Abstract: Different local anesthetic methods, including skin wheal of guinea pig, the cornea of rabbit eye,the paw of brain - ruined toad,the subarachnoid space anesthesia of toad and action potential of isolated sciatic nerve from toad, were used to study the anesthetic effects of osthole，a coumarin extracted from the seeds of Cndium monnieri (L. ) Cusson. The results showed that 2% osthole was effective in infiltration and conduction anesthesia but not in surface anesthesia ,and can markedly strengthen the hypnotic effect of subthreshold dose of pentobarbital sodiumin in mice. Furthermore,infiltration anesthetic effect in guinea pig was strengthened by the administration of epinephrine hydrochloride. When the osthole was injected into the subarachnoid space of the lumbar area in toads,the animal showed excitation first and then followed by inhibition,these responses were reversible.

Key words: Osthole, Local anesthetic action, Mice, Guinea pig, Rabbit, Toad