General Information:
Symphytum officinale, commonly known as comfrey, is native to Europe and Asia, preferring well-drained soils and plenty of sunlight, but do well in afternoon shade. Comfrey is a fairly drought tolerant plant and will do well in dry locations. It is an herbaceous perennial with clusters of white-purple, drooping, flowers and large tuberous roots. It get the name Symphytum from the Greek words symphyo, to put together, and phyton, plant, because it is a plant known for its bone mending properties. Another common name for comfrey is knitbone.
Comfrey plants often grow very large, often around 3ft. tall and 2 1/2ft. wide (first image), but have an expanse of tuberous roots (second image). The roots can be problematic when trying to get rid of, or move, the plant because any roots remaining will eventually grow into a new plant.
Traditional Uses:
Comfrey is known to have been traditionally used since around 400 B.C for its many medicinal uses. Like many other medicinal plants, comfrey can be either ingested as a supplement or applied topically as poultice. When ingested, comfrey can be used to treat ulcers and colitis. When used externally as a poultice, it can help with many ailments, such as inflammation, rashes, swelling, cuts, bruises, sprains, and even broken bones. It does not have nearly as many uses today, though some still use it medicinally, because of the effectiveness of modern medicine, however many people still grow it because it is an attractive addition to a garden.
Chemical Constituents:
Not much is known about the chemicals that are responsible for the medicinal properties of comfrey, or even if the medicinal properties are significant since not many people currently use it. What is known is that comfrey contains poisonous chemicals called pyrrolizidine alkaloids (PAs) in the leaves, stems and roots of the plant. These poisons are also known to be absorbed through the skin, so no matter how comfrey is used as a treatment, poison exposure will still occur. For these reasons, comfrey is listed by the FDA as “possibly safe,” but “likely unsafe.”
Current Research:
Despite comfrey’s historical use as a medicinal herb, most research conducted with the plant today is related to its detrimental health effects. The PAs present in comfrey are severely toxic and can result in many negative effects. As a result, PAs are the most commonly researched aspect of the comfrey plant. These researchers investigate how to better detect the concentrations of PAs and their overall toxicity and viability as a medicine.
Sources:
Alfrey, Paul. “Comfrey: Its History, Uses & Benefits.” Permaculture Magazine, 4 Mar. 2016, http://www.permaculture.co.uk/articles/comfrey-its-history-uses-benefits
Symphytum Officinale – Plant Finder, http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=b472
“Comfrey: Uses, Side Effects, Interactions, Dosage, and Warning.” WebMD, WebMD, http://www.webmd.com/vitamins/ai/ingredientmono-295/comfrey
Janeš, Damjan and Samo Kreft. “TLC densitometric method for screening of lycopsamine in comfrey root (Symphytum officinale L.) extracts using retrorsine as a reference compound” Acta Pharmaceutica, 64.4 (2014): 503-508. Retrieved 22 Apr. 2018, https://www.ncbi.nlm.nih.gov/pubmed/25531790
This page was created by Jerry Willour
UST Medicinal Garden 