RESUMO
Ethnopharmacological and ethnobotanical approaches are described in the literature as efficient to identify plants of interest for phytochemical and pharmacological studies. In the present work, we reflect on the quality of the data collected in ethno-directed studies. In accordance to the problems identified in published studies, and their theoretical and methodological underpinnings, we believe that these studies are poorly suited to contribute to the advancement of research aimed at the development of novel drugs.
RESUMO
The plants used in traditional medicine have been considered an important source of molecules with pharmacological activity, including antitumor. The aim of this study was to present a pharmacological description and the phytochemical components related to antitumor activity of thirty plants commonly cited in Brazil to treat tumors as well as offering an overview of approaches that are necessary for the development of herbal medicines from these resources. In the search for studies with these plants, five database were used (SciELO, Scirus, Scopus, Biological Abstracts and Web of Science), with the following keywords: tumor AND Species AND cancer. We consider all the scientific synonyms of species available in the Tropicos® database (http://www.tropicos.org/). We surveyed papers from the period between 1980 and 2008. Twnety one species (70 percent) have at least one evaluation of a class of molecule or metabolite isolated against a pharmacological model. Most species (60 percent) has in vivo studies. Of the thirty plant species, two stood out for having pharmacological studies in vitro, in vivo and clinical with positive results: Chelidonium majus L., Papaveraceae, and Aloe arborescens Mill., Xanthorrhoeaceae. Although there is generally a good activity of species presented here, there is a need for further studies in order to evaluate the possibility of developing some byproduct.