Pale catechu containsd- anddl-catechin
(7.33%) and the condensation product cate-
chutannic acid (22–50%), quercitin, gambir-
fluorescein, catechu red (EVANS), gallic acid,
ellagic acid, catechol, pigments, and others. In
addition, it contains several indole alkaloids,
including gambirtannine, dihydrogambirtan-
nine, and oxogambirtannine. Gambirine,
gambirdine, and others are also found in
leaves and/or stems (JIANGSU).2–5
PHARMACOLOGY AND BIOLOGICAL
ACTIVITIES
Because of their high tannin content, black
catechu and pale catechu have astringent,
antibacterial, and other pharmacological
properties, as well as toxicities of tannins
(seetannic acid).
d-Catechin has been reported to cause con-
striction of isolated rabbit ear blood vessels
and suppression followed by enhancement
of the amplitude of the isolated toad heart
(JIANGSU).
Gambirine has been reported to have hypo-
tensive properties (GLASBY1).
An aqueous extract ofA. catechu(small
branches) has shown hypotensive effects in
anesthetized dogs and rats following i.v.
administration.^6
TOXICOLOGY
Fed to rats as part of the normal diet (0.1%),
Indian catechu (‘‘katha’’) was found to de-
crease liver and blood levels of niacin by 43%
and 48%, respectively.^7 Also, at 0.5% of the
diet, the minimum daily requirement of niacin
was increased and niacin content of liver,
blood, and muscle was decreased.^8
USES
Medicinal, Pharmaceutical, and Cosmetic.
Both black and pale catechus are used
primarily as an astringent in certain antidiar-
rheal preparations and in mouthwashes.Food. Both are used as flavor components in
major categories of food products, including
alcoholic and nonalcoholic beverages, frozen
dairy desserts, candy, baked goods, and gela-
tins and puddings. Black catechu extract (type
of extract not specified) has been reported as
the more commonly used, with highest aver-
age maximum use levelsof 0.01% and 0.016%
reported in candy and alcoholic beverages,
respectively.Traditional Medicine. Both black and pale
catechusareusedinstoppingnosebleedingand
in treating boils, sores, ulcers, hemorrhoids,
and others; black catechu is also reported to be
used in cancers.^9 In India, an extract of the bark
of black catechu has been orally administered
in the treatment of leprosy.^10 Various parts of
the plant have also been used topically for
bathing leprous sores (NADKARNI). Other Indian
uses of black catechu include abortifacient,^11
antipyretic, anti-inflammatory, anthelminitic,
ulcers, anemia, psoriasis, bronchitis (bark
extract), expectorant, anodyne, and others
(WILLIAMSON). In China, one of the major uses
of black catechu is in treating indigestion in
children.
Pale catechu has been used to treat
aphthous ulcers of the mouth, and, diluted
with water, used as a gargle to treat sore throat
(NADKARNI).Others. As a source of tannic acid used for
tanning and dyeing.COMMERCIAL PREPARATIONSCrude and extracts (e.g., tincture). Black cat-
echu was formerly official in U.S.P., while
pale catechu was official in N.F.Regulatory Status. Black catechu is ap-
proved for food use as a natural flavoring
(§172.510).158 Catechu (black and pale)