Cascara Sagrada (Rhamnus Purshiana), Family:
|| California buckthorn
| Chittem bark
|| Christ's thorn
|| Holy bark
| Persian bark
|| Sacred bark
Habitat: found in Europe and western
Asia, and in North America, from northern Idaho to the Pacific coast;
Description: Cascara sagrada is a small deciduous
tree that grows from 15-20 feet in height. It has pubescent stems covered with
reddish-brown bark and often gray lichen. The tree bears dark green elliptic to
oblong-ovate leaves with prominent veins and toothed margins. The leaves are
rounded at the base and have somewhat hairy undersides. Short-stemmed clusters
of small, greenish-white flowers grow from the upper leaf axils; they
eventually produce black, pea-sized drupes that are poisonous.
Medicinal parts: bark- dried, collected at least a
year before use.
| Aloe emodin
|| Cascarosides A & B
| Chysophanic acid
|| Fatty Acids
| Frangulin factors
* For definition of some of the above terms see the
dictionary section of this book.
Cascara sagrada is perhaps the most common
laxative used in both herbal medicine and orthodox pharmacy. It is technically
classified as a stimulant laxative, since in induces peristalsis.
The active constituents of cascara are the
anthraquinones. They are inactive in the gastrointestinal tract until they
reach the colon; there they produce a soft or formed stool within about six to
eight hours and cause vigorous peristalsis.
One of the most common uses of cascara is to
correct habituation to other laxatives by restoring intestinal tonus. In
smaller amounts, the herb has proven effective in the treatment of liver
disorders and gallstones. The anthraquinones have potent antibacterial
properties; they have been used against leukemia and as immunosuppressants
during skin graft operations. Cascara constituents have also served as
chelating agents in the prevention of urinary stones.
Cascara does not lose efficacy with repeated
use. For the most part, cascara is nonaddictive, and only really heavy abuse,
which is rare, produces "cathartic colon." Normally, its main side-effect is
griping. The herb may have other physiological effects as well, due to one or
more of its numerous constituents (e.g., tri- and dihydroxyanthraquinones -
emodin, fragulin, iso-emodin, aloe-emodin, and chrysophaol - and rhein, and
METHOD OF ACTION
There is presently insufficient data on this
Due to its cathartic activity, cascara sagrada may
potentiate anticoagulant therapy by reducing absorption of vitamin K from the
gut. It may also inhibit absorption of dextrose from the intestines.
This cathartic herb decreases intestinal transit time.
Therefore, cascara sagrada may inhibit the absorption of digitalis glycosides,
and decrease their cardiac action. Cathartic-induced hypokalemia, however,
increases the toxicity and potency of absorbed digitalis, as well as
potentiates muscle relaxants.
In addition to the specific interactions listed, the
cathartic action of cascara sagrada tends to hasten the passage of all oral
medications through the gut, thereby inhibiting their action.
Laxative-induced diarrhea may result in decreased
absorption of isoniazid. The same is true with sulfisoxasole, but this appears
to be a clinically unimportant interaction effect.
Laxatives induce increased speed of intestinal emptying,
which may result in decreased absorption of vitamin K and/or