Some similarities to : Lucerne but the flowers of Goat's-Rue are in a loose spire and Lucerne has purplish flowers with spiral pods.
No relation to : Wall-rue [a plant with similar name]
Not to be semantically confused with: Goat's-beard [a plant of similar name, but which belongs to the Daisy family]
Goat's-Rue is especially prevalent around Sheffield. Its habitat includes grassy places and waste ground and is widely naturalised.
Sheep are more likely to eat Goat's-Rue than other animals, and are thus more likely to be involved in an outbreak of poisoning. Clinical signs of Galega poisoning in cattle develop 6 hours to 2 days after ingestion. Affected animals are usually found dead. In sheep it causes laboured breathing, oedema of the neck, a frothy discharge from the nose, loss of balance, muscular spasms with the head arched back and convulsions.
Goat's-Rue has been used since the Middle Ages to treat diabetes. It has now been discovered that the compound
Guanidine contained within the plant is responsible for this action. Guanidine, C(NH2)2NH, is a molecule with high alkalinity that reduces blood sugar levels and reducing insulin resistance. Guanidine and its salts are well known for their propensity to denature proteins, that is, to make them dysfunctional by randomly folding them. Guanidine is also found in urine, which is presumably from where it obtains its name: guana.
The doubled-up molecule,
Biguanide, is now manufactured for treating diabetes.
Goat's-Rue contains the compound
Galegin (isoAmylene Guanidine), a derivative of
Guanidine, shown above. Galegin has been investigated as a treatment for diabetes to reduce or tame the hypoglycaemic response, where blood sugar levels can rise to a dangerous degree after consumption of sugary or carbohydrate foods, but the conclusion seems to be that its efficacy is indeterminate at best, and at worst has killed laboratory animals by actually increasing blood sugar levels itself! In view of this, it was thought that treatment based on monitoring blood sugar levels and the injection of insulin at appropriate times was more appropriate, and which has much better and more consistent results. Take home-made concoctions at your peril!
Goat's-Rue also contains
4-hydroxygalegine flavones and flavone glycosides [not shown].
Peganine (aka Vasicine) was first isolated from
Syrian Rue (Peganum harmala) which is also found in Goat's-Rue. It is a
quinoline alkaloid which also occurs in
Vinca Minor and is used pharmaceutically as a cerebral stimulant. An artificially synthesized derivative of Peganine,
peganine hydrochloride dihydrate may find applications as an anti-leishmanial agent active against protozoa, which would be particularly advantageous in view of the spreading resistance to current therapies, let alone their toxicity.