Chemical composition and functional properties of essential oils from Nepeta schiraziana Boiss

Nepeta schiraziana Boiss. (Lamiaceae) is a species endemic of Iran used in traditional medicine to treat a number of ailments. This study investigates the chemical composition as well as the cytotoxic, antimicrobial, acetylcholinesterase (AChE) inhibitory and antioxidant activities of N. schiraziana essential oil (EO). EO chemical composition was analysed by GC-MS. Cytotoxicity was evaluated against MCF-7 and Hep-G2 cancer cells, while antimicrobial activity was assessed against fungi (Candida albicans, Aspergillus niger), Gram-positive (Staphylococcus aureus, Bacillus subtilis) and Gramnegative (Klebsiella pneumonia, Pseudomonas aeruginosa) bacteria. Forty-four compounds were identified; the main constituents were 1,8-cineole (33.67%), germacrene D (11.45%), β-caryophyllene (9.88%), caryophyllene oxide (7.34%). N. schiraziana EO showed a concentration-dependent cytotoxicity against both cancer cell lines. It also significantly inhibited the growth of A. niger (MIC 1.85 ± 1.12) and C. albicans (MIC 4.94 ± 3.07 μg/mL). MIC for S. aureus, B. subtilis, K. pneumoniae and P. aeruginosa were 16.37 ± 1.23, 168.22 ± 2.14, 180.99 ± 4.67 and 248.74 ± 5.12 μg/mL, respectively. Slight antiradical and AChE inhibitory activities were measured. This is the first report on the chemical composition and bioactivities of N. schiraziana EO. The antibacterial, antifungal and anticancer properties were confirmed in vitro.