The Aromatogram

A Vital Key to Optimizing Treatment in the French Practice of Aromatherapy

Essential oils have a range of therapeutic properties, and the Aromatogram is an analytical method that brings to light the antibacterial or antifungal activity of an essential oil. The information revealed by the aromatogram is complementary to that made available by gas chromotography, which provides quantitative data on an essential oil's components.

It is a basic tenet of good phyto-aromatherapeutic practice that one should know the precise composition of the essential oil being tested and then prescribed for the patient. Gas chromotagraphy is a common method for determining the amounts of the components of a given essential oil. These quantities, often expressed as percentages, vary with the growing, harvesting and distilling conditions for the essential oil plant.

Knowing the composition of a range of essential oils for potential use for a particular patient, and having a general base of knowledge of the therapeutic actions of a variety of essential oils and their components, a French doctor has the option of prescribing an aromatogram, which is executed by a laboratory. This will show the action of selected essential oils on germs taken from the relevant part of the patient's body, providing a more precisely targeted guide for choosing which essential oils to prescribe.

What is an Aromatogram?

The aromatogram is based on the principle of the antibiogram, which tests the effectiveness of antibiotics against microbes. It allows one to determine the sensitivity of specific germs to specific essential oils. The most widely used technique for performing an aromatogram is the "disc method." A germ sample is taken from the patient and placed in suspension. This fungal or bacterial suspension is then spread on the surface of a gelled growth medium in a petri dish. Small discs of filter paper are placed on the surface of the medium, up to six per petri dish, each disc impregnated with a small amount (usually 5 microliters) of a different essential oil.

The choice of the oils to be tested is based on a body of statistical data on the in-vitro efficacy of essential oils against common bacteria and fungi. An "aromatic index" has been determined for several dozen essential oils, of which a relatively small number have been found to be significantly effective on a broad range of germs. The concentration of the oils to be tested is equal to or greater than what is known to be the Minimum Inhibiting Concentration--in other words, the minimum known to be antifungal or antibacterial.

The petri dishes are then placed in an incubator, generally at 37 degrees centigrade for bacteria, 25 degrees centigrade for fungi. The germs grow in the nutritive medium, except in the concentric zones where the essential oils are active.

The results are usually read after 24 hours, sometimes longer for certain fungi. A clearly visible ring around a disc indicates an absence or inhibition of germs. Beyond this circular area, the medium will be cloudy, indicating the proliferation of germs. The diameter of each ring (including the disc) is measured, making it possible to assess the antimicrobial or antifungal activity--in vitro--of each essential oil being tested.

The laboratory furnishes a chart showing the results for the essential oils and the germs that were tested. The degree of activity of the oils is indicated by the following symbols: +++ for the most active, ++ for those that are fairly active, + for the least active. Oils with no symbol or a minus sign have no action against the given bacterium or fungus. The chart might also specify the diameter of the area of inhibited activity.

How the Results of an Aromatogram Are Read and Interpreted

Below are some concrete results revealed in aromatograms. These are offered as general information and should not be used as references for any specific case, since they were created with germs taken from individual patients and thus can only appropriately be applied to those patients. Forty essential oils from the French producer Florial (all of which are certified organic by the European organization Ecocert) were tested on the
following germs:

Cocci (Gram positive)
1. Staphyloccus aureus
    nasal sample
    vaginal sample
2. Enterococcus
    vaginal sample
    Bacillus (Gram negative)
1. Escherichia coli
    fecal sample
2. Klebsiella rhinoscleromatis
    vaginal sample
3. Proteus mirabilis
   fecal sample
   Yeast
   Candida albicans
   vaginal sample

