Plants have been producing essential oils for millions of years. Early on, humans discovered the benefits of these essential oils, including their antibacterial properties. However, in the 1900s, humans moved to laboratory-produced antibiotics. Although these antibiotics have saved countless lives, they are becoming increasingly problematic in our societies and our environment. Much research has been done showing the bactericidal properties of essential oils. I believe that educating people on the beneficial properties of these oils and how they should be used in the household, work environment, and hospitals will greatly reduce the risk of overuse of antibiotics.
It is not know exactly when plants began producing essential oils, but moss and lichen have existed for 350 million years. Moss and lichen produce chemical constituents that make up essential oils (such as cinnamic acid, limonene and pinene, geraniol, linalyl and bornyl acetates). Therefore, we do know that compounds within essential oils have been produced for millions of years.
Monoterpenes, which are the most common essential oil constituent, have been produced for at least three hundred million years in the ancient conifer trees. Angiosperms (plants with hulled or covered seeds) appeared one hundred million years ago and began producing even more complicated biochemical products, such as phenylpropanoids and aldehydes.
The chemical components of essential oils in each species (and even in different populations of identical species) were varied and evolved to assist the emerging plants to adapt to their particular environment and survive the diverse challenges of the these environments.
As plants developed and evolved over the following millions of years, their essential oil composition changed to include compounds that are medically important today. These essential oils have been used by plants to attract pollinators, repel harmful insects and herbivores, and to protect the plants from bacteria and viruses. When modern humans emerged approximately 120 thousand years ago, essential oil production had been finely tuned. It did not take long for humans to realize the benefits that plants had to offer and to use them in all aspects of their developing civilizations.
Essential oils and aromatics were used medicinally by early Greeks, Chinese, Egyptians, Romans, and many other early civilizations. This use continued for thousands of years and has only recently been replaced by “Western” medicine. It was in the 1600-1700s that the scientific revolution occurred and people started turning away from the herbal remedies that had been used for so long. And it was in the 1900s that herbal medicine was almost completely replaced by widespread use of antibiotics and other medicines introduced by man.
Antibiotics were first discovered early in the 1900s. Penicillin was discovered and was hailed as a wonder drug. Penicillin is taken from a mold (Penicilliun notatum) which effectively kills bacteria without harming healthy cells. This mold is produced in a form that can be consumed by humans. The antibiotics work by stopping the formation of the cell wall, thereby killing the bacteria. After this discovery, many other forms of antibiotics were found to fight other types of bacteria, such as streptomycin, neomycin, and gentamicin. Unfortunately, many of these antibiotics had hazardous side effects, such as blindness and hearing loss.
After World War II, drug companies in the United States searched for other bacteria and mold that could be created in the laboratory and turned into antibiotics. Many variations of the original antibiotics were created including: Tetracyclines, cephalosporins, erythromycin, and Bacitracin, which is an antibiotic, made from bacteria used as an ointment that is applied directly to the skin.
Antibiotic-resistant bacteria were discovered within 4 years of the introduction of penicillin. This drug-resistance occurs when bacteria that are mutants (or variants) of the original bacteria can resist the antibiotic and survive and reproduce, creating a new drug-resistant strain. According to a report in the April 28, 1994, New England Journal of Medicine, researchers have identified bacteria in patient samples that resist all currently available antibiotic drugs.
One of the major drawbacks of antibiotics, and one of the reasons that bacteria so quickly build resistance, is that they generally interfere with one function of the bacteria. In the case of penicillin, bacteria are killed by its attaching to their cell walls, and destroying a key part of the wall. The wall falls apart, and the bacterium dies. Therefore, resistant microbes need only to either alter their cell walls so penicillin can't bind or produce enzymes that dismantle the antibiotic.
Erythromycin attacks ribosomes, which are structures within a cell that enable it to make proteins. Resistant bacteria have slightly altered ribosomes to which the drug cannot bind. This is also how bacteria become resistant to the antibiotics tetracycline, streptomycin and gentamicin.
In both of these instances, it takes only one modification for the bacteria to become resistant to the antibiotic. Whereas, when an essential oil attacks bacteria, it generally attacks on more than one level. Schnaubelt (1999) states that because essential oils are lipid-soluble, they dissolve in the cell membrane. It is therefore, very difficult for the bacteria to have any resistance to the EO. Many different constituents of essential oils are able to interfere with the energy metabolism (which occurs in the cell membrane) and the formation of ATP (Adenosine triphosphate) including, phenols,alcohols, adlehydes, and keytones.
