Vet Parasitol. 2015 Sep 15;212(3-4):193-9. doi: 10.1016/j.vetpar.2015.06.030. Epub 2015 Jul 10.
Author information
- 1Laboratorio de Zoonosis Parasitarias, Departamento de Biología, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata (UNMdP), Funes 3350, 7600 Mar del Plata, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.
- 2Laboratorio de Análisis Clínicos Santisteban, 7000 Tandil, Buenos Aires, Argentina.
- 3Laboratorio de Zoonosis Parasitarias, Departamento de Biología, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata (UNMdP), Funes 3350, 7600 Mar del Plata, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina. Electronic address: mceliss@mdp.edu.ar.
Abstract
Human alveolar echinococcosis (AE) is caused by the fox tapeworm Echinococcus multilocularis
and is usually lethal if left untreated. The current strategy for
treating human AE is surgical resection of the parasite mass
complemented by chemotherapy with benzimidazole compounds. However,
reliable chemotherapeutic alternatives have not yet been developed
stimulating the research of new treatment strategies such as the use of
medicinal plants. The aim of the current study was to investigate the
efficacy of the combination albendazole (ABZ)+thymol on mice infected with E. multilocularis metacestodes. For this purpose, mice infected with parasite material were treated daily for 20 days with ABZ (5 mg/kg), thymol (40 mg/kg) or ABZ (5 mg/kg)+thymol
(40 mg/kg) or left untreated as controls. After mice were euthanized,
cysts were removed from the peritoneal cavity and the treatment efficacy
was evaluated by the mean cysts weight, viability of protoscoleces and
ultrastructural changes of cysts and protoscoleces. The application of thymol or the combination of ABZ+thymol resulted in a significant reduction of the cysts weight compared to untreated mice. We also found that although ABZ and thymol had a scolicidal effect, the combination
of the two compounds had a considerably stronger effect showing a
reduction in the protoscoleces viability of 62%. These results were also
corroborated by optical microscopy, SEM and TEM. Protoscoleces
recovered from ABZ or thymol
treated mice showed alterations as contraction of the soma region,
rostellar disorganization and presence of blebs in the tegument. However
both drugs when combined lead to a total loss of the typical morphology
of protoscoleces. All cysts removed from control mice appeared intact
and no change in ultrastructure was detected. In contrast, cysts
developed in mice treated with ABZ revealed changes in the germinal
layer as reduction in cell number, while the treatment with thymol or the ABZ+thymol combination
predominantly showed presence of cell debris. On the other hand, no
differences were found in alkaline phosphatase (AP), glutamate
oxaloacetate transaminase (GOT) and glutamate pyruvate transaminase
(GPT) activities between control and treated mice, indicating the lack
of toxicity of the different drug treatments during the experiment.
Because combined ABZ+thymol treatment exhibited higher treatment efficiency compared with the drugs applied separately against murine experimental alveolar echinococcosis, we propose it would be a useful option for the treatment of human AE.
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