Hydnocarpus (PROSEA Medicinals)
- Protologue: Fruct. sem. pl. 1: 288, t. 60, f. 3 (1788).
- Family: Flacourtiaceae
- Chromosome number: x= 12; H. alcalae, H. anthelmintica, H. kurzii: 2n= 24
Hydnocarpus alcalae C.DC., H. anthelmintica Pierre ex Lanessan, H. kurzii (King) Warb.
- Malaysia: setumpol (Peninsular), karpus (Sabah)
- Burma (Myanmar): kalaw
- Thailand: krabao
- Vietnam: phong tưr.
Origin and geographic distribution
Hydnocarpus comprises about 40 species occurring in south-western India, Sri Lanka, Burma (Myanmar), Indo-China, southern China, Thailand (7 species), Peninsular Malaysia (12), Sumatra (12), Java (2), Borneo (17), the Philippines (5) and Sulawesi (2). H. kurzii (from Burma (Myanmar)), H. alcalae (from the Philippines) and H. anthelmintica (from Indo-China) used to be cultivated but with the advent of synthetic leprosy drugs in the 1960s, this cultivation has lost its importance.
Seeds of many Hydnocarpus species (notably H. anthelmintica and H. kurzii) yield an oil that has been well known as a cure for leprosy and skin diseases since antiquity. The oil has also been recommended as a topical application to treat rheumatism, sprains and bruises, sciatica and chest complaints, and for dressing wounds. Major sources are H. kurzii from Burma (Myanmar), known as "chaulmoogra" oil, and H. laurifolia (Dennst.) Sleumer (synomyms: H. pentandrus (Ham.) Oken, H. wightiana Blume) from south-western India, known as "moratti" or "marotti" oil. The major source of Hydnocarpus oil in China, where it is known as "lukrabo" or "krabao" oil, is H. anthelmintica seed from Indo-China. In Cambodia, this oil has also been used for illumination and it has been used to make soap. H. venenata Gaertner from Sri Lanka known as "makulu" is used medicinally to treat leprosy but also as a fish poison. The seed of many Hydnocarpus species can be used as a fish poison, similar to Pangium edule Reinw. The oil from H. kurzii seed has been used to treat saddle-sores, and for liniment in veterinary practice.
The fibrous bark of H. anthelmintica is made into cordage, whereas the pulp of the fruits is edible. The wood of Hydnocarpus is used for local house building (poles), temporary heavy construction, posts, fences, interior finishing, panelling and door and window frames.
Production and international trade
In former times seeds or seed oil of Hydnocarpus were traded from India and Indo-China to the Malesian region, China, Hawaii and Europe. However, at present no information on trade is available.
Cyclopentenylglycine and cyclopentenyl fatty acids are found in Hydnocarpus seed. The Malesian species H. alcalae, H. cauliflora Merr., H. subfalcata Merr. and H. woodii Merr. contain high concentrations of the cyclopentenyl fatty acid chaulmoogric acid and of hydnocarpic acid, whereas the seeds of many other species contain glycosides which, upon hydrolysis, discharge the highly toxic hydrocyanic acid. The percentages of individual fatty acids for the seed oils of H. kurzii and H. laurifolia respectively have been found to be (in %): hydnocarpic acid 23.0 and 33.9, chaulmoogric acid 29.6 and 35.0, gorlic acid 25.1 and 12.8, lower cyclic homologues 0.3 and 4.6, myristic acid 0.6 and 0.8, palmitic acid 8.4 and 5.6, stearic acid zero and 0.6, palmitoleic acid 6.0 and 1.3, oleic acid 5.4 and 3.6 and linoleic acid 1.6 and 1.8. Very pure hydnocarpic acid, chaulmoogric acid and gorlic acid have been prepared from the seed oil of H. laurifolia . The isolated acids were used as starting materials to synthesize the corresponding cyclopentenyl alkylmethane sulphonates (mesylates), cyclopentenyl alkanes, cyclopentenyl nitriles, cyclopentenyl alcohols, 1-0-cyclopentenyl and 1,2-0-cyclopentenyl alkylglyceryl ethers. Pure homohydnocarpic acid and homochaulmoogric acid could be obtained, as well as pure hormelic acid. The purity of the fatty products obtained was assessed using chromatographic and spectroscopic techniques and their physicochemical constants were determined. These products may find uses as potential pheromones or as chemotherapeutics against certain mycobacteria.
