Aromatherapy Workbook

As the percentage of lactones present in any oil is extremely low, they may generally be regarded as non-toxic. They have been found to be more effective than ketones for lowering temperatures and relieving catarrh, and are the components responsible for skin photosensitization.

Lactones are widely distributed in nature; the most important members of this class (or chemical family) occurring in essential oils are the coumarins and coumarin derivatives.

Coumarins and Furocoumarins

Coumarins are generally found to be sedative and calming yet at the same time uplifting and refreshing. They are also noted for their anticoagulating properties, which makes them good hypotensives. See Figure 3.22.

FIGURE 3.22: Bergaptene, a coumarin

Furocoumarins, closely related to coumarins, are noted for their hazards in connection with sunbathing. They are photosensitizers and should not be used immediately before going into the sun or onto a sunbed (see chapter 6 (#litres_trial_promo)). Bergaptene, found in bergamot oil (not a terpene and sometimes spelt without the final ‘e’), is the best-known example.

Two hours after applying complete bergamot oil (see folded oils – chapter 2 (#u6edf141d-1ccf-5213-bee3-eedce4b44e0e)) suitably diluted in a carrier, there is no longer a great risk of adverse reactions due to the sun; by that time the oil is safely absorbed into the bloodstream.

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Ethers (Not to be confused with esters)

Here we have yet another component which occurs but rarely in essential oils and can be confusing. Like phenols and phenolic ethers, the properties of ethers are anti-depressant, anti-spasmodic and sedative.

Conclusion

An essential oil is always a complex cocktail of many different naturally occurring components; there are several different kinds of terpenes, alcohols, phenols, ketones, esters and so on in each oil, and these vary from harvest to harvest and plant to plant. The actions of any whole essential oil are difficult to forecast from this complicated make up; I repeat, there is no direct simple relationship between the chemical constituents and the therapeutic qualities (or even the hazards) of an essential oil.

No one in the aromatherapy world understands or knows everything to do with essential oils, so take heart! There is also no way in which a book like this can cover each constituent known of every single oil, but simply by being acquainted with the main constituent families you may be able to see some sort of pattern emerging in relation to therapeutic effects.

There are, nevertheless, some essential oils whose chemical constituents do not seem to conform to their expected pattern and are the ‘black’ (or sometimes perhaps, the ‘white’!) sheep of their family. There are also trace elements which show up on a gas-liquid chromatograph (see chapter 2 (#u6edf141d-1ccf-5213-bee3-eedce4b44e0e)), but have so far not been identified – these too must surely play an important part in the eventual effect of the final chemical ‘cocktail’.

The above points (plus climate and soil variants) may help to explain why no document or book lists every minor chemical, or even gives the same proportions of the major ones. It would take years to research and would take up many volumes! (Guenther’s well-respected reference work on essential oils comprises six thick volumes, without including any therapeutic effects!)

May I suggest that if you have found this chapter (so far) a bit difficult, yet you wish to understand it, you come back to it later. Read it again up to the isoprene unit, perhaps drawing the molecules as you go along, moving on to each new chemical family only when you fully understand how the previous one was formed.

Perhaps you already knew it all, or have neither the wish nor the need to pursue the intricacies of these simple to use and wonderful liquids! In either case I hope you found it interesting.

Electrical Classification of Essential Oils

The therapeutic effects of the different chemicals we have been looking at can be shown by charting the reaction of essential oils and their components to electricity and water. There has been a lot of work done in France by Franchomme, based on investigations begun by Vincent and Mars, to determine the polarity of each chemical constituent in order to discover whether these follow an overall pattern. It presents a fascinating concept and has given very interesting results.

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When essential oil molecules are sprayed between two electric plates (one positively charged and one negatively charged) they will be attracted either to one plate or the other. This attraction stems from the chemical components, each of which has either a negative or a positive charge. Opposites attract, so negative components go towards the positive plate and vice versa. When a component from one chemical family is sprayed between the plates, it is attracted either to the negative or the positive plate. Aliphatic aldehydes (chain based), esters and ketones are attracted towards the negative plate; alcohols, aromatic aldehydes (ring based), monoterpenes, oxides, phenols and phenolic ethers towards the positive one; the sesquiterpenes, lactones and coumarins are neutral and are not attracted – some are slightly more negative – others more positive. See Figure 3.23.

FIGURE 3.23: Movement of alcohol molecules

Essential oils are slightly soluble in water – this is due to the hydrophilic (soluble) or hydrophobic (insoluble) factor of each chemical family. Alcohols, all aldehydes, phenols, ketones, lactones and coumarins are soluble to some degree; monoterpenes and sesquiterpenes are insoluble, as are most of the esters; oxides and phenolic ethers fall in the middle, as do a relatively small proportion of the esters. See Figure 3.24.

With a four-way grid like this, it is easy to see which constituents from the essential oils are cooling and which are warming; which are calming and which are stimulating (Figure 3.25).

