Content uploaded by Tapanee Hongratanaworakit
Author content
All content in this area was uploaded by Tapanee Hongratanaworakit
Content may be subject to copyright.
Original Article 73
http://www.jhr.cphs.chula.ac.th J Health Res
vol.27 no.2 April 2013
THE EFFECTS OF JASMINE OIL INHALATION ON
BRAIN WAVE ACTIVIES AND EMOTIONS
Winai Sayowan1, Vorasith Siripornpanich2, Tapanee Hongratanaworakit3,
Naiphinich Kotchabhakdi4, Nijsiri Ruangrungsi5, *
1Kanchanabhishek Institute of Medical and Public Health Technology, Nonthaburi 11150, Thailand
2Research Center for Neuroscience, Institute of Molecular Biosciences, Mahidol University, Salaya, Nakornpathom 73170,
Thailand, 3Faculty of Pharmacy, Srinakharinwirot University, Nakhon-nayok 26120, Thailand, 4Salaya Stem Cell Research
and Development Project; Research Center for Neuroscience, Mahidol University, Salaya, Nakhonpathom 73170, Thailand
5College of Public Health Sciences, Chulalongkorn University, Bangkok 10330, Thailand
ABSTRACT: In Thailand, jasmine oil is widely used as a preferred odor in aromatherapy.
However, there are a small number of researches investigating effects of jasmine oil on the
nervous system functions. In this study, we aimed to examine effects of jasmine oil inhalation on
the function of central nervous system and mood responses. Twenty healthy volunteers have
been participated in this study. The electroencephalogram (EEG) was then recorded from 31
electrodes on scalp before and after odor inhalation. In addition to the EEG recording, subjects
have also been inquired to estimate their emotion responses. According to the international 10-
20 system, the EEG measurements were recorded and the EEG power spectra were calculated
using the Fast Fourier Transform (FFT). The data was analyzed by comparing two sessions;
first during resting and inhaling sweet almond oil, and second between inhaling sweet almond
and inhaling jasmine oil. These parameters of assessment were measured before and after using
paired t- test statistical procedure.
The results showed that the beta wave power (13-30 Hz) was increase in the anterior centre as
well as the left posterior region. On one hand, the positive emotions including the feeling of
well-being, active, fresh and romantic have been increased by jasmine oil. On the other hand, the
negative emotions for example the feeling of drowsy were significantly decreased.
It could be suggested from these results that jasmine oil has stimulatory effects on the function
of nervous system. Interestingly, it could be concluded from this study that inhalation of jasmine
oil affected to brain wave activities and mood states
Keywords: Jasminum sambac (L.) Ait, EEG, Stimulation
INTRODUCTION
An essential oil is a concentrated volatile aromatic
compound derived from plants. Owing to the
different in environmental conditions and
neighbouring fauna and flora, each plant species
nurtured in a certain country has specific
characteristics. Essential oil can be extracted from
oil ‘sacs’ in flowers, leaves, stems, roots, seeds,
wood and bark [1, 2]. It is widely known that the
odor of essential oils can be used to treat illnesses
using a therapy called aromatherapy. Aromatherapy
can then be defined as a therapy that uses aromas.
More accurately, aromatherapy is a branch of
botanical medicine using volatile and aromatic plant
compounds that has been considered as a treatment
tool for various conditions. It is believed that
essential oils have certain effects on the person
* Correspondence to: Nijsiri Ruangrungsi
E-mail: nijsiri.r@chula.ac.th
inhaling it [2, 3]. The result from the study of Patin
[4] demonstrated that jasmine oil was the most
popular of the essential oils used in Thailand for
aromatherapy, inhalation or massage.
