parasite isolates. Under such conditions, oviposition was drastically reduced in all three isolates. We confirm that Ox preferentially kills male parasites and present for the first time evidence for the preferential killing of female worms by Pz. We propose that the synergistic effect obtained in the present study and in other investigations using low-dose combinations of both drugs may be due to the preferential cytotoxicity of each drug against a different parasite sex.
Revista Da Sociedade Brasileira De Medicina Tropical
Chemotherapeutic effects on larval stages of Schistosoma mansoni during infection and re-infection of mice
2003 •
Sheilla Oliveira
The sensitivity of the larval stages of Schistosoma mansoni to chemotherapy with praziquantel and oxamniquine was tested in mice during primary and secondary infections and after different intervals from cercarial exposure. Worm recovery by perfusion of the porto-mesenteric system, followed by counting and a morphometric study of the parasite, allowed the conclusion that the relative resistance of the larval stages of S. mansoni to schistosomicide drugs, demonstrated in primary infections, also persists when the host is already infected. This indicates that a therapeutic failure may result when an infected host is treated some time after being re-infected, because of the presence of migrating, drug-resistant, immature forms of the parasite.
European Journal of Pharmaceutical Sciences
Schistosomicidal and prophylactic activities of phthalimido-thiazoles derivatives on schistosomula and adult worms
2019 •
Miria Barbosa
Nature Medicine
Identification of oxadiazoles as new drug leads for the control of schistosomiasis
2008 •
Ahmed Sayed
Transactions of the Royal Society of Tropical Medicine and Hygiene
The association of steroids and schistosomicides in the treatment of experimental schistosomiasis
Jay Modha
The best therapeutic approach to acute schistosomiasis (Katayama fever) is still unsettled. In this paper we report a synergistic effect between schistosomicides and steroids in the treatment of the early stages of Schistosoma mansoni infection in the mouse. CBA mice infected with 150 S. mansoni cercariae were treated with oxamniquine or praziquantel and dexamethasone or prednisolone. The rate of parasite egg excretion by treated mice and appropriate controls was monitored, and the mice were perfused 43 d after infection for estimation of worm burdens and tissue egg densities. Mice treated with schistosomicides alone or with schistosomicides plus steroids had worm burdens of similar size. Significant reductions in egg counts were, however, recorded in faeces, and in the intestines and livers (with consequent reduction in liver pathology), of mice treated with schistosomicide and steroid, when compared to mice treated with schistosomicide alone or steroid alone. The apparent inhibiti...
PLOS Neglected Tropical Diseases
The discovery of a novel series of compounds with single-dose efficacy against juvenile and adult Schistosoma species
2021 •
Nuha Mansour
Treatment and control of schistosomiasis depends on a single drug, praziquantel, but this is not ideal for several reasons including lack of potency against the juvenile stage of the parasite, dose size, and risk of resistance. We have optimised the properties of a series of compounds we discovered through high throughput screening and have designed candidates for clinical development. The best compounds demonstrate clearance of both juvenile and adult S. mansoni worms in a mouse model of infection from a single oral dose of < 10 mg/kg. Several compounds in the series are predicted to treat schistosomiasis in humans across a range of species with a single oral dose of less than 5 mg/kg.
Revista do Instituto de Medicina Tropical de São Paulo
Stability of Schistosoma mansoni progeny to antischistosomal drugs
1985 •
Celso Olivier
The susceptibility of the MAP Brazilian strain (F1 to F5 progenies) of S. mansoni to four antischistosomal drugs has been reported in a previous study. In the present investigation, progeny F14 of the same strain, was tested for stability to the same 4 drugs. A new medication, Oltipraz (35,972 RP), was added to the study. Five groups of 12 mice infected with cercariae by tail immersion were treated with hycanthone, oxamniquine, niridazole, praziquantel and Oltipraz. An untreated group was used as control. Schistosomal activity was assessed by the localization of worms in the portal vein system, by oogram changes, and percentage of parasite reduction. The stability of the susceptibility of progeny F14 did not change in relation to generations F1 to F5; the progeny was resistant to hycanthone and oxamniquine; but sensitive to niridazole, praziquantel and Oltipraz. We emphasize the importance of the phenomenon of resistance of the worm in view of the fact that oxamniquine has been wide...
Study of the Prophylactic and Hepatoprotective Effects of Hesperidin on Murine Schistosomiasis mansoni
2015 •
amany rady
5 Abstract: Due to increasing problems of the resistance associated with praziquantel, the drug of choice for treatment of schistosomiasis, alternative therapies are being a highly desirable goal. Hesperidin (HSP) is a natural plant extract which has various effective biological activities. HSP showed promising schistosomicidal properties against adult worms of Schistosoma mansoni (S. mansoni) both in vivo and in vitro. The aim of the present study was to evaluate the in vivo schistosomicidal effects of HSP either alone or combined with Praziquantel (PZQ). Mice were infected with S. mansoni and treated with 600 mg hesperidin/kg body weight twice a week for 3 consecutive weeks alone or followed by PZQ at dose of 500mg/kg body weight at two consecutive days. Intraperitoneal administration of hesperidin and hesperidin + PZQ to infected animals was effective in reducing worm burden and the egg load in the liver and intestine. The highest significant reduction percentages of worm burden ...
