Galega officinalis, commonly known as galega,<ref name=GRIN>Template:GRIN</ref> goat's-rue,<ref name=BSBI07>Template:Cite web</ref> French lilac,<ref name = AP>Template:Cite journal</ref> Italian fitch,<ref name=AP/> or professor-weed,<ref name=AP/> is an herbaceous plant in the Faboideae subfamily.<ref name=cabi>Template:Cite web</ref> It is native to the Middle East, but has been naturalized in Europe and western Asia.<ref name=cabi/> The plant has been extensively cultivated as a forage crop, an ornamental, a bee plant, and as green manure.<ref name=cabi/><ref name=invasive>Template:Cite web</ref>
G. officinalis is rich in galegine, a substance with blood glucose-lowering activity and the foundation for the discovery of metformin, a treatment for managing symptoms of diabetes mellitus.<ref name=Metformin>Template:Cite journal</ref> In ancient herbalism, goat's-rue was used as a diuretic.<ref name="drugs">Template:Cite web</ref> It can be poisonous to mammals, but is a food for various insects.<ref name=cabi/>
The genus name is believed to derive from the Greek terms for milk (Template:Lang) and goat (Template:Lang) because medieval Europeans believed that it increased milk production in livestock when eaten.<ref name=Metformin/> The English name "goat's-rue" is a translation of the Latin Ruta capraria, used for the plant in 1554 when it was considered to be related to Ruta graveolens, or common rue.<ref name=OakeKnowdeSwDaya15>Template:Cite book</ref> Galega bicolor is a synonym.
Widely distributed throughout temperate regions of the world, predominantly in Europe, the plant is a hardy perennial that blooms in the summer months on grasslands, wetlands, and riverbanks, and is classified as an invasive weed in many parts of North America.<ref name=cabi/><ref name=invasive/> It has also been found in countries of South America, North Africa, Pakistan, Turkey, and New Zealand.<ref name=cabi/><ref name=invasive/>
In 1891 in the United States, G. officinalis was introduced experimentally at Utah State University for potential use as a forage crop, but escaped cultivation and is now an agricultural pest.<ref name=cabi/> As a result, it has been placed on the Federal Noxious Weed List in the United States. It was collected in Colorado, Connecticut and New York prior to the 1930s, and in Maine and Pennsylvania in the 1960s, but the populations appear to have died out.<ref name=invasive/>
Chemistry and herbalism
Although not thoroughly studied with 21st century methods, G. officinalis has been analyzed for its constituents, which include galegine, hydroxygalegine, several guanidine derivatives, such as 4-hydroxygalegine flavones, flavone glycosides, kaempferol, and quercetin.<ref name=Metformin/><ref name=drugs/> In addition to its purported effect to lower blood glucose levels and induce diuresis, goat's rue was used as an herbal tonic in folk medicine practices of medieval Europe to treat bubonic plague, worms, and snake bites.<ref name=Metformin/><ref name=drugs/>
Relation to metformin
Once used in traditional medicine over centuries, G. officinalis is at the foundation of the biguanide class of antidiabetic drugs, which also included phenformin and buformin (both discontinued).<ref name=Metformin/><ref name="Witters2001">Template:Cite journal</ref>
G. officinalis contains the phytochemicals, galegine and guanidine, both of which decrease blood sugar, but were discovered to cause adverse effects in human studies.<ref name=Metformin/><ref name=Witters2001/> The study of galegine and related molecules in the first half of the 20th century led to development of oral antidiabetic drugs.<ref name=Metformin/><ref name=Witters2001/> Research on other compounds related to guanidine, including biguanide, led ultimately to the discovery of metformin (trade name, Glucophage), used in the 21st century for management of diabetes by decreasing liver glucose production and increasing insulin sensitivity of body tissues.<ref name=Metformin/><ref>Template:Cite journal</ref>
Goat's-rue may interfere with prescribed diabetes drugs, iron absorption, and anticoagulants.<ref name=drugs/> It may cause headache or muscular weakness, and its safety during pregnancy or breastfeeding is unknown.<ref name=drugs/>
- Taxonomy on NCBI (National Library of Medicine).
- Noxious Weed USDA Noxious & Invasive Weeds.