Common Name: Conessi

General Information

Holarrhena pubescens is a deciduous shrub or tree with fragrant white flowers and abundant white latex in all its parts. It can grows from 0.6 - 18 metres tall, with a trunk that can be 12 - 25cm in diameter[, ].
An important medicinal plant in the tropics, it is gathered in large quantities from the wild for its wide range of medicinal and other uses[]. The plant is sometimes also cultivated for medicinal purposes, the root bark is sold in local markets, whilst the plant is also cultivated in India as an ornamental for its attractive flowers[].
Holarrhena pubescens is a very widespread species and is conserved in several protected areas in several countries. The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2020)[].

Known Hazards

None known

Botanical References

,

Range

Eastern Africa; E. Asia - Indian subcontinent, southern China, Myanmar, Thailand, Laos, Vietnam, Cambodia

Habitat

Montane forests at elevations of 500 - 1,000 metres[]. Dry evergreen to dry deciduous forest, scrub woodland, savannah, or in rocky localities, often near watercourses, at elevations up to 1,500 metres[].

Properties

Conservation Status	Least Concern
Medicinal Rating
Other Uses Rating
Habit	Deciduous Tree
Height	10.00 m
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

Though sensitive to frost, the plant recovers easily from damage[].
Succeeds on a wide range of soils[]. Plants can stand slight shade but develop best when growing in full light[]. Established plants are drought tolerant[].
The tree coppices well and can survive bush fires by producing sucker shoots from burned-down stumps[]. Juvenile plants are more susceptible to damage by fire than older ones[].
Natural reproduction is abundant owing to regular and copious seeding from an early age, comparative immunity of the plant to damage by animals and its power of recovery from injury[]. Seeds, that are dispersed by wind germinate during the early rains, and seedlings attain 10 - 15 cm by the end of the first year[]. In subsequent years, growth is more rapid, the mean annual diameter increment being 7 - 8 mm. In India, early height increment of Holarrhena pubescens is low, only 10 - 15 cm/year under natural conditions[].
Established plants are fast-growing[].
All parts of the plant contain a milky sap[].

Edible Uses

None known

Medicinal

The stem bark and root bark have a long history of traditional use in the treatment of amoebic dysentery throughout the distribution area of the plant[, ]. The stem bark is listed in the Pharmacopoeia of India. Although slow in action compared with emetine, it is less toxic and can be administered orally[]. The seeds or bark are sometimes adulterated with those of Wrightia tinctoria, which do not have the same medicinal properties, although both show antibacterial activity[].
Considerable research has been carried out into the medical applications of these plants, most of which has tended to bear out its traditional uses.
The stem bark, root bark and seeds yield more than 40 alkaloids. The highest concentration is found in the stem bark and root bark with up to 4.3%, but only 0.4% has been reported for flowering plants. The leaves contain 1 - 1.5% and the seeds 0.6 - 1.8%. According to the Pharmacopoeia of India, the bark should contain about 2% alkaloids[].
Most of the alkaloids of the stem bark and root bark are steroid alkaloids derived from conanine or the closely related conamine, which also occur in other Holarrhena species. The main alkaloid of the stem bark and root bark is conessine; other compounds are norconessine (kurchine), conessimine, kurchamine, kurchessine, kurcholessine, conimine, conamine and holarrhenine[].
The leaves contain mainly steroid alkaloids derived from pregnane, such as holarrhimine, holaphyllamine, holamine and holaphylline, as well as the alkaloid triacanthine (an adenine derivative). Various amino-glycosteroids are also present in the leaves. These substances contain an amino-sugar and in some of them, e.g. holarosine and holacurtine, the steroidal part of the molecule is a cardenolide[].
The seeds contain conessine, norconessine, conamine and conarrhimine[].
Conessine has sedative, central nervous system depressant, cardiac depressant, antipyretic and analgesic activities. It also has significant anti-amoebic activity, but it needs to be used with caution because it can produce neurological problems such as vertigo, tremors, insomnia, agitation or anxiety. Conessine also shows antibacterial and antifungal activities against a range of human pathogens in vitro[].
Several other steroidal alkaloids also show antibacterial and antifungal activities[].
The steroid alkaloids present in the stem bark and root bark have hypotensive activity and are simultaneously local anaesthetic and spasmolytic, but they are also cardiotoxic[].
Triacanthine also has hypotensive activity, but is also cardiotonic, antispasmodic and a respiratory analeptic. In addition, triacanthine stimulates the development of mature red blood cells[].
Many of the pregnane derivatives can be used as a starting material for the partial synthesis of pharmaceutical steroids, such as adrenocortical hormones (corticosteroids) and sex hormones (e.g. oestrogens, progestrogens and androgens)[].
Holamine, holaphyllamine and holaphylline show significant anti-inflammatory properties[].
Aqueous extracts of the root bark, stem bark or leaves have relatively low toxicity[].
The alcoholic extract of the fruit showed anticancer activity against human epidermoid carcinoma of the nasopharynx in tissue culture[].
The aqueous extract of the fruits exhibited hypoglycaemic effects[].
Different extracts of the seed or bark showed significant antibacterial and antifungal activities against a wide range of human pathogens, including several antibiotic-resistant strains[]. The bark extract also shows antiplasmodial activity[].
A stem bark decoction showed anti-ulcerogenic effects in different models of gastroduodenal ulcers. It also showed antimicrobial activity against enterohaemorrhagic Escherichia coli strains[].

The bark has anthelmintic, astringent, febrifugal, stomachic and tonic properties[].
A hot decoction of the stem bark is used as a gargle to treat toothache[].
The bark and the leaves are applied externally to treat scabies, boils, ulcers and haemorrhoids[]. A powder prepared from the roots and leaves is administered to stop haemorrhages after childbirth and nose bleeding[].
The oil from the seeds is considered to possess similar properties to the bark[].

The root is said to be abortifacient, antidote, aphrodisiac, galactagogue and laxative[]. An infusion is taken to stimulate milk production, to treat constipation, asthma, abdominal pains and infertility[]. When boiled in milk, it is applied against snakebites and is used in the treatment of venereal diseases[].

The leaves, pounded in water, are taken to cure stomach-ache[].

The juice from the fruit is taken to treat cough[].

Agroforestry Uses:

A pioneer species, it quickly invades open spaces[]. The plant may prove useful for the reforestation of deforested land in comparatively dry regions, especially because it is not readily browsed even by goats[]. In India the species is successfully intercropped with field crops[].

Other Uses

A dye similar to henna is extracted from the leaves[].

The wood ash is used as a mordant[].

The floss from the seeds is used for stuffing pillows[].

Conessine, an alkaloid found in the plant, was found to possess a wide range of disruptive activities against 4 insect species, and showed potential as a larval growth inhibitor, sterilant and antifeedant in laboratory tests[].

The wood is moderately soft and white, turning yellowish or pinkish with age[]. It has a straight grain and fine and even texture; there is no distinction between sapwood and heartwood[]. The wood is easy to saw and machine and fairly durable under cover[]. Popular for turning and carving, it is used to make small articles such as combs, picture frames, carved boxes, toys, spoons, knives, walking sticks and beads, and sometimes for furniture and ploughs[].
The pulp from the wood has been used to make paper[].

Propagation

Seed - direct sowing or raising seedlings in a nursery both work well. Fresh seeds have a high percentage of germination, but in seeds more than one year old the viability is low[]. The seed usually germinates in 2 - 3 weeks[].

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