Pharmacological Studies on the Root Bark of Paeonia Moutan. I. : Central Effects of Paeonol

Pharmacological examination was made on central effects of paeonol, which is a main component of the root bark of paeony (Paeonia moutan). This root bark is frequently used in home medicine and in oriental medicine as analgesic, sedative, antiinflammatory agent, hemostatic, and remedy for female diseases. Keishibukuryo-Gan ( ?? ?? ?? ?? ?? ) and Daiobotampi-To ( ?? ?? ?? ?? ?? ?? ) are frequent and representative prescription in which the root bark of paeony is cotained in about 20%. Mice were used for these tests and the following results were obtained in both intraperitoneal and oral administration of paeonol. The acute toxicity was low. Sedation (decrease of spontaneous motor activity and caffeine-induced hyperactivity) and hypnosis (loss of righting reflex) were recognized, the latter in higher intraperitoneal doses. Hexobarbital-induced anesthesia was prolonged. Analgesic activity was recognized in both the inhibition of writhing symptom induced with intraperitoneal administration of acetic acid and mouse tail pain by pressing. Hypothermia and antipyretic activity in typhoid-paratyphoid vaccine-febrile mouse were found. Anticonvulsive effect on maximal electroshock was obtained and moreover the same effect was also recognized on pentetrazol- and nicotine-induced convulsions. Thus, it was found that paeonol has many central depressive effects and the may be concerned with some parts of the therapeutic effects of paeony bark in oriental medicine.