Jasmine is scientifically labeled as Jasminum
sambac (L.) Ait. Jasmine oil has beneficial in the
treatment of severe depression and soothes the
nerves, producing a feeling of confidence, optimism
and euphoria, while revitalizing and restoring
energy and improving memory [5]. The main
chemical components of jasmine oil are Benzyl
acetate, β – linalool, Benzyl propionate. The
reported properties of volatile oils include being
carminative, aromatic, antispasmodic, antidepressant,
antimicrobial, astringent and stimulatory. The
information regarding the effects of jasmine odor
on research participants is a stimulation of human
attention [6], The basic level being that of alertness
which ranged from sleep to wakefulness. In 1991
Tsuchiya [7] and his colleagues reported the effects
74 Original Article
J Health Res
vol.27 no.2 April 2013 http://www.jhr.cphs.chula.ac.th
Table 1 Demographic data of the subjects
Parameters
Number
Minimum
Maximum
Mean
SD
Age
Height(cm)
Weight (kg)
Body Mass Index
Smell test
20
20
20
20
20
18
154
45
18.21
8
32
179
72
27.97
11
22.70
168.25
58.57
21.33
9.60
4.27
5.12
6.15
2.10
0.86
of jasmine aroma on mice sedated using
pentobarbital. In humans the study by
Hongratanaworakit [8] studied the effects of
applying jasmine oil topically to the abdomen of 40
volunteers. Compared with placebo, jasmine oil
caused significant increases of breathing rate, blood
oxygen saturation, and systolic and diastolic blood
pressure, suggesting an increase of autonomic
arousal. At the emotional level, subjects in the
jasmine oil group rated themselves as more alert,
more vigorous and less relaxed than subjects in the
control group. Some researchers studying the
effects of jasmine on nervous system activity also
showed contrasting results. For example, Jasmine
absolute (Jasminum grandiflora L.) has a relaxant
activity on the guinea-pig ileum and rat uterus in
vitro [9] and jasmin lactone odor enhanced the
amount of alpha and theta waves which suggested a
relaxing effect from the odor [10].
In Thailand, there are only a few recent studies on
the effects of essential oils on physiological and
emotional activities. In addition, human transdermal
techniques have been often used in many researches
to evaluate the effect of essential oils, e.g.
rosemary, orange, ylang-ylang and jasmine oils [9,
11-13]. A review of the literature suggests that this
study is the first experimental research in Thailand
to evaluate the physiological effects of essential oils
on the central nervous system using EEG. Thus, the
purpose of this study is to determine the effects of
jasmine oil on the brain wave function and on
subjective emotions.
METHODS
Essential oil analysis
The composition of jasmine oil obtained from the
Thai China Flavours and Fragrances Company, was
analyzed by gas chromatography/ mass spectrometry
(GC/MS) equipped with Finnigan DSQ MS
detector, Thermo Finnigan model Trace GC Ultra.
Identify the oil’s constituents by matching their
mass spectra and retention times, indicated in
NIST05 MS library; the percentage compositions
also were computed from GC peak area [14]. The
result revealed that jasmine oil mainly consists of
26.09% Benzyl acetate, 11.02% Beta –linalool and
9.65% Benzyl propionate.
Subjects
The study was approved by the Ethical Review
Committee for Research Involving Human
Research Subjects, Health Science Group,
Chulalongkorn University, Permissions no. COA
NO.009/2011.
A total of 10 males and 10 females subjects aged
between 18 to 32 years (mean age 22.70 ±4.27
years) with a body mass index ranged 18-25 kg/m2
[15] (mean BMI 21.33 ± 2.10) were enrolled for the
study. A number of studies have reported that there
is different brain wave activity in left-handed and
right-handed subjects during olfactory tasks. In the
present study only right handers were recruited.
Handedness was tested using Edinburgh
Handedness Inventory scale [16]. The subjects were
then screened for a normal sense of smell by the n-
butyl alcohol test (mean score 9.60 ± 0.86). [17].