In a 2011 study done on the antibacterial effects of lemongrass essential oil by the Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen, Thailand 1, it was shown that lemongrass appeared “to have multiple targets in the bacterial cell, depending on concentration used as well as the amount of its components.”
As well as attacking harmful bacteria, essential oils offer, at the same time, other benefits to those who are ill. Essential oils offer immune stimulant properties which assist the body in boosting its own defenses and they have depurative properties which assist in the elimination of toxins and waste material from the body. A 2006 research article Entomology Research Institute, Loyola College, Chennai – 600 034, India 2 states that:
“Cinnamon, clove and rosemary oils had shown antibacterial and antifungal activity; cinnamon oil also possesses antidiabetic property. Anti-inflammatory activity has been found in basil. Lemon and rosemary oils possess antioxidant property. Peppermint and orange oils have shown anticancer activity. Citronella oil has shown inhibitory effect on biodegrading and storage-contaminating fungi. Lime oil has shown immunomodulatory effect in humans. Lavender oil has shown antibacterial and antifungal activity; it was also found to be effective to treat burns and insect bites.”
Essential oils are incredibly complex compounds made up of sometimes hundreds of constituents. Many of these individual constituents are effective against bacteria. Therefore, if one particular constituent is not effective, it is likely that another will be. Again, from the Journal of Antimicrobial Chemotherapy:
“…MID values of the major constituents were closely related to those of the respective essential oils, indicating that most of the activity of these oils was due to their major constituents, with the following exceptions. Rosemary oil contained numerous components of comparable percentage as shown in Table I, but camphor was assumed to be a major contributor to the bioactivity from the comparison of MID values. A major component of eucalyptus oil in percentage weight was 1,8-cineole, but a major contributor for the bioactivity was assumed to be α-terpineol, which showed eight-fold higher activity than 1,8-cineole against S. aureus. 1,8-Cineole has been reported not to be an active principle in other eucalyptus oils. A similar situation was seen for thyme (geraniol) oil and lavender oil, where the respective major constituents, geranyl acetate and linalyl acetate, were not the active principles of the oils, and active contributors were geraniol and linalool, which co-existed in the respective parent oils. Likewise, limonene, one of the major components, might not contribute significantly to the antibacterial activity of thyme (red) oil.”
This research shows that it is often the combination of the constituents that produce the desired effect, as opposed to a single component of the oil. This is one of the major benefits of using essential oils as bactericides.
As is shown from what research has been done, many essential oils are very effective against bacteria. Essential oils have been used effectively by plants for millions of years to protect themselves from diseases. And, humans have been using plants and essential oils for thousands of years to protect and heal themselves. These oils do not produce resistant strains of bacteria as opposed to the antibacterial products that have been produced by drug companies over the past decades. All of these facts together should make it fairly obvious that humans should return to working with nature and plants to learn how to more effectively and naturally deal with the harmful bacteria. Unfortunately, because of the fact that essential oils are not “patentable”, drug companies do not spend time or money researching the properties or potential medical value of essential oils. It is up to individuals to research these benefits and incorporate them into our daily lives.
References
1. The effect of lemongrass oil and its major components on clinical isolate mastitis pathogens and their mechanisms of action on Staphylococcus aureus DMST 4745. Aiemsaard J., Aiumlamai S, Aromdee C, Taweechaisupapong S., Khuntkitti W, Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen, Thailand.
http://www.ncbi.nlm.nih.gov/pubmed/21316719
2. In vitro antibacterial activity of some plant essential oils, Seenivasan Prabuseenivasan, Manickkam Jayakumar ,and Savarimuthu Ignacimuthu. Entomology Research Institute, Loyola College, Chennai – 600 034, India.
http://www.biomedcentral.com/1472-6882/6/39
3.
http://jac.oxfordjournals.org/content/47/5/565.full Antibacterial activity of essential oils and their major constituents against respiratory tract pathogens by gaseous contact.
Shigeharu Inouyea,
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Toshio Takizawab and
Hideyo Yamaguchia
4. Battaglia, S. The Complete Guide to Aromatherapy. The International Centre of Holistic Aromatherapy, Australia, 2002
5. Tisserand, R. & Balacs, T. Essential Oil Safety. Churchill Livingstone, Scotland, 2008
6. Schnaubelt, K. Medical Healing with Essential Oils. Frog, Ltd., USA, 1999