The Effects of Lavender Oil Inhalation on Emotional States, Autonomic Nervous System,and Brain Electrical Activity Winai Sayorwan MPham*,Vorasith Siripornpanich MD** Teerut Piriyapunyaporn BSc***,Tapanee Hongratanaworakit Dr rer nat**** Naiphinich Kotchabhakdi PhD*****Nijsiri Ruangrungsi PhD* *College of Public Health Sciences,Chulalongkorn University,Bangkok,Thailand **Research Center for Neuroscience,Institute of Molecular Biosciences. Mahidol University.Salaya.Nakhonpathom.Thailand **Salaya Stem Cell Research and Development Project.Research Center for Neuroscience.Institue of Molecular Biosciences. Mahidol University.Salava.Nakhonpathom.Thailand ***Faculty of Pharmacy.Srinakharinwirot University.Nakhon-nayok.Thailand Objective:Investigate the effects of lavender oil on the central nervous system,autonomic nervous system,and mood responses in humans after inhalation. Material and Method:Twenty healthy volunteers participated in the experiments.The present study assessed autonomic parameters such as blood pressure,heart rate,respiratory rate,and skin temperature to determine the arousal level of the autonomic nervous system.In addition,subjects were asked to estimate their mood responses such as feeling pleasant or unpleasant,uncomfortable,sensuality,relaxation,or refreshing in order to assess subjective behavioral arousal.Finally. electroencephalogram (EEG)was recorded from 31 electrodes on the scalp according to the international 10 to 20 system, and EEG power spectra were calculated by Fast Fourier Transform (FFT).Data was analyzed by comparing the effects of lavender oil on physiological and mood states with sweet almond oil.These assessments were measured before and after using paired t-test statistical procedure. Results:The results revealed that lavender oil caused significant decreases ofblood pressure,heart rate,and skin temperature. which indicated a decrease of autonomic arousal.In terms of mood responses,the subjects in the lavender oil group categorized themselves as more active,fresher:relaxed than subjects just inhaling base oil.Compared with base oil,lavender oil increased the power of theta(4-8 H=)and alpha (8-13 H=)brain activities.The topographic map showed obviously more scattering power in alpha range waves particularly in bilateral temporal and central area. Conclusion:The findings provided evidence the relaxing effect of inhaling lavender oil Keywords:Lavandula angustifolia Mill,Physiological parameters,EEG Relaxation J Med Assoc Thai 2012;95 (4):598-606 Full text.e-Journal:http://www.jmat.mat.or.th Aromatherapy can be defined as the use of massage.It is also the best-selling essential oil, essential oils to balance mind.body,and spirit.The particularly in Bangkok2) word is derived from two words:aroma and therapy. Lavenders are members ofa genus Lavendula "Aroma"means smell or fragrance and"therapy"means and belong to the mint family,Lamiaceae,which is treatment.Complementary and alternative medicines native to the Mediterranean.In general,the essential usually use aromatherapy in their treatments by using oil of lavender (Lavendula angustifolia Mill)consists essential oils usually derived from volatile liquid plant of linalyl acetate,B-linalool,and B-caryophyllene) materials and other aromatic compounds from plants). The general properties of lavender oil are antibacterial. In Thailand,lavender is a popular essential oil in antifungal,carminative (smooth muscle relaxant), aromatherapy and administered by inhalation or sedative,antidepressant,promoting wound healing, and increasing the detoxification of enzymes Correspondence to: associated with insecticide resistance(4).A number of Ruangrungsi S.College of Public Health Sciences, Chulalongkorn University.Bongkok 10300,Thailand. researchers report the sedative effects of lavender oil Phone:0-2218-8158 caused by the major components linalyl acetate and E-mail:nijsiri.r@chula.ac.th B-linalool(5.6).These compounds can be rapidly 598 J MedAssoc Thai Vol.95 No.4 2012598 J Med Assoc Thai Vol. 95 No. 4 2012 Correspondence