The oil from H. kurzii is active against Mycobacterium leprae; best results have been obtained by administering ethyl esters of the fatty acids (ethyl chaulmoograte) in combination with sulphone drugs.
Hydnocarpus oil alone and mixed with dapsone fed to mice infected with M. leprae inhibited the growth of the leprosy bacilli. Dapsone and oil combined had an additive inhibitory effect on the growth of the bacilli.
Flavonolignans isolated from H. laurifolia seed, namely hydnowightin, hydnocarpin, and neohydnocarpin, have demonstrated potent hypolipidemic activity in mice, lowering both serum cholesterol and triglyceride levels. Hydnowightin demonstrated the best lipid-lowering effect of the three compounds. Good anti-inflammatory and antineoplastic activity has been demonstrated for hydnocarpin in mice in vivo. The other two derivatives were not as active in these screens. All three compounds were moderately active against murine L-1210 leukaemia growth and demonstrated good activity against the growth of human KB nasopharynx, colon adenocarcinoma, osteosarcoma, and HeLa-S3 uterine growth. Hydnocarpin was the only compound of the three which was active against glioma growth. Hydnocarpin and neohydnocarpin demonstrated significant activity against Tmolt3 leukaemia cell growth.
In India, a pomace of H. laurifolia was found to be nematicidal. Aqueous extract showed greater nematicidal activity than the steam distillate. The nematicidal property is not adversely affected either by boiling or by change in pH (4-10).
A petroleum ether extract of seed of H. laurifolia at up to 1000 ppm was moderately active as an antifeedant against 4th-instar larvae of the noctuid Spodoptera litura. Positive activity was correlated with the percentage of linoleic acid and oleic acid in the seed oil.
- Evergreen, dioecious or occasionally monoecious shrubs or small to medium-sized or rarely large trees up to 25(-50) m tall; bark surface usually smooth, sometimes cracking and scaly.
- Leaves alternate, simple, entire or serrate, variously asymmetrical at base; petiole thickened at apex; stipules early caducous.
- Flowers unisexual, 4-5-merous; sepals (3-)4-5, rarely 7-11, free or rarely slightly connate at base, imbricate; petals 4-5, rarely up to 14, with an in general densely pilose scale at base inside; male flowers in an axillary cyme or rarely in a raceme-like cauliflorous or ramiflorous panicle, with 5-many stamens; female flowers 1-3 together, with superior ovary, unilocular with many ovules, stigma sessile and with 3-5 spreading branches, often shortly bifid.
- Fruit an indehiscent, globose to obovoid drupe.
- Seeds closely packed, with membranous aril, endosperm albuminous-oily.
- Seedling with epigeal germination; cotyledons emergent or not, leafy; hypocotyl elongated; all leaves arranged spirally, conduplicate.
Growth and development
Flowering in Hydnocarpus is usually once a year, but the period differs per region. Fruit takes rather long to develop, for instance about 7-8 months for H. anthelmintica and H. woodii. The fruits are probably dispersed by animals, but there are no reports of this.
Other botanical information
There is widespread confusion on another Flacourtiaceae species Gynocardia odorata R.Br. that is reputed to yield seed oil comparable to Hydnocarpus. Unlike real Hydnocarpus oil, this oil is neither optically active, nor does it have any therapeutic activity.
Most Hydnocarpus species are found scattered in primary rain forest, in well-drained, flat locations or on hillsides, on sandy or clayey soils, up to 1000(-1800) m altitude, occasionally in beach forest or on rocky outcrops. The medicinally important species prefer well-drained, sandy, alluvial flats and floodplains along rivers, or at least moist but well-drained surroundings.
