Eucalyptus spp. (Family Myrtaceae) originated in Australia. It now grows in almost all tropical and subtropical areas and is cultivated in many other climates. Much research has been conducted on the medicinal properties of Eucalyptus spp. Of the different species, E. globulus has been the most widely studied. Eucalyptus is used to treat many human ailments and some livestock ailments. Eucalyptus extracts, oils, or fresh leaves are used in steam inhalation treatments, consumed in teas, or used in bathing.
While Eucalyptus trees are well known for their medicinal properties and their strong fragrance, they are best known as the feed source for koala. The koala only eat a few species of Eucalyptus. However, there are over 500 species of the tree.
- Blue Gum tree
- Fever tree
- Lemon Eucalyptus
- Silver-leaf Ironbark
There are many compounds in Eucalyptus spp.. While the same compounds exist in many of the species, some compounds can be found in only one or a few species. Within species the quantity of essential oil and the specific compounds in the essential oil and extracts of dry and fresh leaves, buds, mature fruit, and bark vary with the origin of the tree and the age of the leaves. The following discussion and list of Eucalyptus spp. and the compounds in them is not comprehensive. The quantity of the compounds in the oils and plant parts are estimates based on several sources (listed in the references). For more information please refer to the references and the USDA Phytochemical and Ethnobotanical Databases.
E. globulusis one of the more important species of Eucalyptus. The essential oil in the leaves is commonly used for medicinal purposes. The quantity of essential oil ranges from less than 1.5 to over 3.5%. On average, between 70 and 95% of the oil is 1,8-cineole (eucalyptol). However, some studies have shown the oil to contain as little as 4% 1,8-cineole. The essential oil from the fruit, buds, and branches contain from 15-57% 1,8-cineole. Activities contributed to this compound include: anesthetic, antibronchitic, anticatarrh, antilaryngitic, antipharyngitic, antiseptic, antitussive, cns-stimulant, choleretic, counterirritant, dentifrice, expectorant, fungicide, hepatotonic, herbicide, hypotensive, pesticide, and sedative. Other major components in the oil are:
- aromadendrene -- 8-23% in fruit, bud, and branch oils and 50-350 ppm in the leaves
- camphene -- traces in leaf oil
- cryptone -- 0-18% in leaf oil
- p-cymene -- <1-27% in leaf oil
- d-limonene -- traces in leaf oil
- alpha-phellandrene -- traces in leaf oil
- alpha-pinene -- <1-18% in leaf oil
- beta-pinene -- traces in leaf oil
- spathulenol -- <1-17% in leaf oil
- y-terpinene -- traces in leaf oil
- alpha-thujene -- 0-12% in fruit, bud, and branch oils
Other important compounds found in the leaves, buds, branches, and bark include:
- antioxidants (from bark) -- eriodictyol, naringenin, quercetin, rhamnazin, rhamnetin, taxifolin
- cuminaldehyde -- 25-135 ppm in the leaves
- epiglobulol -- one study indicated 28,000 ppm in leaves
- euglobals -- These compounds are believed to have anti-tumor promoting activity.
- d-linalool -- leaves
- pinocarvone -- leaves
- rutin -- leaves
- tannins -- as much a 11% have been found in dry powdered leaves. Several activities have been attributed to tannins including antidysenteric, antimutagenic, antinephritic, antioxidant, antiviral, bactericide, cancer-preventive, hepatoprotective, pesticide, psychotropic, and viricide properties.
- gamma-terpinene -- leaves
- terpineol -- leaves
E. citriodora essential oil contains mainly citronellol (approximately 58%), which is best known for its aromatic properties. Other compounds in the plant include:
- citronellal -- 50-18,020 ppm in the leaves
- citronellic acid -- 1% in leaf oil
- citronellol -- 7.6% in leaf oil and 230-4,000 ppm in the leaves
- citronellyl acetate -- 24% in leaf oil and 20-130 ppm in the leaves
- p-cymene -- 10-180 ppm in the leaves
- limonene -- 20-1,420 ppm in the leaves
- linalool -- 15-180 ppm in the leaves
- alpha-pinene -- 5-380 ppm in the leaves
- terpinene -- 1-180 ppm in the leaves
- terpinolene -- 5-160 ppm in the leaves
- ursolic acid
E. camaldulensis essential oil (from the leaves) ranges from less than 1 to over 2%. The quantity of 1,8-cineole in the oil ranges from 15-78%. Other compounds in the leaves include:
- betulinic acid
- eucalyptic and eucalyptolic acid
- oleanolic acid
- ursolic acid
Other Eucalyptus spp. of note and some of the compounds in them include:
- E. amplifolia, E. blakelyi, E. grandis, and E. tereticornis contain euglobals.
