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Copyright © 2013 Korean Society of Exercise Rehabilitation http://www.e-jer.org pISSN 2288-176X
eISSN 2288-1778
*Corresponding author: Yong-Seok Jee
Department of Exercise Physiology & Prescription, Graduate School of Health
Promotion, Hanseo University, 360 Daegok-ri, Haemi-myun, Seosan 356-706,
Korea
Tel: +82-41-660-1028, Fax: +82-41-660-1088, E-mail address: jeeys@hanseo.ac.kr
Received: March 21, 2013/ Revised: April 1, 2013/ Accepted: April 15, 2013
Effects of Ylang-Ylang aroma on blood pressure and heart
rate in healthy men
Da-Jung Jung1, Jun-Youl Cha2, Sung-Eun Kim3, Il-Gyu Ko3, Yong-Seok Jee4,*
1Department of Microbial Engineering, College of Engineering, Konkuk University, Seoul, Korea
2Division of Martial Arts ∙ Guard, Howon University, Kunsan, Korea
3Department of Physiology, College of Medicine, Kyung Hee University, Seoul, Korea
4Department of Exercise Physiology ·Prescription, Graduate School of Health Promotion, Hanseo University, Seosan, Korea
Although the Ylang-Ylang aroma (YYA) has used as a general method
for enhancing sedative effect, there was a little report on the efficacy of
YYA on heart function using the electrocardiogram (EKG). Therefore,
identifying of the effects of YYA on blood pressure (BP) and heart rate
(HR) is important in order to demonstrate the effectiveness of YYA. The
aim of this study was to investigate the effects of YYA on BP and HR in
healthy men. Twenty-nine men took part in this study. The subjects
were randomly divided into 2 groups: Ylang-Ylang group (YYG, n= 15)
and control group (CG, n = 14). Physiological parameters recorded were
BP by using a sphygmomanometer and HR by using an EKG. The pres-
ent results demonstrated that inhalation of YYA significantly decreased
the systolic and diastolic blood pressure. Inhalation of YYA also signifi-
cantly decreased the HRs in 10 leads, except in lead I and aVR. This in-
dicates that the HRs recorded in lead I and aVR were less sensitive or
obtuse compared to those in the 10 other leads. Therefore, such a result
reveals that it is necessary to be aware of the terms regarding the posi-
tion. In the present results, YYA caused a reduction of HR and BP, and a
relief of the arousal level in healthy men. The present results show a
sedative effect of YYA, and this study provides some evidences for the
usage of YYA in medicinal agent.
Keywords: Ylang-Ylang, Heart rate, Systolic blood pressure, Diastolic
blood pressure, Electrocardiogram
INTRODUCTION
Regardless of the lack of sufficient scientific evidence to eluci-
date the effects of aromas’ and their corresponding mechanisms,
some extracted aromas are widely adopted into modern society
and have reportedly generated specific effects (Lahlou, 2004; Su et
al., 2007). As in the European Patent, the odorants, i.e. nutmeg
oil, neroli oil, valerian oil, mace extract, myristicin, elemicin and
isoelemcin, were investigated (Hongratanaworakit, 2004). When
these odorants were used in a perfume compound at appropriate
levels, a significant decrease of systolic blood pressure (SBP) was
found. Warren et al. (1987) also reported that a nutmeg-based
aroma reduced stress in humans as measured by the reduction in
blood pressure (BP) and self-ratings. According to their study,
subjects were stressed by mental arithmetic and sentence comple-
tion tasks under an aroma with and without nutmeg oil. Their
study revealed that nutmeg oil reduced SBP, anxiety, anger and
embarrassment whereas it increased calmness and happiness.
