Curcuma (PROSEA)

Plant Resources of South-East Asia
Introduction

Protologue: Sp. pl. 1: 2 (1753); Gen. pl. ed. 5: 3 (1754).

Family: Zingiberaceae

Chromosome number: x= 16, 21; C. aurantiaca: 2n= 42, C. longa: 2n= 32, 62-64, C. petiolata: 2n= 64, C. xanthorrhiza: 2n= 63, C. zedoaria: 2n= 63, 64, 66

Major species

Curcuma longa L.,
C. xanthorrhiza Roxb.,
C. zedoaria (Christm.) Roscoe.

Vernacular names

Curcuma (En), turmeric (En)
Curcuma (Fr)
Indonesia: temu
Malaysia: temu
Laos: kachièw, khminz
Thailand: khamin
Vietnam: nghệ.

Origin and geographic distribution

Curcuma comprises some 40-50 species and is native to the Indo-Malesian region, from India to Indo-China, Taiwan and Thailand, throughout Malesia, towards the Pacific and northern Australia. Some 20 species are present within Malesia. Several species have been introduced elsewhere in tropical and subtropical areas. The centre of diversity is located in India.

Uses

Rhizomes of many Curcuma species are used medicinally, often to treat liver diseases (jaundice, gallstones), but also for various abdominal complaints. They are considered stomachic, carminative, haematic and styptic. Furthermore, they are sometimes applied to asthma, cough and bronchial catarrh, or to treat itch, scurf, skin infections in general, or are applied to wounds and ulcers. The rhizomes of several Curcuma species are a well-known source of spice (turmeric), of starch and of a yellow-orange dye. The latter may be used in colouring clothing and food as such, or in the preparation of other dyes.

Production and international trade

Annually about 20 000 t of cured dried whole rhizomes of turmeric (C. longa) enter into international trade. India is the largest producer with 400 000 t from 130 000 ha and dominates the international trade. Within Malesia, Indonesia is a major producer. All Asian producers are heavy consumers as well and some are even net importers. No information is available, except on C. longa.

Properties

All Curcuma species are rich in essential oils. On distillation, rhizomes of C. longa yield 1.3-5.5% essential oil whose main constituents are sesquiterpenes called turmerones (about 60%, e.g. ar-turmerone, α-, β-turmerone) and the sesquiterpene zingiberene (about 25%). Dried rhizomes of C. xanthorrhiza contain on average 3.8% essential oil with ar-curcumene, xanthorrhizol, α-, β-curcumene and germacrene as major constituents. The compounds cyclo-isoprenemyrcene and p-tolylmethylcarbinol which are often mentioned as essential oil constituents in older literature are artifacts which originate from the distillation process and fractionation of oils at higher temperatures. The phenolic sesquiterpene xanthorrizol is species specific: its presence can thus be used to distinguish C. xanthorriza from e.g. C. longa. In young rhizomes the essential oil content may be higher; 29.5% essential oil has been found in rhizomes that are just beginning to develop. Dried rhizomes of C. zedoaria contain about 1.5% essential oil with cineol, borneol, d-camphor, camphene and d-α-pinen as main constituents. A further group of constituents in the rhizomes of Curcuma species are the curcuminoids. Curcuminoids are referred to as curcumin (diferuloyl methane or curcumin I) and its derivatives desmethoxy-curcumin (feruloyl-p-hydroxycinnamoyl methane or curcumin II) and bisdesmethoxy-curcumin (bis-(p-hydroxycinnamoyl)-methane or curcumin III). The name curcumin is also often used for the complex yellow-orange mixture of curcuminoids as a whole, isolated from the plant. Curcumin has some broad-spectrum antimicrobial activity, but therapeutic utility of C. longa for this indication has not been recognized. Curcumin I derived from C. longa inhibited the 5-lipoxygenase activity in rat peritoneal neutrophils as well as the 12-lipoxygenase and the cyclooxygenase activities in human platelets. In a cell-free peroxidation system, curcumin exerted strong antioxidative activity. Thus, its effects on the dioxygenases are probably due to its reducing capacity. Oral administration of the antioxidant curcumin, from C. longa, at a concentration of 200 μmol/kg body weight significantly reduced the lung collagen hydroxyproline in whole-body γ-irradiated rats. Serum lipid and liver lipid peroxidation, which were increased by irradiation, were reduced significantly by the antioxidant treatment. The increased frequency of micronucleated polychromatic erythrocytes after whole-body irradiation of mice was significantly reduced by antioxidant treatment. The actual quantity of the three known curcuminoids, which in fact are all potent antioxidants, does not fully explain the antioxidant activity of the extracts of several Curcuma species.

