Senega Root

JAN 2006

Polygala senega L. Family Polygalaceae (milkworts)

Seneca snakeroot , Rattlesnake root , Milkwort , Mountain flax

Uses

Senega has been used as an antitussive.

Dosing

Antitussive dosage of senega root is 1 to 3 g/day.

Contraindications

Contraindicated in pregnancy and in patients with peptic ulcer disease or inflammatory bowel disease.

Pregnancy/Lactation

Documented emmenagogue and uterine stimulant action. Avoid use.

Interactions

None well documented.

Adverse Reactions

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

Toxicology

Research reveals little or no information regarding toxicology with the use of senega root.

Senega root is an uncommon perennial herb about 1 foot high that grows throughout eastern North America. 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. The variety P. senega var. latifolia Torr. & Gray has been distinguished, but occurs throughout the same habitat and differs from P. senega only in the size of leaves and flowers and in having a slightly later flowering period. The related species P. tenuifolia Willd., P. reinii Franch., P. glomerata Lour., and P. japonica Houtt. are used in Asia for similar purposes.

Senega root was used by eastern Native American tribes including the Seneca, from whom its name is derived. Snakeroot refers to the purported use in snakebite. However, even the early European observers gave little credence to this use. Senega root found use among the colonists and in Europe as an emetic, cathartic, diuretic and diaphroetic in a variety of pulmonary diseases such as pneumonia, asthma, and pertussis, and also in gout and rheumatism. ¹ Its main use in the 19th century was as an expectorant cough remedy. It was official in the US Pharmacopeia from 1820 to 1936, and in the National Formulary from 1936 to 1960.

Seneca snakeroot contains a series of saponins constructed from the 2,3,27-trihydroxy-oleanane 23,28-dioic acid triterpene skeleton (presenegenin), having 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. ^2, , ^3, , ^4, , ^5, , ^6, , ^7, , ^8, , ^9, These saponins have been named senegins Ι-ΙV and senegasaponins A-C. The senegins can be analyzed by HPLC. ¹⁰ Several other species of Polygala (see Botany) contain distinct but very similar saponins based on the same sapogenin. ¹¹ An extensive series of ester oligosaccharides, senegoses A-O, have been isolated from P. senega var. latifolia . ^12, , ^13, , ¹⁴ The root also contains a small amount of methyl salicylate, which gives it a characteristic wintergreen odor.

Antitussive The antitussive effect of senega root has generally been attributed to the saponin content of the plant, which is consistent with the general detergent property of saponins in breaking up phlegm. In addition, senega is thought to act by irritation of the gastric mucosa, leading by reflex to an increase in bronchial mucous gland secretion.

Animal/Clinical data Research reveals no animal/clinical data regarding the use of senega root as an antitussive.

Hypoglycemic activity

Animal data The senega saponins have been shown to possess hypoglycemic activity in normal and diabetic mice, but not in streptozotocin-treated mice. ^7, , ^8, , ^9, , ^15, , ^16, , ^17, Thus, these compounds have activity relevant to non-insulin-dependent diabetes. This activity is quite potent when the saponins are injected intraperitoneally, but can also be detected with higher oral doses. The same saponins have also been found to substantially reduce alcohol absorption when given orally 1 hour before alcohol. ^7, , ^8, , ⁹

The aqueous extract of the related species P. tenuifolia has been shown to have a potent effect in blocking inflammatory processes in cultured mouse astrocytes. Substance P and lipopolysaccharide-induced production of tumor necrosis factor and interleukin-1 was blocked by the saponin-containing extract at low concentration. ¹⁸ It is possible that a systemic anti-inflammatory effect may be the result of a similar mechanism.

No biological activity has been reported for the oligosaccharides. Senegose A was found to be inactive in the hypoglycemia model cited above. ¹⁷

Clinical data Research reveals no clinical data regarding the use of senega root for hypoglycemic activity.

Antitussive dosage of senega root is 1 to 3 g/day. ¹⁹

Documented emmenagogue and uterine stimulant action. ^20, , ²¹ Avoid use.

None well documented.

High doses of powdered senega root (> 1 g) or tincture have been reported to be emetic and irritating to the GI tract. The use of senega root is contraindicated in pregnancy and in patients with peptic ulcer disease or inflammatory bowel disease. ²²

Research reveals little or no information regarding toxicology with the use of senega root.

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