RESUMO
Abstract The “bacuri” (Platonia insignis Mart., Clusiaceae) is a native tropical fruit from the Brazilian Amazon and Northeast Regions. Its seeds are used to treat inflammatory diseases, diarrhea and skin problems in traditional medical practices. Regarding its widespread medicinal uses, it is important to evaluate the biological and toxicological potential of this species. This way, the aim of this study was to investigate the in vitro cytotoxic and immunomodulatory effects of the hexanic extract of P. insignis seeds, as well as its in vivo acute oral toxicity. The biological evaluation was performed by the determination of cytotoxic (MTT and hemolysis assay) and immunomodulatory (phagocytic capacity, lysosomal volume and nitrite production) activities of EHSB in murine peritoneal macrophages. In addition, the oral acute toxicity was evaluated using female Wistar rats treated with EHSB (2.0 g/kg), in accordance with the OECD 423 Guideline. The EHSB showed low toxicity for macrophages in the MTT test (CC50 value: 90.03 µg/ml), as well as for erythrocytes, which caused only 2.5% hemolysis at the highest concentration. A strong immunomodulatory activity was observed by a markedly increase of the NO production, phagocytic ability and lysosomal volume. On the other hand, it was not observed deaths or changes in the clinical and behavioral parameters in the toxicological evaluation. This manner, the present study contributes to the knowledge about the immunomodulatory and toxicological properties of the P. insignis. This may provide perspectives for the evaluation and development of effective and safe phytomedicines created from the Brazilian local biodiversity.
RESUMO
Propolis is a complex matrix of chemical constituents extracted from plants and produced by bees which is used in folk medicine due to its several pharmacological properties. Its chemical composition varies according to the region where it is produced. This work has studied the antileishmanial activity and cytotoxicity of brown propolis (BP) originating from the semi-arid region of Piauí, Brazil. The BP showed significant inhibition of the Leishmania amazonensis promastigotes growth as well as being effective in reducing infection of murine macrophages and the number of internalised amastigotes in these cells. The dichloromethane fraction was the most active and showed the best selectivity index. The studied samples presented good activity and the fractioning improved the antileishmanial activity without an increase in the cytotoxicity against mammalian cells. Therefore, BP is a potential source for development of apitherapeutic products for the treatment of leishmaniasis.