 Gen info
- Premna is a genus of flowering plants in the mint family, Lamiaceae, first described in 1771, and widespread through tropical and subtropical regions of Africa, southern Asia, northern Australia, and various islands in the Pacific and Indian oceans. (2)
- Etymology: The genus name Premna derives from Greek premmon, meaning "stump", referring to the disorderly posture of the species type. The species epithet tomentosa derives from Latin tomentosus, a, um, meaning "tomentose", referring to the down covering various parts of the plant. (11)
 Botany
• Magilik is a tree reaching a height of 8 meters or more. Twigs and leaves are densely covered with yellowish-brown, coarse, shaggy hairs. Leaves are large, opposite, ovate or ovately-oblong to subelliptic, 30 centimeters or more in length, borne upon stout, similarly hairy petioles up to 10 centimeters long, broad, rounded or somewhat heart-shaped at the base, and pointed at the tip. Inflorescences are terminal, large, and composed of many small, white flowers. Fruit is rounded, compressed, and subtended by a cupular calyx.
• Premna species straggling or climbing trees, shrubs, undershrubs, rarely herbs. Branches terete, quadrangular, glabrous or pubescent. Leaves simple, decussate-opposite, deciduous, entire or crenate, petiolate or sessile, exstipulate. Inflorescence axillary or terminal, cyme panicle, spike, thyrse or corymb, bracts narrow. Flowers bisexual, zygomorphic, hypogynous, calyx campanulate or tubular 4-5 lobed, corolla infundibular, 2 lipped, 4 subequal lobed, corolla tube tube, subcylindric, densely pubescent at throat, stamens 4, didynamous, epipetalous, filaments glabrous, filiform, anthers versatile, 2 loculed, ovary bicarpellary, 4 lobed, 4 loculed with 1 ovule in each locule, style filiform, stigma bi-lobed, Fruit drupaceous, succulent, globose, 4 loculed with hard pyrenes, seeds nonendospermous. (India Biodiversity Portal)
Distribution
- Native to the Philippines.
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In secondary forests at low and medium altitudes, ascending to 1,000 meters, from northern Luzon to Palawan and Mindanao.
- Also native to Andaman Is., Assam, Bangladesh, Borneo, Cambodia, East Himalaya, India, Jawa, Malaya, Myanmar, Nicobar Is., Queensland, Solomon Is., Sri Lanka, Sulawesi, Sumatera, Thailand, Vietnam. (1)
 Constituents
- Preliminary phytochemical screening of leaves revealed 57.8% D- and DL-limonene, 17.2% ß-caryophyllene, 7.8% cadalene-type sesquiterpene, 5.6% sesquiterpene tertiary alcohol, and 5.5% aditerpene (Lakshminarayen and Muthana, 1953). (7)
- In a study of various leaf extracts for phytochemical composition, the methanol extract was the most effective solvent, extracting the highest concentrations of alkaloids (450 mg/g equivalent), flavonoids (650 mg/g equivalent), phenols (550 mg/g equivalent), and tannins (500 mg/g equivalent). Chloroform extract showed considerable efficacy in extracting flavonoids (650 mg/g equivalent) and alkaloids (400 mg/g equivalent). (see study below) (12)
- Preliminary phytochemical screening of leaf extract yielded alkaloids, flavonoids, tannins, steroids, and phenolic compounds, with absence of anthraquinones, glycosides, amino acid and proteins, and triterpenoids. (13)
- Bioassay-guided fractionation of stem bark of Premna tomentosa isolated four new icetexane diterpenes (1-4) along with 5 known compounds: coniferaldehyde (5), syringaldehyde (6), lupeol (7), betulin (8), and 2-(4-methoxyphenyl)-2-butanone (9). (see study below) (17)
- Bioassay-guided fractionation of whole plant isolated premnalin (1), along with 8 known compounds coniferaldehyde (2), syrangaldehyde (3), acetoxy syrangaldehyde (4), luperol (5), betulin (6), 2-(4-methoxyphenyl)-2-butanone (7), icetexatriene-1 (8), icetexatriene-2 (9). (see study below) (21)
- Study of roots isolated new icetexane diterpenes (1-2), along with six known compounds
namely :acetoxy syranzaldehyde (3), syranzaldehyde (4), coniferaldehyde (5), lupeol (6), betulin (7), and 4-(4-methoxy phenyl)-2-butanone (8). (see study below) (22)
Properties
- Studies have suggested antibacterial, antidiabetic, hepatoprotective, antinociceptive, hypnotic, cytoprotective, antimicrobial, immunomodulatory, cytotoxicity, anticancer, hypolipidemic, antioxidant, nephroprotective, α-glucosidase inhibitory properties.
Parts used
Leaves.
 Uses
Edibility
- Fruits are edible.
- Leaves used for flavoring "ghee", the clarified butter of Indian cuisine. (11)
Folkloric
- In the Philippines, infused leaves used as remedy for dropsy.
- Also used as diuretic.
