Extracts of propolis samples collected in Brazil and (WHO 2004). No vaccines are available for any form of the disease, and the chemotherapy of this disease is still inadequate and expensive (Croft & Yardley 2002). In this context, there is an intense search for potential new synthetic compounds and natural products for the treatment of leishmaniasis. In the last decades occurred a movement sometimes called "back to Nature", which in the area of drug development was accentuated by the success obtained, for example, by taxol in cancer chemotherapy and artemisinin for malaria (Newman et al. 2003). Such intensification in the search for drugs from natural sources was also observed in the area of leishmaniasis. In the literature there are several reports on the activity of a variety of crude natural extracts, especially from plants collected in tropical zones, against Leishmania species of the New World (Fournet et al. 1994, Akendengue et al. 1999, Weniger et al. 2001, Fournet & Munoz 2002. Most of these studies were performed with L. amazonensis and L. braziliensis that cause the cutaneous form of the disease (Lainson 1983, Hepburn 2000, and as second pathology, the first species led to the diffuse cutaneous form (Garnier & Croft 2002), and the second one to the mucocutaneous disease (Jones et al. 1987, Almeida et al. 1996; and also with L. chagasi the causal agent of visceral leishmaniasis (Lainson et al. 1987, Davidson 1999.Our group has been engaged for several years in the investigation of propolis effect against pathogenic trypanosomatids, especially Trypanosoma cruzi, agent of Chagas disease (De Castro & Higashi 1995, Marcucci et al. 2001, Cunha et al. 2004, Dantas et al. 2005. Propolis is a resinous substance that honeybees use to fill gaps and to seal parts of the hive and is collected from different plant exudates resulting in a complex mixture containing known bioactive constituents (Bankova et al. 2000). This product possesses microbicidal, anti-inflammatory, and anti-tumoral activities, which have been associated with the presence of phenolic compounds (reviewed in De Castro 2001). We have previously determined the chemical composition as well as the analgesic and anti-inflammatory activities of a standard ethanol extract of a Bulgarian sample (Et-Blg) (Prytzyk et al. 2003, Paulino et al. 2003) and compared its activity to that of a corresponding Brazilian extract (EtBra) against T. cruzi and several species of fungi and bacteria of medical importance . In the present work, we analyzed the effect of these extracts against different species of Leishmania.
MATERIALS AND METHODSPropolis samples -The Bulgarian propolis (Blg) sample was collected at Burgas (Southeast Bulgaria) (Prytzyk et al. 2003) and the Brazilian one (Bra) at Mar de Espanha (state of Minas Gerais, Brazil) ). The exudates collected by bees in Bulgaria were mainly from buds of Populus nigra, and those in Brazil from a mixture of tropical plants. Each sample was cut in small pieces, after cooling bellow -10°C and extracted with 70% ethanol (...
