www.sciencedirect.com/topics/pharm...nce/colocynth
Naturally occurring, colocynth is prepared from the dried pulp of the fruit of Citrullus colocynthis, a Mediterranean and African herbaceous vine related to the watermelon. Its medicinal benefit as a laxative (cathartic, purgative) was originally reported in the 19th Century Felter and Lloyd (1898). Because of its toxicity it is now largely superseded by less toxic laxatives Sweetman (2002), although colocynth is still used in homeopathic medicine. The components of colocynth include colocynthin, colocynthidin, elaterin, pectin and albuminoids O'Neil et al (2001). A glucoside (colocynthin) from the fruit of Citrullus colocynthis has been identified as possessing laxative properties O'Neil et al (2001).
--- Richard Jewell, in xPharm: The Comprehensive Pharmacology Reference, 2007