Scientific Name/Common Name: Rhamnus purshiana / Cascara Sagrada (Sacred Bark)
Part(s) Used: bark
Constituents/Active Ingredients: Cascara bark contains: 8-10% of a complex mixture of anthraquinone glycosides (cascarosides, aloins, chrysaloins, aloe-emodin, etc.). The bark also contains resins, tannins, linoleic acid, myristic acid, and syringic acid.
Overview: Cascara is native to the forests of the North American Pacific Coast, ranging from northern California to British Columbia and almost to the Alaska panhandle. The bark was traditionally used as a laxative by North American indigenous peoples. Cascara bark is now listed as a laxative in the pharmacopoeias of over 17 different countries around the world. The bark is primarily used for constipation and for conditions that require a softened stool such as hemorrhoids, anal fissures, and after rectal-anal surgery. The bark is taken from the stem and branches in the spring but must be stored for at least a year or, alternatively, heat treated before using to allow anthrones in the fresh bark to oxidize, otherwise preparations will cause stomach upset. Cascara bark acts as a mild laxative that works by preventing electrolytes and water from being absorbed in the large intestine; the excess liquid softens the stool and promotes bowel contractions. The active glycosides are hydrolyzed in the gut into their aglycones at least in part by the action of bacterial enzymes; by influencing the water and electrolyte transport in the colon, these aglycones are responsible for the laxative action, which can take 6-12 hours to occur.
Traditional Use/Benefits/Body Systems: Bitter tonic and stimulant laxative for the digestive system. To support liver function and relieve constipation. Often combined with carminative herbs (cardamom, coriander, cumin, etc.) to prevent griping.
Clinical Studies/Scientific Research/References:
T. Bartram, FNIHM, Bartram’s Encyclopedia of Herbal Medicine, (New York, New York: Marlowe and Company),1998, p.100.
Blumenthal M, Goldberg A, Brinckmann J 2000. Herbal Medicine: Expanded Commission E Monographs. Copyright . Pp. 47-51.
Wichtl M and NG Bisset (Eds). 1994. Rhamni purshiani cortex – Cascara bark (English translation by Norman Grainger Bisset). In Herbal Drugs and Phytopharmaceuticals. CRC Press, Stuttgart, pp. 412-414.
Disclaimer: This information in our Herbal Encyclopedia is intended only as a general reference for educational purposes. It is not a replacement for medical advice. This content does not provide dosage information, cautions/contraindications, or possible interactions with prescription drugs. Please consult any relevant product labels for detailed information on use and with a medical practitioner for individual health advice.