Gmelina arborea
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Gmelina arborea Common Names: Gmelina, Beechwood, White Teak, Yemane,
Parrots Beak Scientific
Classification Kingdom: Plantae Clade: Tracheophytes Clade: Angiosperms Clade: Eudicots Clade: Asterids Order: Lamiales Family: Lamiaceae Genus: Gmelina Species: G. arborea Synonyms: Gmelina arborea var.
canescens Haines, Gmelina arborea var.
glaucescens C.B.Clarke, Gmelina rheedei Hook. [Illegitimate], Gmelina sinuata Morphological Description Gmelina arborea is a fast-growing, deciduous tree that typically reaches
heights of 20–30 meters, with some specimens exceeding 40 meters in optimal
conditions. Its key morphological features include: · Bark: Thin, grayish-yellow to whitish, smooth in young trees,
developing shallow fissures and exfoliating in flakes as it matures; exudes a
yellowish latex when cut. · Leaves: Broadly ovate, opposite, heart-shaped at the base (10–25 cm
long, 8–20 cm wide), glossy green above, paler beneath, with a softly pubescent
texture when young. · Flowers: Bright yellow to orange-yellow, tubular, arranged in dense
axillary or terminal racemes (15–30 cm long); corolla 4–5 cm long, faintly
fragrant. · Fruit: Fleshy drupe, ovoid (2–3 cm long), green when immature,
turning yellow-orange when ripe, containing 1–2 hard seeds within a sweetish,
edible pulp. The tree’s bole is
straight and cylindrical, often developing buttress roots in older individuals,
enhancing stability in tropical soils (Warrier et al., 2021). Distribution and Habitat Gmelina arborea is native to Southeast Asia and parts of South Asia,
spanning latitudes from 30°N to 10°S. Its natural range includes: · Southeast Asia: India, Myanmar, Thailand, Indonesia,
Philippines (annual rainfall 1,000–3,000 mm). · Introduced Regions: Widely planted in tropical Africa (e.g.,
Nigeria, Ghana), Central and South America (e.g., Costa Rica, Brazil), and
northern Australia (altitude 0–1,500 m). It thrives in tropical
rainforests, moist deciduous forests, and savanna woodlands, preferring
well-drained, loamy soils (pH 5.0–7.5). Due to its rapid growth and
adaptability, it is extensively cultivated in plantations and agroforestry
systems worldwide (Lauridsen & Kjaer, 2002). Ethnopharmacology Gmelina arborea, commonly known as beechwood or white teak, is a fast-growing
deciduous tree widely used in traditional medicine across Asia and Africa.
Various parts of the plant—bark, leaves, roots, and fruits—possess significant
medicinal properties. It is traditionally used for its anti-inflammatory,
antimicrobial, antioxidant, analgesic, and antipyretic effects. The bark and
root are used in treating fevers, digestive disorders, diabetes, and rheumatic
pain, while the leaves are applied to wounds, ulcers, and skin infections. The
fruit is considered a liver tonic and is used in some systems of medicine to
manage jaundice and hepatitis. Active phytochemicals such as lignans,
flavonoids, iridoid glycosides, and tannins contribute to its therapeutic
potential. Scientific studies support many of its traditional uses, especially
its antioxidant and hepatoprotective effects, making it a valuable plant in
herbal medicine. · Anti-inflammatory and Analgesic: Bark decoctions are used in India for
stomach issues and joint pain. Kulkarni et al. (2013) found that methanolic
bark extracts (500 mg/kg) reduced carrageenan-induced paw edema in rats by
31.21%, comparable to standard anti-inflammatory drugs. · Wound Healing: Leaf and root pastes treat wounds and ulcers in Nigeria and
Thailand. · Sedative and Antiepileptic: Roots are used in Ayurveda for epilepsy
and anxiety. Acharya et al. (2015) demonstrated that methanolic stem bark
extracts (500 mg/kg) reduced pentylenetetrazole-induced convulsions in mice by
50%, indicating anticonvulsant potential. · Antimicrobial: Bark and leaf extracts combat skin infections. Idowu, et al.
(2024) confirmed that The methanol and ethyl acetate extracts of the plant
showed good antibacterial activities (18 mm inhibitory zones and MIC and MBC
12.5–100mg/mL) against P. aeruginosa ATCC 27853 and S. aureus ATCC 6571.,
supporting traditional use. · Antidiabetic: In Ghana, root decoctions manage diabetes. Attanayake (2016)
showed that Aqueous bark extract of G.
arborea (1.00 g/kg) and glibenclamide as the standard drug (0.50 mg/kg)
were administered orally using a gavage to STZ diabetic rats (65 mg/kg, ip) for
30 days. The antidiabetic mechanisms of aqueous extract of G. arborea (1.00 g/kg) were determined at the end of the
experiment. The fasting blood glucose concentration was significantly lowered
and the serum insulin and C-peptide concentrations were increased by 57% and
39% in plant extract treated rats on day 30, respectively (p < 0.05). The
histopathology and immunohistochemistry results of the plant extract treated
group showed a regenerative effect on β-cells of the pancreas in diabetic rats.
In addition, serum lipid parameters were improved in G. arborea extract treated
diabetic rats. Phytochemicals like
lignans (e.g., gmelinol), flavonoids (e.g., luteolin), and iridoid glycosides
contribute to these effects (Warrier et al., 2021). ⚠ Toxicity Profile: Limited toxicity data exist for Gmelina arborea. High doses of leaf extracts (>2,000 mg/kg)
in rats showed mild hepatotoxicity, possibly due to iridoid glycosides. The
latex is a skin irritant. Traditional use is generally safe, but caution is
advised with prolonged high doses (Kulkarni et al., 2013). Additional Uses · Timber: The lightweight wood (density 450–590 kg/m³) is prized for
furniture, plywood, matchsticks, and pulp, valued for its durability and ease
of carving (Lauridsen & Kjaer, 2002). · Agroforestry: Planted for shade, fodder, and soil stabilization; its deep
roots reduce erosion and improve fertility (Mahendru et al., 2024). · Biofuel: High biomass yield (20–30 tons/ha/year) makes it a candidate
for biofuel production, with seed oil showing potential for biodiesel (Uzoh et
al., 2014). References
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