Senega Root

Scientific Name(s): Polygala senega L.
Common Name(s): Milkwort, Mountain flax, Polygalae radix, Rattlesnake root, Seneca snakeroot

Medically reviewed by Drugs.com. Last updated on Feb 21, 2022.

Clinical Overview

Use

Senega has been traditionally used as an antitussive and has also demonstrated hypoglycemic, immunologic, and anticancer effects. However, there are no clinical trials to support these uses.

Dosing

Root: 1 to 3 g/day. Fluid extract: 1.5 to 3 g/day or 0.3 to 1 mL/day. Tincture: 2.5 to 7.5 g/day or 2.5 to 5 mL/day.

Contraindications

Pregnancy, peptic ulcer disease, or inflammatory bowel disease.

Pregnancy/Lactation

Avoid use. Emmenagogue and uterine stimulant action has been documented.

Interactions

None well documented.

Adverse Reactions

High doses of powdered senega root or tincture are emetic and irritating to the GI tract.

Toxicology

When investigated for their immunological potential as adjuvants in vaccinations, saponin fractions of P. senega were less toxic than those of Quillaja saponaria.

Scientific Family

• Polygalaceae (milkwort)

Botany

Senega root is an uncommon perennial herb found throughout eastern North America1; it has "endangered" status in Connecticut, Maine, and New Jersey and "threatened" status in Maryland.2 The plant grows to approximately 0.5 m in height and has unbranched stems arising from a branched root.1, 3 The leaves are small, alternate, and narrowly lanceolate. Numerous pinkish-white or greenish-white flowers are crowded on a terminal spike. The root is twisted and has an irregular, knotty crown with a distinctive ridge. Senega's faint, sweet scent is similar to that of methyl salicylate.3 The variety P. senega var. latifolia Torr. & Gray has been distinguished; it grows in the same habitat but differs from P. senega in the size of its leaves and flowers and in its slightly later flowering period. Related species include Polygala tenuifolia Willd., Polygala reinii Franch., Polygala glomerata Lour., and Polygala japonica Houtt., all of which are used in Asia in a similar manner to P. senega.

History

Senega root was used by eastern American Indian tribes, including the Seneca tribe (from whom its name is derived), to treat rattlesnake bites1; however, early European observers gave little credence to this use. Colonists and Europeans used senega root as an emetic, cathartic, diuretic, and diaphoretic, and in treatment of pulmonary diseases (such as pneumonia, asthma, and pertussis), gout, and rheumatism.4 Its main use in the 19th century was as an expectorant cough remedy. It was included in the US Pharmacopeia from 1820 to 1936 and in the National Formulary from 1936 to 1960.

Chemistry

Seneca snakeroot contains a series of saponins constructed from the 2,3,27-trihydroxy-oleanane 23,28-dioic acid triterpene skeleton (presenegenin), with a single sugar attached at position 3 and a 4- to 6-sugar chain appended at position 28. A variety of methoxy-cinnamate esters are attached at the internal sugar of the C-28 chain.5, 6, 7, 8, 9, 10, 11, 12 These saponins have been named senegins Ι through ΙV and senegasaponins A through C. The senegins can be analyze...