Elaeocarpus (PROSEA Medicinal plants)

Plant Resources of South-East Asia Introduction

List of species

Elaeocarpus L.

Protologue: Sp. pl. 1: 515 (1753); Gen. pl. ed. 5: 230 (1754).

Family: Elaeocarpaceae

Chromosome number: x= unknown; 2n= unknown

Major species

• Elaeocarpus angustifolius Blume,
• E. floribundus Blume,
• E. grandiflorus J.E. Smith.

Vernacular names

• Oil-fruit (En).
• Brunei: sengkurat, suragam
• Indonesia: mendang
• Malaysia: sengkurat, mendong
• Philippines: kalomala.
• Burma (Myanmar): thitpwe
• Thailand: ma mun
• Vietnam: c√¥m.

Origin and geographic distribution

Elaeocarpus comprises some 300 species occurring from Madagascar and Mauritius to Sri Lanka, India, Indo-China, China, Japan, Thailand, throughout the Malesian region, east to Hawaii and Polynesia (as far as Rarotonga), south to Australia and New Zealand. Malesia harbours the majority of species (some 250); Papua New Guinea alone has about 70 species, Borneo at least 50 and Peninsular Malaysia about 30.

Uses

In Indonesia and Malaysia, bark and leaves of E. floribundus and E. grandiflorus are used in poulticing and an extract is drunk as a general tonic. In Peninsular Malaysia, the leaves of a species resembling E. macrocerus (Turcz.) Merr. are used to poultice insect bites. As the leaves of E. obtusus Blume resemble those of Symplocos odoratissima (Blume) Choisy ex Zoll., they are used in Java as a substitute for the latter species as "obat seriawan" to treat thrush. In Peninsular Malaysia the pulped leaves of E. mastersii King are applied to treat headache, and those of E. stipularis Blume to poultice sores. Juice from the leaves of E. petiolatus (Jack) Wallich is drunk and used as an application for sunstroke; a preparation from the roots may be administered to treat fever. In Sumatra, an infusion of bark scrapings of E. mastersii is drunk for fever, and crushed young leaves are applied to the forehead as a headache treatment. In the Southern Highlands province, Papua New Guinea, the chewed bark of E. buderi Coode is used as a poison antidote. E. angustifolius fruits are used in the traditional Indian Ayurveda system of medicine for mental diseases, epilepsy, asthma, hypertension, arthritis and liver diseases. The wood of Elaeocarpus is used for light interior construction and plywood. It is suitable for the manufacture of particle board, fibreboard and paper pulp. E. angustifolius has been used for reforestation in Java whereas E. grandiflorus is planted as an ornamental.

Production and international trade

The medicinal use of Elaeocarpus is of limited local importance and no trade statistics are available.

Properties

Pharmacological investigations with the water soluble portion of a 90% ethanol extract of the fruits of E. angustifolius showed the presence of a prominent central nervous system (CNS) depressant effect, characterized by typical behavioural actions, potentiating of hexobarbitone hypnosis and morphine analgesia, anticonvulsant and anti-amphetamine effects. The extract also showed cardiostimulant, depressor, smooth muscle relaxant and hydrocholeretic activities, part of these being mediated throughβ-adrenoreceptor stimulation and part through a direct musculotropic effect. Experiments were carried out in mice, rats, rabbits, guinea-pigs, frogs and dogs. The pharmacological profile of activity of the extract substantiates its traditional use in the treatment of mental diseases, epilepsy, hypertension, asthma and liver diseases.

Sequential petroleum ether, benzene, chloroform, acetone and ethanol extracts (50-200 or 200 mg/kg intra peritoneal, or 200 mg/kg per oral) of dried E. angustifolius fruits, pretreatment time 30-45 min, showed significant anti-inflammatory action against both acute and sub-acute models, analgesic, barbiturate-hypnosis potentiating and anti-ulcerogenic activities in rats. All the extracts, except petroleum ether and ethanol decreased swim stress immobility in mice indicating some degree of antidepressant activity. All the extracts protected guinea-pigs against bronchospasms induced by histamine and acetylcholine aerosols. Chemically, the extracts showed the presence of glycosides, steroids, alkaloids and flavonoids.

