Madagascar periwinkle

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.

Madagascar periwinkle can be extremely poisonous if consumed orally by humans.