Three non-phenolic diarylheptanoids isolated from C. xanthorrhiza have been identified as trans,trans-1,7-diphenyl-1,3-heptadien-4-one (alnustone), trans-1,7-diphenyl-1,3-hepten-5-ol, and trans,trans-1,7-diphenyl-1,3-heptadien-5-ol. They all exerted significant anti-inflammatory activity in the carrageenin-induced hind paw oedema assay in rats. 1E,3E,1,7-Diphenylheptadien-5-one exerted potent anti-inflammatory activity (ID₅₀value of 67 μg/ear, topically applied) in an ethyl-phenylpropiolate-induced ear oedema model in rats. The ED₅₀ value of the water extract of C. longa after intraperitoneal administration was 4.7 mg/kg in carrageenin-induced rat paw oedema, that of the alcoholic extract 307 mg/kg, of the petroleum ether extract 40.7 mg/kg, of the sodium curcuminate 2.1 mg/kg and that of curcumin 8.7 mg/kg, but an ED₅₀ of only 0.36 mg/kg has also been reported; the oral ED₅₀ of curcumin was 100.2 mg/kg in mice and 48.0 mg/kg in rats. The mechanism by which curcumin inhibits inflammation is still poorly understood. Curcumin has been found to inhibit several types of phospholipases, notably phospholipase D, and it also inhibited phospholipase D activation induced by 12-0-tetradecanoylphorbol-13-acetate. This suggests that the anti-inflammatory and anti-carcinogenic action of curcumin is partly due to the inhibition of phospholipase D and prostaglandin synthesis.

The aqueous extracts of the crude drug of C. aeruginosa showed significant protective effects against CCl4-induced liver injury in rats and D-galactosamine/lipopolysaccharide-induced liver injury in mice. The aqueous extract of the rhizomes of C. xanthorrhiza significantly reduced the acute elevation of serum glutamate oxaloacetate transaminase (alanine aminotransferase) and serum glutamate pyruvate transaminase (aspartate aminotransferase) induced by paracetamol or CCl4 in mice; it alleviated the degree of liver damage 24 hours after intraperitoneal administration of the hepatotoxic compounds. When the aqueous extract of rhizomes of C. xanthorrhiza (100 mg/kg by oral administration) was investigated in rats treated with β-D-galactosamine (288 mg/kg, intraperitoneally administered), the extract reduced the elevated concentrations of alanine aminotransferase and aspartate aminostransferase, and reduced histopathological changes induced 24 hours after administration. Antihepatotoxic activity of the rhizome of C. longa has also been reported.

Active principles other than curcuminoids from C. xanthorrhiza can modify the metabolism of lipids and lipoproteins. α-Curcumene which can make up to about 65% of the essential oil of C. xanthorrhiza was shown to lower triglyceride levels in rats.

Streptozotocin-induced diabetic rats maintained for 8 weeks on a diet containing 0.5% curcumin showed a significant decrease in blood triglyceride and phospholipid levels, as do diabetic animals maintained on a high cholesterol diet, where hypercholesterolaemia and phospholipidemia is even more severe. In streptozotocin-induced diabetic rats which were fed on purified diets containing 5% C. xanthorrhiza the diabetic symptoms improved. This diet specifically modified the amount and composition of faecal bile acids. The essential oil of C. longa and C. xanthorrhiza and its component d-camphor caused a persistent increase of bile secretion in anaesthetized rats. p-Tolylmethylcarbinol activates the secretion of bile from the gall bladder and curcumin causes rhythmic contractions of the gall bladder. Furthermore, the liquid balm of C. xanthorrhiza was found to lower the total cholesterol content and the total lipid content in rabbits.

Furanogermenone and (4S,5S)-(+)-germacrone-4,5-epoxide had a potent preventive effect against stress ulceration. Moreover, oral administration of fractions of the methanol extract significantly inhibited the formation of both HCl-induced and indomethacin-induced gastric ulcers.

