Phenolic Contents and Biological Activity of Endemic Origanum minutiflorum Grown in Turkey

  Objective: In this study, biological property of Origanum minutiflorum O. Schwarz and P. H. Davis (Lamiaceae) was evaluated. Methods: The total phenolic and flavonoid amount were detected using Folin-Ciocalteu and aluminum chloride colorimetric assays. The antioxidant activity was assayed with phosphomolybdenum, 2,2- diphenyl-1- picrylhydrazyl radical scavenging (DPPH), hydrogen peroxide scavenging, β-carotene bleaching activity, ferric-ion reducing power (FRAP), reducing power and cupric ions (Cu2+) reducing antioxidant capacity (CUPRAC) methods. Antimicrobial activities of the extract and the essential oil were studied by broth microdilution and agar well-diffusion assays using 12 bacteria, 1 yeast and 2 fungi. Results: Twenty nine components were identified by gas chromatography/mass spectrometry (GC/MS), representing 100% of the oil. The main component of O. minutiflorum oil was carvacrol (90.87%). O. minutiflorum extract exhibited strong DPPH scavenging activity (IC50 = 13.68 μg/ml). In addition, O. minutiflorum had an effective hydrogen peroxide scavenging and ferric ions (Fe3+) reducing activities. The extract and essential oil had strong antibacterial effects against all bacteria tested. The methanol extract had no activity against yeast and two fungi tested, but essential oil exhibited prominent antifungal activity. Conclusion: O. minutiflorum extract and essential oil might be alternative agents in vary industries such as food, pharmacy and health.