Antioxidant Properties of Some Medicinal Lamiaceae (Labiatae) Species

Abstract

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, IC₅₀: 9.2 µg/ml), and the lowest one was S. limbata. (decoction, IC₅₀: 619.5 µg/ml). The highest DPPH radical scavenging activity was shown by T. fallax. [decoction, IC₅₀S: 56 µg/ml (IC₅₀S is the extract concentration (µg/ml) required for 50% inhibition of the DPPH solution absorbance at 517 nm)] while the lowest one was S. limbata. (decoction, IC₅₀S: 335.8 µg/ml). The highest reducing power and amount of total phenolic compounds was shown by T. chamaedrys. (decoction, 29.9 µg/ml ascorbic acid equivalent, 27.9 µg/ml gallic acid equivalent, respectively), and the lowest one was S. limbata. (decoction, 5.1 µg/ml ascorbic acid equivalent, 9.9 µg/ml gallic acid equivalent, respectively) at 250 µg/ml extract concentration.

Keywords:

• Antioxidant activity
• Lamiaceae
• phenolic compound
• radical scavenging
• reducing power