Essential Oils – What You Should Know
There has been a growing interest in the use of essential oils for health benefits and aromatherapy uses in the last couple of years although they have actually been in use since antiquity. Essential oils are defined as natural, aromatic compounded substances, isolated from a vegetable substrate, which are liquid, hydrophilic, and characterized by great volatility. They are obtained from the different organs of the plant such as the bark, seeds, fruits, leaves, stems, flowers and any other structures available, by different techniques. Understanding how essential oils work can assist in the utilization of some of its benefits, which is why it is important to note that.
What process is followed to obtain Essential Oils?
They are primarily extracted from plants through steam distillation, which is a process of extracting water soluble extracts by heating water and passing steam through it. This involves putting the plant material in a distillation equipment over water then heating the water to boiling point. It passes through the plant material, popping little bubbles of cells and liberating the scent within the cells into the water vapor. The vapors then pass through a tube where they are returned to a liquid and are then collected in another receptacle. Other methods of extraction involve Expression, Enfleurage, Cold Pressing, Maceration and Solvent extraction.
The oils separated have a more concentrated amount of the complex hydrophobic aromatic compounds; the hydrophobic portions dissolve into the fats and lipids of the human body while the aromatic portion is the part that gives it a smell and possibly the therapeutic values. The high reactivity of the aromatic compounds and their molecular size is indicative of their capacity to pass through cell membranes and mucus layers to elicit pharmacological effects in the body. Essential oils bear chemical composition that makes them unique from other classes of oils.
More than 500 different chemical compounds have been identified in different amounts in essential oils. The most prominent chemical families found in essential oils include:The most prominent chemical families found in essential oils include:
- Terpenes – Basic building blocks called isoprene units that can link together in various ways to develop the tremendous structural variation in the terpenes. Limonene and linalool are two examples of a terpene.
- Phenylpropanoids – These are structures which are derived from cinnamic acid. It includes Eugenol and cinnamaldehyde.
- Benzonoids – Containing benzene ring in their structure. Vanillin and methyl salicylate are aromatic compounds because they contain a benzene ring .
Credited Bioactive Constituents
Even though the components of essential oils are numerous, many have attributed most of the bioactivity to a few compounds of each oil. For example:
- Tea Tree Oil – Terpinen-4-ol has powerful antiseptic activity and can easily kill bacteria and fungi.
- Lavender Oil – Linalool and linalyl acetate possess the ability to alleviate anxiety.
- Peppermint Oil – The element that makes this particular oil great for pain is that it contains Menthol which stimulates cold receptors and it also works as a calcium channel blocker.
- Eucalyptus Oil – 1,8-Cineole has marked bronchial specialist and antioxidant action.
However, other constituents and potentially, their interaction with each other, could also be a contributing factor. Oral ingestion of essential oils can be done in two ways; directly by placing the oil under the tongue or in the cheeks and then swallowing or by adding it to foods and beverages.
Essential oils can enter the body by:
- Inhalation – Absorption takes place through the membranes of the nasal and bronchial tissues and enters the blood stream directly. This is effective because numerous capillaries are located in the lungs, thus constituting a wide surface area.
- Topical Application – The lipids in the outer layer of skin can allow some of constituents of the oil to penetrate and enter systemic circulation. Various substances have dissimilar skin penetration percents depending on the molecular weight, in addition to lipid solubility.
- Solubility – Some of the oil constituents will pass through the circulatory system after passing through the digestion system. Many will undergo first pass hepatic metabolism and will be inactivated in the process. Most oils are too flammable to release constituents during transportation to sum much orally.
Other issues such as the molecular weight, lipid solubility and protein binding affect the manner in which the essential oil constitutes are metabolized. They may act locally on the area where it is applied or absorbed, or affect the rest of the body after being absorbed.
Mechanisms of Action
Essential oils and their individual active compounds can influence the body through numerous pharmacological mechanisms, including:
Regulating Cytokine Production- Depending on the type of cytokine, the essential oils can increase or decrease the cytokine levels in human body through having an influence on interleukin-6, tumor necrosis factor and CRP levels. This helps to control the inflammatory processes occurring in the body.
Some of the components of essential oils have high hormonal activities since they are mimics of estrogen and/or androgens that may enter the hormonal pathway by interacting with receptors in different tissue types such as breast and prostate tissues. They can either copy or block the activity natural hormones in the body as a way of functioning.
Activation of TRP Channels- Some of the chemosensitive ion channels called transient receptor potential cation channels are activated by natural compounds to signal processes as somatosensation, heat, cold and pain. For instance, menthol stimulates cold-sensitive nerve endings while capsaicin activates warm-sensitive nerve endings.
Enzyme Inhibitors – Some of the active constituents of essential oils are inhibitory in character. For instance, 1,8 cineole has the ability to interfere with production of the interleukin 1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) that controls an inflammatory process. The compound eugenol has MAO inhibiting properties that help in controlling neurological over activity.
Antioxidant Effects – The terpenes and phenolics can act as free-radical, which can help in combating the resulting of oxidative stress when there is an overproduction of oxygen-derived species in the body tissues. These help in the redox balance or maintenance of the oxidizing and reducing agents in the body.
Although the full range of effects of using whole essential oils themselves probably extends beyond the abilities of any single constituent, studying the science behind the most important compounds that make up these oils provides a great deal of overall biological activity. It is only when one considers the chemical specifics and variety of effects through which essential oils might address physiological processes that one can improve the utilization toward more accurate and sound approaches. If the source of these oils and how they are handled is appropriate, then there is potential that a lot of the oils are therapeutic.