- E. cladocalyx contains traces of cyanogenic glycosides.
- E. cornea leaves contain up to 25% tannins.
- E. dives oil contains 33% piperitone.
- E. dunnii oil contains 48-58% 1,8-cineole, 5-7% globulol, 10-16.5% alpha-pinene, and 3-8% alpha-terpineol.
- E. macarthurrii oil contains 50% geranyl acetate.
- E. macrocarpa contains macrocarpal A, believed to be antibacterial.
- E. macarorryncha contains 12-20% rutin.
- E. maidenii and E. smithii oils contain 70-85% 1,8-cineole.
- E. viminalis oil contains high quantities of phellandrene (an inhalation irritant) and traces of cyanogenic glycosides.
Eucalyptus spp. contain high levels of phenolics and terpenoids which can be toxic. Animals such as the koala which eat Eucalyptus have developed methods for detoxifying the compounds in the liver. In addition, they have bacteria that degrade tannin-protein complexes. Most animals do not have this ability.
Several adverse reactions have been attributed to the use of or contact with Eucalyptus oils, extracts, and fresh and processed plant material. Some of the specific compounds that can be toxic or cause adverse reactions include: 1,8-cineole, cyanogenic glycosides, rutin, and tannins. Most studies on adverse reactions have been conducted with rodents and most documented cases of adverse reactions focus on humans. Less information is available on livestock.
Overdoses of the oil in humans cause gastro-intestinal burning, abdominal pain, vomiting, and convulsions, depress respiration and the central nervous system, and may lead to comas and death. The data on deaths caused by consumption of eucalyptus oil in humans are not consistent -- death has occurred after consumption of as little as 4-5 ml, while other people have become ill and recovered after consuming 120-220 ml of the oil. Based on rodent studies, the oral LD50 (the orally consumed dose that is lethal to 50% of the animals) for eucalyptus oil is very high -- 4.44g/kg body weight(BW) for rats and 3.32g/kg BW for mice. The LD50 is lower when only 1,8-cineole is used -- 2.48g/kg BW for rats. The dermal LD50 for rabbits is greater than 5g/kg BW.
Eucalyptus oil is not believed to be teratogenic or contaminate milk. However, some studies have indicated that citronellal and phellandrene, which can be found in some Eucalyptus spp., are weak mutagenics and carcinogenics, respectively.
It is very difficult to determine the potential for adverse reactions with the use of Eucalyptus treatments. This is because, as previously stated, the type and quantity of compounds depends on the species (which often is not indicated on the label of purchased preparations), the age of the leaves, the method used for drying leaves, buds, and bark, and the preparation methods of essential oils and extracts. In addition, many studies on adverse reactions do not indicate the species or preparation method used, complicating the situation. While Eucalyptus spp. can cause adverse reactions, the U.S. Food and Drug Administration has approved the use of eucalyptus oil and 1,8-cineole (eucalyptol) for human food use. The Council of Europe also has approved the use of the oil as a human food additive (at a level of 15 ppm). In France, infusions of E. globulus leaves can be registered as products for the treatment human benign bronchial disorders without toxicological studies. However, some toxicological studies are required for the registration of powdered leaf formulas.
While not related to the use of Eucalyptus in treatments, I find it interesting that growing certain species of Eucalyptus can cause its own problems. In Australia sawfly larvae, which contain poisonous polypeptides, often gather in mounds beneath E. melanophloia. When cattle consume the larvae, they become uncoordinated, tremble, and can suffer permanent liver damage.
As with toxicity, the efficacy of eucalyptus oils and extracts is most likely dependent on the their chemical composition. In general, oils from Eucalyptus spp. have antimicrobial properties. Two studies which tested the oils from several species showed that E. citriodora had the most antimicrobial activity. There was no relationship between 1,8-cineole content and antimicrobial activity. Other studies have demonstrated that the oil and leaf extracts of Eucalyptus spp. have antifungal and repellent activity.
