If you suffer from diabetes, traditional and medicinal plants like periwinkle may offer support in controlling your blood sugar. Periwinkle is a common herb found throughout North America, Europe, Asia and Africa, and has been used in herbal medicine to treat a wide range of internal and external diseases. However, the potential toxicity of periwinkle means it may be dangerous to use for long periods of time. Consult with a registered medical herbalist and a doctor before taking periwinkle products.
History
Periwinkle has been used around the world for food, medicine and magic for hundreds of years. According to Scott Cunningham, author of "Cunningham's Encyclopaedia of Magical Herbs," periwinkle is used in Europe to to treat snake bites, remedy poison and to protect against wild beasts, the evil eye and spirits. Dr. Nicholas Culpepper, the 17th century herbalist, recommended periwinkle leaves to treat bleeding in the mouth and noses, to reduce heavy menstrual bleeding, and also suggested married couples should eat periwinkle leaves as to "cause love between them." The use of periwinkle for chronic diseases such as diabetes, cancer and neurodegenerative illnesses began after the scientific discovery of periwinkle alkaloids.
Pharmacology
According to Henry Potter, author of "Potter's Encyclopaedia of Botanical Drugs and Preparations," the species known as "greater periwinkle" is a rich source of alkaloids -- natural plant chemicals that can be both toxic and medicinal in the human body. Some of the alkaloids in greater periwinkle are majdine, majoridine, ervine, serpentine, vinpocetine and vincamajorine. Vinpocetine has been isolated from greater periwinkle to create prescription drugs used to treat neurodegenerative diseases and enhance cognitive function. Tannins present in periwinkle leaves are responsible for the astringent, antiseptic and wound-healing properties attributed to the plant. Dimeric alkaloids from Madagascar periwinkle has significant cytotoxic and anti-cancer properties.
Scientific Studies
Scientists have begun to look at the anti-diabetic and hypoglycemic properties of periwinkle leaves in animal studies. In a study published in "Mymensingh Medical Journal" in 2007, researchers from Mymensingh Medical College in Bangladesh investigated the effects of Madagascar periwinkle in diabetic rats. Madagascar periwinkle had a significant effect on blood sugar levels, demonstrating a strong hypoglycemic effects in both diabetic and non-diabetic rats. Researchers confirmed that the properties of greater periwinkle may be useful in treating diabetes, but more research is required to test the effects and the safety of the plant in humans.
Safety and Toxicity
Cases of toxicity and poisoning from periwinkle alkaloids have been reported in both humans and animals. In a study published in "The Journal of Ethnopharmacology" in 2008, researchers from Nelson Mandela Metropolitan University in South Africa investigated the anti-diabetic actions of 11 different South African plants. Both greater periwinkle and Madagascar periwinkle had significant actions on the glucose absorption of isolated liver, muscle and fatty tissues, with greater periwinkle having the strongest anti-diabetic action of all 11 plants investigated. However, researchers concluded that the alkaloids responsible for this medicinal action are also highly toxic, limiting the use of the plant in treating chronic illness.
References
- "Cunningham's Encyclopaedia of Magical Herbs, 2nd Edition"; Scott Cunningham; 2010
- "Potter's Encyclopaedia of Botanical Drugs and Preparations"; Henry Potter; 1998
- "Mymensingh Medical Journal"; Hypoglycemic Effect of Catharanthus Roseus in Normal and Streptozotocin-Induced Diabetic Rats; A.U. Ahmed, et al.; 2007
- Memorial Sloan-Kettering Cancer Center: Vinpocetine
- "The Journal of Ethnopharmacology"; Anti-Diabetic Screening and Scoring of 11 Plants Traditionally Used in South Africa; M. van de Venter, et al.; 2008
- Drugs.com: Periwinkle
