974 Madagascar Periwinkle Leaf Medicinal 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 2,340