873

12(2): Medicinal and poisonous plants 2

Acalypha L.

Sp. pl. 2: 1003 (1753); Gen. pl. ed. 5: 436 (1754).

EUPHORBIACEAE

x = unknown; Acalypha hispida: 2n = 112, Acalypha indica: 2n = 20, 28, Acalypha lanceolata: 2n = 40, Acalypha wilkesiana: 2n = 20, 80, 120, 140, 180, 200

Major species Acalypha indica L., Acalypha wilkesiana Müll. Arg.

Copper-leaf, three-seeded mercury (En)(for ornamentals only).

Acalypha is widespread throughout the tropics, and comprises about 430 species. In Thailand about 10 species occur, in New Guinea about 18, in Borneo about 4, in Sumatra about 6, in the Philippines about 16 and in Vietnam about 10.

A considerable number of Acalypha is used in local medicine for a variety of complaints. Uses may vary from region to region, sometimes depending on the availability of specific species. The leaves of Acalypha indica are used in decoction or powdered for their laxative properties. They are applied Externally to sores and ulcers. The expressed juice mixed with oil, lime or salt is externally applied to rheumatoid arthritis, and to cure scabies and other skin affections. In addition, the whole plant is used as an expectorant. In the Philippines, the leaves of Acalypha caturus Blume (synonym Acalypha cardiophylla Merr.) are externally applied to the head to relieve headache and the bark is applied on deep ulcers. In the Solomon Islands leaves of Acalypha novoguineensis Warb. are used as an antiseptic and externally applied to reduce swellings.
The shoots of Acalypha indica and Acalypha wilkesiana without flowers are eaten as a cooked vegetable. Acalypha hispida and Acalypha wilkesiana are widely grown as pot plants and garden ornamentals all over the world.

As medicinal uses of Acalypha are found at local level only, trade statistics are not available. The ornamental Acalypha, commonly planted as a hedge plant, are commercially grown as pot plants as well, but trade statistics are only available for Western countries.

The dried aerial parts of Acalypha indica are known to contain a cyanogenic glycoside, acalyphine (0.3%) which is a 3-cyanopyridone derivative. Older publications also mention the alkaloid 'acalyphine', without structural elucidation. This compound is most probably identical to triacetonamine, mentioned in more recent reports. Other constituents include sterols ('BETA'-sitosterol, 0.1%), a resin and an essential oil. In addition to hydrocyanic acid, Acalypha indica contains other substances which cause intense, dark chocolate brown discolouration of blood and gastro-intestinal irritation in rabbits. Furthermore, ingestion of herbal medicine containing Acalypha indica may lead to haemolysis in patients suffering from glucose-6-phosphatase dehydrogenase deficiency. Crude extracts of shoots, leaves and roots show antibacterial and antifungal activity. Activity against gram-positive bacteria strains is more pronounced than against gram-negative strains. Susceptible fungi include Aspergillus niger and Candida albicans.
An amide (acalyphamide I, isolated as its acetate), together with the modified dipeptide aurantiamide and its acetate were isolated from the leaves and twigs of Acalypha indica . Acalyphamide I has been characterized as an amide of tyramine (p-hydroxy-'BETA'-phenethylamine) and dotriacontanoic acid (C₃₁H₆₃COOH). Aurantiamide and its acetate are the first modified dipeptides to be reported from an Euphorbiaceae, and acalyphamide is one of the few natural tyramine amides. The occurrence of these compounds is therefore of considerable biogenetic and chemotaxonomic significance.
Very little is known about the chemical constituents of Acalypha wilkesiana, although information is available on biological activities. The methanol extract of the leaves contains phenolic acids. In an ethanol extract of the leaves, no cyanogenic compounds or triacetonamine could be detected. Screening of an extract of the leaves of Acalypha wilkesiana for antimicrobial activity using the agar diffusion method, showed activity against 7 test organisms: Bacillus cereus, Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, Serratia marcescens and Staphylococcus aureus. In another experiment, water, ethanol, chloroform and hexane extracts of Acalypha wilkesiana leaves were investigated for in vitro antimicrobial activities by agar-diffusion and tube-dilution techniques. The water and ethanol extracts inhibited the growth of standard and local strains of bacteria and fungi including Staphylococcus aureus, Trichophyton rubrum, Trichophyton mentagrophytes, Candida albicans and Aspergillus flavus. The water extract did not exert any inhibitory action on Klebsiella pneumoniae and Proteus mirabilis, while the ethanol extract was active. In general, the water extract was found to be bacteriostatic and fungistatic in action, while the ethanol extract was uniformly microbicidal in effect at a mimimal inhibitory concentration (MIC) of 1—64 mg/ml.
The water extract of the leaves of Acalypha wilkesiana was subjected to a clinical laboratory study in Nigeria to assess its efficacy: i.e. ability to clear standard microorganisms in agar plates and to stop symptoms and clear skin lesions of eczema cases over a 3-week study period. The extract showed significant antibacterial and antifungal properties in vitro. Furthermore, it was found to be reasonably useful in the treatment of 4 patients with eczema using topical preparations (cream or ointment), since no allergy or irritation was documented.
Ethanol extracts of Acalypha indica show selective activity against vesicular stomatitis viruses at an MIC of 5—100 µg/ml. Cytotoxic activity was observed against HeLa cell lines at a CD₅₀ of 1—100 µg/ml.
Analysis of the shoots of Acalypha indica yielded per 100 g edible portion: water 80.5 g, protein 6.7 g, fat 1.4 g, carbohydrates 6.0 g, fibre 2.3 g, ash 3.1 g; calcium 667 mg, phosphorus 99,0 mg, iron 17.3 mg and vitamin C 147 mg. The energy value is 269 kJ/100 g.

