Senna alexandrina is one of several hundred flowering plants in the Senna genus that produce legume fruits, in this case a pod with seeds. Also known as Egyptian Senna, senna is an important export crop in Egypt and the Sudan. The plant is also cultivated for trade in India.
For centuries, senna has been employed as a laxative, usually taken as tea prepared from the pods or leaves. Tea made from the pods tends to be gentler in its action that tea made from senna leaves.
The laxative effect of senna is due to anthraquinone glycosides, which increase water and electrolytes in the intestine and stimulate muscle contractions to enhance digestion and accelerate the rate of elimination. In the US, senna is FDA-approved for both over-the-counter and prescription laxative formulas.
