Tuesday, June 23, 2009

Herbs: Periwinkle


scientific name: Catharanthus roseus

other common names: Rosy periwinkle, vinca rosea, chata

growing areas: Native to Madagascar; cultivated in numerous other places

physical description: It is an herb that grows to a height of about 3 feet. Its leaves are green and shiny, and it produces a pink flower.

traditional uses: The periwinkle is one of the best examples of a plant that has become a prime source of medicine for humans, serving as the basis for drugs to combat Hodgkin's disease and childhood leukemia. While originating in Madagascar, it was brought to Europe in the eighteenth century and spread from there, often being used as an ornamental plant. Before it began to be used as a source of modern drugs, periwinkle had a long history as a treatment for tumors, asthma, and diabetes and for use as an astringent, diuretic, and to increase menstrual flow. In parts of Central America and the Caribbean, the root and leaf are used to treat diabetes.

availability and dosage: It is available in the form of a powder. Dosages vary. Herbalists recommend using a teaspoon of dried herb to make an infusion that can be consumed up to three times a day. Two medicines derived from periwinkle, vinblastine for Hodgkin's disease and vincristine for childhood leukemia, are used by doctors as part of therapeutic regimes.

contraindications: See "Special Precautions."

special precautions: Consult your physician before beginning any use of an ethnobotanical substance for medicinal purposes.
Commission E reports that periwinkle has proved to be destructive to blood components in animal experiments. Because most of its claimed uses have not been documented, Commission E states that the use of periwinkle is not justified.

medical research: Periwinkle has been extensively studied by scientists, who have identified owr seventy alkaloids from the plant parts, including vincristine and vinblastine. The investigation of periwinkle began in the 1950s, when the National Cancer Institute began a program of screening plant chemicals for possible use against leukemia. Some pharmaceutical companies involved in the study expanded the search and found anticancer activity in a number of the alkaloids. Vinblastine was isolated in 1961 and approved for the treatment of Hodgkin's disease and testicular and breast cancer. Two years later vincristine was licensed for use against childhood leukemia. "Long term, disease-free survivals have been observed in the treatment of various lymphomas and leukemias, bladder cancer, and testicular cancer, while significant palliative benefits have been seen in patients with breast cancer, melanoma, and small-cell lung cancer," write Gordon M. Cragg and Michael R. Boyd of the NCI.

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