Eucalyptus tereticornis is a tree reaching a height of 15 meters or more in the Philippines. Trunk is usually straight and at least half the total height. Crown is large and somewhat open. Bark is grayish and peels off in thin layers. Leaves are leathery, lanceolate, somewhat sickle-shaped, and 10 to 25 centimeters i length. Peduncles are axillary or lateral and up to 1.5 centimeters long, each bearing 3 to 5 short-peduncled flowers. Flowers are white, about 1.5 centimeters in diameter, in small clusters. Fruit is obovoid or somewhat rounded, about 8 millimeters in diameter.
- Cultivated in Manila and other large towns.
- Grows vigorously in Baguio.
- Native of Australia.
- Also occurs in Papua New Guinea and India.
- Introduced to many tropical and subtropical countries in Africa, Asia, and South America.
- Particular species giving highest yields of eucalyptus oil were E. gloublus, E. tereticornis, E. polyanthemos, and E. citriodora.
- Qualitative analysis of leaf extract yielded biologically active compounds - tannins, alkaloids, flavonoids, and steroids/triterpenes.
- Methanol extract yielded ursolic acid.
- Study of essential oil yielded: total citronelal (44.8%) and geraniol (9.78%).
Two fractions were composed mostly of p-mentane-3,8-diol (18.95%) and geraniol acetate (24.34%).
- Phytochemical screening of methanol extract of bark and leaves yielded saponins tannins, steroids, and flavonoids; only the bark extract yielded cardiac glycosides. (see study below)
- Stimulant, anesthetic, antiseptic, vulnerary.
- Studies have shown antibacterial, antihyperglycemic, antioxidant, hepatoprotective, anti-inflammatory, anti-filarial properties.
- A major source of pollen and nectar, producing a caramel-flavoured honey. (13)
As bush food, gum put in solution and drunk, nectar is sucked from the flowers, and water extracted from the roots.
- Eucalyptus oil is used extensively in medicine.
- Eucalyptol is used internally and externally. Internally it is used as a stimulant. Locally, it possesses mildly antiseptic and anesthetic properties.
- As Bush medicine, used for treatment of diarrhea and dysentery. Leaves chewed and placed on wounds to facilitate healing.
- Decoction of leaves used to reduce fever and alleviate pulmonary problems. (13)
- Firewood: Wood is hard, heavy, and strong. It produces first class fuelwood and makes good charcoal.
One of the most durable of timbers, immune to termites and dry rot. Valued for underground construction, poles, posts, fiberboard and particle board.
- Pulp: Considered one of the best trees for fiber for paper pulp and rayon-grade pulp in India, Africa, the Pacific basin, and Latin America.
- Oil: Leaves are among the commercial sources of eucalyptus oil.
• Antibacterial: Study investigated the inhibitory effect of ethanol and methanol extracts of E. tereticornis leaf against three contaminant bacterial isdolaytes P. aeruginosa, B. cereus, and B. thuragenisis isolated from steel industry coolants. P. aeruginosa was inhibited the most. Results concluded ET leaf may be pursued as an antibacterial agent for prevention and delaying of contamination of coolants. (2)
• Ursolic Acid / Hepatoprotective : Study yielded ursolic acid as active material from the leaves of hybrid E. tereticornis. It showed a significant dose-dependent preventive effect in vitro against ethanol-induced toxicity in isolated rat hepatocytes. (3)
• Antioxidant / Antifungal / Essential Oil: Study showed the essential oil from foliage of E. tereticornis possesses strong antioxidant and antifungal activity. It showed strong fungitoxicity against three phytopathogenic fungi, viz., Fusarium oxysporum, Rhizoctonia colani and Heminthosporum oryzae. (4) Study of essential oil and 2 fractions against Fusarium oxysporum showed concentration-dependent fungicidal activity. (5)
• Larvicidal Against Malaria Vector / Leaf Oil: Study evaluated the essential leaf oil extract against mature and immature mosquito vector Anopheles stephensis under laboratory conditions. Extract showed strong larvicidal, pupicidal and adulticidal activity. First and second instar larvae were more susceptible to all treatments. Highest dose of 160 ppm plant extract evoked almost 100% mortality. Results suggest E. tereticornis has potential as a natural mosquitocide. (8)
• Antihyperglycemic / Anti-Inflammatory: In a nutritional model using diabetic mice, study demonstrated through in vitro assays that E. tereticornis extracts increase glucose uptake and inhibit their production in insulin resistant C2C12 and HepG2 cells, respectively. The ethyl acetate extract also reduced the expression of proinflammatory cytokines in a T2DM mouse model, which could contribute to the improvement in cell-signaling pathways in target organs as muscles and liver. Study identified 3β-Hydroxy-urs-11-en-28,13β-olide as one of the main molecules of the bioactive F2 extract and is responsible for the antihyperglycemic effects. (9)
• Antimicrobial / Bark and Leaves: Study evluated methanolic bark and leaf extracts of E. teraticornis for antimicrobial activity against common human pathogens, viz., Streptococcus mutans, Staphylococcus aureus, Escherichia coli, and yeast Candida albicans. The bark and leaf extracts showed antimicrobial potential. The methanolic back extract was more effective in inhibiting all four test pathogens. (see constituents above) (10)
• Anti-Inflammatory: Three species of Eucalyptus oil (E. citriodora, E. tereticornis, and E. globulus) showed dose dependent and time-dependent peripheral and central acting analgesic properties in rodents. E. tereticornis showed the highest anti-inflammatory action in a model of rat paw edema. The anti-infammatory action compared to dexamethasone. (11)
• Anti-Filarial / Ursolic Acid: Study of leaves isolated and characterized an anti-filarial agent, ursolic acid, as a major constituent. Ursolic acid was evaluated for anti-filarial activity against humn lymphatic filarial parasite Brugia malayi. Results suggest UA is a promising, inexpensive, widely available natural lead, with the potential for design and development into a microfilaricidal drug. (12)
- Seeds, oil in the cybermarket.