The effect of E. angustifolius fruits on autocoid release has been studied in the rat mesenteric mast cell in vitro. The petroleum ether, benzene, chloroform, acetone and ethanol extracts were found to have mast-cell stabilizing activity, substantiating the efficacy of E. angustifolius against bronchial asthma.

Antibacterial activity of petroleum ether, benzene, chloroform, acetone and ethanol extracts of dried E. angustifolius fruit was furthermore investigated against 28 gram-positive and gram-negative bacteria using disk diffusion- and plate dilution methods. The acetone fraction showed marked antimicrobial activity against 10 organisms. The benzene extract was active against Morganella morganii and Salmonella typhimurium, and the ethanol extract against Plesiomonas shigelloides, Shigella flexneri and Shigella sonnei.

In a double blind placebo controlled study, the effect of crude powder of E. angustifolius on essential hypertension was evaluated in human patients, with mild to moderate hypertension. There was a significant fall in systolic, diastolic and mean blood pressure in the patients treated with 8 g/day of crude powder of E. angustifolius, whereas doses of 2 and 4 g/day failed to result in a significant decrease in blood pressure.

A widespread species such as E. angustifolius shows variation in the composition of its alkaloids; in Indian material the content of aromatic alkaloids such as (+/-)-elaeocarpine and (+/-)-isoelaeocarpine is considerably higher than in material from New Guinea (where dienone alkaloids are predominant).

Some Elaeocarpus species from New Guinea, initially tested for alkaloids, have been included in general screening assays and pharmacological testing. Elaeocarpus species are known to produce numerous indolizidine alkaloids, ranging from simpler elaeokanine C in E. kaniensis Schltr. to more complex ones such as (-)-isoelaeocarpiline in E. angustifolius and the aromatic bases (+/-)-elaeocarpine which predominate in E. polydactylus Schltr. Elaeocarpidine is a major component of E. densiflorus R. Knuth.

E. angustifolius leaves (1.3 kg) produced a mixture of 10 alkaloids totalling 5.8 g: (+)elaeocarpiline, (-)-isoelaeocarpiline, 5 other isomers of (+)elaeocarpiline, elaeocarpidine (+/-)-elaeocarpine, (+/-)-isoelaeocarpine. Under pharmacological testing 1000 mg/kg (orally) of the mixture had no effect in mice, 2000 mg/kg was toxic. In the cat 35 mg/kg given intraperitoneally caused emesis, slight ataxia and marked disorientation. It caused transient hypotension and respiratory arrest at low doses of 1-2.5 mg/kg (intravenous). It also had an analgesic effect, which may be related to respiratory depression. The mixture did not test positive for diuretic, anticonvulsant or hypoglycaemic activity.

Furthermore, 1.55 kg of E. polydactylus leaves produced a mixture of alkaloids totalling 10.6 g:(+/-)-elaeocarpine, (+/-)-isoelaeocarpine, (+/-)-isoelaeocarpicine, some elaeocarpidine and isomers of 4-acetyl-5-methylcyclohex-3-enol. In mice an oral dose of the mixture at 1000 mg/kg and 2000 mg/kg produced low posture, dyspnea, hypothermia, convulsions and death. In the anaesthetized cat, the mixture caused hypotension at 5 mg/kg and cardiac arrest at higher doses. It also enhanced the response to adrenaline and 1,1-dimethyl-4-phenylpiperazinium iodide (DMPP). In rats elaeocarpine and its isomer produced 50% analgesia at 50 mg/kg and tetrabazine antagonism at 300 mg/kg.

E. densiflorus leaves (1.2 kg) produced a mixture of alkaloids totalling 4.0 g; elaeocarpidine being the major alkaloid. In mice, an oral dose of 500 mg/kg produced low posture, slightly decreased activity, dyspnea, analgesia and hypothermia, at 100 mg/kg no effects were observed. At 30 mg/kg it produced depression, low posture, tremors, somnolence and bradypnea. In rats, elaeocarpidine at a dose of 50 mg/kg produced weak analgesia. Elaeocarpidine at 200 μg/ml is active against gram-positive bacteria, Bacillus subtilis, Mycobacterium smegmatis, Sarcina lutea and Streptococcus pyogenes, and the fungi Aspergillus niger, Blastomyces dermatidis, Cryptococcus neoformans, Fusarium oxysporum var. lycopersici, Penicillium citrinum var. leiter and Trichophyton mentagrophytes.

