Chemical Composition and Antimicrobial Properties of Teucrium polium Essential Oil Collected from Dena Mountain in Yasuj, Iran

Aims: Teucrium polium is a medicinal plant that is used due to its antispasmodic and antimicrobial properties. This study aimed to evaluate the effect of the essential oil of T. polium against fungal, bacterial strains, and Giardia lamblia. Materials Methods: In this clinical laboratory study, Teucrium polium was collected from the Dena mountain area in Yasuj, Iran. Essential oil was prepared from plant powder. Clinical Aspergillus species were isolated from otomycosis patients. For Candida species, the researchers used clinical isolates with otomycosis and vaginitis origin. 33 Aspergillus strains, 49 Candida species, and 33 non-albicans species were used as samples. The samples were collected and cultured on Sabouraud dextrose agar and identified based on PCR-sequencing analysis. Different concentrations of essential oil were assessed by broth microdilution method against clinical fungi and bacterial isolates. Also, anti-Giardia activity of this essential oil was investigated at different times and concentrations. Chemical analysis of the essential oil was done by Gas Chromatography–Mass Spectrometry. Findings: The inhibitory effect of essential oil of T. polium on Candida and Aspergillus strains was varied and dependent on species. Generally, the effect of essential oil on non-albicans species was better than C. albicans isolates. Also, essential oil had an inhibitory effect on E. coli and Klebsiella but did not affect methicillin-resistant Staphylococcus aureus. Its effect on Giardia isolates was dependent on time and concentration. Oxygenated monoterpenes are the major compound of T. polium. Conclusion: Teucrium polium essential oil has a considerable inhibitory effect on different strains of microorganisms.