Lilac

Galega officinalis, commonly known as galega,goat's-rue,French lilac,Italian fitch,or professor-weed, is an herbaceous plant in the Faboideae subfamily. It is native to the Middle East, but has been naturalized in Europe and western Asia. The plant has been extensively cultivated as a forage crop, an ornamental, a bee plant, and as green manure.

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).

G. officinalis contains the phytochemicals, galegine and guanidine, both of which decrease blood sugar, but were discovered to cause adverse effects in human studies.The study of galegine and related molecules in the first half of the 20th century led to development of oral antidiabetic drugs.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.