See how top and bottom, left and right, and opposite quadrants, complement each other; using a combination of these opposites, essential oils can be selected to treat the whole person. Franchomme’s approach is that there is a relationship between the chemical components and the effects – if you know the chemical constituents it gives at least an idea of the effect of an essential oil containing these. I am told that he and his colleagues have carried out many clinical experiments in French hospitals to verify his work.

FIGURE 3.24: Polarity and solubility of individual components of essential oils (adapted from grid originated by Roger Jallois and published in Aromathérapie Exactement)

There is much work being done and more yet to be done on these fascinating creations of nature, essential oils. Even though I have only touched the tip of the iceberg, I trust I have awakened in you a desire to utilize the information in it to the good of your own health and, if you are an aromatherapist, of that of your clients.

FIGURE 3.25: Basic effects of individual constituents

TABLE 1: Chemical Constituents of Essential Oils and their Effects

TABLE 2: Some Chief Chemical Constituents of Essential Oils

This table simply gives an idea of a few of the chemicals in selected essential oils and is not meant to be comprehensive.

TABLE 3: List of Oils with Common Name, Latin Name and Plant Family

4 Plant Families (#ulink_28a0e945-482f-5882-b816-8def79e37a91)

Each plant from which essential oil is derived belongs to one of a number of botanical families. These origins are easy to forget once the oils have been put into little glass bottles. Just as plants show family characteristics in their physical appearance, essential oils show family characteristics in their therapeutic effects, which can be helpful when selecting oils for any particular condition. For would-be therapists, knowledge of the families helps to give a system of, and a pattern for, learning.

Not all plants produce essential oils and of those which do, not all contain a sufficient quantity to justify extraction, either by distillation or solvent extraction. There are well over 200 plants from which essential oils are taken and although most may present possibilities to the perfume industry (also for the study of smell – osmology), not all are popular, free enough from toxicity or necessary for the practice of aromatherapy.

The yield of essential oil from each plant varies not only from year to year in the same country (because of climatic changes), but also from country to country, depending on the growing conditions, so the yields given can only be approximate and are given after the plant name. Those quoted in this chapter have been taken from Guenther (The Essential Oils) and The H & R Book of Perfume; a 1 per cent yield means that 100 kilos of plant yields approximately 1 litre of essential oil.

There are 21 families which yield the oils used in aromatherapy. Sixteen families yield the most well-known oils; some, like Santalaceae, having hardly any plants in their repertoire and others, like Lamiaceae, having an enormous number.

Unfortunately, botanical names are changed from time to time (which adds to the difficulty of learning them!) Where this is happening, or has happened, all names will be given. Where the common name is almost the same as the Latin name, the former will not be shown.

All plants to be referred to in chapter 5 (#litres_trial_promo) are entered there under their common name, and this is also the case in all charts, to make them more easily referred to until Latin names become the norm in the UK (see Table 3 (#ulink_50c0c798-b995-561a-837e-3b8ef948d8d2), for easy reference).

General properties and effects characteristic to the plant family will be indicated; any special property or effect of note for any particular oil is given in addition to these family traits. Further properties and effects of each oil can be found in the various charts and lists in chapters chapter 3 (#u35d87537-07fb-5c2f-9af9-cb22524f5805), chapter 6 (#litres_trial_promo) and chapter 14 (#litres_trial_promo).

Cautions are given on the results of toxicity tests on ingestion by animals, plus the assumption that oils may be wrongly used; these cautions do not necessarily apply to the methods of use (and dilutions used) employed by trained aromatherapists.

Abietaceae (or Pinaceae)

The name Abietaceae is becoming more familiar, though Pinaceae is frequently used. Whichever name is employed, this family, together with the Cupressaceae, belongs to the conifer class.

This is quite a large family, though not many essential oils from its members are in common use.

Family Properties and Effects Essential oils obtained from the Abietaceae family are highly antiseptic and effective on respiratory disorders involving catarrh.

Cedrus atlantica – wood (cedarwood) 3–5%

See chapter 5 (#litres_trial_promo) for details on C. atlantica and other plants bearing the common name of cedarwood.

Special Properties and Effects A healing and regenerative oil, Cedrus atlantica is a good lymph tonic and is indicated for cellulite. It is useful in cases of oily skin and scalp and has all the family properties too.

Caution Although the bulk of the oil is composed of terpenes and alcohols, it should be treated with respect, containing as it does around 20 per cent of the ketone atlantone. There seems to be some conflict as to whether or not it is an abortive oil, two authors of well-researched books saying it is and two authors of safety data manuals not mentioning it with respect to toxicity. I suggest it is left alone at the commencement of pregnancy until the baby begins to move (see chapter 5 (#litres_trial_promo) and chapter 11 (#litres_trial_promo)).

Pinus sylvestris – needles (pine) 0.1–0.5%