Antifungal activity of Pterocaulon species (Asteraceae) against Sporothrix schenckii.

Plants of the genus Pterocaulon (Asteraceae) are popularly used in the treatment of skin diseases caused by fungi and bacteria. The aim of this work was to investigate the in vitro activity of the crude methanolic extracts obtained from the aerial parts of Pterocaulon polystachyum, P. balansae, P. lorentzii, P. lanatum, and P. cordobense against 24 Sporothrix schenckii clinical isolates and determine the minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC). MIC were performed by the broth microdilution method according guidelines recommended by Clinical and Laboratory Standards Institute for filamentous fungi and MFC were determined for transference of aliquots of the well that showed 100% of growth inhibition into tubes with culture medium. The extract from P. polystachyum was the most active sample, presenting MIC range of 156 and 312μg/mL. The popular use of these plants corroborates the importance of ethnopharmacological surveys and opens the possibility for finding new clinically effective antifungal agents.