Water extracts of C. zedoaria inhibited the growth of mouse L5178Y leukaemia cells in a dose-dependent manner; inhibitory effects of alcohol extracts were not significant. The bisabolane sesquiterpenoids α-curcumene, ar-turmerone, β-atlantone and xanthorrhizol were isolated as major antitumour constituents from the rhizomes of C. xanthorrhiza. Curcumin from C. longa inhibited the growth of hormone-dependent and -independent, and multi-drug resistant human breast tumour cell lines in a time- and dose-dependent way. The effect was correlated with the compound's inhibition of ornithine decarboxylase activity. A 5% turmeric diet significantly inhibited the tumour burden and tumour incidence in fore-stomach tumours induced by benzo-[a]-pyrene in Swiss mice and oral mucosal tumours induced by methyl-(acetoxymethyl)-nitrosamine in Syrian golden hamsters. Curcumin isolated from C. longa inhibited human colon cancer cell proliferation in vitro, mainly by causing cells to accumulating in the G2/M phase; this effect is independent of its ability to inhibit prostaglandin synthesis. In an assay studying the promotion of tumours induced by croton oil, 90% of the control animals had papillomas in the 10th week of tumour initiation, compared with only 10% of animals treated with curcumin III, 20% of the animals treated with curcumin II, and 40% of animals treated with curcumin I. Of the synthetic curcuminoids studied, salicylcurcuminoid, which had caused no papillomas by the 10th week, was the most potent anti-carcinogen. In vitro and in vivo tests with aqueous and ethanolic extracts of C. longa and C. xanthorrhiza showed marked antitumour activity. Topical application of curcumin together with 5 nmol of the tumour-promoting agent 12-0-tetradecanoylphorbol 13-acetate (TPA) twice weekly inhibited the number of TPA-induced tumours by 39% at a dose of 1 μmol, 77% at a dose of 3 μmol, and 98% at a dose of 10 μmol.

When the antispasmodic activity of C. longa was tested using the isolated guinea-pig ileum, the ED₅₀ values of sodium curcuminate were 30.2 μg/ml (nicotine), 77.2 μg/ml (acetylcholine), 82.8 μg/ml (5-hydroxytryptamine), 81.8 μg/ml (histamine) and 171.4 μg/ml (barium chloride), respectively. Concentrations of this magnitude will not appear in the blood, because if curcumin is absorbed in the blood at all, it is rapidly metabolized in the liver and excreted through the bile.

ar-Turmerone isolated from C. longa is a potent antidote to snake bite. Furthermore, curcumin has a median inhibitory concentration (IC₅₀) for strand transfer of 40 μM on purified human immunodeficiency virus type 1 (HIV-1) integrase.

In a clinical study on turmeric, significant improvement was observed in patients with rheumatoid arthritis or with respiratory diseases. Limited clinical trials on the effects of orally administered turmeric on peptic ulcers showed promising results. Another clinical trial carried out in Thailand showed good results on dyspepsia.

The inhibitory activity of turmeric oil and curcumin isolated from C. longa was tested in Trichophyton rubrum-induced dermatophytosis in guinea-pigs. Turmeric oil at dilutions of 1:40-1:320 inhibited the dermatophytes. At dilutions of 1:40-1:80 it inhibited 4 isolates of pathogenic fungi. Curcumin had no inhibitory effect on either dermatophytes or pathogenic fungi. The essential oil from turmeric showed a moderate antibacterial activity against Escherichia coli.

Curcumin from C. longa has demonstrated phototoxicity to several species of bacteria and to mammalian cells, using a rat basophilic leukaemia cell model, under aerobic conditions. The rhizome powders of C. longa and C. zedoaria applied on Cajanus cajan (L.) Millsp. and Vigna radiata (L.) Wilczek seed before being stored were moderately effective to effective against the pulse beetle Callosobruchus chinensis; the LD₅₀ of the extract of C. longa was 0.05-0.1 ppm. Insecticidal as well as antifungal activity of Curcuma species has also been reported. The extract of the rhizome of C. zedoaria showed significant antifungal activity against Cladosporium cladosporioides.

In a contact residue bioassay the most active sesquiterpenoids xanthorrhizol and furanodienone showed pronounced toxicity against neonate larvae of Spodoptera littoralis. The LD₅₀ of xanthorrhizol following topical application was found to vary between 6.92 and 8.13 μM/kg fresh weight irrespective of the larval stages studied. Xanthorrhizol, however, did not cause significant mortality of neonate larvae when incorporated into artificial diet, suggesting that the compounds are inactived in the larval gut. The chloroform extract of C. longa proved economically useful in the treatment of Trichophyton verrucosum ringworm in cattle.

