Anisomeles (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Anisomeles R.Br.

Protologue: Prodr.: 503 (1810).

Family: Labiatae

Chromosome number: x= 17; A. indica: 2n= 34, A. malabarica: 2n= 32

• Anisomeles indica (L.) O. Kuntze,
• A. malabarica (L.) R.Br. ex Sims.

• Catmint (En).

Anisomeles is a small genus of 3 species distributed through the Old World tropics, from Africa to Japan and southwards through Malesia to Australia. A. indica and A. malabarica are widely distributed but A. salviifolia R.Br. is restricted to Australia and New Guinea.

Catmint is widely used as a medicinal plant in India, Sri Lanka and China, and on a smaller scale in Malesia. It has a strong camphor-like smell. The plant is an astringent, carminative, febrifuge and tonic. A decoction of the leaves is used as an antirheumatic and stomachic, and also to treat uterine infections, kidney gravel, swellings and hypertension. The juice of the leaves is given to children for colic, dyspepsia and fever caused by teething. In the Philippines, A. indica is used for gastric catarrh and intermittent fevers. Inhaling the vapour of the hot infusion induces copious perspiration. The essential oil distilled from the leaves is applied externally as an embrocation in rheumatic arthritis.

In India, Vietnam and China, the essential oil of A. indica is also used as a hair dressing, as a flavouring for sago cakes, and as a compound in perfumes and cosmetics. In Africa, the plant is burnt as a mosquito repellent. In Indonesia, sun-dried leaves are used as fodder; they are more palatable than fresh leaves, but contain less fibre and protein. A. indica is also cultivated as an ornamental, in the whole of its distribution area.

A. malabarica is used in India as a remedy against bites and stings, and also for catarrh, flatulence and arthritis.

Anisomeles is mainly collected from the wild for medicinal purposes, but is also cultivated on a small scale in China. The dried plants are stocked in Chinese pharmacies throughout Malesia. Cultivation as an ornamental or for essential oil extraction is widespread. Statistics on production and international trade however, are not available; in India cultivation for essential oil is important.

The leaves of A. indica yield a volatile oil, which contains α-pinene, β-pinene (28%), δ-limonene, methyl-chavicol (9%), δ-α-thujone, citral (10%), borneol, 1,8-cineole (eucalyptol, 12%), nerol, α-terpineol, eugenol (25%), azulene and caryophyllene (15%). The essential oil shows antimicrobial activity against Bacillus anthracis, Proteus vulgaris, Salmonella stanley, S. newport, Streptococcus agalactiae, Staphylococcus aureus, Escherichia coli, Aspergillus fumigatus and A. niger.

Furthermore, several macrocyclic diterpenes which show pharmacological effects were isolated from the whole dried plant of A. indica. Ovatodiolide, 4,5-epoxyovatodiolide, anisomelic acid, 4,7-oxycycloanisomelic acid and 4-methylene-5-oxoanisomelic acid were found to inhibit the growth of KB cells in vitro. Ovatodiolide also inhibits the growth of Ehrlich carcinoma in mice, and 4-methylene-5-hydroxyovatodiolide possesses general cytotoxic effects. It also shows a transient hypotensive activity on the cardiovascular system in the anaesthetized dog, and inhibits myocardial contraction in the isolated frog heart. Furthermore, ovatodiolide, 4,7-oxycycloanisomelic acid, 4-methylene-5-hydroxyovatodiolide and 4-methylene-5-oxoanisomelic acid were found to possess an antagonistic effect on the Ca²⁺ current (calcium antagonistic activity), and the latter 3 compounds show inhibitory activity on the angiotensin converting enzyme. Ovatodiolide can also be isolated from the ethanolic extract of the roots of A. indica, as well as the flavonoid anisomelin (4',5'-dihydroxy-3',6,7-trimethoxyflavone).

Little is known about the biological activity of the compounds found in A. malabarica. Some diterpenes, anisomelic acid, anisomelol, anisomelide, anysomelyl acetate, 2-acetoxy melabaric acid and ovatodiolide were isolated from the aerial parts. Isolated sapogenins of β-amyrin C-28 carboxylic acid show spermicidal activity towards human semen in International Planned Parenthood Federation tests.

Application of the green leaves of A. indica to the soil reduces both pre- and post-emergence collar rot of chickpea caused by Sclerotium rolfsii.

Several components found in Anisomeles species are also found in Mentha (Labiatae), Amomum (Zingiberaceae) and in Blumea (Compositae).