Personal health status was also recorded; including
weight, height and blood pressure. The subjects
who passed the screening procedure were non-
smokers [18] without any symptoms of upper
respiratory infection, neurological diseases,
hypertension or cardiovascular disease. According
to previous studies, it has been found that the
pleasantness of the oil smell could induce
variability of nervous system function [19];
therefore the subjects were asked to inhale base oil
and jasmine oil to rate the level of pleasantness on a
5-point Likert scale before starting the experiment.
The subjects who rated the pleasantness of the oil
within 2-4 points were allowed to proceed with the
experiment. A summary of the demographic
findings and smell test results are presented in
Table 1.
Procedure
An A-B design was used in this study. Each
individual session consisted of two trails. This
design was chosen because, with olfactory
stimulation, the times court of stimulatory effects is
unknown, which might make results obtained from
other designs, such as A-B-A, difficult to interpret
the data [6]. All activities were done in a silent
room with an ambient temperature of 24±1˚C and
40-50% humidity. After they sat comfortably in the
Original Article 75
http://www.jhr.cphs.chula.ac.th J Health Res
vol.27 no.2 April 2013
Table 2 Mean and SD Power Values in Eyes closed, sweet almond oil and jasmine inhalations.
Area
Eyes closed
Sweet almond oil
Jasmine
p-value
EC and SO
p-value
SO and JO
Mean
SD
Mean
SD
Mean
SD
Beta Power (13-30Hz) (µV2)
left anterior
0.33
0.04
0.34
0.04
0.43
0.04
0.078
0.009*
right anterior
0.34
0.04
0.36
0.04
0.44
0.04
0.072
0.009*
Center
0.44
0.05
0.46
0.05
0.53
0.05
0.071
0.039*
left posterior
0.32
0.04
0.34
0.05
0.45
0.04
0.154
0.017*
right posterior
0.36
0.04
0.39
0.05
0.45
0.04
0.118
0.075
* Significant difference, p-value < 0.05 Rest (R), Sweet almond oil (SO) , Jasmine oil (JO)
Figure 1 Brain topographical map of the distribution of beta brainwave activity
High
Low
Eyes Closed
sweet almond oil
Jasmine
Figure 1 shows the brain topographical map of the distribution of beta brainwave activity. The red areas indicate a
significant increase in power.
adjustable armchair a set of 31 electrodes with 1
additional ground electrode were placed onto the
subject’s head. This was done according to the
international 10-20 system at FP1, FP2,FZ, F3, F4,
F7, F8, FT7, FC3, FCZ, FC4, FT8, T3, T4, T5, T6,
TP7, TP8, C3, CP3, C4, CZ, CPZ, CP4, P3, P4, PZ,
Ol, O2 and OZ. Two mastoids were used as a
recording reference (average of both mastoids, Al +
A2/2). The electro-oculogram (EOG) was measured
by placing 4 electrodes in two external acanthi
(HEOL and HEOR), left supraorbital (VEOU) and
infraorbital (VEOL) regions. Electro-Cap is made
of an elastic spandex-type fabric with recessed
silver/silver chloride (Ag/AgCl) electrodes attached
to the fabric. Electrode impedances were adjusted to
below 5 kOhms. Acquire Neuroscan version 4.3
(Neurosoft, INC) used as recording system. An
online filter was set to band pass; with low
frequency of 70 Hz and high frequency of DC. A/D
rate was 500 Hz and the gain was set at 19. Notch
filter was open at 50 Hz [20, 21]. The relative
power spectrum of the respective frequency bands
derived by Fast Fourier Transformation (FFT) was
expressed as follows: Delta (0 –3.99 Hz), Theta (4–
7.99 Hz), Alpha (8–12.99 Hz), Alpha1 (8–9.99 Hz),
Alpha2 (10–12.99 Hz) and Beta (13–30 Hz) wave
ranges [22]. The procedure was divided into 3
sessions of 7-min each. Baseline EEG recording
was done in eye-close. Sweet almond oil was
administered on the second trial, whereas 10% (v/v)
jasmine oil diluted in sweet almond oil was exposed
on the third trial. Subjects had to rate their emotion
response at the end of each trial. This emotions
scale consisted of a 100 mm monopolar visual
analog scale following by 5 factors: pleasant
(good), unpleasant (bad, uncomfortable, disgusted,
frustrated, and stressful), sensual (romantic),
relaxed (relax, clam, drowsy), and refreshing (fresh,
active) [23].