Meanwhile, Yamaguchi (1990) reported that the changes in heart
rate (HR) for the measurement regarding the effects of lemon and
rose aromas. According to his research, lemon aroma led to an in-
crease of HR whereas rose aroma led to a decrease of it. This find-
ing may indicate that lemon aroma possesses a stimulating effect;
in contrast rose aroma has a sedative effect. Kikuchi et al. (1991)
also reported that lemon aroma enhanced the deceleration of HR;
on the other hand, rose aroma suppressed it. Nagai et al. (1991)
showed that sweet fennel oil suppressed the deceleration of HR as
well. Furthermore, Hongratanaworakit et al. (2003a) investigated
the effects of sweet orange aroma on human behavior and detected
changes of HR in response to olfactory stimulation. They revealed
http://dx.doi.org/10.12965/jer.130007
Original Article
Journal of Exercise Rehabilitation 2013;9(2):250-255
http://www.e-jer.org 251
http://dx.doi.org/10.12965/jer.130007
Jung D-J, et al. • Sedative effect of Ylang-Ylang aroma
that sweet orange aroma caused significant increases of HR and
subjective alertness after inhalation.
Recently, an interest in the usage of Ylang-Ylang oil (Cananga
odorata, Annonaceae) as a therapeutically active agent has grown
considerably with regards to medicine (2006). The Ylang-Ylang
oil has been used as an antidepressant in cases of depression and
nervousness as well as used for reducing BP in the case of hyper-
tension. According to Hongratanaworakit et al. (2002), inhalation
of the Ylang-Ylang oil led to a decrease of BP and an increase of
subjective attention.
The effects of essential oils are exerted through the skin (Hon-
gratanaworakit et al., 2006) or through the olfactory system (Kut-
lu et al., 2008). The former acts directly on the physical organism,
the latter acts through the sense of smell and may thereby elicit
physiological effects (Hongratanaworakit, 2004). Physiological ef-
fects of aromas can be divided into two types: those which act via
the stimulation of the nervous system and those which act directly
on an organ or tissue through an effector-receptor-mechanism
(Tisserand, 1977). In fact, we can know both the psychological
and physiological effects or changes on aromas or other materials
through HR and BP. For example, if we become stressed, our HR
and BP will become elevated, however, if we get depressed, the
opposite occurs.
Until now, although the functional role of aromatherapy in-
cluding Ylang-Ylang oil has been dramatically revealed in cardio-
vascular organs, the effectiveness on normal cardiovascular systems
is of great opinion and the evidence on the cardiovascular systems
via Ylang-Ylang oil is somewhat lacking. Moreover, there was no
report on the efficacy of inhalation for Ylang-Ylang aroma (YYA)
in changing ones heart condition following an electrocardiogram
(EKG). Therefore, identifying HR on a 12-lead EKG and BP in
the normal condition is very important in order to demonstrate
the effectiveness of Ylang-Ylang oil. That being said, in the pres-
ent study we investigated the effects of YYA oil on BP and HR
using a 12-lead EKG in the healthy men.
MATERIALS AND METHODS
Subjects
All of the subjects who took part in the study were volunteer
males. Before the experiment, the subjects were randomly divided
into 2 groups. The subjects were composed of 29 males, 15 of
whom constituted the experimental group or Ylang-Ylang group
(YYG) and 14 were the control group (CG). The ages (mean
±
SEM) of YYG and CG were 21.07
±
0.43, 22.00
±
0.58 years, their
heights (mean
±
SEM) were 171.87
±
1.80, 173.79
±
1.33 cm, and
their body weights (mean
±
SEM) were 64.40
±
2.51, 67.86
±
1.57
kg, respectively. All of the subjects underwent physical examina-
tion including medical history and olfactory function. They read
and signed an informed consent form approved by the Ethical
Committee of Hanseo University Institute and the Korean Acad-
emy of Medical Sciences (KAMS) for Health, prior to participa-
tion. Subjects were excluded if they reported any of the following:
(1) discomfort concerning the odor, (2) nose injury within 3 months
prior to participation, or (3) history of nasal disorders.
Experimental design
First, all of the subjects arrived at research center to sign an in-
formed consent form and to complete a self-report questionnaire
about nasal function included in physical examination. After this
procedure, each subject underwent the experiment conducted by
an expert. Neither the YYG nor the CG was given information
about the effects of the procedure and that the YYA was being
used as an intervention. The YYG was placed in a room in which
doors and windows were closed 20 minutes prior to the experi-
ment and wherein the environment was fragranced by incenses of
Ylang-Ylang oil. The experiment was performed in the atmo-
sphere of the YYA, and the doors and windows of the room were
not opened until the end of the test. The CG was placed in another
room where there was no fragrance by incenses of Ylang-Ylang oil.