The applications that are probably of most interest to livestock producers are as a mastitis preventative and treatment, as a treatment for endometritis, and as an anthelmintic (dewormer). An herbal gel called AV/AMP/14 (produced by Dabur Ayurvet Ltd. and contains Cedrus deodara, Curcuma longa, Glycyrrhiza glabra, and Eucalyptus globulus) was used to treat and prevent subclinical mastitis in crossbred cows. Twice daily topical applications to the udder significantly reduced somatic cell counts (Pavneesh et al. 1996 and Joshi et al. 1996).
In a study on bovine endometritis, cows with endometritis were given, via an intrauterine infusion, 100 mls of a 10% solution of a tincture (alcohol and water mixtures) of Eucalyptus globulus. The eucalyptus tincture was compared to tinctures of Allium sativum (garlic, believed to have antimicrobial activity) and Gnaphalium conoideum (a plant that has no antimicrobial properties). The parameters measured in the study included the number of infusions given (which were repeated every 48 h until there was a change in the endometritis) and the days to first visible oestrus, days open, and number of services before conception. All of these time periods are believed to be longer when there are infections in the reproductive tract. The eucalyptus and garlic tinctures significantly reduced the days to first visible oestrus and the days open, although fewer garlic treatments were needed. There were no significant differences between the three treatment in the number of services required for conception. The study did not included any approved, commercially available treatments for endometritis (Esparza-Borges and Ortiz-Marquez 1996).
Fresh leaves, leaf-extracts, and growth regulators and their intermediaries (which are endoperoxides) of Eucalyptus grandis were tested for their anthelmintic properties by Bennet-Jenkins and Bryant (1996). Leaves were fed to 5 goats with experimental infections of Haemonchus contortus (the barberpole worm) (and natural infections of Ostertagia) for seven days (two days with lucerne/oaten chaff and five days as the sole source of feed). At necropsy, the number of adult H. contortus in the E. grandis-fed goats was 91% lower than the number in 4 control goats. There was no significant difference in the number of Ostertagia. Isolated E. grandis compounds (and synthetic congeners) were affective in vitro and in vivo (in mice and sheep) -- but practical formulation and administration methods for these compounds have not been identified.
Another application that may be of interest to livestock producers is as a treatment for ectoparasites and non-specific skin infections. Two experimental herbal mixtures (AV/EPP/14 and AV/AAGD/14 produced by Dabur Ayurvet Limited in India), which contain Eucalyptus globulus oil along with several other plant oils, have been tested on dogs to treat ectoparasites, fungal skin infections, and non-specific skin infections. While the mixtures appear to be effective, no comparative treatments were used in the studies. Also, it is unknown which plant oils in the mixtures contain the most active ingredients -- that is, the eucalyptus oil may not have been the effective ingredient in the herbal mixture (Agrawal 1997 and Bhilegaonkar and Maske 1997).
Many in vitro and a few in vivo tests have been conducted with extracts and oils of different Ecualyptus species. Following is a summary of some of the specific activities identified for Eucalyptus spp.:
- Eucalyptus oil (species not specified)
- antibacterial -- concentrations ranging from 0.16 to >20 microliters/ml inhibited 22 bacterial strains in vitro.
- antifungal -- concentrations ranging from 0.25 to 10 microliters/ml inhibited 11 fungi in vitro.
- repellent activity -- effective in repelling Pediculus humanus (human body louse), with citronellal being the active compound.
- Isolated compounds from Eucalyptus spp.
- ursolic acid -- exhibited anticholestatic activity and protected against hepatotoxicity (induced by paracetamol and galactosamine) in rats.
- euglobals -- were shown to have antitumor properties.
- E. camaldulensis -- ethanol extracts showed activity against bacteria and fungi.
- E. globulus
- antimicrobial -- essential oil has limited activity against Paenibacillus larvae, the causal agent of American foulbrood disease and methanol extracts of leaves at concentrations of 10mg/ml or less inhibited Staphylococcus aureus, Escherichia coli, Pseudomonas aerginosa, and Candida albicans in vitro.
- antispasmodic -- water/alcohol extracts of leaves decreased smooth muscle contractions in vitro.
- antifungal -- the oil is believed to have limited antifungal activity, although water extracts were not effective against the fungi Epidermophyton floccosum, Microsporum canis, and Trichophton mentagrophytes.
- E. macarthurii and E. riwagum -- mixed results were obtained when the essential oils were tested for antibacterial and antifungal activity in vitro.
- E. citriodora
- antiinflammatory -- alcohol extracts of the leaves given to mice at concentrations of 100, 300, and 1,000 mg/kg BW inhibited induced paw oedema in mice by 12, 22, and 49%, respectively.
