Frangula purshiana Cooper

Last updated: 20 April 2016

Scientific Name

Frangula purshiana Cooper


Cardiolepis obtusa Raf. Frangula anonifolia (Greene) Grubov, Rhamnus annonifolia Greene, Rhamnus purshiana DC. [1]

Vernacular Name

English California buckthorn, California coffee-berry, cascara, cascara buckthorn, coffee-berry, pursh’s buckthorn [2]

Geographical Distributions

Frangula purshiana Cooper is a native plant of the US Pacific Northwest. [3]

Botanical Description

F. purshiana is a member of Rhamnaceae. It is an erect shrub with multiple stems that reach a height up to about 35-40 ft. [3]

Young branches are slender and covered with reddish brown hairs; older branches are smooth and grayish. [3]

The small flowers have five greenish white petals arranged in loose clusters. Individual plants contain both unisexual and bisexual flowers. [3]

The fruits are small, round black drupe with a yellowish inner pulp and tree glossy black seeds. [3]


No documentation

Chemical Constituent

F. purshiana has been reported to contain 1,8-dihydroxyanthracene derivatives (including cascarosides A and B, emodin, aloe-emodin), linoleic acid, myristic acid, lipids, tannins. [4][5]

Plant Part Used

Aged bark [6]

Traditional Use

The bark is claimed to be laxative and is prescribe for healing occasional constipation and in conditions where soft stool is describe , such as in anal fissure or haemorrhoids. In small doses, it is capable of strengthening the intestines as well as providing relief in pre-menstrual syndromes and menstrual pain. [7]

Preclinical Data


Anthranoid laxatives, or stimulant laxatives, are widely used in nonprescription products and dietary supplements. They are carried unabsorbed to the large bowel, where metabolism to the active aglycone form takes place. [8] The aglycones exert their laxative effect by damaging epithelial cells, which leads directly and indirectly to changes in absorption, secretion, and motility.

Of interest is that aloe-emodin, a constituent in cascara and aloe, has been reported to have antiviral activity in vitro[9][10] Aloe-emodin was also reported to have a specific in vitro and in vivo anti-neuroectodermal tumor activity in laboratory mice. [11] Another constituent, emodin, has been reported in studies to possess anti-inflammatory, antibiotic, and antineoplastic properties. [12][13]


No documentation

Clinical Data

Clinical findings

No documentation


F. purshiana has been reported safe in recommended dosages. [14]

Side effects

A recent case report suggested that anthracene glycosides from cascara sagrada were associated with the development of cholestatic hepatitis, thus causing portal hypertension. [15]

In vitro and animal studies have reported a potential role of anthranoid laxatives in both the initiation and promotion of tumorigenesis in the GIT. However, a recent human study reported no adverse effects on GI health. Although the short-term use of these substances is generally safe, long-term use cannot be recommended. [16][17] 

Long-term usage of F. purshiana enhances the toxicity of cardiac glycosides and antiarrhythmic agents due to increase in loss of serum potassium. [18] There is risk of hypokalemia if consumed together with potassium-depleting diuretic drugs. [19]

Pregnancy/Breast Feeding

Do not use in pregnancy and lactation, as anthraquinones may be excreted in breast milk and may cause endometrial stimulation. [20]

Adverse reaction

Griping colic, diarrhoea, potassium and fluid loss, possible hepatic reactions [5]

Interaction & Depletion

No documentation


Contraindicated in individuals with intestinal obstruction, appendicitis, ulcerative colitis, diarrhea, or dehydration. [21]

There is a possible increased risk of colorectal cancer if cascara is consumed on a chronic basis. [15]

Case Report

A single case report associated the use of the cascara with the development of cholestatic hepatitis complicated by fibroisis, portal hypertension, and ascites. Right upper quadrant pain, abdominal bloating , nausea, anorexia, and jaundice began 3 days after initiation of cascara (425 mg capsule of aged cascara sagrada bark with reported 5% cascaroside potency , 3 times daily) .The case report did not include an analysis of the cascara capsules. [3]


Dosage Range

100-300 mg daily; do not recommend taking longer than 7-10 days without seeking medical advice. [21]

Tea: One cup, 2 times daily using 2 gm fresh herb per cup. [21]