Description

Perennial, rhizomatous, erect herbs with spurious stems; subterranean parts fleshy, aromatic, roots fleshy, often bearing ellipsoidal tubers.
Leafy shoots bearing bladeless sheaths forming a spurious stem on which less than 10, distichous, pinnately veined leaves develop; petiole well developed; ligule narrow. Inflorescence either terminal on a leafy shoot or on a separate shoot, spike-like, cylindrical; peduncle well developed; spike with large bracts which are joined for about half their length, forming pouches from which a cincinnus of 2-7(-10) flowers arises, uppermost bracts often larger and forming the "coma".
Flowers bisexual, zygomorphic; bracteoles thin, not connate, enclosing the flower bud; calyx tubular, split unilaterally, about half as long as the corolla, unequally toothed; corolla tube united with the staminal tube, cylindrical below, cup-shaped above, lobes 3, translucent white or pink to purplish, the dorsal lobe hooded and ending in a hollow hairy point; staminodes 3, petaloid, the anterior one, called labellum, obovate, with a thickened median band, the 2 lateral ones elliptical-oblong, their inner edges folded under the hood of the dorsal corolla lobe; fertile stamen 1, filament short, broad, anther versatile, thecae parallel, often spurred at base, connective sometimes enlarged at the apex into a small crest; ovary inferior, 3-locular with axillary placentation and many ovules, style 1, filiform with a cup-shaped, 2-lobed stigma, held between the thecae.
Fruit an ellipsoid capsule, crowned by the calyx remnants; pericarp thin, irregularly dehiscing.
Seeds embedded in mucilage, ellipsoidal, with a lacerate aril of few segments free to the base.

Growth and development

The primary rhizome of Curcuma is at first surrounded by small scales, that remain visible by their annular scars. Secondary and tertiary rhizomes develop from axillary buds of the primary and secondary rhizome, respectively. In Java, most Curcuma species flower in September-February(-March) and June-August; C. aeruginosa, C. purpurascens and C. xanthorrhiza flower almost throughout the year. Flowers generally open late in the afternoon and wither before the next morning. Although flowering is abundant and flowers have been observed to be frequently visited by insects searching for pollen, in Java only C. aurantiaca forms fruits. This is probably because it is diploid whereas virtually all other Curcuma are triploid. In Java, no dormancy period was observed after flowering, but this phenomenon has been reported from northern India, where it usually occurs during winter. Vesicular-arbuscular mycorrhizae have been observed in C. longa and C. zedoaria; many of the sporulating mycorrhizae belong to the genus Glomus.

Other botanical information

Curcuma belongs to the tribe Hedychieae and is characterized by the partly fused bracts. Its taxonomy is still unsatisfactory, the various species being very closely related and sometimes doubtfully distinct. Intensive cultivation, and possibly hybridization, makes it difficult to distinguish species and a thorough revision is badly needed. The fact that many "species" appear to be triploids may be an indication of an origin from cultivation. Although the taxonomic treatment of the Flora of Java is not followed here, the rigorous lumping of species may eventually be justified. As C. aurantiaca is the only Javanese species producing fruit, it may indeed be the only indigenous species of Java. Two subgenera are distinguished: Curcuma with elongated rhizomes, a non-auriculate ligule, conspicuous coma bracts and longitudinally grooved and folded staminodes, and Paracurcuma with short rhizomes, an auriculate ligule, inconspicuous coma bracts and straight staminodes.

Ecology

In the wild, most Curcuma are found in the undergrowth of tropical or subtropical forests or slightly shaded places such as forest margins and plantations, up to 1150 m altitude, but in the Himalayan foothills up to 2000 m. They grow best on well-drained, loamy or alluvial, fertile, friable soils and cannot stand waterlogging. They often occur in deciduous monsoon forest, in Java especially in teak forest, in areas with an annual rainfall of about 1000-2000 mm, exceptionally up to 4000 mm.

Propagation and planting

Propagation of Curcuma is by mother (primary) rhizomes, cut mother rhizomes or by finger rhizomes (also referred to as daughter or lateral rhizomes). Seed rhizomes need to be stored for 2-3 months prior to planting. Finger rhizomes of C. longa store better, are more tolerant to wet soil conditions and can be planted at a lower rate. C. longa is planted in ridges at 30-40 cm distance or in flat beds usually at a spacing of 25 cm, although good results have been obtained using a spacing of 15 cm. C. xanthorrhiza is planted at a distance of 60 cm and C. zedoaria at 25-45 cm. Curcuma is best planted under partial shade and in soils that have been ploughed or turned over to a depth of 30 cm.