- Decoction of roots and leaves used as tonic mixture after childbirth. Poultice of leaves applied on sores. Poultice of dried plant parts applied as poultice on skin irritation caused by caterpillars. (10)
- Bark used for treatment of diarrhea.
- In Indian traditional medicine, used against liver, spleen, and stomach disorders.
- In Sri Lanka, juice from leaves used to remove foetid discharges and worms from ulcers. Decoction of roots and bark used for fever and to increase secretion of milk in women.
- In Siddha medicine, decoction of leaves used for treatment of splenomegaly. Also used as diuretic. Aromatic oil used for stomach disorders.
(8)
Others
- Wood: Pale brown, used for construction of dwellings, furniture, fixtures, handicrafts, and artistic objects.
- Fuel: Moderately hard wood preferred for fuel.
Studies
• Hepatoprotective / Acetaminophen-Induced Mitrochondrial Damage: Study showed P. tomentosa pre-treatment of rats exhibited a protective effect against mitrochondrial damage. The presence of the antioxidant D-limonene in leaves, known to enhance conjugation of toxic metabolites by maintaining GSH concentrations, may explain the hepatoprotective effect. (3)
• Cytoprotective / Immunomodulatory: Study evaluated the immunomodulatory effects of P. tomentosa extract against Chromium (VI) induced immunosuppression in splenic lymphocytes. Chromium at dose of 5 µg showed increase in cytotoxicity apoptosis and ROS and decrease in lymphocyte proliferation and antioxidant levels, while pretreatment with leaves extract at 500 µg resulted in decreased cytotoxicity and ROS levels, maintained antioxidant levels, and restored lymphocyte proliferation. Results suggest cytoprotective and immunomodulatory activities. (4)
• Antidiabetic / Roots: Study demonstrated an in vivo anti-diabetic effect of an ethanolic extract of P. tomentosa in STZ-induced type 2 diabetic rats. (5)
• Antinociceptive / Hypnotics / Leaves: Study evaluated the antinociceptive effects of P. tomentosa leaf extract in experimental animals using acetic acid-induced writhing, tail flick and tail clip tests. Oral doses of 100, 200, 400, and 500 mg/kg led to significant antinociceptive effects. On testing for hypnotic effects, same doses caused a decrease in locomotor activity and potentiation of pentobarbitone-induced sleep time. The responses were dose-dependent. Results showed antinociceptive and hypnotic activities. (7)
• Antimicrobial / Leaves: Study evaluated various leaf extracts of P. tomentosa for phytochemical composition and antimicrobial properties against four bacterial and three fungal strains. The ME showed highest antibacterial activity with zones of inhibition of 12 mm against Pseudomonas fluorescens, 9mm against E. coli, 6 mm against S. aureus, and 5 mm against Bacillus subtilis. ME also showed highest efficacy against fungal strains with 60% inhibitions against both Fusarium oxysporum and Phytophthora infestans, and 50% inhibition against Sclerotium rolfsii. The results highlights the importance of solvent selection in maximizing the extraction of compounds. (see constituents above) (12)
• Antioxidant / Hepatoprotective / Cytotoxic / Icetexane Diterpenoids / Stem-Bark: Study evaluated the antioxidant, hepatoprotective, and antiproliferative effects of novel icetexane diterpenoids from hexane extract of stem bark of P. tomentosa. Antioxidant activity was evaluated invitro by DPPH, NO, and superoxide scavenging assays; hepatoprotective activity in vitro with HepG2 cells and in vivo by tBPH-induced hepatice mice model. Results showed the ice 2 and 3 possess good antiproliferative effect via mitochondrial mediated apoptosis in human lung and breast cancer cells. Ice-4 showed good antioxidant activity. Hepatoprotective activity was evidenced by restoration of serum levels of SGOT, SGPYT, AlkP, liver GSH status and reduction or inhibition of lipid peroxidation in liver of tBHP intoxicated mice after administration of ice-4 dose of 250 mg/kg. (14)
• Hypolipidemic / Hepatoprotective in Acetaminophen hepatotoxicity: Study evaluated the hypolipidemic effect of P. tomentosa extract in acetaminophen ((AA)-induced hepatotoxicity in rats. Animals were pretreated with PT extract for 15 days and then induced with hepatotoxicity by AA 640 mg/kg intra-peritoneally. Results showed PT extract improved lipid metabolism and has potential for use in hepatic disorders. (15)
• Protection Against Liver-Induced Membrane Damage: Study evaluated the membrane protective effect of P. tomentosa. During acetaminophen intoxication, levels of membrane-bound enzymes were significantly decreased, along with changes in levels of inorganic cations N+. K+ and Ca2+. The alterations were prevented by P. tomentosa extract suggesting beneficial effect against liver injury-induced membrane damage. Actvity might be attributable to presence of antioxidant compound limonene. (16)
