Aroma-therapeutic Effects of Massage Blended Essential Oils on Humans

Abstract

Although blended essential oils are increasingly being used for the improvement of the quality of life and for the relief of various symptoms in patients, the scientific evaluation of the aroma-therapeutic effects of blended essential oils in humans is rather scarce. In this study, we hypothesized that applying blended essential oil would provide a synergistic effect that would have a chance for success in treating depression or anxiety. Therefore, the main objective of this study was to investigate the effects of the blended essential oil on autonomic parameters and on emotional responses in humans following transdermal absorption. The blended essential oil consisted of lavender and bergamot oils. Human autonomic parameters, i.e. blood pressure, pulse rate, breathing rate, and skin temperature, were recorded as indicators of the arousal level of the autonomic nervous system. In addition, subjects had to rate their emotional condition in terms of relaxation, vigor, calmness, attentiveness, mood, and alertness in order to assess subjective behavioral arousal. Forty healthy volunteers participated in the experiments. Blended essential oil was applied topically to the skin of the abdomen of each subject. Compared with placebo, blended essential oil caused significant decreases of pulse rate, and systolic and diastolic blood pressure, which indicated a decrease of autonomic arousal. At the emotional level, subjects in the blended essential oil group rated themselves as 'more calm' and 'more relaxed' than subjects in the control group. This finding suggests a decrease of subjective behavioral arousal. In conclusion, our investigation demonstrates the relaxing effect of a mixture of lavender and bergamot oils. This synergistic blend provides evidence for its use in medicine for treating depression or anxiety in humans.

Full text

Aroma-therapeutic Effects of Massage Blended Essential
Oils on Humans
Tapanee Hongratanaworakit
Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Srinakharinwirot University,
Rangsit-Ongkharak Road, Nakhonnayok 26120, Thailand
tapanee@swu.ac.th
Received: October 18th, 2010; Accepted: April 20th, 2011
Although blended essential oils are increasingly being used for the improvement of the quality of life and for the relief of various symptoms
in patients, the scientific evaluation of the aroma-therapeutic effects of blended essential oils in humans is rather scarce. In this study, we
hypothesized that applying blended essential oil would provide a synergistic effect that would have a chance for success in treating
depression or anxiety. Therefore, the main objective of this study was to investigate the effects of the blended essential oil on autonomic
parameters and on emotional responses in humans following transdermal absorption. The blended essential oil consisted of lavender and
bergamot oils. Human autonomic parameters, i.e. blood pressure, pulse rate, breathing rate, and skin temperature, were recorded as indicators
of the arousal level of the autonomic nervous system. In addition, subjects had to rate their emotional condition in terms of relaxation, vigor,
calmness, attentiveness, mood, and alertness in order to assess subjective behavioral arousal. Forty healthy volunteers participated in the
experiments. Blended essential oil was applied topically to the skin of the abdomen of each subject. Compared with placebo, blended
essential oil caused significant decreases of pulse rate, and systolic and diastolic blood pressure, which indicated a decrease of autonomic
arousal. At the emotional level, subjects in the blended essential oil group rated themselves as ‘more calm’ and ‘more relaxed’ than subjects
in the control group. This finding suggests a decrease of subjective behavioral arousal. In conclusion, our investigation demonstrates the
relaxing effect of a mixture of lavender and bergamot oils. This synergistic blend provides evidence for its use in medicine for treating
depression or anxiety in humans.
Keywords: lavender, bergamot, massage aromatherapy, autonomic arousal, behavioral arousal, relaxing effect.