Additionally, 2.2 kg of E. dolichostylus Schltr. leaves produced a mixture of 3 alkaloids totalling 5.9 g: (+)-elaeocarpiline, (-)-isoelaeocarpiline and elaeocarpidine. In mice an oral dose of 1000 mg/kg produced marked central nervous system (CNS) depression and mydriasis, at 2000 mg/kg it produced marked depression, tremors, convulsions and death. In the cat 35 mg/kg given intraperitionally caused emesis, rapid respiration, rage and fine head tremors. In the anaesthetized cat, the mixture caused irregular blood pressure, mydriasis, reversal of bilateral carotid occlusion (BCO) and peripheral vagal stimulation (PVS). This indicates ganglionic blockage or atropine-like or α₁-agonistic cardiovascular activities. The mixture appears to lower the threshold to MES seizures and has weak diuretic action. Finally, in a quest for antitumour compounds the cucurbitacin derivatives hexanorcucurbitacin F, cucurbitacin F and 23,24-dihydrocucurbitacin F were isolated in E. dolichostylus from New Guinea. Only cucurbitacin F showed cytotoxic activity.

Alkaloids produced in E. altisectus Schltr. are similar to those in E. angustifolius and E. dolichostylus ; 1.7 kg of leaves produced 12.9 g of alkaloids. In mice the alkaloid mixture caused bradypnea at an oral dose of 500 mg/kg, at 1000 mg/kg it caused dyspnea and at higher doses it caused tonic convulsions and death. However, the mixture did not produce any cardiovascular, analgesic or anti-inflammatory activity at 100 mg/kg.

Aqueous extracts of leaves and stems of E. mastersii from Sumatra (Indonesia) showed strong antimicrobial activity against gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria.

Description

• Shrubs or small to fairly large, or occasionally large trees up to 40(-50) m tall; bole straight, cylindrical, columnar or poorly shaped, branchless for up to 18 m, up to 80(-160) cm in diameter, sometimes with steep buttresses up to 3(-5) m high, rarely with stilt roots; bark surface smooth to cracked or rugose or fissured, sometimes lenticellate, brown or grey, inner bark fibrous to granular, brown or yellowish-brown to reddish-brown or pink; crown often symmetrical.
• Leaves arranged spirally or alternate, simple, dentate or crenate or occasionally entire; petiole often kneed at apex; with or without stipules.
• Inflorescence an axillary raceme.
• Flowers bisexual, 4-5-merous, pendulous; sepals valvate; petals only slightly longer than the sepals, white, cream or greenish, generally toothed and/or fringed at apex; disk lobed, glabrous or hairy; stamens 10-many, inserted between disk and ovary or rarely on the disk, anthers with transverse apical slits; ovary superior, 2-7-locular with 2-12 ovules in each cell, style simple.
• Fruit an often bluish, purplish or brownish-green drupe; stone hard, with 1-7 seeds.
• Seedling with epigeal germination; cotyledons emergent, leafy; hypocotyl elongated; first two leaves opposite or alternate, subsequent ones alternate.

Growth and development

E. angustifolius has been planted in trials in Java where the mean annual increment of 10.5-year-old trees planted at about 60 m altitude was 1.1-1.3 m in height and 1.9-2.1 cm in diameter. When planted at about 650 m altitude the mean annual increment of isolated trees was 2.5 m in height and 4.7 cm in diameter. In the Solomon Islands the annual increment of E. angustifolius in gaps in natural forest is 0.4 m in height and in plantations 2.9 m in height and 3.9 cm in diameter. Trees often show Terminalia-like branching. Growth form is according to Aubréville's architectural tree model, characterized by a monopodial trunk with rhythmic growth and spiral or decussate phyllotaxis bearing tiers of branches with similar phyllotaxis and indefinite growth of branches. Young leaves are red, pink or purple; old leaves wither red or occasionally yellow. Trees are generally evergreen, but some, e.g. E. angustifolius , are briefly deciduous. They flower at regular intervals, often after a dry period, sometimes 2-3 times a year. In Peninsular Malaysia flowering often takes place in March-May and August-October. In West Java, E. angustifolius carries fruits more or less throughout the year, but in Sulawesi only in October-November. Detailed flowering studies on E. floribundus in India revealed that flowers open at midday and anther dehiscence is completed in 6-8 hours. Development of the fruits shows distinct phases. From 30-60 days after anthesis, fruits grow fast and develop into the "marble-stage"; development from day 60-120 is rather slow; from day 120 onwards growth of the fruit and swelling is fast, and maturity is reached 180 days after anthesis. Birds, bats, rodents and pigs eat the fruits and thus disperse the seeds.

