Antinociceptive effects of the essential oil of Dracocephalum kotschyi in the mouse writhing test.

Abstract

PURPOSE: Dracocephalum kotschyi is a wild-growing flowering plant belonging to the family Labiatae and found abundantly in Iran. This plant has been used in Iran folk medicine as analgesic. METHODS: The Dracocephalum kotschyi essential oil was isolated and studied on writhing test a visceral pain model in mice. Different constituents of the essential oil were determined by gas chromatography mass spectrophotometry technique. RESULTS: Limonene, verbenone, alpha-terpineol, perillyl alcohol and caryophyllene were the major constituents of the essential oil. The essential oil in doses (mg kg-1) used 12.5 (13.9%, P<0.05), 25 (43.1%, P<0.01), 50 (68.7%, P<0.01), 75 (39.8%, P<0.01) induced significant reduction in pain response when compared to control. The ED50 was 61.61 mg kg(-1). Hyoscine (1 mg kg(-1)) and indomethacin (5 mg kg(-1)) induced significant (P<0.01) reductions (74.9% and 76.7% respectively) in pain response in comparison to control. CONCLUSION: This study confirms that antinociceptive properties of D. kotschyi are comparable to those of hyoscine and indomethacin used. Presence of limonene and alpha-terpineol might be responsible for antinociceptive properties of this essential oil. Further studies are necessary to find out a place for it in antispasmodic therapies in human