- Cascara Sagrada
- Sacred Bark
For Patients & Caregivers
Bottom Line: Cascara is a strong laxative. It has not been shown to treat or prevent cancer.
Cascara is made out of the bark of the Cascara sagrada plant. It is known to stimulate the large intestine and produce a well-documented laxative effect. Cascara also causes water and electrolytes (such as sodium and potassium) to flow into the large intestine and be expelled from the body with the feces. This facilitates bowel passage but also can lead to dangerously low potassium and sodium levels if cascara is used for prolonged periods of time. Scientists have isolated a compound called aloe-emodin from cascara. In laboratory studies, this compound is able to inhibit the growth of tumor cells by halting cell division, but it is unknown if this effect would take place in the human body. Scientists have also studied whether cascara might be a carcinogen, with inconsistent results.
- To relieve constipation
Scientific evidence supports this use, but prolonged use is not recommended because it can lead to dangerous blood electrolyte imbalances. The FDA warns that cascara is not safe to use as a laxative.
- To treat cancer
Laboratory studies show that a compound found in cascara, aloe-emodin, has anticancer activity, but laboratory results are often not transferable to the human body. Clinical trials have not yet been conducted.
- Long-term use or overdose of cascara can cause electrolyte imbalances, characterized by very low blood levels of potassium, sodium, and chloride. It may lead to liver injury. The FDA has warned that cascara is not safe to use as a laxative.
- Cascara may be a carcinogen (cancer-causing substance).
- Certain compounds in cascara can discolor urine and interfere with urinalysis.
For Healthcare Professionals
Cascara sagrada is a species of buckthorn plant native to North America. The bark of the plant has been used to relieve constipation. The major constituents are cascarosides that stimulate the large intestine and produce a laxative effect.
In vitro studies indicate that emodin, one of the constituents of cascara, has hepatoprotective (17), neuroprotective (18), and chemopreventive effects (10)(12)(13). Emodin also enhances the cytotoxic effects of some chemotherapeutic agents (14)(15)(19)(20). Human studies have not been conducted to confirm these effects.
A major cause for concern with cascara is that prolonged use or overdose can cause diarrhea, electrolyte imbalance, and hepatitis (7). According to the United States Food and Drug Administration, cascara has not been shown to be safe or effective as a laxative drug (11).
Despite the FDA ruling, cascara continues to be marketed as a dietary supplement. It is also used as an ingredient in the Hoxsey herbal formula, an ineffective alternative cancer treatment.
The major constituents cascarosides stimulate the large intestine and produce a well-documented laxative effect (1)(3). Cascarosides increase intestinal motility and lead to propulsive contractions. This results in an increased water and electrolyte content in the lumen, which further facilitates bowel passage. The other constituent emodin has direct excitatory effect on circular smooth muscle cells in the large intestine (9).
Cascara’s anticancer activities may arise from its emodin and aloe-emodin content. In vitro studies show that aloe-emodin induces p53 and p21 expression resulting in cell cycle arrest in the G1 phase (8). However, more studies are needed to confirm this effect. Studies on the carcinogenic effects of cascara have produced conflicting results (4)(5)(6)(10).
After ingestion, cascara glycosides pass through the small intestine unchanged. Upon reaching the large intestine, glycosides are hydrolysed and activated by local bacteria. Studies show that the dimeric aglycones are well absorbed through the intestinal wall and strongly bind to plasma proteins. Aglycones are excreted through the bile.