The duration of the test was 60 min. The rooms where the YYG
and CG were placed had the same characteristics with respect to
size (16.53 m2), temperature (25-26°C), and humidity (50-60%).
YYA administration
YYA was selected for olfactory stimulation in this study. Ylang-
Ylang, Cananga odorata, is a tree valued for its perfume. The es-
sential oil derived from the flowers is used in aromatherapy. The
fragrance of Ylang-Ylang is rich and deep with notes of rubber
and custard. The essential oil of its flower is obtained through
steam distillation of the flowers and separated into different grades
according to when the distillates are obtained (Harley and Craig,
2006). We used the Ylang-Ylang oil containing linalool (13.6%),
geranyl acetate (5.3%), caryophyllene (1.7%), p-cresyl ether
(16.5%), methyl benzoate (8.7%), benzyl acetate (25.1%), benzyl
benzoate (2.2%), and other sesquiterpenes (7.4%). In this study,
we put 3 drops (0.15 cc) of Ylang-Ylang oil by using a pipette
into a warm water (90˚C) lamp and created incense. All of the
subjects in YYG smelt a fragrance emerging from the lamp for 20
min.
252 http://www.e-jer.org http://dx.doi.org/10.12965/jer.130007
Jung D-J, et al. • Sedative effect of Ylang-Ylang aroma
Blood pressure and heart rate measurement
The SBP and diastolic BP (DBP) were measured using a sphyg-
momanometer (Aneroid Mo 500, Kenzmedico Co., Ltd., Japan)
and heart rates using a 12-lead EKG (FX-2111, Fukudadensh Co.
Ltd., Japan) after Ylang-Ylang exposure for 20 min. The subjects
in YYG and CG were on the bed during the measurement. First
of all, electrodes were attached to the upper body on 10 suitable
positions. Then, the HRs from a 12-lead EKG were measured for
5 min. The SBP and DBP were measured at the end of the HRs’
test. This procedure was repeated in the second trial. At the end
of each trial, the subjects were asked if they had smelled any odor
during the experiment. All subjects of YYG stated that they smelt
odor during the experiment whereas all subjects of CG stated that
they did not smell any odor during the experiment. We recorded
two trials from EKG for HR and used a sphygmomanometer for
BP. Afterwards we selected the mean values from each result.
Statistical analyses
The sample sizes in this study were not adequate since we
achieved a statistical power greater than 90% for the standardized
differences between time greater than 5% at a probability of
Type-I error
<
0.05. All data are reported as mean (standard error
mean: SEM). The Kolmogorov–Smirnov test was used to deter-
mine the normality of distribution for the examined variables. In
order to examine the differences of the variables between YYG
and CG, the non-parametric test (two-independent samples tests -
Mann-Whitney U Test) was completed. Also, to investigate the
changes of the variables between pre-test and post-test, non-para-
metric test (two-related samples tests - Wilcoxon Signed Ranks
Test) was performed. The significance level for all analyses was set
a priori at P
<
0.05. The SPSS program (version 15.0; SPSS Inc.,
Chicago, IL, USA) was used to calculate statistics for this study.
RESULTS
Effect of YYA on blood pressures
The data from SBP and DBP of the both groups were analyzed
for differences in the pre- and post-test results after the experiment
(Table 1). In the post-test, the SBP and DBP of the CG were de-
creased compared to those of the pre-test, but were not statistical-
ly significant. However, the SBP and DBP of the YYG in the post-
test were more significantly (Z
=
-3.436, P
=
0.001 and Z
=
2.375,
P
=
0.018, respectively) decreased than those of the pre-test. More-
over, the SBP between both groups in the post-test were shown to
be significantly (Z
=
-2.799, P
=
0.005) different. The present re-
sults demonstrated that the inhalation of Ylang-Ylang oil signifi-
cantly decreased the SBP and DBP levels.
