PDR for Herbal Medicines

HERBAL MONOGRAPHS CAT'S CLAW/ 161

Other Names: Una de Gato, Paraguaya, Garbato, Tambor

hausca, Toron

ACTIONS AND PHARMACOLOGY

COMPOUNDS

Alkaloids: including 5-alpha-carboxystrictosidine, isoptero-

^* podine, mitraphylline, isomitraphyllin, isorynchophylline,

rynchophyllin

Triterpenes

Organic acids: oleanolic acid, ursolic acid

Glycosides: quinovic acid glycosides

Procyanidins: (-)-epicatechin, cinchonain l a, cinchonain lb

Sterols: beta-sitosterol (60%), stigmasterol, capesterol

EFFECTS

Anti-inflammatory/Immunostimulating Effects — The sterol

componants of Cat's Claw have been found to have anti-

inflammatory activity (Scnatore, 1989). Carrageenan-in-

duced rat paw edema was shown to respond to per oral doses

of various extracts of Cat's Claw dried root bark (Aquino,

1991). The beta-sitosterol fraction, which accounts for 60%

^ of the total steroid content in the herb is thought to be

~ responsible for most of the anti-inflammatory effect (Sena-

tore, 1989). Uncaria tomentosa extract has been found to

stimulate interleukin-l and interleukin-6 production by

alveolar macrophages (Lemaire, 1999).

Effects on Platelet Aggregation — Rhynchophylline, an

alkaloid present in Cat's Claw, has been found to inhibit

venous and cerebral thrombosis in rabbits. It has also

demonstrated platelet aggregation inhibition (Chen, 1992).

Effects on Serotonin and Dopamine — In one study,

rhynchophylline increased the serotonin levels in the hypo-

thalamus and cortex of rat brain and reduced the dopamine

levels in the cortex, amygdala, and spinal cord. Rhyncho-

phylline increased the release of endogenous dopamine from

4 brain regions. The release of serotonin was increased in 2

brain regions (Shi, 1993).

Hirsutine, an alkaloid present in Uncaria tomentosa has a
potent ganglion blocking effect. Hirsutine was found to
block nicotine induced dopamine release in rat pheochromo-
j^ cytoma cells. Hirsutine was found to be equipotent to
hexamethonium in blocking the inward current activated by
nicotine (Nakazawa, 1991).

Antihypertensive Effects — Hirsutine has antihypertensive

effects. This effect can partly be explained by die ability of

hirsutine to reduce intracellular calcium levels by inhibiting

calcium release from the calcium store and increasing

calcium uptake into the calcium store. Hirsutine was also

found to exhibit calcium channel blocking activity by

inhibiting the calcium influx through voltage dependent

calcium channels in the rat aorta (Horie, 1992).

Contraceptive Effect — There is only anecdotal evidence of

the use of Cat's Claw in the prevention of pregnancy. In

Peru, it has been used for this purpose for years in some

rainforest tribes, but the amount of drug used would be

considered very high. A decoction prepared from 11 to 13

pounds of the root is reduced to about 1 cup and taken at the

time of menstruation. It is claimed that sterility can be

maintained for 3 to 4 years after one dose (Cabieses, 1994).

Effects on Cancer — Aqueous extracts of Uncaria tomentosa

suppressed cell growth through induction of apoptosis in two

different human leukemic cell lines. Apoptosis was demon-

strated by the fact that both DNA single and double strand

breaks increased within 24 hours of treatment with the

Uncaria tomentosa extract (Sheng, 1998).

INDICATIONS AND USAGE

Unproven Uses: The effects that have some scientific

evidence of efficacy include antiviral, immunostimulating,

and anti-inflammatory properties.

Cat's Claw has been used in folk medicine for rheumatic

complaints, diarrhea, gastritis, treatment of wounds, as an

adjunct to cancer treatment, asthma, menstrual irregularity

and as a contraceptive.

CONTRAINDICATIONS

Cat's Claw is contraindicated in pregnancy and in nursing

mothers.

PRECAUTIONS AND ADVERSE REACTIONS

General: Serum estradiol and progesterone levels may be

reduced after long-term Cat's Claw use. In one study, long

term use (8 weeks) of Uncaria tomentosa resulted in a

precipitous drop in both estradiol and progesterone serum

levels (Rodriguez, 1998).

Uncaria tomentosa prevented estrogen from binding to

estrogen receptors on breast cancer cells (Salazar & Jay me,

1988).

There is one report of acute renal failure associated wim

Cat's Claw ingestion in a patient with systemic lupus

erythematosus. Though the patient was taking several other

medications at the time, Cat's Claw was the only agent that

was discontinued. Urinalysis results gradually returned to

baseline following discontinuation of the herb (Hilepo,

1997).

DOSAGE

Mode of Administration: Cat's Claw is available in a powder

form, capsules and liquid for internal administration.

Preparation: To prepare a decoction, add 30 g of powder to

800 ml water; allow to simmer on the stove for 45 minutes or