Chemical composition, antibacterial activity, and cytotoxicity of essential oil from Nepeta ucrainica L. spp. kopetdaghensis

Chemical composition, antibacterial activity, and cytotoxicity of essential oil (EO) obtained from the aerial parts of Nepeta ucrainica L. spp. kopetdaghensis was investigated in the present study. Chemical composition of the EO was analyzed using GC-MS method. Sixty compounds representing 98.7% of the total oil were characterized. The oil was predominated by sesquiterpene hydrocarbons, and the main components were germacrene D (53.0%), bicyclogermacrene (6.4%), β-bourbonene (4.3%), β-elemene (3.3%), spathulenol (3.2%), cubenol (2.8%), trans-caryophyllene (2.8%), germacrene A (2.1%), and δ-cadinene (2.0%). The antibacterial activity of the EO was investigated against 6 bacterial strains using serial dilution method. The essential oil showed a good activity against Gram-positive bacteria particularly Staphylococcus aureus (minimum inhibitory concentration [MIC] = 14 μg/mL, minimum bactericidal concentration [MBC] = 14 μg/mL), but Gram-negative bacteria were resistant to the oil. Also, the cytotoxic effects of the EO on human ovarian carcinoma A2780 cell line and human breast adenocarcinoma MCF-7 cell line were examined using 3-(4,5-dimethylthiazole-2-yl)-2,5-biphenyl tetrazolium bromide [MTT] assay. The EO was found to be cytotoxic against the tested cell lines, with IC50 values less than 50 μg/mL for both A2780 and MCF-7 cells.