Screening of five Brazilian plants for anti-inflammatory and antimicrobial activities

Ethanol extracts from the leaves of Cayaponia podantha Cogn. (Cucurbitaceae), Nectandra falcifolia (Nees) Castiglioni (Lauraceae), and Paullinia elegans Cambess. (Sapindaceae), as well as from the aerial parts of Helicteres gardneriana St. Hil. & Naud. (Sterculiaceae) and Melochia arenosa Benth. (Sterculiaceae), all naturally occurring species in the Brazilian part of the Upper Parana River and all belonging to genera used in folk medicine, were screened for anti-inflammatory activity using the carrageenan-induced pleurisy model in rats, and for antimicrobial activity using a broth microdilution assay against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, C. krusei, C. parapsilosis, and C. tropicalis. In the analysis of anti-inflammatory activity, a 500 mg/kg body weight dose of the extracts of C. podantha, N. falcifolia, P. elegans, and H. gardneriana, administered orally (by gavage), reduced the volume of the inflammatory exudates in rats induced by intrapleural injection. H. gardneriana also inhibited migration of leukocytes to the lesion site. Crude extract of M. arenosa was ineffective on the intensity of the inflammatory response. Regarding antimicrobial activity, the best results were obtained with N. falcifolia and M. arenosa against the Gram-positive bacteria tested. N. falcifolia was active against B. subtilis with a minimum inhibitory concentration (MIC) of 39 mu g/ml and a minimum bactericidal concentration (MBC) of 75 mu g/ml and M. arenosa with MIC of 625 mu g/ml against B. subtilis and MIC and MBC of 625 mu g/ml against S. aureus. The results obtained demonstrate the importance of pharmacological studies with neotropical plants, and further research into the specific components responsible for the observed bioactivities is under way.