Propagation and planting
Hydnocarpus is usually propagated by seed. Seeds are separated from the fruit pulp by washing. Seed of H. kunstleri (King) Warb. germinated for 50% in 4-8 months and that of H. woodii for about 50% in 5 months to over 2 years. Under natural conditions, seed germinates during the rains shortly after falling to the ground. Seedlings and saplings should be grown under shade.
Traditionally, fallen fruits of Hydnocarpus were simply collected in the forest, giving often rise to a mixture of species being collected, as several Hydnocarpus contain chaulmoogric acid and hydnocarpic acid. The result was a very variable raw product. Accessibility of the floodplains at the time of harvesting was often difficult.
Handling after harvest
Seeds tend to go rancid rather quickly. Therefore ripe fruits should be opened and the fruit pulp and aril removed from the seeds. Seeds are then washed and dried in the sun. Sun-dried seeds, either whole or broken, are cold-pressed or pressed under concurrent heating to extract the oil. The chemical composition of the end-product of these methods varies.
Genetic resources and breeding
With the exception of H. heterophylla Blume, H. kunstleri and H. woodii, most Hydnocarpus have a limited geographical distribution. Together with the often low density at which species are present, this means there is a serious risk of genetic erosion. Because of their importance as leprosy drugs, many Hydnocarpus species were planted in botanical gardens in the Malesian region, South America and Central Africa, and some of them may still be present.
The use of seed oil of Hydnocarpus to treat leprosy has been replaced by synthetic drugs. However, with the renewed interest in medicines of plant origin, investigations of the oils and extracts of Hydnocarpus seem worthwhile, especially for the treatment of various skin diseases. The cyclopentenyl fatty acids and their synthesized derivatives are of interest as antibacterial compounds, whereas the flavonolignans may have potential as anti-inflammatory and anti-cancer agents.
- Abdel-Moety, E.M., 1989. New products from lipids, cyclopentenyl fatty acids as starting materials. Grasas Aceites 40(1): 15-21.
- Burkill, I.H., 1966. A dictionary of the economic products of the Malay Peninsula. 2nd edition. Vol. 1. Ministry of Agriculture and Co-operatives, Kuala Lumpur, Malaysia. pp. 1224-1229.
- Kumar, B.H. & Thakur, S.S., 1988. Certain non-edible seed oils as feeding deterrents against Spodoptera litura Fb. Journal of the Oil Technologists' Association of India 20(3): 63-65.
- Ong, H.C., 1998. Hydnocarpus Gaertn. In: Sosef, M.S.M., Hong, L.T. & Prawirohatmodjo, S. (Editors): Plant Resources of South-East Asia No 5(3). Lesser-known timbers. Backhuys Publishers, Leiden, the Netherlands. pp. 296-298.
- Pillai, S.N. & Desai, M.V., 1975. Antihelminthic property of "Marotti" cake (Hydnocarpus laurifolia). Pesticides (India) 9(4): 37-39.
- Sengupta, A., Gupta, J.K., Dutta, J. & Ghosh, A., 1973. The component fatty acids of chaulmoogra oil. Journal of the Science of Food and Agriculture 24(6): 669-674.
- Sharma, D.K. & Hall, I.H., 1991. Hypolipidemic, anti-inflammatory, and antineoplastic activity and cytotoxicity of flavonolignans isolated from Hydnocarpus wightiana seeds. Journal of Natural Products 54(5): 1298-1302.
- Sleumer, H., 1938. Monographie der Gattung Hydnocarpus Gaertner [Monograph of the genus Hydnocarpus Gaertner]. Botanische Jahrbucher 69: 1-94.
- Sleumer, H., 1985. The Flacourtiaceae of Thailand. Blumea 30: 217-250.
- Quisumbing, E., 1978. Medicinal plants of the Philippines. Katha publishing Co., Quezon City, the Philippines. pp. 628-629.
Khozirah Shaari & L.S.L. Chua