Evaluation of the effect of oxamniquine, praziquantel and a combination of both drugs on the intramolluscan phase of Schistosoma mansoni

• Published in: Acta tropica Vol. 102; no. 2; pp. 84 - 91
• Main Authors: Mattos, A.C.A., Pereira, G.C., Jannotti-Passos, L.K., Kusel, J.R., Coelho, P.M.Z.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.05.2007; Elsevier
• Subjects: Animals; Anthelmintics - pharmacology; Biological and medical sciences; Biomphalaria - parasitology; Drug Therapy, Combination; General aspects; Intramolluscan phase; Medical sciences; Oxamniquine; Oxamniquine - pharmacology; Praziquantel; Praziquantel - pharmacology; Schistosoma mansoni; Schistosoma mansoni - drug effects; Schistosoma mansoni - growth & development; Schistosomiasis mansoni - drug therapy; Schistosomiasis mansoni - parasitology; Statistics, Nonparametric; Synergistic effect; Schistosoma mansoni; Intramolluscan phase; Oxamniquine; Synergistic effect; Praziquantel; Nitro compound; Evaluation; Drug combination; Isoquinoline derivatives; Anthelmintic; Phase; Plathelmintha; Quinoline derivatives; Synergism; Trematoda; Helmintha; Parasiticide; Tropical medicine; Invertebrata
• ISSN: 0001-706X; 1873-6254
• DOI: 10.1016/j.actatropica.2007.04.002

The activity of oxamniquine (OXA), praziquantel (PZQ), and a combination of both drugs was evaluated at the intramolluscan phase of Schistosoma mansoni. Biomphalaria glabrata snails infected with S. mansoni were treated with 500 mg/kg OXA, 1000 mg/kg PZQ or with 250 mg/kg OXA and 500 mg/kg PZQ, in association, at the pre-patent and patent phases of infection. The results showed that either treatments with OXA or PZQ, alone, at the pre-patent period, delayed the parasite's development, increasing the pre-patent period by approximately 10 days. At the same pre-patent period, treatment with a combination of OXA/PZQ delayed the parasite's development even more, extending the pre-patent period up to 56 days. At the patent period, treatment with OXA and PZQ, alone, interrupted cercarial shedding. When the snails were treated with 1000 mg/kg PZQ, the cercarial production was re-established 15 days after treatment, but in lower numbers than those obtained before treatment, whereas the snails treated with 500 mg/kg OXA were able to shed cercariae in similar quantities to those observed before treatment. The association 250 mg/kg OXA + 500 mg/kg PZQ, at the patent period, not only discontinued cercarial shedding, but also led to the “cure” of the snails, showing a synergistic effect of this combination of drugs. These results suggest that this model will be useful for selection of resistant parasites, as well as for screening new antischistosomal drugs.