Cyclooxygenase-2 inhibitory effects and composition of the volatile oil from the dried roots of Lithospermum erythrorhizon.

The composition of the volatile oil from Lithospermi Radix, the dried roots of Lithospermum erythrorhizon (Boraginaceae), has been investigated by capillary GC and GC-MS. To investigate the anti-inflammatory activity of the oil, in-vitro inhibition of ovine cyclooxygenase-1 and 2 (COX-1 and COX-2) activity by the oil was studied. Fifty-four components of the oil were identified, representing 92.74% of the oil. The main components were 2-methylbutanoic acid (21.50%), 3-methylbutanoic acid (12.61%), 2-methylpropanoic acid (8.99%), methyl linoleate (8.76%), methyl oleate (6.27%), methyl palmitate (6.06%), and 2-methyl-2-butenoic acid (5.74%). Highly selective COX-2 inhibition was observed; at 50 microg/ml the oil inhibited 38.8% of COX-2 activity.