Antioxidant properties of some medicinal Lamiaceae (Labiatae) species

In this study, antioxidant properties of Thymus sipyleus Boiss. subsp. sipyleus var. sipyleus , Teucrium chamaedrys L. , Mentha longifolia (L.) Hudson subsp. longifolia , Salvia limbata C.A. Meyer, and Thymus fallax Fisch. & Mey. were investigated. Antioxidant and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities, reducing powers, and the amount of total phenolic compounds of the extracts were studied. The highest antioxidant activity was shown by T. chamaedrys (decoction, IC 50 : 9.2 mu g/ml), and the lowest one was S. limbata (decoction, IC 50 : 619.5 mu g/ml). The highest DPPH radical scavenging activity was shown by T. fallax [decoction, IC 50 S: 56 mu g/ml (IC 50 S is the extract concentration (mu g/ml) required for 50% inhibition of the DPPH solution absorbance at 517 nm)] while the lowest one was S. limbata (decoction, IC 50 S: 335.8 mu g/ml). The highest reducing power and amount of total phenolic compounds was shown by T. chamaedrys (decoction, 29.9 mu g/ml ascorbic acid equivalent, 27.9 mu g/ml gallic acid equivalent, respectively), and the lowest one was S. limbata (decoction, 5.1 mu g/ml ascorbic acid equivalent, 9.9 mu g/ml gallic acid equivalent, respectively) at 250 mu g/ml extract concentration.