Aromatherapy has grown considerably into a big business
in many countries, as illustrated by the street shops that
sell either products supposedly made with essential oils,
such as skin care, hair care, and fragrance products, or pure
essential oil. Tisserand [1] suggested lavender oil
(Lavendula angustifolia Mill, Labiatae) and bergamot
(Citrus bergamia Risso, Rutaceae) as effective in treating
depression and anxiety. Lavender and bergamot oils have
been shown to be associated with brain-wave relaxation by
Torri et al. [2]. In traditional medicine, lavender oil is
reported used as an antispasmodic, carminative, mild
tranquilizer, sedative, and stomachic. Moreover, lavender
oil is the most used essential oil of all in aromatherapy. Its
greatest attribute is said to be as a relaxant. It is also used
for headache, nervous tension, exhaustion, emotional
extremes, and spiritual balance [3]. Lavender oil was used
by many researchers [4-6] in their studies of aromatherapy
relaxation in association with massage. In addition,
lavender oil was used as a component in topical
formulations to relieve the pain associated with rheumatic
and musculoskeletal disorders, acting as a potent radical
scavenger [7]. Bergamot oil is reportedly used for anxiety,
depression, and headaches. Bergamot oil had a sedative
effect, as shown by contingent negative variation studies
[8]. Antidepressant effects are included in the properties
attributed to bergamot [9].
Recently, interest in the use of aromatherapy with blended
essential oils as therapeutically active agents has grown
considerably. Fibromyalgia, a chronic painful condition,
can be treated with a mixture of seven organically derived
essential oils (Aloe vera, eucalyptus, lemon, orange,
camphor, rosemary, and peppermint) [10]. Lavender oil
was used in a mixture as a hair growth stimulant and for
the treatment of Alopecia areata [11]. Davis [12]
recommends a combination of lavender and bergamot for
relaxation. Moreover, blended essential oils of lavender
and bergamot showed reductions in anxiety in breast
cancer patients [13]. Aromatherapy massage with a
mixture of lavender and neroli was shown to be effective
for postpartum mothers to improve physical and mental
status [14]. Hand massage with blended essential oils of
bergamot, lavender and frankincense had a positive effect
on depression and pain on hospice patients with terminal
cancer [15]. Aromatherapy using topically applied blended
essential oils of lavender, clary sage, and rose is effective
in decreasing the severity of menstrual cramps [16].
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No. 8
1199 - 1204

1200 Natural Product Communications Vol. 6 (8) 2011 Hongratanaworakit
Table 1: Mean and SEM of autonomic parameters of the control and experimental groups.
Autonomic parameters Control group (Mean+SEM) Experimental group (Mean+SEM)
Trial 1 Trial 2 Trial 1 Trial 2
SBP
115.7+3.0
116.2+4.1
115.3+3.3
110.4+3.2
DBP
71.1+2.1
71.4+2.4
71.3+1.5
67.1+1.5
ST
36.9+0.2
36.5 +0.2
36.5+0.2
36.3+0.3
BR
17.0+0.8
17.2+0.9
17.1+0.9
16.6+0.9
PR
68.1+1.8
69.2+1.8
68.2+2.5
66.2+2.3
SBP: systolic blood pressure ; DBP: diastolic blood pressure; ST: skin temperature; BR: breathing rate; PR: pulse rate; SEM: standard error mean
Although blended essential oils are increasingly being used
for the improvement of the quality of life, as well as for the
relief of various symptoms in patients, the scientific
evaluation of the aroma-therapeutic effects of blended
essential oils in humans is rather scarce. In this study, we
hypothesized that applying two essential oils, namely,
lavender and bergamot, together would provide a
synergistic effect that would have the chance of success in
treating depression or anxiety. Therefore, the main
objective of this study was to investigate the effects of this
blended essential oil on autonomic parameters, as well as
on emotional responses in humans following transdermal
absorption.
In the present investigation a mixture of lavender and
bergamot was administered transdermally to healthy
subjects. Autonomic parameters, i.e. systolic blood
pressure (SBP), diastolic blood pressure (DBP), pulse rate
(PR), breathing rate (BR), and skin temperature (ST), were
recorded as indicators of the arousal level of the autonomic
nervous system (ANS). In addition, subjects had to rate
their mental and emotional condition in terms of
relaxation, vigor, calmness, attentiveness, mood, and
alertness in order to assess subjective behavioral arousal.
