Biological activities of the extracts from wild growing Origanum vulgare L

The present work was undertaken to determine the total phenol, flavonoid and tannin content in five extracts of Origanum vulgare growing wild in southwest Serbia as well as to evaluate antioxidant and antimicrobial activity towards 29 strains of human pathogenic and food spoilage bacteria and fungi. In order to define a chemotype of this O. vulgare, chemical composition of essential oil was determined. The major compounds were: sabinene, terpinen-4-ol, 1.8 cineole, γ-terpinene and caryophyllene oxide. The concentrations of total phenols were examined using Folin-Ciocalteu reagent and the obtained values ranged from 84.5 to 235 mg GA/g. By using aluminium chloride method, the concentrations of flavonoids were obtained and the values ranged from 57.1 to 132 mg RU/g. In determining the amount of tannins, the method with butanol-HCl reagent was used and the obtained values were between 1.25 and 4.02 mg CCh/g. Antioxidant activity was evaluated by measuring the scavenging capacity of extracts on DPPH. Tested extracts expressed strong scavenger activity with IC50 values between 34.5 and 86 μg/ml. The ethanol extract was the most active. The strongest antibacterial activity, determined by microdilution method, was detected on G+ bacteria such as Bacillus species and Staphylococcus aureus, obtaining minimal inhibitory concentration (MIC) 0.16 mg/ml while antifungal activity was moderate with MICs between 2.5 and 20 mg/mL.