Alagau is a small hairy tree,
3 to 8 meters high. Leaves are ovate to broadly ovate, 10 to 20
centimeters long, with broad, rounded, or somewhat heart-shaped base, and pointed
tips. Under surface of the blade is usually covered with
short hairs, aromatic when crushed. Flowers are greenish-white
or nearly white, 4 to 5 millimeters long and borne on terminal inflorescences
(cymes) 8 to 20 centimeters in diameter. Fruit is fleshy, dark purple, rounded,
about 5 millimeters in diameter.
- Common In thickets and
secondary forests at low altitudes from the Batan Islands and northern Luzon to Mindanao, in most islands and provinces.
- Reported in Nepal, India to Myanmar, China, Taiwan, Indo-China, Thailand, Japan, Malaysia and Australia.
- Leaves do not contain
alkaloid, tannin, saponin or cyanogenetic substance.
- Leaves yield 0.02 percent yellowish-green essential oil with a characteristic
- Study isolated two iridoid glycosides: 2″- and 3″-caffeoyl-6-α-l-rhamnopyranosylcatalpol respectively. (6)
- Study isolated ten 10-O-acylated derivatives of catalpol and asystasioside E from a 1-butanol-soluble fraction of a methanol extract of leaves.
- Study isolated acyclic monoterpenediol diesters, premnaodorosides A, B, and C, together with
phenethyl alcohol glycosid4es, verbscoside, isoacteoside, bioside (decaffeoylverbascoside) and cistanoside F. (10)
- Sudorific, pectoral, carminative.
- Studies have shown antimicrobial, cardiotonic, anticoagulant, hepatoprotective, antitubercular, antitumor properties.
Leaves and flowering tops,
fresh or dried.
Young leaves used in the cooking of "paksiw" and "bopis."
· In the Philippines, sugared
decoction of leaves with a little "calamansi" as tea helps loosen up phlegm and effective for coughs.
· Decoction of fresh leaves used for vaginal irrigation.
· Decoction of leaves for fever and colds, cough and bronchitis, fever blisters of the lips and stomachaches.
· "Kochoi," a local patent preparation, is claimed to benefit tuberculosis.
· Decoction of leaves used for flatulence (gas pains) in adults; in children, crushed leaves mixed with a little coconut or sesame oil are applied to the abdomen.
· Crushed leaves applied to forehead and temples for headaches.
· Leaf decoction has been used for tuberculosis.
· Roots are chewed and the saliva swallowed for cardiac troubles.
· Infusion of leaves is carminative.
· Decoction of roots, leaves, flowers, and fruits used as sudorific, pectoral, and carminative.
· Decoction of shoots used as parasiticide.
· Decoction of leaves used for bathing infants; also used as treatment for beriberi.
· Extract of leaves for cleaning wounds and for ticks and fleas.
· Leaves applied over the bladder facilitates urination.
• Pito-pito: Leaves are one of the
seven ingredients of the popular herbal Filipino tea blend – alagaw,
banaba, bayabas, pandan, manga, anis and cilantro. (See: Pito-Pito)
• Ethno-Veterinary / Fumigation: Dried leaves and bark used for fumigation of poultry houses, reportedly effective for getting rid of lice and ticks. (11)
• Decoction of leaves and flowering tops used as vaginal wash
or douche; antiseptic properties make it useful for cleansing and incorporation
with bath-care products.
• Collagen Network / Acetoside: Study of methanol extract of leaves of Premna
odorata exhibited a promotion of collagen network formation by M cells
and isolated acetoside, an phenylethanoid with a variety of biological
activities. Acetoside may contribute to wound healing. (1)
• Anti-Viral Activity: Study of 61 medicinal plants in Malaysia showed P odorata was 1 of 11 plants to show selective activity against vesicular stomatitis (VSV) viruses. (2)
• In-vitro Photo-Cytotoxic Activity: A study of 155 extracts from 93 species of plants in Malaysia screened for in vitro photo-cytotoxic activity using a human leukemia cell line, P odorata was one of 29 plants that was able to reduce in vitro cell viability by more than 50% when exposed to broad spectrum light. (3)
• Hepatoprotective / Cytotoxic Activity: Study showed the alcoholic extract with significant hepatoprotective activity evidenced by decrease of serum enzymes, bilirubin and lipid peroxidation, comparable to drug silymarin. It also exhibited significant in-vitro cytotoxic activity. Results showed the alcoholic extract not only as an effective hepatoprotective agent, but with also significant antitumor activity. (4)
• Antiparasitic Activity: In a study of 18 medicinal plants in New Caledonia evaluated in vitro against several parasites, Scaevola balansae and Premna serratifolia were the most active against Leishmania donovani. (5)
• E. Coli Inhibitory Activity: Various extracts were tested against E. Coli. A 100% ethanol bark extract showed activity against E. coli, while aqueous extract concentrations were inactive against E. coli. However, the inhibitory activity could not compete with ciprofloxacin. (7)
• Diosmetin / Acacetin: Study of leaves isolated diosmetin and acacetin. Diometin has been commercially available as the glycoside diosmin, used as a vasotonic agent for the treatment of varicose veins, hemorrhoids and other venous diseases.
• Flavones / Antimicrobial / Anti-Inflammatory / Chemopreventive: Partitioning and fractionation of crude ethanolic extract of leaves yielded two amorphous powders identified as flavone aglycones — acacetin and the non-widespread diosmetin. Earlier studies reported antimicrobial, anti-inflammatory, and chemopreventive activities. (8)
• Silver Nanoparticles / Anti-Cancer Activity / Leaves: Study reports the biosynthesis of silver nanoparticles using an ethanolic leaf powder extract of Premna serratifolia L. and its anticancer activity in carbon tetrachloride-induced liver cancer in Swiss albino mice. The silver NP were effective in treating liver cancer in mice when compared with P. serratifolia leaf extract with isoleucine. (12)
• Antitubercular Constituents / Leaves: Study evaluated the antitubercular property of crude extract and sub-extracts of leaves and isolated the bioactive principles from active fractions. Crude methanolic extract and sub-extracts showed poor inhibitory activity against MTb H37Rv. However, increased inhibitory potency was seen from fractions eluted from the DCM extract. Purification of the most active fraction yielded 1-heneicosyl formate (1), 4:1 mixture of β-sitosterol (2), stigmasterol (3) and diosmetin (4). Compound 1 had an MIC of 8 µg/mL. (14)
• Cytotoxicity Against Selected Human Cancer Cell Lines: Study evaluated the cytotoxic activities of P. odorata leaves and bark, A. camansi and G. sepium against selected human cancer cell lines. Results showed the leaves and bark hexane fractions of P. odorata and A. camansi leaves to be highly cytotoxic against the cancer cell lines. The PO bark hexane extract showed highest selectivity index for HCT116, MCF-7 and A549 cancer cell lines. (15)
• Antibacterial / Leaves: Study evaluated the antibacterial activity of leaves extract against selected human pathogens viz. Bacillus subtilis, E. coli, S. aureus. Results showed antibacterial activity with dose dependent inhibition. (16)