Table 1. Changes of systolic and diastolic blood pressure in times and groups
Pre Post Wilcoxon testa)
Z (P)
Systolic blood pressure
Ylang-Ylang group 115.40± 2.96 97.87 ± 2.12 -3.436 (0.001)
Control group 113.79 ± 2.82 111.14 ± 3.24 -1.444 (0.149)
Mann-Whitney U tesb) Z (P) -0.515 (0.606) -2.799 (0.005)
Diastolic blood pressure
Ylang-Ylang group 66.00 ± 2.48 59.20± 1.65 -2.375 (0.018)
Control group 66.57 ± 2.42 64.07± 2.89 -1.382 (0.167)
Mann-Whitney U testb) Z (P) -0.111 (0.911) -0.790 (0.429)
All data represents mean ± standard error mean (SEM). a)represents the statistical
analysis method between pre and post. b)means the statistical analysis method be-
tween Ylang-Ylang group and control group.
Table 2. Changes of heart rates of six limb leads in times and groups
Pre Post Wilcoxon testa)
Z (P)
Lead I
Ylang-Ylang group 61.67 ± 2.16 60.20± 2.38 -0.998 (0.318)
Control group 64.36 ± 2.42 63.71± 2.95 -0.251 (0.802)
Mann-Whitney U testb) Z (P) -0.111 (0.911) -0.790 (0.429)
Lead II
Ylang-Ylang group 65.27 ± 2.29 59.60± 2.15 -2.477 (0.013)
Control group 63.21 ± 2.64 65.86± 3.10 -1.190 (0.234)
Mann-Whitney U testb) Z (P) -0.525 (0.599) -1.530 (0.126)
Lead III
Ylang-Ylang group 66.87 ± 2.80 60.27± 1.97 -2.365 (0.018)
Control group 63.29 ± 2.74 65.07± 2.56 -0.723 (0.469)
Mann-Whitney U testb) Z (P) -0.700 (0.484) -1.467 (0.142)
aVR
Ylang-Ylang group 64.20 ± 2.56 60.53± 2.37 -1.912 (0.055)
Control group 63.07 ± 2.93 64.14± 2.85 -0.503 (0.615)
Mann-Whitney U testb) Z (P) -0.175 (0.861) -0.919 (0.358)
aVL
Ylang-Ylang group 64.00 ± 2.75 59.67± 2.14 -2.561 (0.010)
Control group 61.71 ± 2.55 65.71± 3.10 -1.926 (0.054)
Mann-Whitney U testb) Z (P) -0.612 (0.540) -1.663 (0.096)
aVF
Ylang-Ylang group 63.80 ± 2.35 58.73± 2.08 -2.818 (0.005)
Control group 61.36 ± 2.48 65.43± 2.71 -1.959 (0.051)
Mann-Whitney U testb) Z (P) -0.350 (0.726) -1.923 (0.054)
All data represents mean ± standard error mean (SEM). a)represents the statistical
analysis method between pre and post. b)means the statistical analysis method be-
tween Ylang-Ylang group and control group. aVR, aVL, aVF mean lead augmented
vector right, lead augmented vector left and lead augmented vector foot, respectively.
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Jung D-J, et al. • Sedative effect of Ylang-Ylang aroma
Effect of YYA on heart rates in six limb leads
The data from HR for both groups in six limb leads were ana-
lyzed for differences in the pre- and post-test results after the ex-
periment (Table 2). In the post-test, the HRs of the CG changed
little compared to those of the pre-test. However, in the post-test,
the HRs of the YYG except for those of lead I and aVR (lead aug-
mented vector right) were significantly decreased compared to
those of the pre-test. The present results revealed that the inhala-
tion of Ylang-Ylang oil significantly decreased the HRs’ levels for
the majority of limb leads (Fig. 1).