• Cytotoxic Icetexane Diterpenes / Stem Bark: Bioassay-guided fractionation of stem bark of Premna tomentosa isolated four new icetexane diterpenes (1-4) along with 5 known compounds. Cytotoxic activities of icetexanes (1-3) were evaluated for inhibitory effects on human cancer cell lines (MNCF7, HT-29, HepG2, A-431 and A-549). Compounds 1 and 3 showed selective inhibitory activity against MCF-7 (15.96 µg/mL and 15.84 µg/mL) and HT-29 cell lines (16.21 µg/mL and 14.57 µg/mL), respectively. (see constituents above) (17)
• Antioxidant / Aerial Parts: Study evaluated the in vitro antioxidant activities of various extracts of aerial parts of Premna tomentosa using DPPH radical scavenging and iron chelating assays. Results showed the methanolic extract of aerial parts exhibited high antioxidant and free radical scavenging activities, attributed to large amounts of phenolic compounds content. In vitro assays suggest a good source of natural antioxidant. (18)
• Immunomodulatory Against Cr (VI) Induced Toxicity / Leaves: Study evaluated the immunomodu-latory effects of P. tomentosa extract against Chromium (VI) induced immunosuppression in splenic lymphocytes. Chromium at dose of 5 µg showed increase in cytotoxicity apoptosis and ROS and decrease in lymphocyte proliferation and antioxidant levels, while pretreatment with leaves extract at 500 µg resulted in decreased cytotoxicity and ROS levels, maintained antioxidant levels, and restored lymphocyte proliferation. Results suggest cytoprotective and immunomodulatory activities. (19)
• Immunomodulatory Against Cr (VI) Induced Toxicity in J779 Macrophage Cell Line / Leaves: Study evaluated the immunomodulatory effects of P. tomentosa extract against chromate (VI)-induced toxicity in J779 macrophage cell line. Chromate treatment resulted in significant increase in cytotoxicity and free radical production, along with significant decrease in GSH levels and GPx activity. Pretreatment with P. tomentosa extract resulted in significant inhibition of chromate-induced cytotoxicity and ROS production, restoration of antioxidant status, cell proliferation and phagocytosis similar to control. (20)
• α-Glucosidase Inhibition / DPPH Radical Scavenging / Free Radical Scavenging / Whole Plant: Bioassay-guided fractionation of whole plant isolated premnalin (1), along with 8 known compounds coniferaldehyde (2), syrangaldehyde (3), acetoxy syrangaldehyde (4), luperol (5), betulin (6), 2-(4-methoxyphenyl)-2-butanone (7), icetexatriene-1 (8), icetexatriene-2 (9). Study suggested potent intestinal α-glucosidase and free radical scavenging activities with IC50 and SC50 values: premnalin (IC50: 12.11 μg/mL) & (SC50: 20.58 μg/mL), acetoxy syrangaldehyde (IC50: 18.41 μg/mL) & (SC50: 20.83 μg/mL) displayed potent α-glucosidase inhibition and free radical scavengers (DPPH). (21)
• α-Glucosidase Inhibition / Antioxidant / Icetexane Diterpenes / Roots: Study of roots isolated new icetexane diterpenes (1-2), along with six known compounds
(3-8). The compounds were screenend for rat intestinal α-glucosidase inhibitory and free radical (DPPH) scavenging potential. The new icetexane diterpenes (1,2) and compound 3 (acetoxy syranzaldehyde) showed significant α-glucosidase inhibitory and free radical scavenging activities. (see constituents above) (22)
• Cytotoxic Clerodane Diterpenes / Hepatocellular Carcinoma Cell Line / Leaves: Bioactivity-guided study of hexane extract of leaves of Premna tomentosa isolated three new clerodane diterpenes (1-3) along with four known compounds (4-7). The crude hexane extract and isolated compounds were evaluated for In vitro cytotoxicity against seven human cancer cell lines. Results showed compounds 2 and 4 exhibited significant cytotoxicity against hepatocellular carcinoma cell line. (23)
• Amelioration of Alcohol Induced Hepatotoxicity / Leaves: Study evaluated the hepatoprotective effect of ethanolic extract of P. tomentosa on ethanolic toxicity of the liver in male albino Wistar rats. The EEPT at 500 and 750 mg/kg showed significant (p<0.01) reduction of liver enzymes, suggesting protection against ethanol-induced hepatotoxicity. (24)
• Anti-Inflammatory / Anti-Arthritic / Whole Plant: Study showed oral doses of methanol extract of P. tomentosa whole plant showed potent antioxidant, anti-inflammatory and anti-arthritic activity against exudative and proliferative phases of inflammation. (25)
• Nephroprotective / Alcohol-Induced Toxicity / Leaves: Study evaluated the nephroprotective effect of P. tomentosa extract against alcohol-induced nephrotoxicity in rats. Deleterious histopathological changes in the kidney were associated with glomerular and tubular changes in the alcohol intoxicated rats. Extract treatment (500 mg/kbw) showed significant effect against alcohol induced nephrotoxicity, blood parameters, with good histopathological changes. (26)
Availability
Wild-crafted.
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