Free radical scavenging and antimicrobial activities of some Geranium species

Antimicrobial and free radical scavenging potential of different extracts of Geranium tuberosum L. subsp. tuberosum (GT), G. purpureum Vill. (GP), and G. lasiopus Boiss&Heldr. (GL) were evaulated in this study. The minimum inhibitory concentrations (MICs) of these extracts against 2 Gram-positive bacteria, 2 Gram-negative bacteria and 3 yeasts determined using broth microdilution method. Among the tested microorganisms, S. aureus showed the most susceptibility. Radical scavenging activity tested with the DPPH method (25-200 μg/ml). All of the studied extracts showed free radical scavenging activity and among them, the EtOAc extracts of studied plants were found to be with the highest activity. GT EtOAc extract showed almost two times higher activitiy than of ascorbic acid at 50 μg/ml.