to: Ruangrungsi S, College of Public Health Sciences, Chulalongkorn University, Bongkok 10300, Thailand. Phone: 0-2218-8158 E-mail: nijsiri.r@chula.ac.th The Effects of Lavender Oil Inhalation on Emotional States, Autonomic Nervous System, and Brain Electrical Activity Winai Sayorwan MPham*, Vorasith Siripornpanich MD**, Teerut Piriyapunyaporn BSc***, Tapanee Hongratanaworakit Dr rer nat****, Naiphinich Kotchabhakdi PhD**, ***, Nijsiri Ruangrungsi PhD* * College of Public Health Sciences, Chulalongkorn University, Bangkok, Thailand ** Research Center for Neuroscience, Institute of Molecular Biosciences, Mahidol University, Salaya, Nakhonpathom, Thailand *** Salaya Stem Cell Research and Development Project, Research Center for Neuroscience, Institute of Molecular Biosciences, Mahidol University, Salaya, Nakhonpathom, Thailand **** Faculty of Pharmacy, Srinakharinwirot University, Nakhon-nayok, Thailand Objective: Investigate the effects of lavender oil on the central nervous system, autonomic nervous system, and mood responses in humans after inhalation. Material and Method: Twenty healthy volunteers participated in the experiments. The present study assessed autonomic parameters such as blood pressure, heart rate, respiratory rate, and skin temperature to determine the arousal level of the autonomic nervous system. In addition, subjects were asked to estimate their mood responses such as feeling pleasant or unpleasant, uncomfortable, sensuality, relaxation, or refreshing in order to assess subjective behavioral arousal. Finally, electroencephalogram (EEG) was recorded from 31 electrodes on the scalp according to the international 10 to 20 system, and EEG power spectra were calculated by Fast Fourier Transform (FFT). Data was analyzed by comparing the effects of lavender oil on physiological and mood states with sweet almond oil. These assessments were measured before and after using paired t-test statistical procedure. Results: The results revealed that lavender oil caused significant decreases of blood pressure, heart rate, and skin temperature, which indicated a decrease of autonomic arousal. In terms of mood responses, the subjects in the lavender oil group categorized themselves as more active, fresher, relaxed than subjects just inhaling base oil. Compared with base oil, lavender oil increased the power of theta (4-8 Hz) and alpha (8-13 Hz) brain activities. The topographic map showed obviously more scattering power in alpha range waves particularly in bilateral temporal and central area. Conclusion: The findings provided evidence the relaxing effect of inhaling lavender oil Keywords: Lavandula angustifolia Mill, Physiological parameters, EEG, Relaxation Aromatherapy can be defined as the use of essential oils to balance mind, body, and spirit. The word is derived from two words: aroma and therapy. “Aroma” means smell or fragrance and “therapy” means treatment. Complementary and alternative medicines usually use aromatherapy in their treatments by using essential oils usually derived from volatile liquid plant materials and other aromatic compounds from plants(1). In Thailand, lavender is a popular essential oil in aromatherapy and administered by inhalation or massage. It is also the best-selling essential oil, particularly in Bangkok(2). Lavenders are members of a genus Lavendula and belong to the mint family, Lamiaceae, which is native to the Mediterranean. In general, the essential oil of lavender (Lavendula angustifolia Mill) consists of linalyl acetate, β-linalool, and β-caryophyllene(3). The general properties of lavender oil are antibacterial, antifungal, carminative (smooth muscle relaxant), sedative, antidepressant, promoting wound healing, and increasing the detoxification of enzymes associated with insecticide resistance (4). A number of researchers report the sedative effects of lavender oil caused by the major components linalyl acetate and β-linalool(5,6). These compounds can be rapidly J Med Assoc Thai 2012; 95 (4): 598-606 Full text. e-Journal: http://www.jmat.mat.or.th