Cascara

Clinical summary

Derived from the bark of the plant. Cascara is mainly used to relieve constipation. The major constituents are cascarosides that stimulate the large intestine and produce a laxative effect. Cascara is one of the herbs incorporated in the Hoxey herbal therapy. In vitro studies suggest an active ingredient emodin may have chemo preventive effects. No controlled human trials are available to confirm these effects. Cascara is not indicated for long term use. Prolonged use or overdose may cause diarrhea, electrolyte imbalance and hepatitis. The FDA rules that cascara is not safe as a stimulant laxative.

 Purported uses

• Cancer treatment
• Constipation

 Mechanism of action

The major constituents cascarosides stimulate the large intestine and produce a well-documented laxative effect. 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. 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. However, more studies are needed to confirm this effect. Studies on the carcinogenic effects of cascara have produced conflicting results.