Common Name: Madagascar Periwinkle

General Information

Catharanthus roseus is a profusely branched, erect or decumbent perennial plant with stems that can become more or less woody. It grows from 30 - 100cm tall[, ]. A white latex is present in all parts of the plant[].
The plant is widely used in traditional medicine in Africa and Asia. Often gathered from the wild, it is also widely cultivated. Recent discovery of the compound vincristine in the plant has led to its commercial cultivation, especially in Spain, China and the USA, since the compound has proved itself useful in the treatment of leukaemia[]. A popular garden ornamental, it is grown as a perennial in the tropics and as an annual in temperate regions, although it can overwinter as a pot plant in a conservatory. It is valued for its bushy habit and many large flowers carried above dark green foliage. It can also be kept as a cut flower; the branches will last for weeks or even months, producing new, but smaller, flowers all the time[].

Known Hazards

None known

Botanical References

Range

Africa - eastern and southern Madagascar.

Habitat

Often found in sandy locations along the coast, but also inland on river banks, in savannah vegetation and in dry waste places and roadsides, sometimes in open forest or scrub, usually near seal level, but occasionally to 1,500 metres[].

Properties

Weed Potential	Yes
Medicinal Rating
Other Uses Rating
Habit	Perennial
Height	0.70 m
Pollinators	Self, Butterflies
Self-fertile	Yes
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

A plant of the tropics and subtropics, it can also be cultivated as an annual crop in warm temperate areas[]. It grows best in areas where annual daytime temperatures are within the range 20 - 30°c, but can tolerate 10 - 34°c[]. At temperatures below 5°c, some branches or even the whole plant will die. When the temperature rises, the plant will usually regrow from basal axillary buds, especially after hard pruning of the shoots and roots. Without pruning, the plant regrows mainly from the tops[]. It prefers a mean annual rainfall in the range 1,000 - 1,200mm, but tolerates 800 - 1,400mm[]. Established plants are drought tolerant[].
An easily grown plant, it prefers a fertile, moist but well-drained soil in a sunny to partially shaded position[]. Usually found on sandy soils in the wild, but sometimes also on rocky soils[]. It is very tolerant of salt in the soil[]. Prefers a pH in the range 6 - 7, tolerating 5.5 - 7.5[].
The plant can flower all year round[]. It may become a naturalised weed, especially when growing in dry habitats[].
In the tropics, the roots are ready for harvest after one year[].
In Hungary, when grown as an annual, average yield is 3.5 - 4.5 tonnes/ha of the fresh herb, or 1 - 1.5 tonnes/ha of dried herb[].
Under irrigation conditions, 1.5 tonnes/ha of roots, 1.5 tonnes/ha of stems and 3 tonnes/ha of leaves can be obtained[].
The plant is usually self-fertile, but self-incompatible strains exist and can be locally common in the wild[].

Edible Uses

None known

Medicinal

Madagascar periwinkle has long been used as a traditional medicine.
Tests by pharmaceutical companies in the 1950's showed the presence of a number of medically active alkaloids, especially the compound vincristine, which has been shown to have activity against leukaemia[, , ]. The alkaloids, when isolated from the plant, are highly toxic but have also been shown to reduce the numbers of white blood cells, leading to applications which have revolutionized conventional cancer therapy[]. The plant is cultivated as a source of these alkaloids, a number of which are extracted and used allopathically[].
The isolated alkaloids are used to treat and other cancers[].
The alkaloids vincristine and vinblastine are prescribed in anticancer therapy, particularly in cases of acute leukaemia (especially in children) and Hodgkin's lymphoma. They are usually part of a complex chemotherapy protocol[]. Used in isolation, they have a number of side-effects, including alopecia, nausea and bone marrow depression[].
The dried root is an industrial source of ajmalicine, which increases the blood flow in the brain and peripheral parts of the body. Preparations of ajmalicine are used to treat the psychological and behavioural problems of senility, sensory problems (dizziness, tinnitus), cranial traumas and their neurological complications[].
Ajmalicine, and another alkaloid serpentine, are prescribed in the treatment of hypertension[].

The leaves and aerial parts of the plant have a wide range of traditional uses. Well known as an oral hypoglycaemic agent, the plant is also considered to be depurative, diaphoretic, diuretic, emetic, purgative and vermifuge. A decoction is taken to treat hypertension, asthma, menstrual irregularities, chronic constipation, diarrhoea, indigestion, dyspepsis, malaria, dengue fever, diabetes, cancer and skin diseases[, , ].
Extracts prepared from the leaves have been applied externally as antiseptic agents for the healing of wounds; to relieve the effects of wasp stings; against haemorrhage, skin rash and as a mouthwash to treat toothache[].
The leaves are harvested when the plant is flowering, and can be dried for later use[].

An infusion of the flowers is used to treat mild diabetes[].

A decoction of the roots is taken to treat dysmenorrhoea[].

Other Uses

An ethanol extraction of the leaves has been shown to be an effective fungicide in treating pathogenic fungi on the cultivated plant Jatropha curcas[].

Propagation

Seed - sow in a seed tray in a greenhouse. Germination takes 15 - 21 days at 21°c, with more than 95% of the seed sprouting[, ]. Seedlings are ready to pot up after 3 weeks[].
Seed can remain viable for 3 - 5 years[].
Greenwood or semi-ripe cuttings. When rooting hormone is used, the cuttings will start to root after 4 - 5 weeks[]. Putting the cuttings in water will also induce rooting, but it will take longer than in the soil[].