Rhamnus purshiana
Part Used: Dried bark (aged 1 year)
Cascara Sagrada (Rhamnus purshiana) is a small-to medium-size tree native to the provinces and states of the Pacific coast, including British Columbia, Washington, Oregon, and Northern California. The bark of the tree is removed, cut into small pieces, and dried for one year before being used medicinally. Its reddish-brown bark is often covered with a grey lichen. It has mild purgative, stimulating laxative, bitter digestive tonic, stomachic, cholagogue, and antiparasitic properties. It has been used for atonic constipation, especially habitual constipation, dyspepsia, digestive complaints and in the treatment of haemorrhoids. It has also been used for gallstones and liver ailments.
Cascara Sagrada bark is high in hydroxyanthraquinone glycosides called cascarosides. Resins, tannins, and lipids make up the bulk of the other bark ingredients. Cascarosides have a cathartic action, inducing the large intestine to increase its muscular contraction (peristalsis), resulting in bowel movement. The basis of Cascara's laxative effect is the presence of a mixture of anthraquinones, either free (aloe-emodin) or as sugar derivatives (glycosides). The free anthraquinones remain in the intestines and cause catharsis by irritating the intestinal wall. Those anthraquinones present in the plant as sugar derivatives are largely absorbed from the intestine, circulate through the blood stream, and eventually stimulate the nerve center in the lower part of the intestine, which causes a laxative effect.
Cascara Sagrada is one of the oldest, time-proven, and most reliable remedies for chronic constipation. It is a good intestinal tonic and an excellent remedy for gallstones and increases the secretion of bile. Hence, it is beleived to be good for liver complaints; especially enlarged liver. Since it is a mild laxative, acting principally on the large intestine, it can be considered suitable for delicate and elderly persons, and may with advantage be given in chronic constipation, being generally administered in the form of the fluid extract. It acts also as a stomachic tonic and bitter, in small doses, promoting gastric digestion and appetite. However this herb and its preparations should be used with caution since in excess it causes vomiting and diarrhea. It should not be prescribed for pregnant or lactating women, or patients with intestinal obstruction.
References:
Plants for a Future. http://www.pfaf.org/database/plants.php?Rhamnus+purshianus
Holistic Online. http://www.holisticonline.com/Herbal-Med/_Herbs/h39.htm
