สารบัญ

Category  Expectorant.

       Senega Root consists of the dried, whole or fragmented root and root crown of Polygala senega L. or root of Polygala tenuifolia Willd., with rootlets removed (Family Polygalaceae).

Origin of plant  Senega is native to North America, including eastern Canada and north-eastern United States of America.

Constituents  Senega Root contains triterpene saponins as its major components.  It also contains methyl salicylate. 

Description  Odour, mild, sweet, slightly rancid, or reminiscent of methyl salicylate; taste, sweet at first, with acrid aftertaste which irritating to the throat.
Macroscopical
Polygala senega L.  Dried whole or fragmented of root and root crown, with rootlets removed.  A whole root crown greyish brown and distinctively wider than the root, forming an irregular head of up to 3 cm in diameter consisting of numerous tightly packed remnants or scars of stems and violet-brown buds.  The tap roots are flexuous and tortuous, brown or yellow, single or 2- to 3-branched, 1 to 8 mm in diameter at the crown, tapering to the apex; externally transversely and longitudinally striated with more or less decurrent spiral ridge; internally paler yellow.
Polygala tenuifolia Willd.  Dried whole root or fragment of cylindrical slice of a root with rootlets removed.  Whole root straight or curved, 3 to 15 cm long, 3 to 8 mm in diameter, pale yellowish brown or brown with numerous transverse wrinkles and fissures and lesser longitudinal striations; round rootlet scars are also often visible; xylem light yellow and readily detached, with some fragments consisting of rolls of bark and their folded inwards edges. The fracture shows a yellowish cortex and a pale yellow, usually circular, central woody area.  Fragmented root:  externally yellowish grey to brownish grey; internally solid or hollow in the central part where the xylem has detached.
Microscopical    
Polygala senega L.  Transverse section of the root is more or less triangular, showing cortex and central woody area.  Cortex, yellowish, with different degree of thickness surrounding the woody area.  Woody area, pale yellow, irregular in shape, especially at the ridge.
Powdered drug of Senega Root from Polygala senega possesses the microscopical characteristic of the unground drug.  Fragments of lignified tissues made up of a number of tracheids and slightly larger reticulate and bordered-pitted vessels, yellowish parenchyma containing oil droplets, and fragments of cork which occasionally accompanied by phelloderm, and parenchyma some containing oil droplets are observed.  Epidermis from bud scales with stomata and unicellular trichomes may also be found.
Polygala tenuifolia Willd. Transverse section of the root shows a yellowish brown outer part and a round, pale yellow central woody area. 
Powdered drug of Senega Root from Polygala tenuifolia possesses the microscopical characteristic of the unground drug and is mostly similar to that of the powdered drug of Senega Root from P. senega.   However, calcium oxalate cluster crystal tissues, isolated or included in parenchyma cells, and long, fine thick-walled lignified fibres, most often fragmented, in cluster or associated with vessels, are also found.

Other relevant information
Caution should be exercised when using senega root in pregnant women.
Since solid evidence on the use of senega root in nursing mothers and pediatrics has yet been established.  Senega root should not be administered during lactation or to children without medical supervision.
It is recommended to seek medical advice if coughing persists after 7 days of use.
Senega root may exacerbate existing gastro-intestinal inflammation such as gastritis or gastric ulcers, and excessive consumption may cause vomiting.  Therefore, caution should be exercised when using the drug in patients with the said conditions.

Packaging and storage  Senega Root shall be kept in well-closed containers, protected from light and moisture.

Identification  Carry out the test as described in the “Thin-Layer Chromatography” (Appendix 3.1).
Standard solution (a)  Dissolve 1 mg of rutoside trihydrate and 30 mg of puerarin in methanol and dilute to 25.0 mL with the same solvent. 
Standard solution (b)  Dilute 2.5 mL of Standard solution (a) to 10.0 mL with methanol. 
Standard solution (c)  Dissolve 2 mg of chlorogenic acid and 30 mg of pueuarin in methanol and dilute to 25.0 mL with the same solvent.
Test solution  To 500 mg, in No. 355 powder, add 5.0 mL of ethanol (70 per cent).  Sonicate at 80° for 15 minutes, filter or centrifuge and use the filtrate or supernatant.
Adsorbent  Silica gel F254.
Mobile phase  Anhydrous formic acid, glacial acetic acid, water, and ethyl acetate (11:11:26:100).
Application  Apply 3 µL of Standard solutions and Test solution as 8-mm bands.
Development and drying  Allow the solvent front to ascend 7 cm above from the lower edge of the plate.  Dry the developed plate at 105° for 3 minutes.
Detection   Spray the warm plate with a 1 per cent w/v solution of diphenylboric acid aminoethyl ester in methanol, then with a 5 per cent w/v solution of macrogol 400 in methanol or, alternatively, dip the warm plate in a 0.5 per cent w/v solution of diphenylboric acid aminoethyl ester in ethyl acetate, then in a 5 per cent w/v of macrogol 400 in dichloromethane, allow the plate to dry in air for about 1 minute and examine under ultraviolet light (366 nm).
Results for Polygala senega L.  When examined under ultraviolet light (366 nm), the test solution shows a faint, orange fluorescent band of rutoside in the middle and a blue fluorescent band of puerarin in the upper third of the chromatogram, corresponding in R_f and colour to the bands shown by the standard solution.  Other blue fluorescent bands may be present in the middle and the lower third of the chromatogram.
Results for Polygala tenuifolia Willd.  When examined under ultraviolet light (366 nm), the test solution shows a blue fluorescent band due to puerarin in the upper third of the chromatogram, corresponding in R_f and colour to the band shown by the standard solution. A greenish blue fluorescent band at the border between the middle and lower third and other blue fluorescent bands in the middle and the lower third of the chromatogram are present.

Loss on drying  Not more than 12.0 per cent w/w after drying at 105° for 2 hours; use 1 g, in No. 355 powder (Appendix 4.15).

Acid-insoluble ash  Not more than 3.0 per cent w/w (Method II, Appendix 7.6).

Total ash  Not more than 6.0 per cent w/w (Appendix 7.7).

Extractable matter  Not less than 20 per cent w/w.  To about 1 g, in No. 355 powder and accurately weighed, add a mixture of 4.5 g of ethanol and 15.5 g of water and allow to macerate for 3 hours, shaking frequently.  Filter.  Evaporate 5.0 g of the filtrate to dryness on a water-bath and dry at 105° for 2 hours.  The residue weighs a minimum of 50 mg. 

Foam index  Not more than 3.5; use 1 g, in No. 355 powder.

SENEGA ROOT, POWDERED

Senega, Powdered

Complies with the requirements for Packaging and storage, Identification, Loss on drying, Acid-insoluble ash, Total ash, Extractable matter, and Foam index stated under Senega Root and with the following requirement.

Description  Light brown; odour, irritant and sternutatory.  Powdered drug of Senega Root possesses the microscopical characteristic of the unground drug.  Fragments of lignified tissues made up of a number of tracheids and slightly larger reticulate and bordered-pitted vessels, yellowish parenchyma containing oil droplets, and fragments of cork which occasionally accompanied by phelloderm, and parenchyma some containing oil droplets are observed.  Epidermis from bud scales with stomata and unicellular trichomes may also be found.