The Alleviating Effects of Plant Derived Chemicals on Stress
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Transcript of The Alleviating Effects of Plant Derived Chemicals on Stress
Smell and the Brain Odorous substances, including plant-derived fragrances,
induce various physiological, emotional, and behavioural responses in human and other mammalian species
Smell and the Brain Neuronal impulses conduct along the olfactory tract
to: prepiriform cortex, limbic system, thalamus and much more
Complex interconnected networks are responsible for many behaviours:
eating, affective, sexual and reflexes like salivation (trigeminal n.)
Plant Derived Chemicals Have long been utilised as holistic relaxants in
aromatherapy and complementary medicine
Only recently have their physiological mechanisms been investigated
PraescentTM alpha-pinenetrans-2-hexenalcis-3-hexen-1-ol
Presented by Aaron Sparshott
Alleviating Effects of Plant-Derived Fragrances on Stress-Induced
Hyperthermia in Rats
By Akutsu et al
Introduction Investigated the effects of exposure to plant-derived
odours on the autonomic and behavioural responses to novel environment in rats.
A transient increase of body temperature has been shown to be a typical and reproducible autonomic response to various physical as well as psychological stressors.
This response is often referred to as stress induced hyperthermia or emotional fever.
What they did... Rats were moved to a novel environment, by being
transferred to an unfamiliar cage with a certain odour present.
42 Rats in Total: Alpha-pinene, Lavender and Green Odour cages were each presented with 12 rats. Control Group rats were placed back in original cage after handling.
Half of each odour group (n=6) except control, were exposed to solvent only.
12 12 12 6
Biosignals and Behaviour Heart Rate and Temperature were monitored using a bio-
signal transmitter implanted a week prior to experimentation.
Behavioural Analysis via video camera. Sniffing Rearing Grooming Resting General Activity
What they discovered... Green Odour
accelerated the declining phase of body temperature
Alpha-pinene suppressed stress-induced hyperthermia from the beginning
T i m e (min)
Tem
pe
ratu
re D
iffe
ren
ce (
oC
)
What they discovered... Exposure to any of the three fragrances made no
significant difference to Heart Rate
T i m e (min)
∆ B
PM
No significant differences in behaviour were observed as a result of any fragrance
What does it mean? Body Temperature rose as a result of being moved to a
novel environment, reflected as a stress-induced hyperthermia response.
Previous studies have shown that stress-induced hyperthermia responses can be attenuated by pretreating the subject with centrally acting drugs such as; noradrenaline β receptor antagonist, vasopressin, prostaglandin inhibitors 5-HT1A receptor agonists
What does it mean? In the present study, the rats were exposed to odorants
without being given any severe stress, and the exposure to the green odour or the alpha-pinene was found to have alleviating effects of the stress-induced hyperthermia.
However it would appear that the mechanism of alleviation differs between the two odours.
Other points of interest Heart Rate might be a less sensitive parameter as compared
with the Body Temperature for detecting the possible alleviating effects of fragrances on stress responses
‘Sedative effects’ of lavender in human’s are more likely to be a psychological property rather than physiological. Autonomic responses showed no significant difference to control
No observed change in behaviour.
Summing UpBy recording autonomic and behavioural
parameters from unrestrained rats, Akutsu et al found that the
green odour and alpha-pinene have anti-stress potency, namely that they exerted alleviating effects on stress-induced
hyperthermia.
Presented by Zoe Hutchins
Attenuation of Stress-Induced Elevations in Plasma ACTH Level and Body Temperature in Rats by
Green Odour
By Nakashima et al
Introduction Investigated the effect of green odour on plasma
adenocorticotropic hormone (ATCH) and body
temperature (Tb) of stress-induced rats
GREEN ODOURtrans-2-hexanal [0.03%]
cis-3-hexenal [0.03%]
↓ Tb↓ACTH
Hypothalamus
Olfa
ctor
y In
puts
Anterior Pituitary
Preoptic Centre
Stress Response:Elevation of ACTH Level and Tb
Rats were relocated and immobilised via restraint for 2 hours
Control: immobilisation without green odour
Treatment: exposure to green odour at various times prior, during or following immobilisation
Blood was collected and assayed for ACTH either immediately following immobilisation or 2 days later.
STRESS
1h 1h½ h 0h 2h 4h 6h 48h
Immediate ACTH Long-Lasting ACTH
Method - ACTH Measurements
Green odour [0.03%] decreased ACTH levels when applied during or following immobilisation.
Results – ACTH Levels
Rats were implanted with telemetry transmitters and given 10 days to recover until ACTH levels stabilised.
Tb was recorded every 20 minutes for 3 consecutive days.
Treatment rats were exposed to green odour for 30 minutes during the beginning of the 2 hour immobilisation.
Device Implantation
10 daysRecovery
Day 1(Prior)
Day 3(Post)
Green Odour (½hr)
Stress (2hr)
Temperature Recording
Method – Tb Measurements
Green odour [0.03%] decreased Tb immediately after stress and during the light phase of the following day.
Results – Tb Recording
During immobilisation the odorous paper was held 3cm from the nose of the rat, however when applied before or after immobilisation, the paper was placed in a corner of the cage.
Potential inconsistencies in the levels of green odour exposure the different groups received.
IMMOBILISED NON - IMMOBILISED
Methods - Weaknesses
Immediately following stress & two days post-stress
When applied during or following stress
Results Summary
GREEN ODOUR
↓ ACTH↓ Tb
ACTH Levels Hypothalamus & Catecholamine System ↓ Fos in the Paraventricular Nucleus (PVN) down-
regulating CRH secretion and subsequently ACTH Tb Reduction
↓ Sympathetic activity ↓ ACTH and Glucocorticoids
Further research is required to fully elucidate the physiologic mechanisms of green odour
Possible Mechanisms of Action
Due to current unpublished work the remainder of this presentation is not available to slideshare.
For more information regarding Praescent or SerenaScent go to