Husbandry

Mulching increases resprouting of the Curcuma rhizomes and rhizome yield and should be done at planting and 2 months thereafter. Curcuma requires heavy manuring to obtain a high yield; about 25 t/ha of manure is usually recommended. Recommendations for fertilization vary widely between locations.

Diseases and pests

Leaf spot or leaf blotch caused by Taphrina malucans and rhizome rot caused by Pythium aphanidermatum are considered the most important diseases of turmeric. Bacterial wilt caused by Pseudomonas solanacearum has been found killing C. mangga in Java.

Harvesting

Curcuma propagated by whole mother rhizomes can be harvested after 8-12 months; if propagated from cut mother rhizomes or finger rhizomes, plants can be lifted after 2 years. Rhizomes of C. longa begin to develop about 5 months after planting and can be lifted after 7-10 months when the lower leaves turn yellow. At harvesting, care should be taken not to damage the rhizomes; the finger rhizomes are separated from the mother rhizomes.

Yield

Yields of Curcuma are 17-23 t/ha when irrigated. Under rainfed conditions 6.5-9 t/ha are obtained for C. longa, 20 t/ha for C. xanthorrhiza and 7.5-12 t/ha for C. zedoaria.

Handling after harvest

Whole rhizomes of Curcuma are dried, or first cut in slices and then dried.

Genetic resources and breeding

A germplasm collection of about 500-600 C. longa accessions is maintained in India, but crop improvement of turmeric is limited. Neither germplasm collections nor breeding activities are known to exist for the other Curcuma species.

Prospects

Many Curcuma species are planted in home gardens by small farmers. Hardly any efforts have been undertaken in agronomy, plant breeding and pest management, not even in the well-known spice C. longa, to improve performance. C. longa and C. xanthorrhiza show promising prospects for medicinal applications but research is needed to establish their therapeutic value.

Literature

Ammon, H.P.T. & Wahl, M.A., 1991. Pharmacology of Curcuma longa. Planta Medica 57(1): 1-7.
Anto, R.J., George, J., Babu, K.V., Rajasekaran, K.N. & Kuttan, R., 1996. Antimutagenic and anti carcinogenic activity of natural and synthetic curcuminoids. Mutation Research 370(2): 127-131.
Dahal, K.R. & Salma Idris, in prep. Curcuma longa L. In: De Guzman, C.C. & Siemonsma, J.S. (Editors): Plant Resources of South-East Asia 13. Spices.
Halijah Ibrahim & Jansen, P.C.M., 1996. Curcuma Roxburgh, Curcuma xanthorrhiza Roxburgh, Curcuma zedoaria (Christmann) Roscoe. In: Flach, M. & Rumawas, F. (Editors): Plant Resources of South-East Asia No 9. Plants yielding non-seed carbohydrates. Backhuys Publishers, Leiden, the Netherlands. pp. 72-78.
Hikino, H., 1985. Antihepatotoxic activity of crude drugs. Yakugaku Zasshi 105(2): 109-118.
Lin, S.C., Lin, C.C., Lin, Y.H., Supriyatna, S. & Teng, C.W., 1995. Protective and therapeutic effects of Curcuma xanthorrhiza on hepatotoxin-induced liver damage. American Journal of Chinese Medicine 23(3-4): 243-254.
Lin, S.C., Teng, C.W., Lin, C.C., Lin, Y.H. & Supriyatna, S., 1996. Protective and therapeutic effect of the Indonesian medicinal herb Curcuma xanthorrhiza on β-D-galactosamine-induced liver damage. Phytotherapy Research 10(2): 131-135.
Masuda, T., Isobe, J., Jitoe, A. & Nakatani, N., 1992. Antioxidative curcuminoids from rhizomes of Curcuma xanthorrhiza. Phytochemistry 31(10): 3645-3647.
Prucksumand, C., Indrasukesri, B., Leethochawalit, H., Nilvises, N., Prijavudhi, A. & Wimolwattanapun, S., 1986. Effect of the long turmeric (Curcuma longa Linn.) on healing of peptic ulcer: a preliminary report of 10 cases. Thai Journal of Pharmacology 8(3): 139-151.
Thamlikitkul, V. et al., 1989. Randomized double blind study of Curcuma domestica Val. for dyspepsia. Journal of the Medical Association of Thailand 72(11): 613-620.

Selection of species

Authors

Trimurti H. Wardini & Budi Prakoso