Ação de cordia verbenacea sobre schistosoma mansoni / Activity of cordia verbenacea on schistosoma mandoni

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

17/01/2012

RESUMO

The trematode Schistosoma mansoni is responsible for causing a form of schistosomiasis that kills around 280,000 people each year. Since there are cases of tolerance and resistance to the drugs currently used in the treatment for this disease, namely praziquantel (PZQ) and oxamniquine, there is a need for new schistosomicidal drugs. In that regard, the research with medicinal plants is a viable alternative. The purpose of this work was to evaluate the activity of Cordia verbenacea on S. mansoni by means of both in vitro and in vivo tests. The in vitro tests were performed using 4 concentrations (50, 100, 200, and 400 ?g/mL) of essential oil (OE), aqueous fraction (FAEE) and organic fraction (FOEE), obtained from aerial parts of the plant; fractions of the organic fraction; and artemitin. The FOEE showed stronger schistosomicidal activity with the higher concentrations, and it was fractionated. Among the resulting fractions, fraction 3 (F3) yielded the highest mortality of worms. Therefore, both fractions were chosen for the in vivo tests, in which Balb/c mice, infected 45 or 60 days before, received different concentrations of the fractions (40, 100, 200, or 300 mg/kg), administered orally in a single dose. The activity of the fractions was evaluated based on the following parameters: activity on adult worms, eggs released in the environment, egg count, formation of granulomatous reactions, hepatosplenomegaly, and activity on the tegument of worms retrieved from the in vivo tests by scanning electron microscopy (SEM). Administered 45 days after the infection at 40 mg/kg, the FOEE provided a reduction of up to 31% of the worms (PZQ did not result in any reduction at that concentration); administered 60 days after the infection at 200 mg/kg, the FOEE provided a reduction of 85.1% of eggs per gram of faeces, whereas PZQ reached 20.5%; fraction 3, at 100 mg/kg, resulted in a large quantity of dead eggs in the egg count, the same happening for PZQ at 300 mg/kg; administered 45 days after the infection at 300 mg/kg, the FOEE resulted in less granulomas per liver (average of 3.0 granulomas per organ), whilst PZQ, under the same treatment conditions, resulted in an average of 9.6 granulomas; on the 60th day of infection and at 200 mg/kg, both fractions caused a reduction of hepatomegaly. Images obtained by SEM showed large changes on the tegument of male worms subjected to both fractions, such changes being larger than those caused by PZQ. These results indicate that the plant C. verbenacea presents activity against both S. mansoni and the disease caused by this helminth. In some cases C. verbenacea provided better results than PZQ, which is a pure substance. The data related to the reduction of the pathology can be a consequence of the anti-inflammatory properties of the plant.

ASSUNTO(S)

cordia verbenacea schistosoma mansoni in vitro fracionamento planta medicinais cordia verbenacea schistosoma mansoni collection in vitro/in vivo fractionation medicinal plants

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