Carmona retusa (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

1, flower; 2, 4-merous corolla; 3, 5-merous corolla; 4, fruiting twig; 5, fruit (Iskak Syamsudin)

Carmona retusa (Vahl) Masam.

Protologue: Trans. Nat. Hist. Soc. Formosa 30: 61 (1940).

Family: Boraginaceae

Chromosome number: 2n= 32

Synonyms

• Ehretia microphylla Lamk (1792),
• Ehretia buxifolia Roxb. (1796),
• Carmona microphylla (Lamk) G. Don (1837).

Vernacular names

• Indonesia: kinangan, serut lanang (Javanese), pinaan (Madurese)
• Philippines: putputai (Bikol), alangit (Bisaya), tsaang gubat (Tagalog)
• Thailand: khoi cheen (Bangkok), chaa yeepun (central), chaa (Chiang Mai)
• Vietnam: kim liên, cùm rụn, bùm rụn.

Origin and geographic distribution

Carmona is a monotypic genus. The only species C. retusa is found from India eastward to southern China, Taiwan and Japan, and further south throughout Malesia to New Guinea and the Solomon Islands. It is often grown as an ornamental.

Uses

In the Philippines an infusion of the leaves of C. retusa is taken as a substitute for tea. It is considered stomachic, antidiarrhoeal and as a remedy for dysentery and cough. In Ternate an infusion of the leaves is taken as a febrifuge. A decoction of the leaves is taken against stomach troubles and cough in the Philippines. In Madura the roots are reported to be ingested to clean the body after childbirth. In India, the plant is considered an antidote against plant-based poisoning and an alterative in cachexia and syphilis. Furthermore, it is traditionally used to stop the haemorrhaging resulting from the bite of the viper Echis carinatus.

Properties

Boraginaceae commonly contain pyrrolizidine alkaloids, biosynthesized from the amino acid ornithine, and quinoid or phenolic compounds, derived from C-prenylated, C-geranylated or C-farnesylated 4-hydroxybenzoic acid. The isomeric red pigments alkannin and shikonin are the best known representatives of such hydroxybenzoic acid derivatives.

The portion of the methanol extract of the aerial parts of C. retusa that is soluble in ethyl acetate has shown inhibitory activity on exocytosis of hexosaminidase in antigen-stimulated rat basophils. Activity guided studies have shown 5 dimeric prenylbenzoquinones as active compounds: microphyllone (4a,5,8,8a-tetrahydro-11,14-dihydroxy-7-methyl-4a-(3-methyl-2-butenyl)-5,8a-o-benzo-1,4-naphthoquinone) and 4 closely related components. Furthermore, the methanol extract of the leaves showed strong antihistamine release properties. Rosmarinic acid, a phenylacrylic acid derivative, which is a known inhibitor of histamine release, has been isolated as an active constituent. Astragalin, nicotoflorin (both flavonoid glycosides), and α-amyrin, β-amyrin and baurenol (triterpenoids) were also isolated.

Ehretianone, a quinonoid xanthene, (7-hydroxy-9a-α-(3-methylbut-2-enyl)-4a,α9-α-(2-methylprop-2-enyl)-4a,9a-dihydro-1,4-dioxoxanthene) was isolated from a methanol extract of the root bark of C. retusa. The compound, administered before and after administration of Echis carinatus venom, was shown to protect mice against the action of the snake venom.

Finally, both microphyllone and ehretianone isolated from root-bark material showed antibacterial activity against a panel of bacteria. In an experiment in the Philippines, tablets from the dried leaves reduced the formation of micronucleated polychromatic erythrocytes induced by mitomycin C, tetracycline, and dimethylnitrosamine. This suggests that these tablets possess antimutagenic activity.