- antibacterial and antifungal activity -- essential oil inhibited Bacillus megaterium, Staphylococcus aureus, Escherichia coli, Candida albicans, Aspergillus niger, and Zygorrhynchus spp. in vitro and inhibited ringworm causing fungi.
Listed below are some uses of E. globulus in humans:
- Anodyne -- China
- Antimalaria -- Honduras
- Antiseptic -- China, Honduras, and Turkey
- Arthritis -- China
- Astringent -- Turkey
- Bronchitis -- Mexico and U.S.
- Burn -- China
- Cancer -- Australia (Aborigine), China, Spain, and U.S.
- Catarrh -- Mexico, Turkey, and U.S.
- Cold -- Honduras and Mexico
- Cough -- Honduras
- Deodorant -- Turkey
- Diabetes -- Mexico
- Dysentery -- China
- Expectorant -- Honduras
- Fever -- China, Honduras, and Turkey
- Flu -- Mexico
- Gingivitis -- U.S.
- Hemostat -- Turkey
- Insect repellent -- Honduras and Venezuela
- Laryngitis -- Mexico
- Malaria -- Spain and Venezuela
- Miasma -- Venezuela
- Skin diseases (ringworm) -- Guatemala
- Sores, wounds -- China
- Spasms -- Honduras and Turkey
- Stimulant -- Turkey
- Tuberculosis -- China
- Tumors (Breast)
Not all of the references in the list below were used in writing this web page. Some references could not be easily located and others were in non-romance languages. They are included here so that a more complete resource list is available for those interested in the subject area.
- Adhikari, S.R., R. Shakya, H.D. Shrestha, D.M. Shakya, and D. Shrivastava. 1992. Variation of essential oil and eucalyptol content of randomly selected Eucalyptus camaldulensis trees. Banko Janakari, 3 (4): 3-7.
- Agrawal, A.K. 1997. Therapeutic efficacy of a herbal gel for skin affections in dogs. Indian Veterinary Journal, 74 (5): 417-419.
- Alippi, A.M., J.A. Ringuelet, E.L. Cerimele, M.S. Re, and C.P. Henning. 1996. Antimicrobial activity of some essential oils against Paenibacillus larvae, the causal agent of American foulbrood disease. Journal of Herbs, Spices & Medicinal Plants, 4 (2); 9-16.
- Alkofahi, A., R. Batshoun, W. Owais, and N. Najib. 1997. Biological activity of some Jordanian medicinal plant extracts. Part II. Fitoterapia, 68 (2): 163-168.
- Argilagos, G.B., B.V. Perez, M.M. Izada, O.R. Garcia, Y.L. Mas, and H.R. Torrens. 1993. Effect of an eucalyptus based drug (Eucabev) on enterotoxigenic E. coli F5 receptors. Revista de Produccion Animal, 7 (3): 135-136.
- Atta, A.H. and A. Alkofahi. 1998. Anti-nociceptive and anti-inflammatory effects of some Jordanian medicinal plant extracts. Journal of Ethnopharmacology, 60 (2): 117-124.
- Beckstrom-Sternberg, Stephen M., James A. Duke, and K.K. Wain. "The Ethnobotany Database." http://probe.nalusda.gov:8300/cgi-bin/browse/ethnobotdb. (ACEDB version 4.3 -data version July 1994).
- Beckstrom-Sternberg, Stephen M., and James A. Duke. "The Phytochemical Database." http://probe.nalusda.gov:8300/cgi-bin/browse/phytochemdb. (ACEDB version 4.3 - data version July 1994).
- Bennet-Jenkins, Eva and C. Bryant. 1996. Novel sources of anthelmintics. International Journal for Parasitology, 26 (8/9): 937-947.
- Bhilegaonkar, N.G. and D.K. Maske. 1997. Efficacy of a herbal compound AV/EPP/14 against ectoparasites of dogs. Indian Veterinary Journal, 74 (10): 869-870.
- Caceres, A., B.R. Lopez, M.A. Giron, and H. Logemann. 1991. Plants used in Guatemala for the treatment of dermatophytic infections. 1. Screening for antimycotic activity of 44 plant extracts. Journal of Ethnopharmacology, 31: 263-276.
- Chalchat, J.C., A. Muhayimana, J.B. Habimana, J.L. Chabard. 1997. Aromatic plants of Rwanda. II. Chemical composition of essential oils of ten Eucalyptus species growing in Ruhande Arboretum, Butare, Rwanda. Journal of Essential Oil Research, 9 (2): 159-165.
