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Activity of coumarin extracts from leaves of Calophyllum brasiliense on Leishmania braziliensis
Leishmania braziliensis is the most common etiologic agent of leishmaniasis  which is an endemic disease in South America. In our previous studies, Calophyllum brasiliense showed activity against Leishmania amazonensis . In the present study, we evaluated the activity of extracts and (-) mammea A/BB from leaves of Calophyllum brasiliense Camb. (Clusiaceae), against Leishmania braziliensis. The dichloromethane extract and coumarin (-) mammea A/BB showed significant activity against the promastigote forms of L. braziliensis, with 50% lethal dose (LD50) at concentrations of 60 and 23.2µg/mL, respectively. However, the aqueous extract from the leaves and amentoflavone showed no activity against promastigote forms; both of them showed LD50>320µg/mL. For the intracellular amastigote forms, the dichloromethane extract and coumarin (-) mammea A/BB reduced by 50% the infection index of parasites in macrophages at concentrations of 22 and 29µg/mL, respectively. In addition, the dichloromethane extract showed no cytotoxic effects on mouse peritoneal macrophages at concentrations up to 1000µg/mL. On the other hand, coumarin (-) mammea A/BB showed more cytotoxicity than the dichloromethane extract: coumarin inhibited the growth of mouse peritoneal macrophages by 29.7% at concentrations of 80µg/mL. The compounds were characterized by one- and two-dimensional 1H and 13C NMR analyses. These results provide new perspectives on the development of novel drugs with leishmanicidal activity obtained from natural products.
Acknowledgements: This study was supported through grants from the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and CAPES.
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