Poisonous Management

No documentation

Line drawing

No documentation


  1. The Plant List. Ver1.1. Frangula purshiana Cooper. [homepage on the Internet]. c2013 [updated 2012 Mar 23; cited 2016 May 12]. Available from:
  2. Quattrocchi U. CRC world dictionary of medicinal and poisonous plants: Common names, scientific names, eponyms, synonyms, and etymology. Volume IV E-L. Boca Raton, Florida: CRC Press, 2012; p. 271.
  3. Donald GB. Medical toxicology of natural substances: Foods, fungi, medicinal herbs, plants, and venomous Animals. Hoboken, New Jersey: John Wiley & Sons, 2012; p. 54
  4. Vogt E, Mühlemann H. Anthraquinones and anthraquinone glycosides. 20. Partial synthetic experiments with chrysophanol-and chrysacin-anthraquinones and glycosides. Pharm Acta Helv. 1971;46(7):431-440.
  5. Fairbairn JW, Evans FJ, Phillipson JD. Cascarosides A and B. J Pharm Sci. 1977;66(9):1300-1303.
  6. Mills SY, Bone K. The essential guide to herbal safety. 1st ed. US: Elsevier, 2005; p. 315.
  7. Herbal Medicine Research Centre, Institute for Medical Research. Compendium of medicinal plants used in Malaysia. Volume 2. Kuala Lumpur: HMRC IMR, 2002; p.299
  8. De Witte P, Lemli L. The metabolism of anthranoid laxatives. Hepatogastroenterology. 1990;37(6):p.601-605.
  9. Andersen DO, Weber ND, Wood SG, Hughes BG, Murray BK, North JA. In vitro virucidal activity of selected anthraquinones and anthraquinone derivatives. Antiviral Res. 1991;16(2):185-196.
  10. Sydiskis RJ, Owen DG, Lohr JL, Rosler KH, Blomster RN. Inactivation of enveloped viruses by anthraquinones extracted from plants. Antimicrob Agents Chemother. 1991;35(12):2463-2466.
  11. Pecere T, Gazzola MV, Mucignat C, et al. Aloe-emodin is a new type of anticancer agent with selective activity against neuroectodermal tumors. Cancer Res. 2000;60(11):2800-2804.
  12. Goel RK, Das Gupta G, Ram SN, Pandey VB. Antiulcerogenic and anti-inflammatory effects of emodin, isolated from Rhamnus triquerta wall. Indian J Exp Biol. 1991;29(3):230-232.
  13. Jin ZH, Ma DL, Lin XZ. Study on effect of emodin on the isolated intestinal smooth muscle of guinea-pigs. Zhongguo Zhong Xi Yi Jie He Za Zhi. 1994;14(7):p.429-431. Chinese.
  14. Natural therapeutics pocket guide. Hudson, Ohio: LexiComp Inc, 2000; p. 404.
  15. Nadir A, Reddy D, Van Thiel DH. Cascara sagrada-induced intrahepatic cholestasis causing portal hypertension: Case report and review of herbal hepatotoxicity. Am J Gastroenterol. 2000;95(12):3634-3637.
  16. Van Gorkom BA, de Vries EG, Karrenbeld A, Kleibeuker JH. Review article: Anthranoid laxatives and their potential carcinogenic effects. Aliment Pharmacol Ther. 1999;13(4):443-452.
  17. Nusko G, Schneider B, Schneider I, Wittekind C, Hahn EG. Anthranoid laxative use is not a risk factor for colorectal neoplasia: Results of a prospective case control study. Gut. 2000;46(5):651-655.
  18. Lans C, Turner N, Khan T, Brauer G. Ethnoveterinary medicines used to treat endoparasites and stomach problems in pigs and pets in British Columbia, Canada. Vet Parasitol. 2007;148(3-4):325-340.
  19. Marie CL, Normandeau M, Lord A, et al. Use of over-the-counter medications and natural products in patients with moderate and severe chronic renal insufficiency. Am J Kidney Dis. 2007;49(2):245-256.
  20. De Smet PAGM, Keller K, Hansel R, Chandler RF, editors. Adverse effects of herbal drugs 2. Berlin: Springer-Verlag, 1993; p. 70.
  21. PDR for herbal medicines. 2nd ed. Montvale, New Jersey: Medical Economics Company, 2000; p. 155.