Composition, cytotoxicity and antioxidant activity of the essential oil of Dracocephalum surmandinum from Iran.

The composition of the hydrodistilled essential oil from the aerial parts of Dracocephalum surmandinum was analyzed by GC and GC-MS. Monoterpenoids, including oxygenated compounds and hydrocarbons, comprising 63.4 and 33.9%, respectively, were the principal compound groups of the essential oil. In total, 25 constituents accounting for 97.8% of the oil were identified. Perilla aldehyde (54.3%) and limonene (30.1%) were characterized as the main components. The essential oil of D. surmandinum and its two main constituents showed a marked antioxidant and radical scavenging activity using different model systems, including 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and beta-carotene-linoleic acid blenching assays. The results of cytotoxicity activity using the MTT assay exhibited that the oil of D. surmandinum has a good effect against human breast adenocarcinoma (MCF-7) and erythromyeloblastoid leukemia cell lines (K562) with IC50 values of 14 and 16 microg/mL, respectively. The cytotoxic potential of D. surmandinum oil against rat adrenal pheochromocytoma cell line (PC 12) was weak (IC50 of >100 microg/mL). Perilla aldehyde and limonene, the main constituents of D. surmandinum essential oil, inhibited all investigated cell growth in a dose- and time-dependent manner with IC50 values ranged from 0.25-5.0 mmol/L.