Autonomic parameters: The mean and SEM of
autonomic parameters of the control group and the
experimental group are presented in Table 1. SBP of
subjects in the control group increased at the end of the
second trial compared with the end of the first. In contrast,
SBP of subjects in the blended essential oil group
decreased at the end of the second trial compared with the
end of the first. The difference scores of SBP between the
second and first trials for the control group and the blended
essential oil group are shown in Figure 1. Comparison of
these difference scores revealed a significantly larger
decrease of SBP in the blended essential oil group than in
the control group (P=0.014).
DBP of subjects in the control group only marginally
changed in the second trial compared with the first one. In
contrast, DBP of subjects in the blended essential oil group
decreased in the second trial compared with the first. The
different scores of DBP between the second and first trials
for the control group and the blended essential oil group
are shown in Figure 1. Comparison of these scores
revealed a significantly larger decrease of DBP in the
blended essential oil group than in the control group
(P=0.007). The blended essential oil group showed
significant decreases of systolic and diastolic blood
pressure. Since blood pressure is determined by the
activity of the sympathetic branch of the ANS, a decrease
in blood pressure shows a decrease in sympathetic tone,
i.e., a decrease of autonomic arousal [17,18].
-4
-2
0
2
4
6
8
Control group Blended essential oil group
Difference sco re
SBP DBP BR ST PR
*
*
*
Figure 1: The difference scores of systolic blood pressure (SBP), diastolic
blood pressure (DBP), breathing rate (BR), skin temperature (ST) and pulse
rate (PR) for the control group and the blended essential oil group. * on the top
of the bars indicates significant differences (P<0.05).
Table 2: Mean and SEM of emotional parameters of the control and
experimental groups.
Control (Mean+SEM) Experiment (Mean+SEM)
Trial 1 Trial 2 Trial 1 Trial 2
AT
21.5+3.1
22.5+3.5
21.2+3.0
25.7+3.5
AL
40.0+3.0
39.7+3.8
39.1+3.4
36.3+3.8
C
23.8+2.7
24.9+3.6
23.4+2.5
17.4+2.9
R
28.3+3.8
29.9+3.8
28.3+4.1
22.3+3.1
M
33.9+3.2
35.3+3.5
33.4+2.3
33.6+3.2
V
47.5+3.4
45.7+3.9
47.6+4.3
43.8+4.5
AT: attentiveness; AL: alertness; C: calmness; R: relaxation; M: mood; V:
vigor; SEM: standard error mean
PR of subjects in the control group increased at the end of
the second trial compared with the end of the first one. In
contrast, PR of subjects in the blended essential oil group
decreased at the end of the second trial compared with the
end of the first. The difference scores of PR between the
second trial and the first for the control group and the
blended essential oil group are shown in Figure 1.
Comparison of these scores revealed a significantly larger
decrease of PR in the blended essential oil group than in
the control group (P=0.033). Since pulse rate is mainly
controlled by the ANS, the decrease of pulse rate after
transdermal absorption of blended essential oil is likely to
show an increase in vagal tone, i.e., a decrease of ANS
arousal. The change in the cardiovascular parameter, i.e.,
pulse rate, was consistent with a decrease of peripheral
autonomic nervous activity [17,18].

Aroma-therapeutic effect of massage blended essential oil Natural Product Communications Vol. 6 (8) 2011 1201
No significant effects of the blended essential oil on ST
and BR were found (P>0.05 for all).
Emotional parameters: The mean and SEM of emotional
parameters of the control group and the experimental
group are presented in Table 2. Subjects in the control
group felt less calm at the end of the second trial compared
with the end of the first. On the other hand, subjects in the
blended essential oil group judged themselves ‘more calm’
at the end of the second trial compared with the end of the
first. The difference scores of subjective calmness between
the second and first trials for the control group and the
blended essential oil group are shown in Figure 2.
