Volume 5, Issue 8, August 2015, Pages 601–611
Review article
Essential oils used in aromatherapy: A systemic review
- Open Access funded by Hainan Medical University
- Under a Creative Commons license
Open Access
Abstract
Nowadays,
use of alternative and complementary therapies with mainstream medicine
has gained the momentum. Aromatherapy is one of the complementary
therapies which use essential oils as the major therapeutic agents to
treat several diseases. The essential or volatile oils are extracted
from the flowers, barks, stem, leaves, roots, fruits and other parts of
the plant by various methods. It came into existence after the
scientists deciphered the antiseptic and skin permeability properties of
essential oils. Inhalation, local application and baths are the major
methods used in aromatherapy that utilize these oils to penetrate the
human skin surface with marked aura. Once the oils are in the system,
they remodulate themselves and work in a friendly manner at the site of
malfunction or at the affected area. This type of therapy utilizes
various permutation and combinations to get relief from numerous
ailments like depression, indigestion, headache, insomnia, muscular
pain, respiratory problems, skin ailments, swollen joints, urine
associated complications etc. The essential oils are found to
be more beneficial when other aspects of life and diet are given due
consideration. This review explores the information available in the
literature regarding therapeutic, medical, cosmetic, psychological,
olfactory, massage aromatherapy, safety issues and different plants used
in aromatherapy. All the available information was compiled from
electronic databases such as Academic Journals, Ethnobotany, Google
Scholar, PubMed, Science Direct, Web of Science, and library search.
Keywords
- Complementary therapy;
- Aromatherapy;
- Essential oils;
- Inhalation
1. Introduction
Aromatherapy
derived its name from the word aroma, which means fragrance or smell
and therapy which means treatment. This therapy is a natural way of
healing a person's mind, body and soul [1].
Many ancient civilizations like Egypt, China and India have used this
as a popular complementary and alternative therapy from at least 6 000
years [2] and [3].
Aromatherapy has established itself for the treatment of various arrays
of complications and conditions. Literature survey reveals that this
therapy has gained a lot of attention in the late 20th century and is
very popular in the 21st century too, and due to its importance,
popularity and widespread use, it is recognized as aroma science therapy
[4]. The essential oils have gained their importance in therapeutic, cosmetic, aromatic, fragrant and spiritual uses [5] and [6].
Aromatherapy uses essential oils, as the main therapeutic agents, which
are said to be highly concentrated substances extracted from flowers,
leaves, stalks, fruits and roots, and also distilled from resins [7].
Essential oils are a mixture of saturated and unsaturated hydrocarbons,
alcohol, aldehydes, esters, ethers, ketones, oxides phenols and
terpenes, which may produce characteristic odors [8] and [9].
They are colorless pleasant smelling liquids with high refractive
index. These oils are so potent and concentrated that they work on
pressure points and rejuvenate. The essential oils in plants are present
in different areas like, pockets and reservoirs, glandular hairs,
specialized cells, or even in the intercellular spaces. Essences
evaporation from the plants, shields them from bacterial attack and a
warming aura due to essences protects the plant from temperature
fluctuations [2].
There are various methods by which they are administered in small
quantity like inhalation, massage or simple applications on the skin
surface and rarely, they are taken internally [6] and [10].
Inhalation and the external application of these oils for the treatment
of mental and physical balance are the very basics of aromatherapy. The
therapy of these oils is known to relieve the stress, rejuvenate and
regenerate the individual for a next day's work. Olfactory nerves from
nose to the brain are the site of action for these essential oils. These
oils have well proven antibacterial, antibiotic, and antiviral
properties and many published reports elsewhere as well as folkloric
practitioners have suggested them to be useful in many other diseases
like alzheimer, cardiovascular, cancer and labor pain in pregnancy etc [11], [12], [13], [14] and [15]. There is an increased trend nowadays to use this therapy in the treatment of cancer and sleep disorder [16], [17] and [18]. Their organic character and to act in a supportive manner with the body, provide a feeling of well-beingness [19].
It was found that the locomotor activity of mice increased
significantly by inhalation of rosemary essential oils, which are used
in phytotherapy as activating and refreshing remedy for exhaustion [20].
The use of aromatherapy in holistic medicine has taken a long leap within a couple of years [21].
On reviewing the literature on this therapy, it is found that numerous
studies have been carried out to study the effects of this therapy on
human brain and its emotions. Its role in mood, alertness, and mental
stress in healthy subjects was a topic of hot discussion among
scientific community recently. Some researchers tried to investigate the
effects on work ability, reaction time, and some spontaneous actions on
the brain through electroencephalograph patterns and functional imaging
studies [22].
This therapy was found to be superior when compared to synthetic odors.
Synthetic fragrances generally contain irritants, like solvents and
propellants causing irritation in some people [23], [24] and [25].
According to aroma therapists, synthetic odor does not match the
importance of essential oils as they are deficient in natural or vital
energy; however, this has been remained a matter of debate between odor
psychologists and biochemists [26].
