The Effects of Inhaled Limnophila aromatica Essential Oil on Brain Wave Activities and Emotional States in Healthy Volunteers: a Randomized Crossover Study

Document Type: Original paper

Authors

1 College of Public Health Sciences, Chulalongkorn University, Bangkok, Thailand. Faculty of Medicine, Mahasarakham University, Maha Sarakham, Thailand.

2 Research Center for Neuroscience, Institute of Molecular Biosciences, Mahidol University, Nakhonpathom, Thailand.

3 Kanchanabhisek Institute of Medical and Public Health Technology, Nontaburi, Thailand.

4 College of Public Health Sciences, Chulalongkorn University, Bangkok, Thailand.

5 College of Public Health Sciences, Chulalongkorn University, Bangkok, Thailand. Department of Pharmacognosy, College of Pharmacy, Rangsit University, Pathum Thani, Thailand.

Abstract

Background and objectives: Limnophila aromatica (Lam.) Merr., a characteristic odorous vegetable, is commonly used in Thai dishes and folk medicine. Limnophila aromatica essential oil has never been investigated on brain activities before. This study aimed to evaluate the effects of L. aromatica essential oil inhalation on brain wave activities through EEG recordings and emotional states among healthy volunteers using a randomized crossover design. Methods: Limnophila aromatica essential oil was extracted from the aerial parts by hydro-distillation method and its chemical components were analyzed by GC/MS. The essential oil was diluted to 8% v/v with sweet almond oil. Twenty-four healthy participants aged between 18 and 25 years, recruited from general public, inhaled both L. aromatica essential oil and sweet almond oil with seven-day washout period. Nicolet EEG v32 was used to record brain activities and the self-evaluated questionnaire on emotional states in Thai version of The Geneva Emotion and Odor Scale was used to measure the subjective feelings of the participants. Data were analyzed using paired t-test with a significance level of 0.05. Results: Limnophila aromatica essential oil icreases theta and alpha wave and induced more relaxed feelings compared to the vehicle. Conclusion: The inhalation of L. aromatica essential oil could cause the relaxing effects on positive mood states and the relaxation of brain state.

