Plants used traditionally in Ecuador with potential anti-leishmanial activity

Leishmaniasis is a disease caused by an intracellular parasite of the genus Leishmania, which is transmitted to humans by sand-flies. This illness is common in 88 tropical countries around the world with an annual incidence of 1–1.5 million cases and one of its clinical forms, visceral leishmaniasis, is the second largest parasitic killer in the world [1].

As part of a project based on ethnobotanical research in Ecuador [2], 13 plant taxa have been found to have potential in the treatment of Leishmaniasis. The plants were collected from the coast, highlands and jungles of Ecuador during August-September 2006. The plant material (bark, leaves, etc.) was milled and extracted successively with hexane, dichloromethane and methanol. The crude extracts were tested against Leishmania donovani at two concentrations, 9.7µg/mL (high) and 1.6µg/mL (low).

The biological screening shows that the bark of Bocconia integrifolia Bonpl. (Papaveraceae), at the two concentration levels assayed high/low, presents a percentage of growth inhibition of 84.1/49.8 for the hexane extract, of 96.2/73.1 for the dichloromethane extract and of 95.9/72.2 for the methanol extract. The leaves of Minquartia guianensis Aubl. (Olacaceae) show growth inhibition of 96.5% and 83.5% for the high and low concentration levels tested but only for the dichloromethane extract.

Acknowledgements: This research is part of a dissertation funded by the Austrian Exchange Service (ÖAD).

References: [1] World Health Organization WHO, Special Programme for Research an Training in Tropical Diseases TDR. Electronic publication: „Strategic Direction for Research: Leishmaniasis“. Published online: February 2002. Access date: March 15, 2007. www.who.int/tdr. [2] De la Torre, L., et al., Catálogo de Plantas Útiles del Ecuador (in preparation).