Other botanical information

Probably because of ongoing speciation processes and hybridization, some species groups are regarded as "complexes" within which it is hard to recognize individual species. The genus Acronodia has been incorporated into Elaeocarpus. Elaeocarpus is occasionally regarded as a member of the tribe Elaeocarpeae within the family Tiliaceae.

Ecology

Elaeocarpus may be encountered in primary but more often in secondary rain forest at low to medium altitudes, but sometimes as high as 3500 m and, in Papua New Guinea, can be locally common in montane forest in association with Nothofagus. It may occur gregariously and is found in a wide range of habitats including coastal forest, freshwater swamp forest, kerangas and on ultrabasic soils.

Propagation and planting

Elaeocarpus can be propagated from seeds (which do not tolerate desiccation); the seeds are well enclosed by the hard dry stone. E. angustifolius has about 510 dry stones/kg and these should be sown in the shade. The stones of E. floribundus have about 15% germination in 4-8 months, and those of E. stipularis about 15% in 2.5-4.5 months. Sown fruits of E. petiolatus show about 50% germination in 2.5-4 months. It has been recommended that the stones be opened and the seeds sown. Elaeocarpus is not resistant to fire.

Husbandry

There are techniques for partially ring-barking flowering branches of E. angustifolius which results in smaller fruits and stones. These stones were highly sought after for trade, e.g. for the production of traditional Hindu bead chains, mainly in India and Peninsular Malaysia.

Handling after harvest

In general, leaves and bark of Elaeocarpus are used fresh. Mature fruits of E. angustifolius are collected in vats. After fermentation for 2 days the fruit pulp can be easily removed mechanically, and the stones are cleaned by washing, followed by drying.

Genetic resources and breeding

Most of the Elaeocarpus species are endemic and hence have a fair risk of genetic erosion. However, medicinally important species treated here have a large area of distribution, either naturally or as a result of cultivation, and do not seem to be at risk of genetic erosion. There are no known breeding programmes of Elaeocarpus.

Prospects

Extract and alkaloids from Elaeocarpus species exhibit a range of interesting pharmacological effects, which merit further research. For instance, the full toxicological profile has to be firmly established before their possibilities for future medicine can be evaluated comprehensively.

Literature

• Bhattacharya, S.K., Debnath, P.K., Pandey, V.B. & Sanyal, A.K., 1975. Pharmacological investigations on Elaeocarpus ganitrus. Planta Medica 28(2): 174-177.
• Collins, D.J., Culvenor, C.C.J., Lamberton, J.A., Loder, J. & Price, J.R., 1990. Plants for medicine: A chemical and pharmacological survey of plants in the Australian region. CSIRO printing, Canberra, Australia. pp. 7, 36, 71-75, 92, 93, 132-134, 147, 164-166.
• Fang, X., Phoebe Jr, C.H., Pezzuto, J.M., Fong, H.H., Farnsworth, N.R., Yellin, B. & Hecht, S.M., 1984. Plant anticancer agents, XXXIV. Cucurbitacins from Elaeocarpus dolichostylus. Journal of Natural Products 47(6): 988-993.
• Keating, W.G. & Sosef, M.S.M., 1998. Elaeocarpus L. In: Sosef, M.S.M., Hong, L.T. & Prawirohatmodjo, S. (Editors): Plant Resources of South-East Asia No 5(3). Timber trees: Lesser-known timbers. Backhuys Publishers, Leiden, the Netherlands. pp. 204-209.
• Singh, R.K., Acharya, S.B. & Bhattacharya, S.K., 2000. Pharmacological activity of Elaeocarpus sphaericus. Phytotherapy Research 14(1): 36-39.
• Singh, R.K. & Nath, G., 1999. Antimicrobial activity of Elaeocarpus sphaericus. Phytotherapy Research 13(5): 448-450.

Selection of species

• Elaeocarpus angustifolius
• Elaeocarpus floribundus
• Elaeocarpus grandiflorus

Authors

• S. Aggarwal