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

OBJECTIVE

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.

CONCLUSIONS

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