ABSTRACT Geopropolis is produced by some stingless bee species such as Melipona fasciculata and consists of a mixture of plant resins, salivary secretions of the bee, wax, and soil. This study evaluated the antileishmanial activity in vitro, cytotoxicity and chemical composition of geopropolis produced by M. fasciculata in the savannah region of Maranhão, Brazil. The geopropolis extract was obtained through maceration using in 70% ethanol. The hydroalcoholic extract of geopropolis after liquid–liquid partition yielded the hexane, chloroformic, ethyl acetate and hydroalcoholic fractions. Antileishmanial activity was evaluated against promastigote and intracellular amastigote of Leishmania amazonensis. Cytotoxic was realized in BALB/c mice peritoneal macrophages. Chemical analysis was performed by gas chromatography–mass spectrometry and high performance liquid chromatography coupled to an ultraviolet–visible detector. The geopropolis inhibited the L. amazonensis promastigotes growth and was effective in reducing the infection of murine macrophages since the number of internalized amastigotes were smaller in cells treated with the geopropolis extract in relation to the untreated group. The ethyl acetate fraction was the most active and showed the highest index of selectivity as antileishmanial product. The geopropolis from M. fasciculata had an antileishmanial effect, mainly after the obtention of the ethyl acetate fraction that improved the activity without increasing the cytotoxicity against murine macrophages. Analysis for gas chromatography-mass spectrometer identified as main compounds the gallic and ellagic phenolic acids, either in the extract or in the active fraction. The results obtained by high performance liquid chromatography it was possible to confirm the presence and quantify the concentration gallic and ellagic acid either in the extract or in the active fraction. These results suggest that the antileishmanial activity of geopropolis is related to the presence of derivatives of these phenolic acids, mainly gallic and ellagic acids.

RESUMO Geoprópolis, uma mistura de resinas vegetais, cera, terra e secreção salivar, produzida pela abelha sem ferrão Melipona fasciculata. Este estudo investigou a composição química e a atividade antioxidante da geoprópolis coletada em colmeias em duas regiões fitogeográficas de campos alagados e de cerrado, nos municípios de Palmeirândia e Fernando Falcão, no Estado do Maranhão, Nordeste do Brasil. Os compostos da geoprópolis foram identificados por cromatografia gasosa acoplada a espectrometria de massas (CG/EM). Foram determinados os teores de fenólicos totais pelo reagente de Folin−Ciocalteu, e atividade antioxidante utilizando o ensaio in vitro com 2,2-difenil-1-picrilhidrazil (DPPH) e capacidade redutora do ferro (FRAP). As quatro amostras de geoprópolis apresentaram variações no teor de fenólicos totais e atividade antioxidante, as geoprópolis de Fernando Falcão, apresentaram maiores teores. Nas geoprópolis do município de Palmeirândia foram identificados, triterpenos do tipo cicloartano, ursano e oleanano e ácidos fenólicos (ácido protocatecuico e ácido gálico), enquanto que na geoprópolis de Fernando Falcão, ácidos fenólicos, ácido gálico e elágico foram os principais constituintes. A propriedade antioxidante da geoprópolis pode ser atribuída aos altos teores de fenólicos totais e de ácido gálico e elágico. Os resultados demonstram que as fontes vegetais das duas regiões fitogeográficas do Maranhão, Brasil, utilizadas pelas abelhas para a produção da geoprópolis contribuem para a composição química e bioatividade deste produto.

ABSTRACT Geopropolis, a mixture of plant resin, wax, soil and salivary secretion, is produced by the stingless bee Melipona fasciculata. This aim of this study was to investigate the chemical composition and antioxidant activity of geopropolis collected from beehives in two phytogeographical regions, flooded fields and cerrado, in the municipalities of Palmeirândia and Fernando Falcão, Maranhão State, northeastern Brazil. The geopropolis compounds were identified by gas chromatography-mass spectrometry (GC/MS). Additionally, total phenolic content was determined with the Folin−Ciocalteu reagent and antioxidant activity was evaluated in vitro by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. The four geopropolis samples varied in terms of total phenolic content and antioxidant activity and the highest values were observed for geopropolis from Fernando Falcão. Triterpenes such as cycloartane, ursane and oleanane and phenolic acids (protocatechuic acid and gallic acid) were identified in the geopropolis from Palmeirândia, while the phenolic acids, gallic and ellagic acid were the main compounds in geopropolis from Fernando Falcão. The antioxidant property of geopropolis is due to its high total phenolic content and predominance of gallic acid and ellagic acid. The results showed that the plant resources in two phytogeographical regions of Maranhão used by bees for the production of geopropolis contribute to the chemical composition and bioactivity of this product.