The Sleep-Enhancing Effect of Valerian Inhalation and Sleep-Shortening Effect of Lemon Inhalation

Abstract

We examined the effects of odorant inhalation on the sleep-wake states in rats. Odorants used in the experiment were clove, jasmine, lavender, lemon, peppermint, pine, rose, sandalwood, valerian, and ylang-ylang. Valerian and rose inhalation significantly prolonged the pentobarbital-induced sleeping time, whereas lemon inhalation significantly shortened it. The effect of valerian inhalation was markedly noticeable. In the anosmic rats, a significant effect of odorants on the pentobarbital sleep time was not seen. Electroencephalographic studies on natural sleep revealed that rose inhalation did not exert any significant effect on sleep, but a significant shortening in sleep latency and a significant prolonging in total sleep time were observed with valerian inhalation, whereas a significant prolonging in sleep latency was observed with lemon inhalation. Such effects of valerian and lemon inhalation were not admitted in anosmic rats. gamma-Aminobutyric acid (GABA) transaminase assay indicates that valerian inhalation decreases the activity of the enzyme and enhances GABA activity. Although valerian has been reported to exert a good effect for sleep as a medicine for internal use, the present study is the first medical report suggesting that the inhalation of valerian may enhance the sleep. On the other hand, the present results may suggest the possibility that lemon inhalation may cause a worsening of insomnia symptoms.

Evaluation of volatile components from spikenard: valerena-4,7(11)-diene is a highly active sedative compound

“…Valerian preparations are widely used as herbal tranquillizers whose sedative activity is said to arise from sesquiterpene derivatives such as valerenic acid [8]. This mechanism is supported by results of experiments using spikenard oil [2]. Valerena-4,7(11)-diene was first isolated from valerian, and the same compound was found in spikenard as an active component in the present study.…”

“…More in-depth functional analyses of olfactory receptors may in the future clarify the molecular mechanisms related to odor recognition, from receptor binding to higher information processing in the brain. Komori et al examined the effects of odorant inhalation on sleep-wake status in rats [2] and found that valerian oil sedated the autonomic nervous system and that lemon oil activated it; inhalation of valerian oil remarkably prolonged the pentobarbital-induced sleeping time (46% prolongation), whereas that of lemon oil significantly shortened it (22% shortening).…”

Trends in research related to “Shinrin-yoku” (taking in the forest atmosphere or forest bathing) in Japan

“…The most recent human study demonstrated that cedrol directly inhaled through the lower airway, but not introduced to the upper airway, causes a suppression of sympathetic outflow and an increase in parasympathetic outflow [31]. The results of various studies on other scents, such as lavender, lemon, valerian, and others, showed considerable agreement with respect to the fact that the effectiveness of odors in prolonging pentobarbital sleep time [32,33], lowering Environ Health Prev Med (2010) 15:27-37 31 blood pressure [34], and suppressing renal sympathetic nerve activity [34] disappeared in anosmic mice or rats, thus indicating the mediation of the olfactory system in the whole process. The authors consider that odors affect human physiology mainly through the olfactory processing pathway; however, in the case of laboratory experiments, the possibility that odorous compounds act directly via the blood-borne pathway could not be eliminated since the concentration of inhaled compounds is relatively high.…”

États nerveux et dystonie neurovégétative, sédation avec les huiles essentielles

“…L'inhalation de vapeur d'HE de valériane augmente le sommeil induit par le pentobarbital de 46% cela s'accompagne d'une réduction de 39% de l'activité de la GABA transaminase. Le même traitement n'a pas d'effet chez les animaux anosmiques [43]. Ceci permet de supposer que l'olfaction est mise en jeu pour que l'inhalation d'HE agisse sur le SNC.…”

“…Les récepteurs olfactifs sont en relation avec les structures du SNC par des projections du bulbe sur le néocortex qui intervient dans la reconnaissance olfactive. Les relations existent aussi entre récepteurs olfactifs et le système limbique, siège de l'émotion et de l'affect [43,44]. …”