Planta Med 2003; 69(7): 637-641
DOI: 10.1055/s-2003-41114
Original Paper
Pharmacology
© Georg Thieme Verlag Stuttgart · New York

The Sedative Effects and Mechanism of Action of Cedrol Inhalation with Behavioral Pharmacological Evaluation

Daiji Kagawa1 , Hiroko Jokura1 , Ryuji Ochiai1 , Ichiro Tokimitsu1 , Hirokazu Tsubone2
  • 1Biological Science Laboratories, Kao Corporation, Tochigi, Japan
  • 2Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan
Further Information

Publication History

Received: November 4, 2002

Accepted: March 22, 2003

Publication Date:
04 August 2003 (online)

Abstract

It has been reported that cedarwood oil has sedative effects when inhaled. In this study, we evaluated sedative effects of inhaled cedrol, which is a major component of cedarwood oil. Accumulative spontaneous motor activity was significantly decreased in the cedrol-exposed Wistar rats. Similar results were confirmed in caffeine-treated Wistar rats, spontaneously hypertensive rats (SHR), and ddY mice. In addition, exposure to cedrol prolonged pentobarbital-induced sleeping time in Wistar rats. To investigate whether cedrol, which has a very faint aroma, affects the olfactory system, the nasal cavities of Wistar rats were treated with zinc sulfate to reduce olfactory function. Two days later, the pentobarbital-induced sleep time was measured as described above. Compared to intact rats, the sleep prolongation effect was decreased in a lavender-roman chamomile mixed oil exposure positive control group, indicating that olfactory function was impaired. In contrast, prolongation of the sleeping time did not change in the cedrol exposure group. The above findings indicate that cedrol inhalation had marked sedative effects regardless of the animal species or the functional state of the autonomic nerves, suggesting that the mechanism of action is via a pathway other than the olfactory system.