Polygala is a large genus of flowering plants which are commonly known as snakeroots or milkworts and are members of the Polygalaceae family. More than 700 species have been described and the genus shows an intercontinental geographical distribution with representatives native to the Americas, Asia, Africa and Australia.
The best known representative of the snakeroots is Polygala senega L. This plant is native to North America where it is chiefly found in southern Canada and the central and eastern United States. The plant is more commonly known as Seneca snakeroot or simply Senega root, the former of which is derived from the Seneca tribe, Native Americans who used the root to treat snakebite.
The root has been popular in traditional North American herbal medicine where it was used as an expectorant, diuretic, as well as an anti-inflammatory and a medicine to treat toothaches. It is also used as an ingredient of cough syrups, teas, lozenges and gargles. This has caused concerns about overexploitation as the root is primarily harvested from the wild. P. tenuifolia Willd is cultivated on a commercial scale in the Far East, primarily in China and Japan. Pharmacopoeias such as the Ph. Eur. prescribing that the herbal drug Polygalae radix can consist of the dried roots of Polygala senega or of certain other closely related species or a mixture of these Polygala species. There are two main official herbal drug preparations containing Senega root namely Senega Liquid Extract BP1980 and Concentrated Senega Infusion BP1980. Senega extracts are present as an API in a number of traditional herbal medicinal products (THRs).
The active constituents believed to be responsible for the therapeutic properties of the herbal drug are saponins. A complex mixture of bidesmosidic saponin glycosides have been identified in the root of P. senega which are based on the aglycone presenegenin (1).
Ransom Naturals Ltd manufactures a number of herbal drug preparations containing Senega root namely SE/34 – EFM (Extract for Making) Concentrated Senega Infusion BP1980, SE/27 – EFM Senega Liquid Extract BP1980 and a number of bespoke liquid extracts prepared from Senega root (SE/6 and SE/19 which is 1:2 or 1:1 liquid extract).