In the present era of nutraceuticals and functional foods, many persons resort to different techniques to relive lifestyle stress. Stress-reducing therapies help maintain cognitive performance during stress. Aromatherapy is popular for stress reduction, but its effectiveness and mechanism are unclear. Aromatherapy is one of the complementary therapies which use essential oils as the major therapeutic agent to treat several diseases. Aromatherapy is the therapeutic use of essential oil from herbs, flowers, and other plants. Essential oils can be absorbed into the body via the skin or via the olfactory system. Different methods are used to deliver aromatherapy, such as diffusers, baths, massage, and compresses. Several studies have reported that aromatherapy is effective for reducing pain in patients with many types of pain conditions, including postoperative pain, fibromyalgia and dysmenorrhoea. However, the therapeutic effects of aromatherapy are not well supported by clinical studies. 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. Once the oils are in the system, they re-modulate 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.
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. Many ancient civilizations like Egypt, China and India have used this as a popular complementary and alternative therapy for at least 6000 years. Aromatherapy has established itself for the treatment of an array of complications and conditions. The essential oils have gained their importance in therapeutic, cosmetic, aromatic, fragrant and spiritual uses. 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. Essential oils are a mixture of saturated and unsaturated hydrocarbons, alcohol, aldehydes, esters, ethers, ketones, oxides phenols and terpenes, which may produce characteristic odors . 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. 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 traditional medicine practitioners have suggested them to be useful in many other diseases like Alzheimer, cardiovascular, cancer and labor pain in pregnancy etc. There is an increased trend nowadays to use this therapy in the treatment of cancer and sleep disorder. Their organic character acts in a supportive manner with the body, providing a feeling of wellbeing. 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. 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.
Proposed mode of action of aroma therapy
Aroma therapy has been employed for relief in dementia, hypertension, pain relief, psychological problems, anxiety, depression etc. Essential oils are complementary to medical treatment and can never be taken as a replacement for it. These aroma molecules are very potent organic plant chemicals that might help the surroundings free from disease, bacteria, virus and fungus. Their versatile character of antibacterial, antiviral, anti-inflammatory nature along with immune booster body with hormonal, glandular, emotional, circulatory, calming effect, memory and alertness enhancer is well documented by many researchers. These oils are known for their specific character, as their potency is not lost with time and age. Their effects are also complex and subtle due to their complex structure and chemical properties.
The mechanism of their action involves integration of essential oils into a biological signal of the receptor cells in the nose when inhaled. The signal is transmitted to limbic and hypothalamus parts of the brain via olfactory bulb. These signals cause brain to release neuro messengers like serotonin, endorphin etc., to link our nervous and other body systems assuring a desired change and to provide a feeling of relief. Serotonin, endorphin and noradrenalin are released from calming oil, euphoric, and stimulating oil respectively to give expected effect on mind and body.
This therapy utilizes certain essential oils for skin, body, face and hair cosmetic products. These products are used for their various effects as cleansing, moisturizing, drying and toning. A healthy skin can be obtained by use of essential oils in facial products. On a personal level, cosmetic aromatherapy will be a simple and effective way to have an experience. Similarly, few drops of appropriate oil give a rejuvenating and revitalizing experience.
The use of grape seed, almond, or jojoba oil in pure vegetable oil during massage has been shown to have wonderful effects. This is also known as healing touch of massage therapy.
The founder of modern aromatherapy Rene-Maurice Gattefosse has used essential oils to massage patients during surgery, thus utilizing the medical aromatherapy knowledge of the effect of essential oils for treating clinically diagnosed medical ailments.
Inhalation of essential oils has given rise to olfactory aromatherapy, where simple inhalation has resulted in enhanced emotional wellness, calmness, relaxation or rejuvenation of the human body. The release of stress is welded with pleasurable scents which unlock odor memories.
In psycho-aromatherapy, certain states of moods and emotions can be obtained by these oils giving the pleasure of relaxation, invigoration or a pleasant memory. The inhalation of the oils in this therapy is direct though the infusion in the room of a patient.
Major plants used in aromatherapy
Some internationally used essential oil plants are listed in table1.
Eucalyptus [Eucalyptus globulus Labill (E. globulus)] belonging to the family of Myrtaceae, is a tall evergreen plant with a height up to 250 feet. Eucalyptus oil is known for its constituents like cineole (70%–85%), aromadendrene limonene terpinene, cymene, phellandrene and pinene. Its oils have been used to regulate and activate the various systems like nervous system for neuralgia, headache and debility. It is also known to boost immunity against measles, flu, cold and chickenpox. Throat infections, catarrh, coughs, bronchitis, asthma and sinusitis associated with respiratory system have been taken care of by oils of this plant. Moreover, skin problems like wounds, cuts, burns, herpes, lice, insect repellent and insect bites can be treated with it.