Comparison of these difference scores revealed a
significant increase of subjective calmness in the blended
essential oil group compared with the control group
(P=0.028). Subjects in the blended essential oil group
rated themselves as ‘more calm’ than subjects in the
control group. This finding points towards a decrease of
arousal in terms of self-evaluation [17,18].
Furthermore, subjects in the control group felt less relaxed
at the end of the second trial compared with the end of the
first one. In contrast, subjects in the blended essential oil
group judged themselves ‘more relaxed’ at the end of the
second trial compared with the end of the first. The
difference scores of subjective relaxation between the
second and first trials for the control and blended essential
oil groups are shown in Figure 2. Comparison of these
difference scores revealed a significant increase of
subjective relaxation in the blended essential oil group
compared with the control (P=0.021). Subjects in the
blended essential oil group rated themselves as ‘more
relaxed’ than subjects in the control group. This finding
points towards an increase of arousal in terms of self-
evaluation [17,18].
-9
-6
-3
0
3
6
9
12
Control group Blended essential oil group
Difference sco re
Attentiveness Alertness Mood Vigor Calmness Relaxation
*
*
Figure 2: The difference scores of subjective attentiveness, alertness, mood,
vigor, calmness, and relaxation for the control group and the blended essential
oil group. * on the top of the bars indicates significant differences
(P<0.05).
No significant effects of the blended essential oil on
subjective attentiveness, alertness, mood and vigor were
found (P>0.05 for all).
Transdermal absorption of blended essential oil decreased
the level of arousal of the ANS, i.e. decreases of systolic
and diastolic blood pressure, and pulse rate. Moreover,
massage of blended essential oil led to deactivation at the
behavioral level, i.e. subjects feel ‘more calm’ and ‘more
relaxed’ than before the administration of the oil. This
finding points towards a decrease of arousal in terms of
self-evaluation. Thus, the effects of blended essential oil
by massage may be characterized by the concept of
relaxing effect, which has also been described for rose
(Rosa damascena) [19], sandalwood [20], and ylang ylang
(Cananga odorata) essential oils [21]. Our findings clearly
support previous studies indicating the relaxing effect of
blended essential oil [12,13,15]. Although our findings
agree with other reports, it is important to assess further
biochemical measures (e.g., serotonin), as these would
further confirm the presence of a relaxing effect.
Blended essential oil mainly contained linalyl acetate and
linalool. Buchbauer et al. [22,23] described that both
linalyl acetate and linalool showed a sedative effect in
animals, namely, a decrease in motility of normal mice and
reverse caffeine-induced over-agitation in mice.
Transdermal absorption of (-)-linalool in humans induced a
deactivating effect on the ANS, that is, decreases of
systolic blood pressure and skin temperature as compared
with a control group receiving a placebo [24]. In addition,
previous reports [25-27] have suggested that the odor of
blended tea had lavender-like sedative effects on
autonomic nerve activity and mood states at a very low
intensity. Their results showed that (-)-linalool had a
sedative effect. Moreover, Hoeferl and colleagues [28]
showed that (-)-linalool had a sedative effect on heart rate.
It is known that essential oil is absorbed into the body via
skin [29,30]. Percutaneous absorption of lavender oil from
massage oil was investigated by our group [31]. They
reported that the main component of lavender oil, i.e.,
linalool, could be detected in human blood samples 5 min
after massage of the oil. This is one possible explanation
for the relaxing/sedating effect of the blended essential oil.
Correlation analysis between the ANS and behavior
parameters showed that the decreases of blood pressure
and pulse rate were not correlated with changes in
behavioral responses (data not shown). These findings
suggest the effectiveness of pharmacological mechanisms,
for example direct interactions between fragrance
molecules and receptor sites which are involved in the
regulation of ANS arousal. Due to their high lipophilicity,
fragrance molecules easily penetrate the blood brain
barrier and then affect the GABAA receptor-mediated
response, which would have a tranquilizing effect on the
brain following either inhalation or massage [32,33].