Effect of YYA on heart rates in six chest leads
The data from HRs for both groups in six chest leads were ana-
lyzed for differences in the pre- and post-test results after the ex-
periment (Table 3). In the post-test, the HRs of the CG changed
little or increased compared to those of the pre-test. However, in
the post-test, the HRs of the YYG from V1 to V6 were signifi-
cantly decreased compared to those of the pre-test. Moreover, the
HR of V5 between both groups in the post-test were shown to be
significantly (Z
=
-2.229, P
=
0.026) different. The present results
represented that the inhalation of Ylang-Ylang oil significantly
decreased the HR levels for all of the chest leads (Fig. 2).
DISCUSSION
In this study, the demographic features between both groups
were not significantly different (age P
=
0.400; height P
=
0.354;
body weight P
=
0.377, respectively). This is of importance with
regard to the fact that both groups were homogeneous from the
pre-test. The present investigation administered YYA to healthy
men. The BP and HR, which were considered physiological pa-
rameters, were recorded as indicators of the arousal level in regards
to the autonomic nervous system referred to Kutlu et al. (2008)
Fig. 1. Changes of heart rates in six limb leads in the Ylang-Ylang group. Left
lines: Sample figures of six limb leads (from lead I to aVF) in the pre-test. Right
lines: Sample figures of the same leads in the post-test. The heart rate is rep-
resented in the upper right end.
Table 3. Changes of heart rates of six chest leads in times and groups
Pre Post Wilcoxon testa)
Z (P)
V1
Ylang-Ylang group 64.13 ± 2.27 60.20± 2.09 -2.532 (0.011)
Control group 63.36 ± 2.87 65.71± 3.10 -0.974 (0.330)
Mann-Whitney U testb) Z (P) -0.219 (0.827) -1.268 (0.205)
V2
Ylang-Ylang group 63.73 ± 2.06 59.33± 2.23 -2.861 (0.004)
Control group 63.43 ± 2.46 64.21± 2.70 -0.094 (0.925)
Mann-Whitney U testb) Z (P) -0.044 (0.965) -1.246 (0.213)
V3
Ylang-Ylang group 63.80 ± 2.29 59.33± 2.35 -2.423 (0.015)
Control group 61.14 ± 2.44 64.50± 2.69 -1.508 (0.131)
Mann-Whitney U testb) Z (P) -0.656 (0.512) -1.399 (0.162)
V4
Ylang-Ylang group 66.13 ± 2.17 60.07± 2.25 -2.340 (0.019)
Control group 62.71 ± 2.72 64.43± 2.60 -0.597 (0.551)
Mann-Whitney U testb) Z (P) -0.963 (0.336) -1.225 (0.220)
V5
Ylang-Ylang group 66.40 ± 2.44 58.40± 2.31 -3.185 (0.001)
Control group 62.93 ± 3.13 65.50± 2.44 -0.865 (0.387)
Mann-Whitney U testb) Z (P) -0.831 (0.406) -2.229 (0.026)
V6
Ylang-Ylang group 65.73 ± 2.96 58.40± 2.12 -2.986 (0.003)
Control group 64.07 ± 2.78 64.50± 2.77 -0.175 (0.861)
Mann-Whitney U testb) Z (P) -0.066 (0.948) -1.531 (0.126)
All data represents mean ± standard error mean (SEM). a)represents the statistical
analysis method between pre and post. b)means the statistical analysis method be-
tween Ylang-Ylang group and control group.
254 http://www.e-jer.org http://dx.doi.org/10.12965/jer.130007
Jung D-J, et al. • Sedative effect of Ylang-Ylang aroma
In this study, although the SBP between both groups was not sig-
nificantly different in the results of the pre-test, it was significant-
ly different between groups in the results of the post-test. More-
over, the SBP in the YYG significantly decreased whereas it was
not changed in the CG after the experiment. In the DBP case, it
was similar to the SBP in pre-result; it was not significantly dif-
ferent between groups in the results of the post-test. However, the
DBP in the YYG significantly decreased compared to that of the
CG. Such results showed that the inhalation of YYA significantly
decreased both the SBP and DBP levels. In this context, Hon-
gratanaworakit et al. (2002, 2003b) demonstrated that the inhala-
tion of the YYA led to a decrease of BP and an increase of subjec-
tive attention. They also reported that their findings pointed to-
wards a decrease of autonomic arousal. Distinct from this study,
many researchers revealed that beneficial effects of essential oils
were exerted by absorption of fragrance molecules via the skin.
