Avaliação da toxicidade dos extratos do Araribá (Centrolobium tomentosum) com utilização do bioensaio com Artemia salina

Abstract

Since the dawn of medicine, man has used natural products for the treatment of disease. There has been a recent increase in studies of the therapeutic characteristics plants in popular use in many places of the world. In this context, the species Centrolobium tomentosum, Fabaceae, known popularly as Arariba or Araruva, is used in Brazilian folk medicine as an astringent for wound treatment and bruises due to the large amount of tannins contained in the bark. This work used toxicity tests to assess the biological activity of ethanolic extracts from C. tomentosum with the specific objectives of obtaining concentrated extracts from the bark and wood of this species and determining the total phenols and tannins present in these extracts. We collected arariba samples in order to obtain ethanolic extracts through the percolation process. We then made a qualitative chemical identification of hydrolysable tannins and condensed tannins. We used the Folin-Ciocalteu method for the phenols quantification and the casein precipitation method for the tannins determination. The toxicity of extracts was evaluated using the brine shrimp bioassay (Artemia salina), in which the C. tomentosum bark extract showed moderate toxicity, with estimated LC50 = 416 μg.ml-1, whereas the leaves and wood extracts of this species showed low toxicity with LC50 = 537 μg.ml-1 and 826 μg.ml-1, respectively.