Keywords

Main Subjects


[1]  Nanasombat S, Teckchuen N.Antimicrobial, antioxidant and anticanceractivities of Thai local vegetables. J Med Plants Res.2009; 3(5): 443-449.
[2]  Wanyo P, Huaisan K, Boothaisong S, Nitisuk P, Wongpreedee P, Chamsai T. Effect of hot-air drying and vacuum drying on oxalate contents of Limnophila aromatica and Limnophila geoffrayi. Food Appl Biosci J. 2018; 6(2): 65-75.
[3]  Soimaloon P, Tinchan P, Horng-Liang L. Effect of extraction conditions on color, pH, flavor profile and ribonucleotide contents of Limnophila aromatica (Lam.) Merr. extracts. Appl Sci Eng Prog. 2018; 11(2): 109-116.
[4]  Brahmachari G.Limnophila(Scrophulariaceae): chemical and pharmaceutical aspects. Open Nat Prod J. 2008; 1(1): 34-43.
[5]  Kukongviriyapan U, Luangaram S, Leekhaosoong K, Kukongviriyapan V, Preeprame S. Antioxidant and vascular protective activities of Cratoxylum formosum, Syzygium gratum and Limnophila aromatica. Biol Pharm Bull. 2007; 30(4): 661-666.
[6]  Sribusarakum A, Bunyapraphatsara N, Vajragupta O, Watanabe H. Antioxidant activity of Limnophila aromatica Merr. Thai J Phytopharm. 2004; 11(2): 11-17.
[7]  Chowdhury JU, Bhuiyan MN, Begum J. Constituents of volatile oils from Limnophila aromatica and Adenosma capitatum. Bangladesh J Sci Ind Res. 2011; 46(3): 385-388.
[8]  Hongratanaworakit T. Physiological effects in aromatherapy.Songklanakarin J Sci Technical. 2004;26(1):117-125.
[9]  Niedermeyer E, da Silva FL, Eds. Electroencephalography: basic principles, clinical applications, and related fields.  Philadelphia: Lippincott Williams & Wilkins, 2005.
[10] Sowndhararajan K, Kim S. Influence of fragrances on human psychophysiological activity: with special reference to human electroencephalographic response. Sci Pharm. 2016; 84(4): 724-751.
[11] Teplan M. Fundamentals of EEG measurement. Meas Sci Rev. 2002; 2(2): 1-11.
[12] Sayorwan W, Siripornpanich V, Piriyapunyaporn T, Hongratanaworakit T, Kotchabhakdi N, Ruangrungsi N. The effects of lavender oil inhalation on emotional states, autonomic nervous system, and brain electrical activity. J Med Assoc Thai. 2012;95(4):1-9.
[13] Sayowan W, Siripornpanich V, Piriyapunyaporn T, Hongratanaworakit T, Kotchabhakdi N, Ruangrungsi N. The harmonizing effects of citronella oil on mood states and brain activities. J Health Res. 2012; 26(2): 69-75.
[14] Sayowan W, Siripornpanich V, Hongratanaworakit T, Kotchabhakdi N, Ruangrungsi N. The effects of jasmine oil inhalation on brain wave activities and emotions. J Health Res.  2013; 27(2): 73-77.
[15] Sayorwan W, Ruangrungsi N, Piriyapunyporn T, Hongratanaworakit T, Kotchabhakdi N, Siripornpanich V. Effects of inhaled rosemary oil on subjective feelings and activities of the nervous system. Sci Pharm. 2013; 81(2): 531-542.
[16] Manion CR, Widder RM. Essentials of essential oils. Am J Health Syst Pharm. 2017; 74(9): 153-162.
[17] NuidenN,Sayowan W, Siripornpanich V, Palanuvej C, Ruangrungsi N.The effects of Cinnamomum porrectum essential oil inhalation on human autonomic nervous system and emotional states. J Royal Thai Army Nurse. 2019; 20(2):83-92.
[18] World Health Organization. Quality control methods for herbal materials. Geneva: World Health Organization, 2011.
[19] Adams RP. Identification of essential oil components by gas chromatography/ mass spectrometry. 4th ed. Illinois: Allured Publishing Corporation, 2007.
[20] Llido LO, Mirasol R.Comparison of body mass index based nutritional status using WHO criteria versus Asiancriteria: report from the Philippines.PhilSPEN Online J Parenter Enteral Nutr. 2011; Article ID POJ_0005.
[21] Hummel T, Mohammadian P, Kobal G.Handedness is a determining factor in lateralized olfactory discrimination.Chem Senses. 1998; 23(5): 541-544.
[22] Cain W.Testing olfaction in a clinical setting.Ear Nose Throat J. 1989; 68(4): 316-322.
[23] Chrea C, Grandjean D, Delplanque S, Cayeux I, Le Calve B, Aymard L, Velazco MI, Sander D, Scherer KR. Mapping the semantic space for the subjective experience of emotional responses to odors. Chem Senses. 2009; 34(1): 49-62.
[24] Tucker AO, Maciarello MJ, Hendi M, Wheeler KA. Volatile leaf and stem of commercial Limnophila chinensis (Osb.) Merrill ssp. aromatica (Lam.) Yamazaki (Scrophulariaceae). J Essent Oil Res. 2002; 14(3): 228-229.
[25] Bhuiyan MNI, Akter F, Chowdhury JU,  Begum J. Chemical constituents of essential oils from aerial parts of Adenosma capitatum and Limnophila aromatica. Bangladesh J Pharmacol. 2010; 5(1): 13-16.
[26] Vairappan CS, Nagappan T. Major volatile hydrocarbons of rice paddy herb, Limnophila aromatica Lam. Merr as possible chemotaxonomic marker. J Trop Biol Conserv. 2014; 11(1): 41-48.
[27] Pittayapruek P, Boonyahotra V, Sittiprapaporn P. Electroencephalographic studies of inner wisdom meditation training program. Proceedings of the 14th International Conference on Electrical Engineering/Electronics, Computer, Telecommunication and Information Technology (ECTI-CON). 2017 Jun 27-30; Phuket, Thailand.
[28] Lee I. Effects of inhalation of relaxing essential oils on electroencephalogram activity. Int J New Technol Res. 2016; 2(5): 37-43.
[29] Kwangai J, Hiranyachattada S, Wattapiromsakul C, Kumarnsit E. Modification of electrical brain wave by Citrus sp. essential oil inhalation. J Physiol Biomed Sci. 2013; 26(1): 5-8.
[30] Sowndhararajan K, Cho H, Yu B, Kim S. Effect of olfactory stimulation of isomeric aroma compounds, (+)-limonene and terpinolene on human electroencephalographic activity. Eur J Integr Med. 2015; 7(6): 561-566.
[31] Lorig TS, Herman KB, Schwartz GE, Cain WS. EEG activity during administration of low-concentration odors. Bull Psychon Soc. 1990; 28(5): 405-408.
[32] Lorig TS, Malin EL, Horwitz JE. Odor mixture alters neural resources during symbolic problem solving. Biol Psychol. 2005; 69(2): 205-216.