Therefore, one possibility that explains the relaxing effect
of blended essential oil could be that the oil possibly
stimulates the raphe nuclei in the brain into releasing
serotonin, a neurotransmitter that creates a
relaxing/sedative effect [34,35]. The raphe nuclei are also

1202 Natural Product Communications Vol. 6 (8) 2011 Hongratanaworakit
involved in sleep and relaxation [18,36]. Another
possibility that could explain its effect is that blended
essential oil interacts with central (e.g. hypothalamic,
limbic, thalamus) structures which control the level of
autonomic and/or behavioral arousal.
In conclusion, our investigation demonstrates the relaxing
effect of the mixture of lavender and bergamot oils. This
synergistic blend shows evidence for its use in medicine
for treating depression or anxiety in humans.
Experimental
Subjects and essential oil: Forty healthy volunteers aged
between 19 and 48 years (mean age 24.95 6.67 years)
took part in the experiments. Demographic data for the
control group and the experimental group are presented in
Table 3. Subjects were tested in individual sessions and
randomly assigned to either the control group or the
blended essential oil group according to random numbers.
They were fully briefed, given written informed consent to
all aspects of the study (Srinakharinwirot University Ethics
Committees) and were free to withdraw at any time. Forty-
eight hours prior to testing, subjects were asked to abstain
from food, beverages and toiletries containing the essential
oil, as well as from any stimulants (for example, caffeine
and nicotine).
Table 3: Demographic data for the control group and the experimental group.
Parameter Control group Blended oil group
Number of
volunteers
20
20
Sex (M:F)
8:12
9:11
Height (cm)
(mean+SD)
Male
Female
172.75+6.02
159.92+4.48
169.00+5.89
160.27+5.98
Weight (kg)
(mean+SD)
Male
Female
59.38+9.24
56.50+10.17
61.33+11.26
50.91+6.76
The essential oil of lavender (Lavandula angustifolia) and
bergamot bergaptane-free oil (Citrus bergamia) were
obtained from FPI Sale Ltd., Stamford, England. Blended
essential oil consisted of 9.6%, w/w, lavender oil and
0.4%, w/w, bergamot bergaptane-free in sweet almond
carrier oil. The oils were analyzed by GC/FID and GC/MS.
The bergamot oil contained linalyl acetate (28.7%),
linalool (16.5%), and limonene (13.5%). The lavender oil
contained linalyl acetate (35.7%), linalool (31.5%), and
terpinen-4-ol (5.5%).
Essential oil administration: In the experimental group, 1
mL of a 10%, w/w, solution of blended essential oil in
sweet almond oil was applied to the skin of the lower
abdomen of each subject and the subjects self-massaged
the oil into the skin for 5 min. Afterwards, the massage
area was covered with a plastic film in order to prevent
evaporation of the oil. In the control group, 1 mL of the
placebo oil, pure sweet almond oil, was used. In both
groups, subjects were supplied with pure air through
breathing masks in order to eliminate any olfactory
stimulation by nose or mouth.
Experimental protocol: The experimental protocol has
been previously described [19-21,37-42]. Briefly, one
session consisted of two trials of 20 min each. At the
beginning and at the end of each trial, emotional responses
were assessed by visual analogue scales. Autonomic
parameters were recorded continuously during each trial.
In the first trial, which served as a control for influences of
the experimental setup, the placebo substance was
administered to all subjects. In the second trial, the placebo
was again administered to the control group, whereas in
the experimental groups the appropriate fragrance was
administered.