- Chalchat, J.C., J.L. Chabard, M.S. Gorunovic, V. Djermanovic, and V. Bulatovic. 1995. Chemical composition of Eucalyptus globulus oils from the Montenegro coast and east coast of Spain. Journal of Essential Oil Research, 7 (2): 147-152.
- Chanegriha, N., Cherif Y. Foudil, A. Baailouamer, and B.Y. Meklati. 1998. Antimicrobial activity of Algerian cyprus and eucalyptus essential oils. Rivista Italiana EPPOS, No. 25: 11-16.
- Cheeke, P.R. 1998. Natural Toxicants in Feeds, Forages, and Poisonous Plants, 2nd ed. Interstate Pubs., IL.
- Cheng, Q. and J.K. Snyder. 1988. Revised structures of robustadials A and B from Eucalyptus robusta. Journal of Organic Chemistry, 53(19): 4562-4567.
- Darben, T., B. Cominos, and C.T. Lee. 1998. Topical eucalyptus oil poisoning. Australasian Journal of Dermatology, 39 (4): 265-267.
- Dellacassa, E., P. Menendez, P. Moyna, and P. Cerdeiras. 1989. Antimicrobial activity of Eucalyptus essential oils. Fitoterapia, 60 (6): 544-546.
- Esparza, Borges H. and Marquez A. Ortiz. 1996. Therapeutic efficacy of plant extracts in the treatment of bovine endometritis. Acta Horticulturae, No. 426: 39-46.
- Giron, L.M., G.A. Aguilar, A. Caceres, and G.L. Arroyo. 1988. Anticandidal activity of plants used for the treatment of vaginitis in Guatemala and clinical trial of a Solanum nigrescens preparation. Journal of Ethnopharmacology, 22 (3): 307-313.
- Gobel, H., G. Schmidt, M. Dworschak, H. Stolze, and D. Heuss. 1995. Essential plant oils and headache mechanisms. Phytomedicine, 2 (2): 93-102.
- Gobel, H., G. Schmidt, and D. Soyka. 1994. Effect of peppermint and eucalyptus oil preparations on neurophysiological and experimental algesimetric headache parameters. Cephalalgia, 14 (3): 228-234.
- Gundidza, M., F. Chinyanganya, and S. Mavi. 1993. Antimicrobial activity [against 12 bacteria and 7 fungi] of the essential oil from Eucalyptus maidenii. Planta Medica, 59 (7): A705.
- Hajji, F., Tetouani S. Fkih, and Elaraki A. Tantaoui. 1993. Antimicrobial activity of twenty-one Eucalyptus essential oils. Fitoterapia, 64 (1): 71-77.
- Hmamouchi, M., Elaraki A. Tantaoui, Safi N. Es, and A. Agoumi. 1990. Elucidation of the antibacterial and antifungal properties of the essential oils of Eucalyptus. Plantes Medicinales et Phytotherapie, 24 (4): 278-289.
- House, P., S. Lagos-Witte, and C. Torres. 1992. Manual Popular de 50 Plantas Medicinales de Honduras, 3rd Ed. Guaymuras, Honduras.
- Izzo, A.A., R. Capasso, F. Senatore, S. Seccia, and P. Morrica. 1996. Spasmolytic activity of medicinal plants used for the treatment of disorders involving smooth muscles. Phytotherapy Research, 10 (Supplement 1): S107-S108.
- Joshi, H.C., M. Kumar, M.J. Saxena, and M.B. Chhabra. 1996. Herbal gel for the control of subclinical mastitis. Indian Journal of Dairy Science, 49 (9): 631-634.
- Lee, InKyoung, BongSik Yun, JongPyung Kim, SungHyun Chung, GyuSeop Shim, and IckDong Yoo. 1998. Antioxidative compounds isolated from the stem bark of Eucalyptus globulus. Korean Journal of Pharmacognosy, 29 (3): 163-168.
- Lis, Balchin M., S.G. Deans, and E. Eaglesham. 1998. Relationship between bioactivity and chemical composition of commercial essential oils. Flavour and Fragrance Journal, 13 (2): 98-104.
- Lis, Balchin M., S. Deans, and S. Hart. 1996. Bioactivity of New Zealand medicinal plant essential oils. Acta Horticulturae, No. 426: 13-30.
