Suppression

Senna pods

Category: Medicines - plant based

Type

Voluntary

Introduction and description

Senna pods are the seed pods of the plant Cassia Angustifolia.  Medicinally they are used for constipation.  The correct terminology being that senna pods are a 'purgative'.

Senna belongs to the family N.O. Leguminosae and is also called Sanay, Senna, Alexandrian Senna,  Nubian Senna, Cassia Senna, Cassia lenitive,  Cassia Lanceolata,  Cassia officinalis,  Cassia aethiopica, Senna acutifolia, Egyptian Senna, Sene de la palthe,  Tinnevelly Senna, East Indian Senna, and Cassia acutifolia.   Although the main part used is the dried pods, the dried leaflets may also be used.

The plant is native to Egypt, Nubia, Arabia, and Sennar. 

According to Mrs Grieve “Several species of Cassia contribute to the drug of commerce, and were comprised in a single species by Linnaeus under the name of Cassia Senna. Since his day, the subject has been more fully investigated, and it is known that several countries utilize the leaves of their own indigenous varieties in the same way. The two most widely exported and officially recognized are C. acutifolia and C. angustifolia (India or Tinnevelly Senna). 
C. acutifolia, yielding the finest and most valuable variety of the drug is a small shrub about 2 feet high. The stem is erect, smooth, and pale green, with long, spreading branches, bearing leaflets in four or five pairs, averaging an inch long, lanceolate or obovate, unequally oblique at the base, veins distinct on the under surface, brittle, greyish-green, of a faint, peculiar odour, and mucilaginous, sweetish taste. The form of the base, and freedom from bitterness, distinguish the Senna from the Argel leaves, which are also thicker and stiffer. The flowers are small and yellow. The pods are broadly oblong, about 2 inches long by 7/8 inch broad, and contain about six seeds."

Background

Senna is an Arabian name, and the drug was first brought into use by the Arabian physicians Serapion and Mesue.  Achiarius was the first of the Greeks to notice it.  He recommends not the leaves but the fruit, and Mesue also preferred the pods to the leaves, "thinking them more powerful, though they are actually less so, but they do not cause griping".  The leaves of C. acutifolia are collected principally in Nubia. Ignatius Pallme, who travelled much in Africa, wrote:

'Senna is found in abundance in many parts of Kardofan, but the leaves are not collected on account of the existing monopoly. The Government draws its supplies from Dongola in Nubia.'

Two crops used to be collected annually in Nubia, the more abundant in September, after the rains, the other in April.  The plants were cut down, exposed on the rocks in hot sunshine until thoroughly dry, then stripped, and packed in palm-leaf bags, being sent on camels to Essouan and Darao, and by the Nile to Cairo, or via Massowah and Suakin on the Red Sea. It was then made up at Boulak, near Cairo, under the superintendence of the Egyptian Government.

One of the problems with senna is that it can be adulterated, of which more in a moment, and one of the places that adulteration took place was in Egypt.

Egyptian packed leaves were loosely packed, and as they curl when drying, often present this appearance.  In contrast Indian Senna is packed tightly, and the leaves come out flat.

Senna appears to have been cultivated in England about 1640. By keeping the plants in a hot-bed all the summer, they frequently flowered; but rarely perfected their seeds.

"Good Senna may be known by the bright, fresh, yellowishgreen colour of the leaves, with a faint and peculiar odour rather like green tea, and a nauseous, mucilaginous, sweetish, slightly bitter taste. It should be powdered only as wanted, because the powder absorbs moisture, becomes mouldy, and loses its value. Boiling destroys its virtues, unless it be in vacuo, or in a covered vessel".

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