Planta Med 2003; 69(7): 637-641
DOI: 10.1055/s-2003-41114
Original Paper
© 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)


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.


  • 1 Vesell E S. Induction of drug-metabolizing enzymes in liver microsomes of mice and rats by softwood bedding.  Science. 1967;  157 1057-8
  • 2 Miyazaki Y. Forest bathing and health enhancement.  Sanrin. 1991;  128 18-29
  • 3 Yamaoka S. Effect of phytoncides on sleep and circadian sleep rhythm.  Int J Biometeorol. 1988;  32 217-29
  • 4 Terauchi F, Kubo M, Ohgama T, Aoki H. Effect of odors from coniferous woods on contingent negative variation (CNV).  J Soc Mat Sci. 1996;  45 397-402
  • 5 Buchbauer G, Jirovetz L, Jager W, Plank C, Dietrich H. Fragrance compounds and essential oils with sedative effects upon inhalation.  J Pharmac Sci. 1993;  82 660-4
  • 6 Sabine J R. Exposure to an environment containing the aromatic red cedar, Juniperus virginiana: procarcinogenic, enzyme-inducing and insecticidal effects.  Toxicology. 1975;  5 221-35
  • 7 Koller J, Baumer U, Kaup Y, Etspueler H, Weser U. Embalming was used in old kingdom.  Nature. 1998;  391 343-4
  • 8 Shieh J C, Sumimoto M. Antifungal wood component of Cunninghamia lanceolata .  Mokuzai Gakkaishi. 1992;  38 482-9
  • 9 Tsuji R, Isobe N, Kawasaki H. Mechanism of prolongation of pentobarbital-induced sleeping time by empenthrin in mice.  Toxicology. 1996;  108 185-90
  • 10 Saito H. Effects of fragrance exposure on central nervous system in mice.  Fragr J. 1999;  27 63-6
  • 11 Adams R P, Thappa R K, Agarwal S G, Kapahi B K, Sarin Y K. The volatile leaf oils Juniperus semiglobosa Regel from India compared with J. excelsa M.-Bieb. from Greece.  J Ess Oil Res. 1992;  4 143-9
  • 12 Song S H, Sawamura M, Ito T, Ido A, Ukeda H. Quantitative determination and characteristic flavour of daidai (Citrus aurantium L. var. cyathifera Y. Tanaka) peel oil.  Flavour Fragr J. 2000;  15 323-8
  • 13 Shimosato K, Ohkuma S. Simultaneous monitoring of conditioned place preference and locomotor sensitization following repeated administration of cocaine and methamphetamine.  Pharmacol Biochem Behav. 2000;  66 285-92
  • 14 Winans S S, Powers J B. Olfactory and vomeronasal deafferentation of male hamsters: histological and behavioral analyses.  Brain Research. 1977;  126 325-44
  • 15 Okugawa H, Ueda R, Matsumoto K, Kawanishi K, Kato A. Effect of jinkoh-eremol and agarospirol from agarwood on the central nervous system in mice.  Planta Med. 1996;  62 2-6
  • 16 Aoshima H, Hamamoto K. Potentiation of GABAA receptors expressed in Xenopus oocytes by perfume and phytoncid.  Biosci Biotechnol Biochem. 1999;  63 743-8
  • 17 Gupta M, Mazumder U K, Bhawal S R, Swamy S MK. CNS activity of petroleum ether extract of Vitex negundo Linn in mice.  Indian J Pharm Sci. 1997;  59 240-5
  • 18 Sano A, Sei H, Seno H, Morita Y, Moritoki H. Influence of cedar essence on spontaneous activity and sleep of rats and human daytime nap.  Psychiatry Clin Neurosci. 1998;  52 133-5
  • 19 Mehta S C, Vardhan H, Saxena S P. Some pharmacological actions of the essential oil of Blumea membranacea .  Ind J Physiol Pharmac. 1986;  30 149-54
  • 20 Umezu T, Sakata A, Ito H. Ambulation-promoting effect of peppermint oil and identification of its active constituents.  Pharmacol Biochem Behav. 2001;  69 383-90
  • 21 Elisabetsky E, Marschner J, Souza D O. Effects of linalool on glutamatergic system in the rat cerebral cortex.  Neurochem Res. 1995;  20 461-5
  • 22 Garcia D A, Perillo M A, Zygadlo J A, Martijena I D. The essential oil from Tagetes minuta L. modulates the binding of [3H]flunitrazepam to crude membranes from chick brain.  Lipids. 1995;  30 1105-10

Ichiro Tokimitsu, Ph. D.

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