Ochrosia (PROSEA)
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Introduction |
Ochrosia A.L. Juss.
- Protologue: Gen. pl.: 144 (1789).
- Family: Apocynaceae
- Chromosome number: x= 10, 11; O. oppositifolia: 2n= 22
Major species
- Ochrosia oppositifolia (Lamk) K. Schum.
Origin and geographic distribution
Ochrosia s.l. comprises about 40 species and is found from the Mascarenes to the Pacific and Northern Australia including South-East Asia. New Caledonia is particularly rich in endemics.
Uses
In the Moluccas, the root or the seeds of O. oppositifolia are used in bilious disorders, in particular as an antidote to the effect of eating poisonous fish or crabs. In Vietnam, the bark is used as a febrifuge and stomachic. Cups made from the wood will give a bitter taste to drinks when allowed to stand for some time. The drinks are then taken as a stomachic. The leaves are also used for their attributed tonic and febrifugal properties. In Lubang Island (Mindoro Province), the Philippines, the plant is used for minor ailments and also as firewood and as a shade tree. In the Philippines, the bark of O. glomerata (Blume) F. Muell. (synonym Paralstonia clusiacea auct. non Baillon) is used to reduce swellings. In China, 3 species are cultivated for their use in traditional Chinese medicine: O. borbonica J.F. Gmelin, O. coccinea (Teijsm. & Binnend.) Miq. and O. elliptica Labill. However, the identity of O. borbonica is somewhat doubtful. The seeds of O. ackeringae (Teijsm. & Binnend.) Miq. (synonym O. littoralis Merr.) are edible both cooked and raw. The timber of some species is locally used (e.g. O. acuminata Trimen ex Valeton, O. oppositifolia (Lamk) K. Schum.). O. elliptica is widely distributed as an ornamental; it shows startling bright red fruits and dense clusters of cream flowers produced throughout the year on an open spreading leafy canopy.
Properties
Research on active constituents in Ochrosia has focused on anticancer compounds following the isolation of the alkaloid ellipticine (5,11-dimethyl-(6H)-pyrido(4,3-bicarbazole) from O. elliptica. Many Ochrosia spp., in particular those from New Caledonia, have since been subjected to investigations of their alkaloid content.
The major alkaloids isolated from O. elliptica are ellipticine, elliptinine, 9-ellipticine, 9-methoxy-ellipticine and isoreserpiline, which are all of the indole type, derived from the amino acid tryptophan. In addition, the bark of O. coccinea from the Moluccas contains the indole alkaloids ellipticine, 9-methoxy-ellipticine and reserpiline. The main base present in the bark of O. oppositifolia is isoreserpiline, which is accompanied by a considerable quantity of its stereoisomer reserpiline. The quaternary ammonium base corresponding to isoreserpiline and reserpiline, ochropposine, is also a major constituent. The principal constituent of the leaves is isoreserpiline. Numerous other indole alkaloids have been recorded, including epi-rauvanine and bleekerine.
Ellipticine and its derivatives possess anticancer properties against several experimental neoplasms as well as towards some human cancers. Substitutions on the C-9 and N-2 positions of the dimethyl-pyrido-carbazole nucleus result in the formation of semisynthetic derivatives which are even more effective. Two additional sites of action of these drugs have been reported: (i) ellipticine and 9-methoxy-ellipticine disturb biological membranes in their enzymatic functions, or in their role as permeability barriers, and (ii) ellipticine derivatives or its analogs are reversibly non-competitive inhibitors of cholinesterases and interact with muscarine receptors.
So far, only one ellipticine derivative, celiptium® (N-methyl-9-hydroxy ellipticine, as the acetate salt) has been introduced onto the market for treatment of metastatic breast cancer. This drug shows significant activity against leukaemia L 21210, leukaemia L 388, melanome B16 ependymoblastoma, lymphosarcoma of Gardner and tumour of Shay. Furthermore, it shows intermediate activity against pulmonary carcinoma of Lewis, and no activity against lymphosarcoma of Yoshida, lymphoma LLx 15 and myeloid.
Description
- Shrubs or trees with white latex.
- Leaves in whorls of 3-5 or rarely opposite, simple, entire to rather undulate, variable in size and shape; petiolate.
- Inflorescence terminal or axillary, in whorls or solitary, pedunculate.
- Flowers bisexual, 5-merous, sepals ovate to broadly so, or rarely orbicular, obtuse, without colleters inside; corolla lobes overlapping to the right in bud, salver-shaped, lobes oblong, apex obtuse to rounded, white or whitish; stamens included, free from the pistil head, disk present or not.