According to Hongratanaworakit and Buchbauer (2006), the
Ylang-Ylang oil caused a significant decrease of BP and a signifi-
cant increase of skin temperature following transdermal absorp-
tion. They also reported that the subjects in the Ylang-Ylang oil
group rated themselves calmer and more relaxed in the behavioral
level compared to the subjects in the control group. This finding
points towards a decrease of arousal in terms of self-evaluation.
Transdermal absorption of Ylang-Ylang oil reduced the level of
arousal for the autonomic nervous system and led to deactivation
at the behavioral level, i.e. subjects felt calmer and more relaxed
than before the administration of the oil. Thus, the effects of YYA
by means of percutaneous administration may be characterized by
the concept of relaxation, which has also been described for the
sandalwood essential oil (Hongratanaworakit et al., 2004). Their
findings were likely to show a relaxing effect of the Ylang-Ylang
oil and to provide some evidence for the usage of the Ylang-Ylang
oil in causing relief for depression and stress. Our findings indi-
cate that the inhalation of the YYA is similar to the transdermal
usage of it in terms of decreasing both the SBP and DBP levels.
In other words, the beneficial effects of Ylang-Ylang oil are not
only exerted by inhalation of the vapor but also by absorption of
the fragrance molecules through the skin.
Meanwhile, although many researchers attempted to prove the
scientific effects of aromatherapy, most of the aromatherapy stud-
ies were not controlled and their results were possibly biased and
not scientific (Hongratanaworakit et al., 2006). Especially, in the
HR case, the HR observed in aromatherapy studies were only in-
vestigated through a simple method, i.e. pulse rate checked in the
carotid, temporal or radial arteries. Thus, we believe that the pres-
ent study is very important to expiscate the changes in HR levels
via diversified observation, which is a 12-lead EKG.
The results of HR, which appeared in this study, were quite
similar to those of BP in the six chest leads (Table 3). However,
the results of HR, which appeared in six limb leads, were dissimi-
lar to those of the six chest leads (Table 2). In the post-test of this
study, the HRs of lead I and aVR in the YYG displayed declining
tendencies but were not significantly decreased compared to those
of the pre-test. In other word, we believe that those of lead I and
aVR were less sensitive or obtuse compared to the ten other leads.
Therefore, such a result provides a hint that it is necessary to be
aware of the terms regarding the position. In the YYG, however,
most of the HRs’ levels for a 12-lead EKG in the post-test signifi-
cantly declined compared to those of the pre-test. On the other
hand, in the CG, most of the HRs’ levels for a 12-lead EKG in
the post-test did not change or displayed inclining tendencies
Fig. 2. Changes of heart rates in six chest leads in the Ylang-Ylang group. Left
lines: Sample figures of six chest leads (from V1 to V6) in the pre-test. Right
lines: Sample figures of the same leads in the post-test. The heart rate is rep-
resented in the upper right end.
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Jung D-J, et al. • Sedative effect of Ylang-Ylang aroma
compared to those of the pre-test. In this context, Cha et al. (2010)
investigated the effectiveness of aromatherapy on BP, HR variabil-
ity and so on in essential hypertensive patients. The experimental
group in their study was given a blend of oils pertaining to lem-
on, lavender, and ylang-ylang, which were prepared in the ratio of
2:2:1, respectively. The control group was given an artificial lem-
on fragrance of a mixture of limonene and citral. According to
their results, there was a notable difference in sympathetic nervous
system activity for HR variability. From other materials’ stand-
point, a few researchers reported that lemon aroma increased HR
whereas rose aroma decreased it. This finding indicates that lemon
aroma possesses a stimulating effect whereas rose aroma possesses
a sedative effect (Kikuchi et al., 1991; Yamaguchi, 1990). Thus,
we learn that the YYA is similar to the rose aroma, which has a
sedative effectiveness.