Acquisition of autonomic parameters: BR, PR and ST
were recorded simultaneously and in real time on the non-
dominant side of the body. All parameters were measured
using MP100WSW hardware (Biopac Systems, Inc., Santa
Barbara, California, USA), including sensors and Ag/AgCl
surface electrodes and Acqknowledge software (Biopac
Systems, Inc., Santa Barbara, California, USA). BR was
measured using a SKT100C amplifier and TSD102D
surface temperature thermistor probe. PR was assessed
using a Pulse Oximeter Module (OXY100C) and a
photoelectric transducer (TSD123B). ST was measured
with a SKT100C amplifier and a fast response thermistor
(TSD102A). SBP and DBP were measured in the dominant
arm by sphygmomanometry using an automated system
(Digital Electronic Model DS-155E, Japan). Details of the
recording system and procedure have been described
elsewhere [19-21,37-42].
Acquisition of visual analogue scales (VAS): VAS were
used to assess subjective mental and emotional conditions.
They consisted of 100 mm lines for 6 items: relaxation,
vigor, calmness, attentiveness, mood and alertness. Each
subject was asked to mark his or her feeling for each item
between the two possible extremes: relaxed and tense for
the item ‘relaxation’, vigorous and feeble for the item
‘vigor’, calm and restless for the item ‘calmness’, attentive
and inattentive for the item ‘attentiveness’, cheerful and
bad tempered for the item ‘mood’, alert and tired for the
item ‘alertness’.
Procedure: All experiments were conducted in a bright
and quiet room. Ambient temperature was 24-26°C. Upon
arrival, the volunteers were interviewed about their
personal data, e.g. sex, age, height, weight. In addition,
they were asked about the rating of emotional responses.
After completion of the interview and the rating scales,
SBP and DBP were measured. Subsequently, subjects were
seated in a semi-reclined position, providing easy access to
attach the ANS electrodes or probes. Electrodes were
placed on suitable positions, as mentioned above. The
breathing mask was fitted to the volunteer’s face to cover
the nose and mouth. Oxygen was then supplied directly.

Aroma-therapeutic effect of massage blended essential oil Natural Product Communications Vol. 6 (8) 2011 1203
Either the oil or the placebo was administered, as
described, together with recording of the autonomic
parameters. After completion of the first trial, the subjects
were asked to rate the VAS. SBP and DBP were measured
at the end of each trial. At the end of each trial, the
subjects were asked if they had perceived any odor during
the experiment. All subjects stated that they had not.
Data and statistical analyses: The autonomic recordings
of each subject were computed by trial using
Acqknowledge software (Biopac Systems, Inc., Santa
Barbara, California, USA). For each subject and every
parameter the mean value in the second trial was
subtracted from the mean value in the first to give the
individual inter-trial difference score. For emotional
ratings, on each scale the distance of the mark from the
left-hand side was measured in mm. Individual difference
scores between ratings were calculated for each item. The
SPSS version 11.5 was used for statistical analysis. Mann-
Whitney-U-Test analysis of variances was used in this
study. The effects of fragrances on autonomic parameters
and ratings of emotional responses were determined by
comparing the difference scores between the control group
and the experimental group. Correlational analyses
between ratings of emotional responses and autonomic
parameters were performed by means of Spearman rank-
order correlation coefficient.
Acknowledgments - This work was supported by grants from
Srinakharinwirot University. The author is grateful to Prof. Dr G.
Buchbauer and Dr E. Heuberger for experimental design
suggestion.
References
[1] Tisserand R. (1985) The art of aromatherapy. C.W. Daniel, Essex, United Kingdom.
[2] Torii S, Fukuda H, Kanemoto H, Miyanchi R, Hamauzu Y, Kawasaki M. (1988) Contingent negative variation and the
psychological effects of odor. In Perfumery: the psychology and biology of fragrance. van Toller S, Dodd GH. (Eds). Chapman &
Hall, New York, 107-120.
[3] Lis-Balchin M. (2006) Aromatherapy science: a guide for healthcare professionals. Pharmaceutical Press, London, 219-226.
[4] Buckle J. (1993) Aromatherapy: Does it matter which lavender oil is used?. Nursing Times, 89, 32-35.
