Antimicrobial and antioxidant activities of Stachys lavandulifolia subsp. lavandulifolia essential oil and its infusion.

Stachys lavandulifolia Vahl. subsp. lavandulifolia (Lamiaceae) is widely used in south Anatolia as a herbal tea. It is used for the treatment of gastrointestinal and respiratory disorders. Constituents of the essential oil obtained by hydrodistillation were analyzed both by GC-FID and GC/MS, simultaneously. Thirty-seven compounds representing 98.3% of the oil were characterized. Beta-Phellandrene (27%), alpha-pinene (18.5%) and germacrene-D (13%) were found as major components of the oil. Anticandidal, antibacterial and antioxidant properties of the oil and the prepared infusion were evaluated using several methods. The oil exhibited good inhibitory activity on Candida tropicalis (MIC 0.094 mg/mL). Staphylococcus aureus and Salmonella typhimurium growths were also inhibited by the oil at a concentration of 0.375 mg/mL. The prepared infusion of the flowering aerial parts showed weak antimicrobial effects against all the tested microorganisms, but demonstrated a remarkably radical scavenging activity (IC50: 3.9 microg/mL).