Botany
A medium-sized tree, the leaves in whorls of three, oblong-obovate, 10 to 30 cm long, 5 to 7 cm wide, pointede at both ends, and shot-stalked. Flowers are small, yellowish-white, on short, terminal cymes. Calyx is small, the corolla tubular, 1 to 1.5 cm long, lobed towards the top. Fruit is a double follicle, pendant, long and slender, 20 to 40 cm long. Seeds are small and flat, with deep-brown hairs.

Distribution
In open forests and thickets at low and medium altitudes throughout the Philippines.

Chemical constituents and properties
The bark yields four alkaloids: macralstonine, macralstonidine, villalstonine and a base M.
Febrifuge, tonic, aphrodisiac, emmenagogue, vulnerary.
Reported antipyretic, antibacterial, antifungal and antiinflammatory.

Constituents
Total alkaloids 0.99% - macrophylline, macrastonine, macalstonidine, villastonine, monomeric indole alkaloids, dimethoxy alstophylline.

Parts used and preparation
Fresh leaves, bark.

Uses
Folkloric
• Crush leaves, mix with a little coconut oil, warm and apply on affected area applied to sprains, bruises and contusions.
The bark, in powder, decoction, tincture, or infusion is used a febrifuge, tonic, aphrodisiac, antidysentery, emmenagogue, anticholeric and vulnerary.
• In India, decoction of leaves and stem bark widely used to treat stomachache, skin diseases, urinary infections.

Studies
• Antimicrobial activity of Alstonia macrophylla: a folklore of bay islands: The extract studies showed antimicrobial activity against various strains of Staph aureus, Stapyh saprophyticus, Strep faecalis, Proteum mirabilis, Trichophyton rubrum, Tricophyton mentagrophytes and Microsporum gypseum.
• CNS Depressant Activities: An ethnomedicine of Onge of Bay Islands : Study showed of Alstonia macryphylla leaves caused a significant reduction in spontaneous activity, decrease in exploratory behavioral pattern, reduction in muscle relaxant activity. Crude leaf extract showed the presence of tannin, triterpenoid, flavonoid, sterol and alkaloids.
• Cytotoxic activity of indole alkaloids from Alstonia macrophylla : 13 alkaloids isolated from the root bark of Alstonia macrophylla and a semisynthetic bisindole was studied for cytotoxic activity against two human lung cancer cell lines. The bisindoles were found to possess pronounced activity against cancer cell lines.
• Antipyretic Activity / Ursolic Acid: Study showed the methanol extract to possess a significant antipyretic effect. Phytochemical testing yielded ursolic acid as a major constituent, with its diverse pharmacologic actions – antiinflammatory, antihistamine and analgesic.
• Antiinflammatory Activity: Study of methanolic extract of dried leaves of Alstonia macrophylla showed significant dose-dependent antiinflammatory activity in a rat study, comparable to that of standard drug Indomethacin.
• Sperm-motility Inhibition: Study showed potent inhibition of sperm motility and a potential use as vaginal contraceptive.
• Antiplasmodial / Vasorelaxant: Study yielded four new alkaloids, alstiphyllanines A-D which showed moderate antiplasmodial activity against Plasmodium falcifarum and vaorelaxant activity against phenylephrine-induced contraction of isolated rat aorta.
• Chemomodulatory: Chemomodulatory activity of AS extract was studied in combination with berberine Hcl (BCL), a topoisomerase inhibitor, which showed antineoplastic benefits in the early stages.
• Antibacterial: In a study of 12 extracts from 6 medicinal plants, the crude ethanolic extracts from the bark of Alstonia macrophylla showed potential antibacterial effect against S aureus.
• Antiprotozoal: Study showed three alkaloids from A macrophylla to possess significant activity against E histolytica and Plasmodium falcifarum, although less in potency than emetine and chloroquine.

Availability
Wild-crafted.