RESUMO
Propolis, a bee product, can be regarded as one of the potential natural sources in folk medicine, displaying strong antimicrobial activity. Previous work showed that propolis extracts exhibited in vitro activity against Trypanosoma cruzi (Higashi and de Castro, 1994). Different formulations of propolis were administered to experimentally Trypanosoma cruzi-infected mice and the parasitemia kinetics and survival rate were monitored. The oral administration of ethanolic extracts up to 1.2 g propolis/kg per day or propolis offered ad libitum in the drinking water (up to 4 g/kg per day) or added to the food (up to 5 g/kg per day) did not interfere with both parameters. The differences between in vitro and in vivo trypanocidal activity of propolis and future perspectives are discussed.
Assuntos
Doença de Chagas/tratamento farmacológico , Parasitemia/tratamento farmacológico , Própole/uso terapêutico , Trypanosoma cruzi/efeitos dos fármacos , Administração Oral , Animais , Modelos Animais de Doenças , Etanol/química , Feminino , Masculino , Camundongos , Própole/administração & dosagem , Própole/isolamento & purificação , Própole/farmacologiaRESUMO
Propolis, a natural resin produced by honey bees, that displays strong antimicrobial activity, has been used as a chemotherapeutic agent since ancient times. The anti-protozoan properties of different propolis extracts were studied regarding T. cruzi and its interaction with host cells. Ethanolic (EEP) and dimethylsulphoxide extracts (DEP) were both active against the three forms of the parasite, with the former being more active than the latter against the vertebrate forms, amastigotes and trypomastigotes. Total lysis of bloodstream trypomastigotes was observed after 24 h in the presence of EEP at a concentration of 100 micrograms/ml. The effect was found to be temperature dependent. Treatment of infected peritoneal macrophages and heart muscle cells with EEP strongly inhibited infection levels. The utilization of propolis as a possible antitrypanosomal agent is discussed.
Assuntos
Própole/farmacologia , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Dimetil Sulfóxido , Etanol , Interações Hospedeiro-Parasita/efeitos dos fármacos , Macrófagos Peritoneais/efeitos dos fármacos , Camundongos , Solventes , Trypanosoma cruzi/crescimento & desenvolvimentoRESUMO
1. Amphotericin B (Am.B) was shown to have a direct effect on T. cruzi, with the three forms of the parasite presenting different susceptibilities to the drug in the following order: amastigotes > trypomastigotes > epimastigotes. These differences highlight the importance of using the vertebrate forms of the parasite in tests of new drugs. 2. The treated parasites showed alterations of the plasma membrane, suggesting that, as in fungi, the primary effect of Am.B was probably via formation of complexes with membrane components. 3. When exposed to filipin, another polyene antibiotic, the three parasite forms were observed to present a similar order of susceptibility, with comparable ultrastructural modifications. 4. Higher concentrations of Am.B were required to damage the intracellular parasites in vitro, 2.3 micrograms/ml for parasites inside peritoneal macrophages and 7 micrograms/ml for parasites inside heart muscle cells. 5. Am.B is effective against the parasite, but is also toxic to mammalian cells. Testing of Am.B for the control of Chagas' disease by blood transfusion may be useful, since bloodstream forms are lysed by lower concentrations of the drug than those required to affect intracellular parasites.
Assuntos
Anfotericina B/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Transfusão de Sangue , Doença de Chagas/prevenção & controle , Relação Dose-Resposta a Droga , Filipina/farmacologia , Interações Hospedeiro-Parasita/efeitos dos fármacos , Macrófagos Peritoneais/efeitos dos fármacos , CamundongosRESUMO
1. Amphotericin B (Am.B) was shown to have a direct effect on T. cruzi, with the three forms of the parasite presenting different susceptibilities to the drug in the following order: amastigotes > trypomastigotes > epimastigotes. These differences highlight the importance of using the vertebrate forms of the parasite in tests of new drugs. 2. The treated parasites showed alterations of the plasma membrane, suggesting that, as in fungi, the primary effect of Am.B was probably via formation of complexes with membrane components. 3. When exposed to filipin, another polyene antibiotic, the three parasite forms were observed to present a similar order of susceptibility, with comparable ultrastructural modifications. 4. Higher concentrations of Am.B were required to damage the intracellular parasites in vitro, 2.3 micrograms/ml for parasites inside peritoneal macrophages and 7 micrograms/ml for parasites inside heart muscle cells. 5. Am.B is effective against the parasite, but is also toxic to mammalian cells. Testing of Am.B for the control of Chagas' disease by blood transfusion may be useful, since bloodstream forms are lysed by lower concentrations of the drug than those required to affect intracellular parasites