PHOTO 1 Germ: Escherichia coli -- fecal sample A: BIO ROMARIN 1-8 CINEOLE / ROSEMARY -            Rosmarinus officinalis cineoliferum (FL-74) B: BIO SAUGE OFFICINALE /SAGE -            Salvia officinalis (FL-84) C: BIO SARIETTE / SAVORY -            Satureja montana (FL-82) D: BIO THYME THYMOL / THYME CV THYMOL            Thymus vulgaris thymoliferum (FL-91) E: BIO THYME LINALOL / THYME CV LINALOL            Thymus vulgaris linaloliferum
Definite antibacterial activity of mountain savory and thyme (chemotype thymol) on Escherichia coli.
PHOTO 2 Germ: Enterococcus, vaginal sample A: BIO CANNELLE ECORCE / CINNAMON BARK           Cinnamomum zeylanicum (FL-101) B: BIO CITRONELLE / CITRONELLA           Cymbopogon winterianus (FL-25) C: BIO EUCALYPTUS           Eucalyptus globulus (FL-33) D: BIO EUCALYPTUS           Eucalyptus radiata (FL-35) E: BIO GIROFLE CLOU / CLOVE BUD           Eugenia caryophyllus (FL-42)
Clear indication of the activity of cinnamon bark essential oil on Enterococcus. Citronella and Clove bud are less effective. The germs are resistant to the different chemotypes of Eucalyptus.
PHOTO 3 Germ: Staphylococcus aureus, vaginal sample A: BIO MARJOLAINE COQUILLE / MARJORAM SWEET           Origanum majorana (FL-53) B: BIO ORIGAN / OREGANO           French Origanum sylvestris (FL-66) C: BIO ORIGAN / SPANISH OREGANO           Thymus capitatus (FL-65) D: BIO BAY SAINT THOMAS           Pimenta racemosa E: BIO RAVENSARA / RAVENSARA           Ravensara aromatica (FL-73)

Spanish Oregano (Thymus capitatus) is more effective against Staphylococcus aureus (vaginal sample) than a French Oregano (Origanum sylvestris).

Summary of Results Revealed in These Aromatograms

The following essential oils were shown to have a major anti-infectious effect with a broad range of activity on the above-mentioned germs:

Cinnamon bark (Cinnamomum zeylanicum)
Oregano, Spanish (Thymus capitatus)
Savory, mountain (Satureja montana)
Thyme, chemotype thymol (Thymus vulgaris thymoliferum)

Other essential oils were shown to have activity that was limited but nonetheless significant:

Clove bud (Eugenia caryophyllus)
Marjoram (Origanum majorana)
Coriander (Coriandrum sativum)
Tea tree (Melaleuca alternifolia)

The results of these aromatograms are well within the range of what might have been predicted, since the major components of these essential oils are
known to have anti-infectious properties: cinnamic aldehyde (cinnamon), thymol (Thyme, chemotype thymol; Savory), carvacrol (Thyme, Spanish
Oregano), eugenol (Clove bud), monoterpenoids (Tea Tree), etc.

When Would a French Doctor Prescribe an Aromatogram?

Aromatograms are commonly called for in cases of chronic illness. This procedure would be carried out on a regular basis--every month or every
three months, for example, in order to monitor the evolution of an infection and modify the essential oil prescription accordingly.

An aromatogram is not necessary or appropriate in many simple emergency situations; generally one must act urgently in this sort of case. But in an
emergency with a history of chronic illness, an aromatogram might nonetheless be prescribed as a follow-up procedure.

The aromatogram is usually called for in addition to traditional tests to determine the presence of particular germs in the patient.

How a French Doctor Might Proceed with Treatment Based on the Aromatogram?

A French doctor will not necessarily chose to treat the patient with the essential oil that was the most effective against the germs in the petri
dish. Rather, the practitioner will always keep in mind any counter-indicating factors based on the patient's general condition, or
other symptoms the patient might be exhibiting. It is therefore important to have at one's disposal a range of possible essential oils to prescribe,
which may have varying degrees of effectiveness against a specific microbe or fungus. Also, it is common to prescribe a few essential oils in
combination, to counteract any tendency to develop resistance to a particular oil.

How Do Essential Oil Molecules Act Against Germs?

The essential oil component molecules create conditions that inhibit the development of the germs. Specifically, the hydroxylic molecules cause
variations in the pH and the potential for oxyreduction; they also interfere with the cell's enzyme system. They have a similar action on the human
organism as a whole and indirectly activate various biological processes in neuro-endocrino-immunitary functions. In these ways, essential oils produce
changes that are both localized and general in nature.

The Aromatogram--A Valuable Therapeutic Tool

The aromatogram is thus a significant resource for the French phyto-aromatherapeutic practitioner. Often serving as an adjunct to other
means of treating the patient's general or specific condition, it provides information that guides the doctor in choosing the most appropriate
essential oils.

Alain Durante, Florial, France
Sylvie Malerba, biologist

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