In another dimension, the evaluation for the effects of aromas
on the nervous system may be divided into two different forms of
arousal, the cortical arousal such as brain wave activity and the au-
tonomic arousal such as HR. Decreases of the cortical arousal or
the autonomic arousal are interpreted in terms of a sedative/ relax-
ing effect of aromas. In contrast, increases of the cortical arousal or
autonomic arousal are interpreted in terms of the stimulating ef-
fect of aromas (Stern et al., 2001). Overall, the YYA inhibited the
sympathetic nervous system whereas it activated the parasympa-
thetic nervous system. Finally, it results in decreased BP and HR.
In the present study, we confirmed that YYA showed the seda-
tive effectiveness and provided some evidence for causing decreas-
es of BP and HR or for the relief of the arousal level regarding the
autonomic nervous system.
CONFLICT OF INTEREST
No potential conflict of interest relevant to this article was re-
ported.
REFERENCES
Cha JH, Lee SH, Yoo YS. Effects of aromatherapy on changes in the auto-
nomic nervous system, aortic pulse wave velocity and aortic augmen-
tation index in patients with essential hypertension. J Korean Acad
Nurs 2010;40:705-713.
Harley M, Craig E. Traditional tree initiative. In Species Profiles for Pacific
Island Agroforestry. Permanent Agricultural Resources Publishers,
Honolulu, USA; 2006.
Hongratanaworakit T, Buchbauer G. Relaxing effect of ylang ylang oil on
humans after transdermal absorption. Phytother Res 2006;20:758-763.
Hongratanaworakit T. Physiological effects in aromatherapy. Songklana-
karin J Sci Technol 2004;26:117-125.
Hongratanaworakit T, Heuberger E, Buchbauer G. Influence of ylang-
ylang oil on mental, emotional and human physiological parameters.
In Proceedings in the 33rd International Symposium on Essential Oils
2002;37:4-7.
Hongratanaworakit T, Heuberger E, Buchbauer G. Human behavioral
and physiological reactions to inhalation of sweet orange oil. In Pro-
ceedings in the 3rd World Congress on Medical and Aromatic Plants
for Human Welfare 2003a;455:3-7.
Hongratanaworakit T, Heuberger E, Buchbauer G. A screening test for ef-
ficacy of aroma in humans. In Proceedings in the 51st Annual Con-
gress of the Society for Medical Plant Research 2003b;209.
Hongratanaworakit T, Heuberger E, Buchbauer G. Evaluation of the ef-
fects of East Indian sandalwood oil and alpha-santalol on humans af-
ter transdermal absorption. Planta Med 2004;70:3-7.
Kikuchi A, Tanida M, Veboyama S, Abe T, Yamaguchi H. Effect of odors
in cardiac response patterns in a reaction time task. Chem Senses 1991;
16:183.
Kutlu AK, Yılmaz E, Çeçen D. Effects of aroma inhalation on examination
anxiety. Teach Learn Nurs 2008;3:125-130.
Lahlou M. Essential oils and fragrance compounds: bioactivity and mech-
anisms of action. Flavour Fragr J 2004;19:159-165.
Lawrence B. Ylang ylang oil. Perfum Flavor 1986;11:195.
Nagai H, Nakamura M, Fujii W, Inui T, Asakura Y. Effects of odors on hu-
mans II: Reducing effects of mental stress and fatigue. Chem Senses
1991;16:198.
Stern RM, Ray WJ, Quigley KS. Psychopyhsiological recording. Oxford
University Press, New York, USA; 2001.
Su HJ, Chao CJ, Chang HY, Wu PC. The effects of evaporating essential
oils on indoor air quality. Atmos Environ 2007;41:1230-1236.
Tisserand R. The Art of Aromatherapy. C.W. Daniel, Essex; 1977.
Warren CB, Munteanu MA, Schwartz GE, Benaim C, Walter HG, Leight
RS, Withycombe DA, Mookerjee BD, Trenkle RW. Method of causing
the reduction of physiological and/or subjective reactivity to stress in
humans being subjected to stress conditions. US Patent No. 4671959;
1987.
Yamaguchi H. Effects of odor on heart rate. In the psychophysiological ef-
fects of odor. Aromachol Koryo 1990;168.
