Delonix regia is a large, deciduous tree with fern-like leaves. Leaves are bipinnate, slightly hairy, about 30 centimeters long. Leaflets are oblong, in 18 to 30 pairs, about 1.5 centimeters long. Flowerw are large, showy, red or red and yellow, up to 12 centimeters across. Pods are pendulous, elongate, woody, compressed, and up to 50 centimeters long.
- Introduced to the Philippines during the early Spanish period.
- Planted along roadsides and gardens.
- Phytochemical screening yielded sterols, triterpenoids, phenolic compounds, and falvonoids.
- Bark yields ß-sitosterol, saponins, alkaloids, carotene, hydrocarbons phytotoxins, and flavonoids.
- Flowers yielded carotenoides, tannins, saponins, flaonoids, steroids, alkaloids, and ß-sitosterol.
- Leaves yield lupeol and ß-sitosterol.
- Stem bark yielded four triterpenes: lupeol, epilupeol, ß-sitosterol, stigmasterol, and an aromatic compound p-methoxybenzaldehyde.
- Antimicrobial, antioxidant, anti-diarrhea, hepatoprotective, anti-inflammatory.
Flowers, leaves, stem, bark.
- No reported folkloric medicinal use in the Philippines.
- In Bangladesh folk medicine, used for the treatment of diabetes.
• Antibacterial: Delonix regia was one of 12 medicinal plants studied for antibacterial activity. The methanol extracts showed more activity than the aqueous extracts for all 12 plants studied. The most susceptible bacterial were S. subtilis, followed by S. epidermis.
• Anti-Inflammatory: Study evaluated the anti-inflammatory activity of leaves using a carrageenan-induced rat paw edema and cotton pellet granuloma models. Results showed significant anti-inflammatory activity in both models.
• Flowers Constituents / Phenols and Flavonoids: Study was done to estimate the total phenolic and flavonoidal content of the flowers. Results showed the flowers to contain significant amounts of phenols and flavonoids, with the total phenolic content to be much higher than the flavonoidal content.
• Hepatoprotective / Cytotoxic: Study of an ethanolic extract isolated three sterols (stigmasterol, ß-sitosterol, and its 3-O-gucoside), a triterpene (ursolic acid) and four flavonoids (quercetin, quercitrin, isoquercitrin, and rutin), plus an amino acid. Results showed cytotoxic activity against human liver cancer cell line (HEPG2). It also showed hepatoprotective activity against CCl4-induced hepatic damage, attributed to the free radical scavenging property of the favonoids.
• Antidiabetic: Study of an methanol extract of leaf in glucose-induced hyperglycemic mice showed significant oral hypoglcemic activity.
• Antimicrobial: In antimicrobial screening, a dichlormethane soluble fraction of a methanolic extract showed strong inhibition of S. paratyphi growth, with moderate inhibition of S. typhi, S. aureus and S. dysenteriae. Other fractions showed inhibition of C. albicans, S. cerevisiae.
• Antidiarrheal: Evaluation of ethanolic extract of D. regia for in vivo anti-diarrheal activity in experimentally induced diarrhea, prostaglandin Ez-induced enteropooling and charcoal-induced motility tet in rats showed dose-dependent antidiarrheal properties.
• Seed Mucilage / Tablet Binder: Seeds of plant contain glucomannose. Mucilage obtained from the seeds were used in the preparation of calcium carbonate tablets. Resultw showed the endospermic mucilage obtained from the seeds possesses comparable binding properties.