- Fruit a drupe, apocarpous to syncarpous, consisting of 2 mericarps, mesocarp fibrous or not, endocarp with or without 2 lateral cavities, 1-3 seeds in each carpel.
- Seed flat, suborbicular to elliptical.
- Seedling with epigeal germination, cotyledons leafy, hypocotyl elongated, first leaves opposite.
Growth and development
The fruits of Ochrosia species from shoreline habitats float with their thick fibrous mesocarp after the pulp has worn off and are dispersed by sea currents. Likewise, Ochrosia species float because of additional cavities in the endocarp, which facilitates their dispersal by fresh water or sea currents. The seeds germinate readily when washed ashore. However, O. oppositifolia fruits planted without removal of the pulp germinate poorly and only after about 8 months.
Other botanical information
There is considerable dispute about whether Ochrosia and Neisosperma are distinct genera. There has still been no monographic revision covering all species concerned. Chemical constituents seem to support a separation. In Ochrosia s.s. ellipticine-base compounds are present, whereas in Neisosperma corynane-base compounds are present.
Ecology
Ochrosia species are found in shoreline habitats, periodically inundated forest, as well as rain forest or lower montane forest up to 800 m altitude.
Propagation and planting
O. elliptica is usually propagated by seed but can also be propagated by ripe wood cuttings. Under glasshouse conditions in temperate climates ripe wood cuttings in early spring are rooted in moist sand in a closed case with bottom heat.
In vitro production of active compounds
Young seedlings of O. elliptica are a good source for developing callus cultures. The callus of cotyledon origin was found best for developing a rapidly growing system. B5 medium containing a combination of kinetin at 0.1 mg/l, 2,4-D at 10 mg/l, coconut water at 5% and sucrose at 20 g/l is most suitable for callus induction. A short subculture period of 7 days in liquid medium was necessary to maintain the cultures in healthy condition. Tissues grown on B5 medium supplemented with kinetin at 0.1 mg/l, 2,4-D at 1 mg/l and naphthalene acetic acid (NAA) at 0.5 mg/l produced maximum ellipticine content.
Husbandry
O. elliptica should preferably be grown in full light but also tolerates partial shade. Preference is given to fertile moist but well-drained loams with additional leaf mould.
Genetic resources and breeding
The widespread natural distribution of O. oppositifolia, and its tolerance for disturbed habitats, makes the risk of genetic erosion limited. Cultivation of O. elliptica as an ornamental also diminishes this risk of genetic erosion.
Prospects
The indole alkaloids isolated from Ochrosia species possess an interesting pharmacology in the field of anti-neoplastic activity. So far, one semisynthetic derivative has successfully been introduced onto the market. The bioproduction of the ellipticine base skeleton of Ochrosia may therefore have some potential for the pharmaceutical industry.
Literature
- Bisset, N.G., 1988. Phytochemistry of Ochrosia borbonica and O. oppositifolia. Agricultural University Wageningen Papers, 87-5. pp. 59-60.
- Boiteau, P., 1981. Apocynacées [Apocynaceae]. In: Flore de la Nouvelle Calédonie et dépendances [Flora of New Caledonia (incl. Loyalty Islands)]. Vol. 10. Muséum National d’Histoire Naturelle, Paris, France. pp. 47-79.
- Chénieux, J.C., Ramawat, K.G. & Rideau, M., 1988. Ochrosia spp.: in vitro production of ellipticine, an antitumour agent. In: Bajaj, Y.P.S. (Editor): Biotechnology in agriculture and forestry 4. Medicinal and aromatic plants I. Springer-Verlag, Berlin, Germany. pp. 448-463.
- Leeuwenberg, A.J.M., 1987. Series of revisions of Apocynaceae. Part XXIII. The African species of Ochrosia Juss. Agricultural University Wageningen Papers 87-5. pp. 45-53.
- Pételot, A., 1953. Les plantes médicinales du Cambodge, du Laos et du Vietnam [The medicinal plants of Cambodia, Laos and Vietnam]. Vol. II. Centre National de Recherches Scientifiques et Techniques, Saigon, Vietnam. pp. 110-111.
- Valeton, T., 1895. Les Ochrosia du Jardin Botanique de Buitenzorg [The Ochrosia in the Botanical Garden of Buitenzorg]. Annales du Jardin Botanique de Buitenzorg 12: 223-237, pl. 22-25.
Selection of species
Authors
- J.L.C.H. van Valkenburg & R. Hendrian