- Manual Popular de Plantas Medicinales Comunes de la Costa Atlantica de Honduras. 1996. Programa Tramil-Centroamérica/ENDA CARIBE.
- Mizrahi, I., Traverso J. Rodriguez, M.A. Juarez, A.L. Bandoni, L. Muschietti, and C. van Baren. 1997. Composition of the essential oil of Eucalyptus dunnii Maiden growing in Argentina. Journal of Essential Oil Research, 9 (6): 715-717.
- Mumcuoglu, K.Y., R. Galun, U. Bach, J. Miller, and S. Magdassi. 1996. Repellency of essential oils and their components to their components to the human body louse, Pediculus humanus humanus. Entomologia Experimentalis et Applicata, 78 (3): 309-314.
- Murata, M., Y. Yamakoshi, S. Homma, K. Aida, K. Hori, and Y. Ohashi. 1990. Macrocarpal A, a novel antibacterial compound from Eucalyptus macrocarpa. Agricultural and Biological Chemistry, 54 (12): 3221-3226.
- Navarro, V., M.L. Villarreal, G. Rojas, and X. Lozoya. 1996. Antimicrobial evaluation of some plants used in Mexican traditional medicine for the treatment of infectious diseases. Journal of Ethnopharmacology, 53 (3): 143-147.
- Nikogosyan A.N., G.S. Grigoryan, A.G. Safaryan, S.K. Khachatryan, and I.G. Sokhikyan. 1988. The effect of medicinal plants on some blood indices of intact lambs. Biologicheskii Zhurnal Armenii, 41 (6): 525-528.
- Ou, M., N.S. Wang, Y.W. Li, X.Q. Chen, X.C. Liu, H.S. Lou, and C. Lu. 1992. Chinese-English manual of commonly-used [preparations] in traditional Chinese medicine.
- Pages, N., G. Fournier, F. Le Luyer, and M.C. Marques. 1990. Essential oils and their teratogenic potential: essential oil of Eucalyptus globulus. Preliminary study on mice. Plantes Medicinales et Phytotherapie, 24 (1): 21-26.
- Pattnaik, S., V.R. Subramanyam, and C. Kole. 1996. Antibacterial and antifungal activity of ten essential oils in vitro. Microbios, 86 (349): 237-246.
- Pavneesh, Madan, S.K. Pandey, M.B. Chhabra, and M.J. Saxena. 1996. Efficacy of a topical herbal gel for mastitis control. International Journal of Animal Sciences, 11 (2): 289-291.
- Shukla, B., P.K.S. Visen, G.K. Patnaik, S.C. Tripathi, R.C. Srimal, R. Dayal, and P.C. Dobhal. 1992. Hepatoprotective activity in the rat of ursolic acid isolated from eucalyptus hybrid. Phytotherapy Research, 6 (2): 74-79.
- Siddiqui, B.S., Farhat, Begum Sabira, and Siddiqui Salimuzzaman. 1997. Isolation and structural elucidation of acylated pentacyclic triterpenoids from the leaves of Eucalyptus camaldulensis var. obtusa. Planta Medica, 63 (1): 47-50.
- Takasaki, M., T. Konoshima, M. Kozuka, and H. Tokuda. 1995. Anti-tumor-promoting activities of euglobals from Eucalyptus plants. Biological & Pharmaceutical Bulletin, 18 (3): 435-438.
- Tandon, S.K., S. Chandra, S. Gupta, and Jawahar Lal. 1995. Pharmacological effects of alcoholic extract of Eucalyptus citriodora leaves. Indian Veterinary Journal, 72 (7): 762-764.
- Tibballs J. 1995. Clinical effects and management of eucalyptus oil ingestion in infants and young children. Medical Journal of Australia, 163 (4): 177-180.
- Whitman, B.W. and H. Ghazizadeh. 1994. Eucalyptus oil [from Eucalyptus spp. including E. globulus]: therapeutic and toxic aspects of pharmacology in humans and animals. Journal of Paediatrics and Child Health, 30 (2): 190-191.
- XuanDung Nguyen and Nghia Thin Nguyen. 1992. Some important medicinal and aromatic plants from Vietnam. Recent advances in medicinal, aromatic and spice crops (Volume 2). International conference held on 28-31 January 1989, at New Delhi, India: 299-308.
- Yadav, P. and N.K. Dubey. 1994. Screening of some essential oils against ringworm fungi. Indian Journal of Pharmaceutical Sciences, 56 (6): 227-230.