DATA AND STATISTIC ANALYSIS
The statistical software was used for data analysis
on the effects of jasmine oil on physiological and
mood states before and after assessments. A paired
t-test was carried out on the data from power of
brain wave and mood ratings.
RESULS
EEG data
The mean and standard deviation (SD) of EEG
power was calculated for each frequency band –
during resting, sweet almond oil and jasmine oil
inhalations. The results are shown in Table 2. The
areas of interest were grouped into left anterior
(Fp1, F3, F7), right anterior (Fp2, F4, F8), left
posterior (P3, T5, O1), right posterior (P4, T6, O2)
76 Original Article
J Health Res
vol.27 no.2 April 2013 http://www.jhr.cphs.chula.ac.th
Table 3 Mean and SD of emotional state change, resting, sweet almond oil and jasmine
Emotion
Eyes closed
sweet almond oil
Jasmine
P-value
EC and SO
P-value
SO and JO
Mean
SD
Mean
SD
Mean
SD
Good
55.90
14.46
54.30
18.18
78.10
12.74
0.620
0.000*
Active
50.40
13.78
37.10
19.02
53.40
20.56
0.062
0.014*
Drowsy
33.20
19.41
40.85
17.35
30.10
16.81
0.121
0.042*
Fresh
55.20
14.96
41.85
17.35
60.80
17.84
0.15
0.002*
Romantic
34.40
19.93
30.55
22.07
49.05
22.76
0.582
0.007*
* Significant difference, p-value < 0.05 SO = Sweet almond oil, JO = Jasmine oil
and central (Fcz, Cz, Cpz) regions [22]. In jasmine
session, the band power of beta in the left and right
anterior center and left regions showed a significant
increase (p-value < 0.05). However, theta and alpha
band power decreased with no significant statistic
change (p-value > 0.05, data not show). Brain
Topography Compared to resting and sweet almond
oil, the topographic map after smelling jasmine oil,
shown in Figure 1, demonstrated obviously less
spreading power in alpha brain, particularly in
bilateral temporal and central area. In contrast, the
power in beta brain increased in the frontal and
posterior areas.
Emotional State response
The mean and standard deviation SD of mood state
responses are shown in Table 3. In the second trial,
the subjects became significantly less fresh after
inhaling sweet almond oil, as compared to eyes
closed condition (at rest). In the third trial, exposure
to jasmine oil increased positive emotions including
the feelings of well-being, active, fresh, and
romantic (p-value < 0.05). Furthermore, negative
emotions such as feeling drowsy were significantly
reduced (p-value < 0.05).
DISCUSSION
In the present study jasmine oil was
inhaled by healthy subjects. Brain wave activity
was recorded to assess the arousal levels of the
central nervous system. In addition, subjects had to
rate their mood state in terms of pleasant (good),
unpleasant (bad, uncomfortable, disgusted, frustrated,
and stressful), sensual (romantic), relaxed (relax,
clam, drowsy), and refreshing (fresh, active) in
order to assess subjective behavioural arousal.