Treatment of rheumatoid arthritis, muscle and joint pains and aches is well reported from the essential oils of this plant. Eucalyptus oil has demonstrated its antioxidant, anti-inflammatory, anti-proliferative and antibacterial activities and researchers have proved its efficacy beyond doubt in treatment of various metabolic and infectious diseases.
Lavender (Lavandula officinalis Chaix.) belonging to the family of Lamiaceae, is a beautiful herb It contains camphor, terpinen-4-ol, linalool, linalyl acetate, betaocimene and 1,8-cineole . Its constituent varies in concentration and therapeutic effects with the different species. Linalool and linalyl acetate have maximum and great absorbing properties from skin during massage with a depression of central nervous system.
Linalool shows sedative effects and linalyl acetate shows marked narcotic actions. These two actions may be responsible for its use in lavender pillow anxiety patients with sleep disturbance pattern, improving the feeling of well being, supporting mental alertness and suppressing aggression and anxiety. Lavender oil shows its antibacterial and antifungal properties against many species of bacteria, especially when antibiotics fail to work, but the exact mechanisms are yet to be established.
Lemon [Citrus limon Linn. (C. limon)] belongs to the family of Rutaceae. Its oil constituents are abundant in the terpenes, D-limonene and Llimonene,together forming about 90 percent of the bulk of the oil. Traces of phellandrene, pinene and sesquiterpene are also present. The valuable portion of the oil is the remaining 10% which consists of oxygenated bodies, chiefly the aldehyde citral, to which the odor of the oil is largely due and of which there is 3.5%–5% odor present in the oil. When compared to other essential oils, its constituents have antiseptic, astringent and detoxifying properties, for blemishes associated with oily skin. Its oil brightens and rejuvenates dull skin.
Lemon essential oil is mainly used to boost the immune system and to accelerate the white corpuscles production along with counteracting acidity and ulcers through citric acid, which helps digestion, by forming carbonates and bicarbonates of potassium and calcium. Study on aromatherapy has suggested that citrus oil is good in relieving the first stage labor pain. It is effective in controlling the nausea and vomiting along with its mood elevating properties
Peppermint[Mentha piperita Linn. (M. piperita)] belongs to the family of Lamiaceae. The two most important are peppermint (M. piperita) and spearmint (Mentha spicata). Spearmint bears the strong aroma of sweet character with a sharp menthol undertone. Its oil constituents include carvacrol, menthol, carvone, methyl acetate, limonene and menthone. The pharmacological action is due to menthol, primary constituent of peppermint oil. At least 44% free menthol is present in peppermint oil. It is used in many liniments dosage form to relieve pain spasms and arthritic problems. Peppermint oil is reported to possess anti-inflammatory, analgesic, anti-infectious, antimicrobial, antiseptic, antispasmodic, astringent, digestive, carminative, fungicidal effects, nervine stimulant, vasoconstrictor, decongestant and stomachic properties.
When superficially applied around the head and temple, it has very good action on headache. It is observed that it can relieve many bacterial, fungal, and viral infections when inhaled or applied in the form of a vapor balm. Sinus and lung congestion are also known to be cleared by this oil.
The mechanisms by which aromatherapy reduces stress maybe related to sympathetic nervous system and parasympathetic modulation. Aromatherapy may decrease sympathetic nervous system activity and increase parasympathetic nervous system .These may promote relaxation and reduce stress level. However, more basic research is needed to fully understand the mechanisms underlying the effects of aromatherapy.
Aromatherapy may appear to be generally safe; regardless, the safety of aromatherapy requires further research. To establish the role of aromatherapy in the stress management, adequately designed trials are required. Future studies should be of high quality, with particular emphasis on designing adequate and appropriate control groups. In conclusion, based on published data there is limited evidence for the effectiveness of aromatherapy in reducing stress level of healthy subjects.
Babar Ali, Naser Ali Al-Wabel, Saiba Shams, Aftab Ahamad, Shah Alam Khan and Firoz Anwar.Essential oils used in aromatherapy: A systemic review. Asian Pacific Journal of Tropical Biomedicine 5(2015):601-611
Myeong Soo Lee, Jiae Choi, Paul Posadzki and , Edzard Ernst. Aromatherapy for health care: An overview of systematic reviews. Maturitas 71 (2012):257– 260