C. Senna which is also known as Alexandrian Senna is native to Africa and commonly cultivated in Egypt - as its alternative name suggests - and the Sudan while C. angustifolia, or Tinnevelly senna, is found in India and Pakistan. 

Senna is a proven and effective laxative. It works by interacting with the bacteria in the digestive track, resulting in intestinal contractions. These contractions are caused by the compounds known as anthraquinone glycosides that are contained in Senna. These anthraquinone glycosides derivatives are known as sennosides. The main forms of these sennosides are often referred to by: A, B, C & D. The sennosides are absorbed into the bloodstream and circulate through the body until they reach the colon where they stimulate the lining of the bowel and have a powerful laxative effect.

Senna releases histamine from the colon and prostaglandins and other autacoids are implicated in the effect.

Both leaves and pods of the senna plant are used as laxatives. The pods are less potent than the leaves.

A French study on the mechanism of action of sennosides indicates that the main modification of colonic motility induced by sennosides was a stimulation of propulsive activity (MLSBs), which occurred between 6­12 hrs after oral administration, the delay required for orocecal transit and metabolism of the drug.

Found in Potter’s Cleansing Herbs Tea and Potter’s Cleansing Herb Tablets.