After jasmine oil inhalation, the CNS effects of the
oil were assessed. The power beta (13-30 Hz)
increased considerably in frontal center and left
posterior brain areas. No significant changes of the
power of alpha1 (8-10.99 Hz) and alpha2 (11-12.99
Hz) in all brain regions. This result showed that the
effect of aromas is to produce cortical brain wave
activity responses. Brain waves are known to vary
with extreme sensitivity according to the level of
consciousness of the subject [11]. Beta activity
increase is closely linked to motor behaviour and is
generally attenuated during active movements. Low
amplitude beta with multiple and varying
frequencies is often associated with active, busy or
anxious thinking and active concentration [21]. Our
result are similar to Nakagawa, et al [24] found
methyl jasmonate and cineole, a major component
of jasmine oil, increased beta wave and inhibited
alpha and theta waves with a enhancement that
corresponded with the stimulating effect on the
brain function. Furthermore, a study conducted at
the University of Occupational and Environmental
Health, Kitakyushu Japan, indicated a stimulating
effect of jasmine odor. There was a significant
increase of beta wave activity [25]. According to
Tsuchiya and colleagues’ experiment, they found
that jasmine and lemon oil responded to the
sleeping time in mice by reducing the duration of
sleep induced by barbiturates [8].
The result demonstrated that subjects felt better,
more active, fresher, and more romantic after the
inhalation. Consequently, negative emotions such
as drowsiness had been decreased. The results also
supported previous study referring jasmine odor
induced stimulating effects [7, 8]. To study the
underlying mechanisms of the main components of
jasmine oil it may also relevant to notes that the
second messenger for some serotonin receptors is
also cAMP and serotonin is felt to be involved in
the control of emotion within the central nervous
system. The stimulant effect of inhaling jasmine
vapor is probably due to its absorptions and sequent
pharmacological action within the brain or is
merely due to the stimulation of odor receptors
[26]. For example, one study investigated the
effects a jasmine oil massage on menopausal
symptoms in Korean climacteric women for 8
weeks. Kupperman's menopausal index was used to
compare an experimental group of 25 climacteric
women with a wait-listed control group of 27
climacteric women. The experimental group
reported a significantly lower total menopausal
index than wait-listed controls (P < 0.05). These
Original Article 77
http://www.jhr.cphs.chula.ac.th J Health Res
vol.27 no.2 April 2013
findings suggest that aromatherapy massage may be
an effective treatment of menopausal symptoms
such as hot flushes, depression and pain in
climacteric women [27].
CONCLUSIONS
In conclusion, our study shows a stimulating effect
of inhaling jasmine oil. The findings suggest that
brain wave activity and emotions. The results lend
some support for including jasmine oil in the group
of stimulating essential oils.
Psychoactive medications for treating mood
disorders have a range of unpleasant and
undesirable side-effects. Studies on the effects on
mood from aromatic oils may assist in the
development of medications with less adverse
effects.
ACKNOWLEDGEMENTS
This study was financially supported by Herbal
Remedies and Alternative Task Force of STAR:
Special Task Force for Activating Research under
100 years Chulalongkorn University fund and
Kanchanabhishek Institute of Medical and Public
Health for the research grant support this study. The
author is grateful to Dr. Chanida Palanuvej and
Miss Thidarat Duangyod for GCMS protocol
recommend.
REFERENCES
1. Battagla S. The complete guide to aromatherapy. 2nd ed.
Australia Brisbane: Watson Ferguson and Co.; 1997.
2. Hongratanaworakit T. Essential oil and aromatherapy.
Bangkok: Witoonkanpok press; 2008.
3. Reungrangsee N, Wongyai S. Aromatherapy text book.
Nonthaburi: Thai Veteran Organization; 2007.
4. Patin R. The most commonly used essential oils for
aromatherapy massage in Thai spa business. [Master’s
Thesis]. Chang Rai: Mae Fah Luang University; 2007.
5. Holmes P. Jasmine the queen of the night. International
Journal of Aromatherapy. 1998; 8(4): 8-12.
6. Ilmberger J, Heuberger E, Mahrhofer C, Dessovic H,
Kowarik D, Buchbauer G. The influence of essential
oils on human attention. I: Alertness. Chem Senses.
2001; 26(3): 239-45.