[5] Dunn C, Sleep J, Collett D. (1995) Sensing an improvement: An experimental study to evaluate the use of aromatherapy, massage
and periods of rest in an intensive care unit. Journal of Advanced Nursing, 21, 34-40.
[6] Corner B, Cawley N, Hildebrand S. (1995) An evaluation of the use of massage and essential oils in the well being of cancer
patients. International Journal of Palliative Nursing, 21, 34-40.
[7] Billany MR, Denman S, Jameel S, Sugden JK. (1995) Topical antirheumatic agents as hydroxyl radical scavengers. International
Journal of Pharmaceutics, 124, 279-283.
[8] Manley CH. (1993) Psychophysiological effect of odor. Critical Reviews in Food Science and Nutrition, 33, 57-62.
[9] Trevelyan J, Booth B. (1994) Aromatherapy: The history, therapeutic value and implications for nurse, midwives and health
visitors. Nursing Times, 90, 3-12.
[10] Rutledge DN, Jones CJ. (2007) Effects of topical essential oil on exercise volume after a 12-week exercise program for women
with fibromyalgia: a pilot study. The Journal of Alternative and Complementary Medicine, 13, 1099-1106.
[11] Hay IC, Jamieson M, Ormerod AD. (1998) Randomized trial of aromatherapy. Successful treatment for Alopecia areata. Archives
of Dermatology, 134, 1349-1352.
[12] Davis P. (1988) Aromatherapy: An A to Z. C.W. Daniel, Essex, United Kingdom.
[13] Kite SM, Maher EJ, Anderson K, Young T, Young J, Wood J, Howells N, Bradburn J. (1998) Development of an aromatherapy
service at a cancer centre. Palliative Medicine, 12, 171-180.
[14] Imura M, Misao H, Ushijima H. (2006) The psychological effects of aromatherapy-massage in healthy postpartum mothers.
Journal of Midwifery & Women’s Health, 51, e21-e27.
[15] Chang SY. (2008) Effects of aroma hand massage on pain, state anxiety and depression in hospice patients with terminal cancer.
Taehan Kanho Hakhoe Chi, 38, 493-502.
[16] Han SH, Hur MH, Buckle J, Choi J, Lee MS. (2006) Effect of aromatherapy on symptoms of dysmenorrhea in college students: A
randomized placebo-controlled clinical trial. Journal of Alternative and Complementary Medicine, 12, 535-541.
[17] Andreassi JL. (2000) Psychophysiology: human behavior & physiological response. Lawrence Erlbaum Associated, London, 301-329.
[18] Hugdahl K. (1995) Psychophysiology: the mind-body perspective. University Press, England, 1-98.
[19] Hongratanaworakit T. (2009) Relaxing effect of rose oil on humans. Natural Product Communications, 4, 291-296.
[20] Hongratanaworakit T, Heuberger E, Buchbauer G. (2004) Evaluation of the effects of East Indian sandalwood oil and alpha-santalol
on humans after transdermal absorption. Planta Medica, 70, 3-7.
[21] Hongratanaworakit T, Buchbauer G. (2006) Relaxing effect of ylang ylang oil on humans after transdermal absorption.
Phytotherapy Research, 20, 758-763.
[22] Buchbauer G, Jirovetz L, Jaeger W, Plank C, Dietrich H. (1993) Fragrance compounds and essential oils with sedative effects upon
inhalation. Journal of Pharmaceutical Sciences, 82, 660-664.
[23] Buchbauer G, Jirovetz L, Jaeger W. (1991) Aromatherapy: evidence for sedative effects of the essential oil of lavender after
inhalation. Zeitschrift fur Naturforschung, 46c, 1067-1072.
[24] Eva Heuberger E, Redhammer S, Buchbauer G. (2004) Trandermal absorption of (-)- linalool induces autonomic deactivation but
has no impact on ratings of well-being. Neuropsychopharmacology, 29, 1925-1932.
