Chemical Composition and Antimicrobial Activity of the Essential Oil from the Endemic Species Pycnocycla bashagardiana Mozaff

Pycnocycla bashagardiana (Apiaceae) is an endemic plant to the south of Iran and is used for the treatment of some microbial disorders. Regarding the presence of volatile terpenoids in the aerial parts we were prompted to investigate the antimicrobial activities of the essential oil from P. bashagardiana aerial parts scientifically against microorganisms including Staphylococcus aureus, S. epidermidis, Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans. The oil was also analyzed by GC and GC-MS in order to identify the potentially responsible compounds for observed property. The antimicrobial effect of the essential oil was primarily evaluated by agar diffusion methods and its MIC and MBC were determined by broth macro dilution method. P. bashagardiana essential oil was found to be effective against all tested microorganisms but the most significant activities were observed against C. albicans, followed by B. cereus. Forty three constituents, representing 94.9% of the essential oil, were identified. The major components of the oil were characterized as myristicin (21.6%), cis-isomyristicin (17.1%) and E-beta-ocimene (9.2%) which might be responsible for the antimicrobial activities. The results suggest that the essential oil possesses biologically active constituent(s) that have antimicrobial activity which supports the ethnomedicinal claims for the use of this plant in the management of some infectious diseases.