Catharanthus roseus


Catharanthus roseus, commonly known as bright eyes, Cape periwinkle, graveyard plant, Madagascar periwinkle, old maid, pink periwinkle, rose periwinkle, is a species of flowering plant in the family Apocynaceae. It is native and endemic to Madagascar, but grown elsewhere as an ornamental and medicinal plant, a source of the drugs vincristine and vinblastine, used to treat cancer. It was formerly included in the genus Vinca as Vinca rosea.

Synonyms

Two varieties are recognized
Catharanthus roseus is an evergreen subshrub or herbaceous plant growing tall. The leaves are oval to oblong, long and broad, glossy green, hairless, with a pale midrib and a short petiole long; they are arranged in opposite pairs. The flowers are white to dark pink with a darker red centre, with a basal tube long and a corolla diameter with five petal-like lobes. The fruit is a pair of follicles long and broad.

Ecology

Cape periwinkles are of two types - foliage periwinkle and annual periwinkle. In the wild, C. roseus is an endangered plant; the main cause of decline is habitat destruction by slash and burn agriculture. It is also, however, widely cultivated and is naturalised in subtropical and tropical areas of the world like Australia, Malaysia, India, Pakistan and Bangladesh. It is so well adapted to growth in Australia, that it is listed as a noxious weed in Western Australia and the Australian Capital Territory, and also in parts of eastern Queensland.

Cultivation

As an ornamental plant, it is appreciated for its hardiness in dry and nutritionally deficient conditions, popular in subtropical gardens where temperatures never fall below, and as a warm-season bedding plant in temperate gardens. It is noted for its long flowering period, throughout the year in tropical conditions, and from spring to late autumn, in warm temperate climates. Full sun and well-drained soil are preferred. Numerous cultivars have been selected, for variation in flower colour, and also for tolerance of cooler growing conditions in temperate regions. Notable cultivars include 'Albus', 'Grape Cooler', the Ocellatus Group, and 'Peppermint Cooler'.
In the UK it has gained the Royal Horticultural Society’s Award of Garden Merit.

Uses

The species has long been cultivated for herbal medicine. In Ayurveda the extracts of its roots and shoots, though poisonous, are used against several diseases. In traditional Chinese medicine, extracts from it have been used against numerous diseases, including diabetes, malaria, and Hodgkin's lymphoma. Many of the vinca alkaloids were first isolated from Catharanthus roseus, including vinblastine and vincristine used in the treatment of leukemia and Hodgkin's lymphoma.
This conflict between historical indigenous use, and recent patents on C.roseus-derived drugs by western pharmaceutical companies, without compensation, has led to accusations of biopiracy.
C. roseus can be extremely toxic if consumed orally by humans, and is cited in the Louisiana State Act 159.
C. roseus is used in plant pathology as an experimental host for phytoplasmas. This is because it is easy to infect with a large majority of phytoplasmas, and also often has very distinctive symptoms such as phyllody and significantly reduced leaf size.

Chemical constituents

and vincristine, chemotherapy medications used to treat several types of cancers, are found in the plant and are biosynthesised from the coupling of the alkaloids catharanthine and vindoline. The newer semi-synthetic chemotherapeutic agent vinorelbine, used in the treatment of non-small-cell lung cancer, can be prepared either from vindoline and catharanthine or from the vinca alkaloid leurosine, in both cases via anhydrovinblastine.
Rosinidin is the pink anthocyanidin pigment found in the flowers of C. roseus.Lochnericine is a major alkaloid in roots.

Gallery