Ispaghula

ISPAGHULA

Synonyms

Ispaghula, Ispagol, Ishabgula, Spongel seeds.

Botanical Source

Ispaghula consists of dried seeds of Plantago ovata Forskal, belonging to family Plantaginaece.

Geographical Source

Ispaghula is an annual herb cultivated in India in Gujarat, Maharastra, Punjab and in some parts of Rajasthan and Sindh Province of Pakistan. It is cultivated extensively around Sidhpur in north Gujarat.

History

Blonde psyllium (Plantago ovata) is a low herbaceous annual plant native to Iran and India, extensively cultivated there and in other countries, including Pakistan. Black psyllium of the P. afra species is native to the western Mediterranean region, Northern Africa, and Western Asia, now cultivated in Southern France and Spain. Black psyllium of the P. indica species is native to Southeastern Europe and Asia. In commerce, blonde psyllium is obtained mainly from India, Pakistan, and Iran. Black psyllium is obtained mainly from southern France.

Psyllium has a long history of medical use in both con-ventional and traditional systems of medicine throughout Asia, Europe and North America. Blonde psyllium is official in the National Pharmacopeias of France, Germany, Great Britain, and the United States. Psyllium monographs also appear in the Ayurvedic Pharmacopoeia, British Herbal Pharmacopoeia, British Herbal Compendium, ESCOP Monographs, Commission E Monographs, and the German Standard License Monographs. The World Health Orga-nization (WHO) has published a monograph on psyllium seed covering P. afra, P. indica, P. ovata, and P. asiatica (WHO, 1999). Asian psyllium seed (P. asiatica Linn or P. depressa Willd.) is official in the National pharmacopeias of China and Japan.

Cultivation and Collection

Isabgol seeds are sown in the month of November by broadcasting method. Well-drained loamy soil with a pH of 7.5–8.5, cool and dry climate is suitable for its growth. Ammonium sulphate is also added as a fertilizer. Good water supply to the plants is to be provided at 8–10 days interval, seven to eight times. Though ispaghula is not affected by pests or disease, the percentage yield is decreased to great extend due to heavy rainfall or storms. The fruits are collected in the month of March/April after the fruits are completely mature and ripe. The fruits are then dried and the seeds separated.

                                Plantago ovata plant 

Morphology

Microscopy

A thin transverse section observed under microscope shows the following characters-

Epidermis: Single layered, thick walled transparent, tangentially elongated cells containing mucilage, which exudes if brought in contact with water.

Pigment Layer: Usually collapsed which is yellow in colour.

Endosperm: Outer layer consists of palisade like cells which are thick walled but inner cells are irregular and are also thick walled consisting of aleurone grains and oil globules.

Embryo: Have two cotyledons, with three to five vascular bundles in each, a portion of raphe remains attached to the seed.

Chemical Constituents

Ispaghula seeds contain about 10% mucilage which is present in the epidermis of testa. Mucilage consists of two complex polysaccharides, of which one is soluble in cold water and the other soluble in hot water. Chemically it is pentosan and aldobionic acid. Pentosan on hydrolysis yields xylose and arabinose and aldobionic acid yields galactouronic acid and rhamnose. Protein and fixed oil are present in endosperm and embryo.

                         (a) Dorsal (b) Ventral

                           T.S. (schematic) of surface of ispaghula seed

                             Transverse section of ispaghula seed

Chemical Tests

1.   Ispaghula seeds when treated with ruthenium red give red colour due to the presence of mucilage.

2.    Add water to few seeds on a slide, mucilage comes out and  forms zone surrounding the seeds.

3.   Swelling factor: Swelling factor is the parameter to determine the purity of seeds. Swelling can be determined quantitatively by swelling factor. 1 g of the drug is put in a measuring cylinder of 25 ml capacity and 20 ml water is added. It is shaken periodically for first 23 h and kept for one more hour. The volume occupied by the drug is called swelling factor. Swelling factor of ispaghula seeds is 10–13.

Uses

Ispaghula seeds are used as an excellent demulcent and bulk laxative in chronic constipation. The laxative activity of ispaghula mucilage is purely mechanical. It is also useful in dysentery, chronic diarrhoea, in cases of duodenal ulcers and piles. It works effectively as a soothing agent. Ispaghula husk is also used for similar purpose.

Substitutes and Adulterants

P. lanceolata Linn., occurring wild in India, is adulterated in ispaghula. Its seeds are oblong elliptical in shape with yellowish brown colour. The seeds of P. asiatica, (syn. P. major L.), found in Andhra Pradesh and Tamil Nadu, are substituted to ispaghula. It is also adulterated with the seeds of P. arenaria. The seeds of Salvia aegyptica are frequently mixed which also yield copious mucilage. The seeds of P. media L. have different colour and swell very little in water.

P. asiatica contains mucilage which is composed of β-1,4-linked D-xylopyranose residues having three kinds of branches.

Marketed Products

Sat Isabgol, Trifgol by Dabur, Sat-Isabgol by Dr Morepen.