Description

• A shrub or much-branched small tree, 1-4(-10) m tall; young branches hispid, with buds or short shoots producing clusters of leaves and inflorescences.
• Leaves simple, alternate, obovate to spatulate, 1-6(-10) cm × 0.5-2.5(-4) cm, thick, gradually narrowing towards base, toothed or crenate towards apex, with short rigid hairs, lateral veins about 5, arching; petiole 0.1-0.5(-1) cm long, stipules absent.
• Inflorescence in axil of leaves or on apex of short shoots, flowers in fascicles of 2-6 or in a cyme.
• Flowers actinomorphic, bisexual, (4-)5-merous, pedicelled; calyx 3-6 mm long, with (4-)5 linear lobes, densely hairy inside; corolla sub-rotate, white, 6-9 mm in diameter, tube about 2 mm long, widening, lobes spreading, 2.5-4.5 mm long; stamens (4-)5 with filaments 2.5-3.5 mm long and anthers oblong; ovary superior, globose, about 1 mm in diameter, style deeply bifid, 4.5-6 mm long.
• Fruit drupaceous, globose, 5-6 mm in diameter, red or yellow, with 1-4 seeds, not breaking up into pyrenes.
• Seeds with a straight or slightly curved embryo, embedded in thin albumen.
• Seedling with epigeal germination; cotyledons leafy, green, hypocotyl elongated.

Growth and development

Branch shoots are developed at every node, but are of two types: short shoots that do not elongate and long shoots that resemble the leader shoot. The fruits are reported to be dispersed by birds.

Other botanical information

In the view of most authors, the Boraginaceae family can be divided into five subfamilies. Carmona belongs to the subfamily Ehretioideae. Together with the other Malesian representatives of this subfamily (Coldenia, Ehretia and Rotula) and with the subfamily Cordioideae (represented by Cordia in Malesia) Carmona is sometimes placed in the family Cordiaceae. Most authors have included Carmona in Ehretia. However, Carmona can be distinguished by the undivided, short-beaked endocarp, and its distinctive growth habit and general appearance.

Ecology

C. retusa is a rare or locally common species found in open, dry, sunny habitats, such as thickets, shrub vegetation and teak forest at low and moderate elevations.

Propagation and planting

C. retusa can be propagated by cuttings, preferably top shoots or young leafy shoots. Roots develop slowly (1-2 months). Planting is at 1 m intervals with 2 m between rows.

In vitro production of active compounds

Using leaf tissue of C. retusa as explant, callus growth can be observed after 2 days. The callus contains alkaloids.

Harvesting

Mature leaves of C. retusa are harvested and senescent leaves discarded.

Handling after harvest

In the Philippines, leaves of C. retusa are air-dried for 4-5 days in shallow containers with screened bases. Containers are kept in well-ventilated rooms. The dried leaves are powdered and processed into pills.

Genetic resources and breeding

C. retusa is a widespread species, and there are no reports of overexploitation. The risk of genetic erosion seems to be limited, and in addition it is cultivated as a garden ornamental.

Prospects

C. retusa ranks among the top 10 of medicinal plants with potential in the Philippines, and thus a small-scale industry has developed. Its constituents, e.g. microphyllone and ehretianone show interesting biological activities, which merit further research. Furthermore, alkannin esters of various organic acids have recently been introduced in therapy for their wound-healing properties.

Literature

• Agarwal, S.K., Rastogi, R.P., Van Koningsveld, H., Goubitz, K. & Olthof, G.J., 1980. The molecular structure of 4a,5,8,8a-tetrahydro-11,14-dimethoxy-7-methyl-4a-(3-methyl-2-butenyl)-5,8a- o -benzeno-1,4-naphthoquinone. Tetrahedron 36(10): 1435-1438.
• Bruneton, J., 1995. Pharmacognosy, phytochemistry, medicinal plants. Technique & Documentation Lavoisier, Paris, France. pp. 675-679.
• Gopal, R.H., Balakrishna, K., Ramkumar, V., Rao, R.R., Selvanayagam, Z.E. & Gnanavendhan, S., 1997. Antibacterial activity of Ehretia buxifolia. Fitoterapia 68(1): 85-86.
• Gutierrez, H.G., 1982. An illustrated manual of Philippine materia medica. Vol. 2. National Research Council of the Philippines, Tagig, Metro Manila, the Philippines. pp. 445-446.
• Lim-Sylianco, C.Y., Blanco, F.R.B. & Lim, C.M., 1987. Mutagenicity, clastogenicity and antimutagenicity of medicinal plant tablets produced by the NSTA Pilot Plant IV. Tsaang gubat tablets. The Philippine Journal of Science 116(3): 273-280.
• Quintana, E.G., Saludez, J.D., Batoon, M.P. & Generalao, M.L., 1982. Agricultural production of selected medicinal plants: propagation to postharvest handling. PCARRD Monitor 10(4): 8-10.
• Riedl, H., 1997. Boraginaceae. In: Kalkman, C. et al. (Editors): Flora Malesiana. Series 1. Vol. 13. Rijksherbarium/Hortus Botanicus, Leiden, the Netherlands. pp. 43-144.
• Rimando, A.M., Inoshiri, S., Otsuka, H., Kohda, H., Yamasaki, K., Padolina, W.G., Torres, L., Quintana, E.G. & Cantoria, M.C., 1987. Screening for mast cell histamine release inhibitory activity of Philippine medicinal plants active constituent of Ehretia microphylla. Shoyakugaku Zasshi 41(3): 242-247.
• Selvanayagam, Z.E., Gnanavendhan, S.G., Balakrishna, K., Rao, R.B., Sivaraman, J., Subramanian, K., Puri, R. & Puri, R.K., 1996. Ehretianone, a novel quinonoid xanthene from Ehretia buxifolia with antisnake venom activity. Journal of Natural Products 59(7): 664-667.
• Yamamura, S., Simpol, L.R., Ozawa, K., Ohtani, K., Otsuka, H., Kasai, R., Yamasaki, K. & Padolina, W.G., 1995. Antiallergic dimeric prenylbenzoquinones from Ehretia microphylla. Phytochemistry 39(1): 105-110.