7. Tsuchiya T, Tanida M, Uenoyama S, Nakayama Y.
Effects of olfactory stimulation with jasmine and its
component chemicals on the duration of pentobarbital-
induced sleep in mice. Life Sci. 1992; 50(15): 1097-
102.
8. Hongratanaworakit T. Stimulating effect of
aromatherapy massage with jasmine oil. Nat Prod
Commun. 2010; 5(1):157-62.
9. Lis-Balchin M, Hart S, Wan Hang Lo B. Jasmine
absolute (Jasminum grandiflora L.) and its mode of
action on guinea-pig ileum in vitro. Phytother Res.
2002; 16(5): 437-9.
10. Hongratanaworakit, T. Physiological effects in
aromatherapy. Songklanakarin J Sci Technol, 2004;
26(1): 118-25
11. Hongratanaworakit T. Simultaneous aromatherapy
massage with rosemary oil on humans. Sci Pharm.
2009; 77: 375-87.
12. Hongratanaworakit T, Buchbauer G. Evaluation of the
harmonizing effect of ylang-ylang oil on humans after
inhalation. Planta Med. 2004; 70(7): 632-6.
13. Hongratanaworakit T, Buchbauer G. Human behavioral
and physiological reactions to inhalation of sweet
orange oil. Acta Hort. 2005; 679: 75-81
14. Hübschmann HJ. Handbook of GC/MS: Fundamentals
and applications. 2nd ed. Weinheim: Wiley-VCH; 2009.
15. Obrebowski A, Obrebowska-Karsznia Z, Gawlinski M.
Smell and taste in children with simple obesity. Int J
Pediatr Otorhinolaryngol. 2000; 55(3): 191-6.
16. Hummel T, Mohammadian P, Kobal G. Handedness is
a determining factor in lateralized olfactory
discrimination. Chem Senses. 1998; 23(5): 541-4.
17. Cain WS. Testing olfaction in a clinical setting. Ear
Nose Throat J. 1989; 68(4): 316, 322-8.
18. Ahlstrom R, Berglund B, Berglund U, Engen T,
Lindvall T. A comparison of odor perception in
smokers, nonsmokers, and passive smokers. Am J
Otolaryngol. 1987; 8(1): 1-6.
19. Brauchli P, Ruegg PB, Etzweiler F, Zeier H.
Electrocortical and autonomic alteration by
administration of a pleasant and an unpleasant odor.
Chem Senses. 1995; 20(5): 505-15.
20. Niedermeyer E, Dasilva LF. Electroencephalography:
Basic principles, clinical applications, and related fields.
5th ed. Philadelphia: Lippincott Williams Wilkins; 2005.
21. Lorig TS. The application of electroencephalographic
techniques to the study of human olfaction: a review
and tutorial. Int J Psychophysiol. 2000; 36(2): 91-104.
22. Iijima M, Osawa M, Nishitani N, Iwata M. Effects of
incense on brain function: evaluation using
electroencephalograms and event-related potentials.
Neuropsychobiology. 2009; 59(2): 80-6.
23. Chrea C, Grandjean D, Delplanque S, Cayeux I, Le
Calve B, Aymard L, et al. Mapping the semantic space
for the subjective experience of emotional responses to
odors. Chem Senses. 2009; 34(1): 49-62.
24. Nagakawa M, Nagai H, Inui T. Evaluation of
drowsiness by EEGs-Odors controlling drowsiness.
Fragrance J. 2006; 10: 68-72.
25. Sugano H. Effects of odours on mental function. Chem
Senses. 1989; 14(2): 303.
26. Lorig TS, Roberts M. Odor and cognitive alteration of
the contingent negative variation. Chem Senses. 1990;
15(5): 537-45.
27. Hur MH, Yang YS, Lee MS. Aromatherapy massage
affects menopausal symptoms in korean climacteric
women: a pilot-controlled clinical trial. Evid Based
Complement Alternat Med. 2008; 5(3): 325-8.
