Comparative study of the antimicrobial activity of native and exotic plants from the Caatinga and Atlantic Forest selected through an ethnobotanical survey.

Context: The idea that many commonly used medicinal plants may lead to the discovery of new drugs has encouraged the study of local knowledge of these resources.

Objective: An ethnobotanical survey of species traditionally used for the treatment of infectious diseases was undertaken in two areas of northeastern Brazil: one in the Caatinga (dry forest) and another in the Atlantic Forest (humid forest).

Materials: Initially, diffusion tests using paper disks and subsequently, for extracts presenting significant results (inhibition halos above 15 mm), minimum inhibitory concentrations were determined.

Antiproliferative activity, antioxidant capacity and tannin content in plants of semi-arid northeastern Brazil.

The objective of this study was to evaluate antiproliferative activity, antioxidant capacity and tannin content in plants from semi-arid northeastern Brazil (Caatinga). For this study, we selected 14 species and we assayed the methanol extracts for antiproliferative activity against the HEp-2 (laryngeal cancer) and NCI-H292 (lung cancer) cell lines using the (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazole) (MTT) method. In addition, the antioxidant activity was evaluated with the DPPH (2,2-diphenyl-2-picrylhydrazyl) assay, and the tannin content was determined by the radial diffusion method.