Shrubs, rarely small trees, occasionally scrambling, or nettle-like perennial or annual herbs, mostly monoecious. Leaves simple, alternate, crenate, dentate or subentire, palmati- or penninerved, petiolate; stipules lanceolate, subulate or setaceous, sometimes minute. Inflorescence unisexual or bisexual; when bisexual the sexes are very diversely arranged; male flowers commonly in slender dense-flowered spikes, with 1—few female flowers at the base, or female flowers alone in relatively short and less dense-flowered racemes; bracts often lobed or dentate and accrescent in fruit. Male flower mostly minute, calyx closed in bud, splitting valvately into 4 segments; petals absent; disk absent; stamens 8—12, free; pistillode absent. Female flower with 3—5 sepals, shortly connate, imbricate; ovary 2—3 locular, 1 ovule per locule, styles mostly conspicuous and laciniate. Fruit a small 2—3-locular capsule. Seed rounded, smooth sometimes with a conspicuous hilum or caruncle; testa crustaceous; albumen fleshy; cotyledons broad, flat.

Acalypha hispida, Acalypha indica and Acalypha wilkesiana flower throughout the year in regions without a pronounced dry season.

An overall revision of Acalypha for the Malesian region is badly needed. Some species appear to be well defined whereas other species complexes may well be considered as broad aggregate species. Here the more narrowly defined conservative concept has been followed. Two well-known ornamentals, Acalypha godseffiana Masters and Acalypha hamiltoniana Bruant, are regarded as cultigens and derived from Acalypha wilkesiana. In general the widely cultivated Acalypha species are polyploids.

Acalypha is found in a wide range of vegetation types on various soils.

Under greenhouse conditions Acalypha hispida and Acalypha wilkesiana are propagated from cuttings which root in 4 weeks at 22?C soil temperature and are ready for marketing in 6 months. Acalypha hispida is pinched only once to produce large showy plants whereas Acalypha wilkesiana hybrids must be pinched at least twice to produce low, compact plants that do not need chlormequat treatment. The most effective medium for in vitro propagation of Acalypha wilkesiana is composed of Murashige and Skoog medium and vitamins, 2% sucrose, 170 mg/l NaH₂PO₄.H₂O and 0.2 mg/l butyric acid (BA) without auxin. A modified White's medium without auxin gave effective rooting in 10—14 days. Plantlets set into soil in the greenhouse were ready for transplanting outdoors in 45 days.

Acalypha indica is often considered an obnoxious weed. Its leaves may suffer from Alternaria leaf spot; in India it is sometimes severely affected by Pseudocercospora acalyphae. Roots may suffer from nematode infestation (e.g. Meloidogyne spp.).

Leaves, roots or whole plants of Acalypha indica are harvested when in full bloom.

After harvesting, plants of Acalypha indica are simply dried for future use.

Acalypha wilkesiana with mosaic foliage is raised in Denmark, under the name Acalypha cv. Musaica and includes the multicoloured cultivars 'Batik', 'Harlekin' and 'Kankan'. In the United Kingdom a multitude of cultivars of Acalypha wilkesiana is distinguished by foliage colour and pattern like 'Ceylon', 'Hoffmanna', 'Macafeeana', 'Macrophylla', 'Marginata', 'Miltonia', 'Moorea', 'Musaica' and 'Obovata'.

Little is known about the chemical constituents and biological activity of Acalypha. They are, however, of local importance e.g. in the treatment of skin infections or eczemas.

Alade, P.I. & Irobi, O.N., 1993.Antimicrobial activities of crude leaf extracts of Acalypha wilkesiana. Journal of Ethnopharmacology 39(3): 171—174.
Ali, A.M., Mackeen, M.M., El-Sharkawy, S.H., Hamid, J.A., Ismail, N.H., Ahmad, F.B.H. & Lajis, N.H., 1996. Antiviral and cytotoxic activities of some plants used in Malaysian indigenous medicine. Pertanika; Journal of Tropical Agricultural Science 19(2—3): 129—136.
Forster, P.I., 1994. A taxonomic revision of Acalypha L. (Euphorbiaceae) in Australia. Austrobaileya 4(2): 209—226.
Jekayinfa, A.O., George, A.O. & Jaiyeoba, K.T., 1997. Acalypha wilkesiana: preliminary in vitro microbiological and clinical trial on dermatitis. African Journal of Health Sciences 4(1): 39—42.
Lamabadusuriya, S.P. & Jayantha, U.K., 1994. Acalypha indica induced haemolysis in G6PD deficiency. Ceylon Medical Journal 39(1): 46—47.
Talapatra, B., Goswami, S. & Talapatra, S.K., 1981. Acalyphamide a new amide and other chemical constituents of Acalypha indica. Indian Journal of Chemistry section B Organic Chemistry including Medicinal Chemistry 20(11): 974—977.

Arbayah H. Siregar

Acalypha australis
Acalypha grandis
Acalypha hellwigii
Acalypha hispida
Acalypha indica
Acalypha lanceolata
Acalypha siamensis
Acalypha wilkesiana

Siregar, A.H., 2001. Acalypha L.. In: van Valkenburg, J.L.C.H. and Bunyapraphatsara, N. (Editors): Plant Resources of South-East Asia No 12(2): Medicinal and poisonous plants 2. PROSEA Foundation, Bogor, Indonesia. Database record: prota4u.org/prosea

The following species in this genus are important in this commodity group and are treated separatedly in this database:
Acalypha australis
Acalypha grandis
Acalypha hellwigii
Acalypha hispida
Acalypha indica
Acalypha lanceolata
Acalypha siamensis
Acalypha wilkesiana