Eucalyptus radiata

Eucalyptus radiata

[span class=alert]In regards to the Traditional Use and Therapeutic Action sections of Essential Oils, the oils are rated as is standard practice in the French school of aromatherapy and others. The ratings ranked from one (+) to four (++++) with four indicating the highest value, indicate the oil’s therapeutic value from a practicing clinician’s point of view. The French rating system mentioned are obtained from this book reference entitle ‘Les Cahiers Pratiques D'Aromatherapie Selon L'Ecole Francaise’ (Authors: Francine Baudry, Pascal Debauche & Dominique Baudoux). However, further clarification might be required and will be updated once additional information of the rating system is obtained.[/span]

Family Name

Myrtaceae

Genus Name

Eucalyptus

Vernacular Name

Narrow-leaved peppermint eucalyptus, grey peppermint eucalyptus, fourth river peppermint

Original Habitat

E. radiata is a medium-sized tree growing up to 35 metres. It is often confused with other similar species therefore identification must be carefully made and attention paid to the size and shape of the leaves as well as to the area of the trunk covered by the bark.[1] This tree is native to Australia and is found primarily in the Tablelands.  It is pollinated by insects and produces a small bud-like fruit that is less than 10mm in size. It is presently classified as “endangered” in Tasmania.[2]

Plant Part Used

Leaves

Formulation

The essential oil of E. radiata is used in the food and beverage industry but less often than related species such as E. globulus and E. citriodora.[3] It is not often used in the fragrance industry due to its medicinal aroma. In therapeutic aromatherapy it is often used as a single oil and is also found in targeted formulations.

Description

The steam-distilled oil from the leaves of E. radiata is thin in consistency, clear or pale yellow in colour and has a medicinal, camphorous scent.[3]

Chemical Constituents

Terpenic oxides (60-70%) 1.8 cineole
Terpenic alcohols: alpha-terpineol (14%)
Terpenes: 8% [4][5][6]

Medicinal Uses

Anticatarrhal, expectorant ++++
Antiviral +++
Antibacterial ++

 Antimicrobial- Most Eucalyptus essential oils have anti-microbial activity against a variety of pathogens.  While there are numerous studies investigating these properties, only a few identify the species used and while chemical constituents are similar, the actions from each species differ. Investigations into the activity of the chemical constituents have indicated that those plants with higher levels of monoterpenes demonstrate anti-bacterial activity against specific bacterial species.[6][7] In addition, E. radiata was found to be effective against L. monocytogenes, a food-borne pathogen that is resistant.[8]

 Insecticidal- The essential oil of E. radiata demonstrated moderate activity against the Aedes albopictus mosquito in a laboratory setting [9] and in comparison studies, demonstrated strong insecticidal activity against termites.[10]

Traditional Use

Influenza, serious and chronic respiratory problems +++
Loss of energy, fatigue +++

There are no clinical studies to support the traditional use of this specific essential oil. While there are studies that investigate the effects of Eucalyptus oils in regard to respiratory illness and fatigue, they are not species specific.

Contraindications and Precautions

Oil is irritating to the eyes and to mucous membranes.[11]

Not to be used by pregnant or nursing women.

Efforts should be made to insure the correct species is used when using any oil of Eucalyptus.

 

[span class=alert]Keep out of reach of children as oils are highly concentrated.Essential oils are irritating to the eyes.  Avoid contact with eye area.Always dilute essential oils with carrier oil, lotion, cream or gel even when using in diffuser or bath.Essential oils are sometimes prescribed to be used internally, but should only be used internally under professional supervision.[/span]

References

1.         Threatened Flora of Tasmania. Available from: http://www.dpiw.tas.gov.au/inter.nsf/attachments/ljem-75246l/$file/eucalyptus%20radiata%20ssp.%20robertsonii.pdf. [Accessed on July 25th, 2009].

2.         Department of Primary Industries Parks, Water and Environment. Threatened Species List. Available from: http://www.dpiw.tas.gov.au/inter.nsf/WebPages/SLEN-5P3ACA?open. [Accessed on July 24th, 2009].

3.         Lis-Balchin M. Aromatherapy Science: A Guide for Healthcare Professionals.Pharmaceutical Press; 2006.185.

4.         Higley C, Higley A. Reference Guide for Essential Oils. USA: Abundant Health; 2006.

5.         Cimanga K, Kambu K, Tona L, Apers S, De Bruyne T, Hermans N, Totté J, Pieters L, Vlietinck AJ.Correlation between chemical composition and antibacterial activity of essential oils of some aromatic medicinal plants growing in the Democratic Republic of Congo. J Ethnopharmacol. Feb 2002:79(2):213-220.

6.         Inouyea S, Takizawab T, Yamaguchia H.Antibacterial activity of essential oils and their major constituents against respiratory tract pathogens by gaseous contact. J Antimicrob Chemother: 2001; 47:565.

7.         Takarada, K.; Kimizuka, R.; Takahashi, N.; Honma, K.; Okuda, K.; Kato, T. A comparison of the antibacterial efficacies of essential oils against oral pathogens. Oral Microbiology & Immunology. Feb 2004:19(1):61-64.

8.         Watson RR, Preedy V.  Botanical Medicine in Clinical Practice. UK:CABI; 2009:166.

9.         Cutler SJ. Biologically Active Natural Products. Great Britain: Taylor and Francis; 1999:138.

10.        Park IK, Shin SC. Fumigant activity of plant essential oils and components from garlic (Allium sativum) and clove bud (Eugenia caryophyllata) oils against the Japanese termite (Reticulitermes speratus Kolbe). J Agric Food Chem.1Jun 2005 ;53(11):4388-4392.

11.        Ebadi M.  Pharmacodynamic Basis of Herbal Medicine. Boca Raton: CRC Press; 2001:135