<em>In vitro</em> screening for antioxidant and antimicrobial properties of five commercial <em>Origanum </em>species from Turkey

Abstract

The present study was conducted to evaluate the antioxidant and antimicrobial properties of methanol extracts of the five<em> Origanum </em>species, which are commercial importance in Turkey. Antioxidant activity was measured employing three methods namely, DPPH free radical scavenging activity, ABTS⁺ radical cation scavenging activity and ferric reducing antioxidant/power activity<em>,</em> including total phenolic and total flavonoid contents. In addition, antimicrobial activities of methanol extracts from five <em>Origanum </em>species aerial parts were investigated against <em>Staphylococcus aureus, </em><em>Staphylococcus epidermidis,</em><em> Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa</em>,<em> Proteus mirabilis </em>and<em> Candida albicans</em> test organisms using the disk diffusion and microdilution methods. Antioxidant studies suggested that methanol extracts behaved as a strong DPPH free radical, ABTS⁺ radical cation scavenging activity and ferric reducing antioxidant/power activity<em>.</em> The antimicrobial test results showed that the methanol extracts of all<em> Origanum </em>species had great potential of antibacterial activity against <em>Staphylococcus aureus. </em>As a conclusion of this study, the methanol extracts of five<em> Origanum </em>species showed strong antioxidant and antibacterial activity and therefore, they can be used as a natural preservative ingredient in food and/or pharmaceutical industry.