2571

12(3): Medicinal and poisonous plants 3

Ehretia philippinensis A.DC.

Prodr. 9: 504 (1845).

BORAGINACEAE

2n = unknown

Philippines: alibungog (Cebu Bisaya), bayukon (Tagalog), talibobong (Bikol).

Ehretia philippinensis is restricted to the Philippines (Luzon, Mindanao and Palawan).

The stem bark of Ehretia philippinensis, scraped into a pulp, and the fresh leaves are commonly used as a medicine. Usually they are applied as a poultice to painful swellings or infected wounds, acting as an emollient or as an anti-inflammatory. A decoction of the stem bark or the roots is widely taken against diarrhoea or dysentery accompanied by tenesmus. It is also used as a mouthwash to treat toothache.
Ehretia resinosa Hance (synonym: Ehretia navesii S. Vidal) from Taiwan and the Philippines is used in the Philippines as a febrifuge. A preparation containing an extract of Ehretia resinosa has been patented for skin care; it is credited with anti-inflammatory, wound healing and skin improvement effects.
The leaves of Ehretia acuminata R.Br. (synonym Ehretia ovalifolia Hassk.), occurring from China to Australia, are pounded and applied to swellings. The fruit is edible.
The wood of Ehretia is only used on a local scale, as it is not very strong, and the leaves are used for fodder.

In tests with mice, a crude stem bark extract of Ehretia philippinensis was found to be moderately toxic when administered intraperitoneally and slightly toxic when administered orally. A decrease in motor activity and slight analgesia were observed, but no further significant physiological changes. The butanol and ethylacetate fractions of the methanol extract of stem bark showed antihistamine release activity against compound 48/80, a potent histamine liberator. Rosmarinic acid was isolated and identified as the active constituent. Five cyanoglucosides were also isolated: ehretiosides A1, A2, A3 and B, and simmondsin. A stem bark extract was also tested for anti-inflammatory activity using different animal models. The extract was found to be equally potent as an aspirin reference.
From the stem bark of Ehretia acuminata two 2-methoxyhydroquinone glucosides, a sesquilignan and a neolignan were isolated, as well as four lignans.

A small tree up to 5 m tall; branches crooked, young branches brown to greenish-brown, glabrous. Leaves alternate, simple, broadly lanceolate to oblong-lanceolate, 4—15 cm x 1.5—7.5 cm, base attenuate, obliquely truncate, apex acute or acuminate, margins entire, glabrous to subglabrous; petiole 1—3 cm long; stipules absent. Inflorescence axillary or on short lateral branches, corymbose, many-flowered. Flowers bisexual, regular, 5-merous, fragrant; pedicel short; calyx broadly cup-shaped, 1.3—1.5 mm x 1.3—2 mm, usually glabrous, lobes triangular; corolla 3.5—4(—5) mm long and c. 5 mm in diameter, white, tube cylindrical-campanulate, lobes more or less reflexed, broadly rounded, up to 2.5 mm long; stamens inserted on corolla, long exserted; ovary superior, 2-celled with 2 ovules in each cell, style 4.5—6 mm long, forked for 0.8 mm, stigmas capitate. Fruit a subglobose drupe 3—4 mm in diameter, orange or reddish, with 2 separate 2-seeded pyrenes.
Ehretia comprises about 50 species and occurs in the tropics and subtropics of Africa, Asia, Australia and America (3 species). In Malesia, 12 species are found. Ehretia is sometimes placed in the small family Ehretiaceae.

Ehretia philippinensis occurs in forests along rivers and in secondary growth, at low and medium altitudes.

Although Ehretia philippinensis only occurs in the Philippines it is rather common there, and there are no records of overexploitation.

Ehretia philippinensis has compounds with interesting biological activities, which merit further research. The wound-healing and anti-inflammatory properties are of special interest and comparable to those of Carmona retusa (Vahl) Masam., which is an important medicinal plant in the Philippines. Perhaps Ehretia philippinensis can be developed as a supplement to this species.

[247]Flora Malesiana (various editors), 1950—. Foundation Flora Malesiana. Rijksherbarium/Hortus Botanicus, Leiden, the Netherlands.
[760]Quisumbing, E., 1978. Medicinal plants of the Philippines. Katha Publishing Co., Quezon City, the Philippines. 1262 pp.
[858]Simpol, L.R., Otsuka, H., Ohtani, K., Kasai, R. & Yamasaki, K., 1994. Nitrile glucosides and rosmarinic acid, the histamine inhibitor from Ehretia philippinensis. Phytochemistry 36(1): 91—95.

[227]Ejerta, C.I. & Solevilla, R.C., 1988. Determination of the acute toxicity effects of five Philippine plants. Acta Manilana 37(10): 85—92.
[1037]Yoshikawa, K., Kageyama, H. & Arihaa, S., 1995. Phenolic glucosides and lignans from Ehretia ovalifolia. Phytochemistry 39(3): 659—664.
[1042]Ysrael, M.C. & Croft, K.D., 1988. A biochemical assessment of the anti-inflammatory activity of compounds from Philippine medicinal plants. Acta Manilana 37: 65—70.

G.H. Schmelzer

Schmelzer, G.H., 2003. Ehretia philippinensis A.DC.. In: Lemmens, R.H.M.J. and Bunyapraphatsara, N. (Editors): Plant Resources of South-East Asia No 12(3): Medicinal and poisonous plants 3. PROSEA Foundation, Bogor, Indonesia. Database record: prota4u.org/prosea