[25] Sugawara Y, Hara C, Tamura K, Fujii T, Nakamura K, Masujima T, Aoki T. (1998) Sedative effect on humans of inhalation of
essential oil of linalool: sensory evaluation and physiological measurements using optically active linalool. Analytical Chim Acta,
365, 293-299.

1204 Natural Product Communications Vol. 6 (8) 2011 Hongratanaworakit
[26] Inoue N, Kuroda K, Sugimoto A, Kakuda T, Fushiki T. (2003) Different autonomic nervous responses according to preference for
the odor of jasmine tea. Bioscience Biotechnology Biochemistry, 67, 1206-1214.
[27] Kuroda K, Inoue N, Ito Y, Kubota K, Sugimoto A, Kakuda T. (2005) Sedative effects of the jasmine tea odor and (R)-(-)-linalool, one
of its major odor components, on autonomic nerve activity and mood states. European Journal of Applied Physiology, 95, 107-114.
[28] Hoeferl M, Krist S, Buchbauer G. (2006) Chirality influences the effects of linalool on physiological parameters of stress. Planta
Medica, 72, 1188-1192.
[29] Bronaugh RL, Wester RC, Bucks D, Maibach HI, Sarason R. (1990) In vivo percutaneous absorption of fragrance ingredients in
rhesus monkeys and humans. Food and Chemical Toxicology, 28, 369-373.
[30] Hotchkiss SA, Chidgey MAJ, Rose S, Caldwell J. (1990) Percutaneous absorption of benzyl acetate through rat skin in vitro. Food
and Chemical Toxicology, 28, 443-447.
[31] Jaeger W, Buchbauer G, Jirovetz L, Fritzer M. (1992) Percutaneous absorption of lavender oil from a massage oil. Journal of the
Society of Cosmetic Chemists, 43, 49-54.
[32] Hossain SJ, Aoshima H, Koda H, Kiso Y. (2002) Potentiation of the ionotropic GABA receptor response by whisky fragrance.
Journal of Agricultural Food Chemistry, 50, 6828-6834.
[33] Hossain SJ, Aoshima H, Koda H, Kiso Y. (2004) Fragrance in oolong tea that enhances the response of GABAA receptors.
Bioscience Biotechnology Biochemistry, 68, 1842-1848.
[34] Jones GH, Hernandez TD, Kendall DA, Marsden CA, Robbins TW. (1992) Dopaminergic and serotonergic function following
isolation rearing in rats: Study of behavioural response and postmortem and in vivo neurochemistry. Pharmacology Biochemistry
and Behavior, 43, 17-35.
[35] Sonavane GS, Sarveiya VP, Kasture SB. (2002) Anxiogenic activity of Myristica fragrans seeds. Pharmacology Biochemistry and
Behavior, 71, 239-344.
[36] Kalat JW. (1995) Biological Psychology. Brooks/Cole Publishing Company, Washington.
[37] Hongratanaworakit T, Buchbauer G. (2007) Chemical composition and stimulating effect of Citrus hystrix oil on humans. Flavour
and Fragrance Journal, 22, 443-449
[38] Hongratanaworakit T. (2009) Simultaneous aromatherapy massage with rosemary on humans. Scientia Pharmaceutica, 77,
375-387.
[39] Heuberger E, Hongratanaworakit T, Buchbauer G. (2006) East Indian sandalwood oil and alpha-santalol odor increase
physiological and self-rated arousal in humans. Planta Medica, 72, 792-800.
[40] Heuberger E, Hongratanaworakit T, Boehm C, Weber R, Buchbauer G. (2000) Effects of chiral fragrances on human autonomic
nervous system parameters and self-evaluation. Chemical Senses, 26, 281-292.
[41] Hongratanaworakit T. (2010) Stimulating effect of aromatherapy massage with jasmine oil. Natural Product Communications, 5
157-161.
[42] Hongratanaworakit T, Buchbauer G. (2004) Evaluation of the harmonizing effect of ylang-ylang oil on humans after inhalation.
Planta Medica, 70, 632-636.