Other selected sources

• Backer, C.A. & Bakhuizen van den Brink Jr, R.C., 1963-1968. Flora of Java. 3 volumes. Noordhoff, Groningen, the Netherlands. Vol. 1 (1963) 647 pp., Vol. 2 (1965) 641 pp., Vol. 3 (1968) 761 pp.
• Brown, W.H., 1951-1957. Useful plants of the Philippines. Reprint of the 1941-1943 edition. 3 volumes. Technical Bulletin 10. Department of Agriculture and Natural Resources. Bureau of Printing, Manila, the Philippines. Vol. 1 (1951) 590 pp., Vol. 2 (1954) 513 pp., Vol. 3 (1957) 507 pp.
• Burkill, I.H., 1966. A dictionary of the economic products of the Malay Peninsula. Revised reprint. 2 volumes. Ministry of Agriculture and Co operatives, Kuala Lumpur, Malaysia. Vol. 1 (A-H) pp. 1-1240. Vol. 2 (I- Z) pp. 1241-2444.
• Cardenas, L.B. & Quimado, M.O., 1986. Tissue culture of medicinal plants: an investment for the future. Research at Los Baños (Philippines) 5(2): 14-15.
• de Padua, L.S., Lugod, G.C. & Pancho, J.V., 1977-1983. Handbook on Philippine medicinal plants. 4 volumes. Documentation and Information Section, Office of the Director of Research, University of the Philippines at Los Baños, the Philippines.
• Johnston, I.M., 1951. Studies in the Boraginaceae XX. Carmona. Journal of the Arnold Arboretum 32: 16-19.
• Matthew, K.M., 1981-1988. The flora of the Tamilnadu Carnatic. 4 volumes. The Rapinat Herbarium, St. Joseph's College, Tiruchirapalli, India.
• Ng, F.S.P., 1991-1992. Manual of forest fruits, seeds and seedlings. 2 volumes. Malayan Forest Record No 34. Forest Research Institute Malaysia, Kepong, Malaysia. 997 pp.
• Perry, L.M., 1980. Medicinal plants of East and Southeast Asia. Attributed properties and uses. MIT Press, Cambridge, Massachusetts, United States & London, United Kingdom. 620 pp.
• Quisumbing, E., 1978. Medicinal plants of the Philippines. Katha Publishing Co., Quezon City, the Philippines. 1262 pp.
• Sayavathi, D.V.L. & Narayana, L.L., 1990. The distribution pattern of free amino acids in certain Boraginaceae. Feddes Repertorium 101(11 12): 593-599.
• Whitmore, T.C. & Ng, F.S.P. (Editors), 1972-1989. Tree flora of Malaya. A manual for foresters. 2nd Edition. 4 volumes. Malayan Forest Records No 26. Longman Malaysia Sdn. Berhad, Kuala Lumpur & Petaling Jaya, Malaysia.

Authors

• A.P. Guevara