2.8.2.3 Senega
Synonyms Senega snakeroot; Seneca snakeroot; Rattlesnake root; Radix senegae; Senega root.
Biological Source Senega is the dried root and root stock of Polygala senega L., or Polygala senega var latifolia Torret Gray or Polygala alba Nutt. belonging to family Polygalaceae.
Geographical Source The plant is grown in North America and Eastern Canada. Presently, the drug is chiefly sourced from the cultivated species in Japan. However, the species grown in North West United States is known as Northern Senega, whereas the one found in Canada, Minnesota and Mannitoba is called as Western Senega.
Preparation The root is collected from the wild plants normally in summer. The stems are promptly cut off and the roots are sorted out, washed thoroughly and dried either in the shade or artificial environment between 50-60°C.
Description
Colour : Brownish grey
Odour : Characteristic odour of methyl salicylate
Taste : First sweet and then acrid taste
Size : Length = 5 to 20 cm; Diameter = 3 to 10 cm
Appearance : A large knotty crown with a long tapering root normally curved, twisted having two or more large branches
Fracture : Short in the bark and splintery in the wood.
Chemical Constituents Senega essentially contains two saponin glycosides that are triterpenoid in character, namely: senegin (4%) and polygallic acid (5.5%).
Hydrolysis of senegin gives rise to one mole each of senegenin, senegenic acid and
presenegenin. It has been established that senega contains certain other derived forms of
presenegenin known as Senegin II as shown below:
The sweet taste of the drug is owing to the presence of 1, 5-anhydrosorbitol (or polygalitol). Besides, the senega root contains fixed oil, resin, sucrose, proteins, sterol and methyl salicylate (which is formed by the enzymatic hydrolysis of the glycosides called as primveroside).
Substituents and Adulterants The roots obtained from Polygala chinensis Linn., grown almost throughout India at an altitude of 5000 feet is mostly used as an adulterant in Senega root.
Uses
1. The senega root is used extensively as an expectorant and in chronic bronchitis to relieve the spasms.
2. It is also employed as an emetic.