• Perennial, rhizomatic, strong smelling herbs or shrubs, stems and branches pubescent.
• Leaves simple, decussate, ovate, base broadly cordate to cuneate, apex acute, margins serrate to crenate, pubescent; petiole present; stipules absent.
• Inflorescence a loose terminal spike.
• Flowers in axillary whorls, numerous, subsessile, bisexual, irregular; calyx campanulate, 10-veined, 5-toothed, teeth equal, inside hairy; corolla 2-lipped, upper lip narrow, entire, lower lip 3-lobed, much longer than the upper lip, central lobe of the lower lip 2-winged; annulate rim within the corolla tube, fringed with simple hairs; stamens 4, slightly didynamous, filaments inserted on the corolla tube, exserted, but not exceeding the lower lip, the upper pair with 1-celled anthers, sterile, the lower pair with 2-celled anthers, fertile, the filaments hairy on the upper part; stigma bifid, subequal; disk nectariferous, 4-lobed.
• Fruit consisting of 4 dry 1-seeded schizocarpous nutlets enclosed in the persistent calyx, nutlet broadly ovoid, slightly compressed, smooth, with a rather prominent scar on the ventral surface.
• Seedling with epigeal germination.

Growth starts from the rhizome after the rains have started, and the species flower for a long period. The flowers are nectariferous and are visited by insects as well as birds for nectar and pollen. The insects Xylocopa spp. (carpenter bees), Amegilla spp., Apis florea and Megachile spp., and sunbirds (Nectarinia spp.) are the principal pollinators of A. indica. Nectarinia spp., Xylocopa spp., Amegilla spp. and the wasp Rhynchium metallicum are the principal pollinators for A. malabarica. Anisomeles species are capable of producing seeds by self-pollination in the absence of cross-pollinators. The hairy rim probably forms a protection against ineffective pollinators and nutlet eaters, like ants. The nutlets are dispersed by water. The shiny pericarp may be attractive to seed-eating birds.

It is uncertain whether Anisomeles belongs to the subfamily Lamioideae or Pogostemonoideae, since it has characteristics of both groups. A. indica can hybridize with A. malabarica, forming hybrid segregates or local variants. Some of these hybrids have formerly been recognized at species level, but are nowadays incorporated in the parental species, or sometimes recognized at variety level.

Anisomeles species have a tendency to weediness and grow well on open, often waste places, in the lowlands and hills. The adaptation of Anisomeles to insect and bird pollination and to a flexible breeding system, safeguards their survival under changing environments.

Anisomeles can be propagated by seed or by rhizome cuttings.

Anisomeles is collected for medicinal purposes from the wild when the need arises.

After collecting, Anisomeles plants are washed and used fresh, or dried and stored for later use.

Both major Anisomeles species are widespread, and do not seem to be at risk of genetic erosion. Hybridization between these species can be achieved through conventional breeding methods. There is a small germplasm collection of A. indica in the United Kingdom.

The diterpenes isolated from A. indica show interesting pharmacological effects. However, further research will be needed to fully evaluate their possible potential.

• Aluri, R.J.S., 1992. The mint genus Anisomeles (Lamiaceae). Proceedings of the Indian National Science Academy Part B. Biological Sciences 58(6): 387-394.
• Arisawa, M., Nimura, M., Fujita, A., Hayashi, T., Morita, N. & Koshimura, S., 1986. Biologically active macrocyclic diterpenoids from the Chinese drug "Fang Feng Cao" II. Derivates of ovatodiolides and their cytotoxicity. Planta Medica 4: 297-299.
• Bhatti, G.R. & Ingrouille, M.J., 1996. The systematics of Anisomeles R. Br. (Lamiaceae). Fontqueria 44: 77-84.
• Momose, Y., Nimura, M., Arisawa, M., Hayashi, T., Takeda, R. & Nakanishi, S., 1994. Hypotensive activity of ovatodiolides isolated from a Chinese crude drug "Fang Feng Cao". Phytotherapy Research 8(8): 482-484.
• Keng, H., 1978. Labiatae. In: van Steenis, C.G.G.J. (Editor): Flora Malesiana. Series 1, Vol. 8. Sijthoff & Noordhoff International Publishers, Alphen aan den Rijn, the Netherlands. pp. 301-394.
• Yadav, R.N. & Saini, V.K., 1991. Antimicrobial efficacy of essential oils of Majorana hortensis Moench and Anisomeles indica (Linn.) Kuntze. Indian Perfumer 35(1): 58-60.

• L.T. Ng & S.K. Ling