Uva Ursi

Overview

Uva-ursi is a small shrub found North America, Canada, Europe and northern Asia that has been long used traditionally by Native Americans, as well as other cultures. Uva ursi has been used in the treatment of bladder and kidney diseases due to its long known use as an astringent and diuretic. Preparations of the leaves are also known to have antiseptic qualities. Many Native American tribes used uva ursi for treating inflammation of the genitourinary tract and venereal disease. Other Native American uses included for weight control, for stomach ailments, rheumatic conditions, and sprains. The more widespread uses of uva ursi today are for inflammatory conditions of the urinary tract, including urethritis, chronic cystitis, nephritis, and kidney stones (McKenna et al., 2002).

Uva ursi known to contain a number of compounds that are thought to contribute to its wide therapeutic activity, including hydroquinone derivatives, often calculated as arbutin, and flavonoids, such as ursolic acid, and quercetin. The leaves are mostly used in extracts for treating urinary tract infections, normally in the form of an infusion, tea or tincture (McKenna et al., 2002). Pharmacologically, uva ursi has been found to inhibit melanin synthesis, have anti-allergic, anti-oedemic and anti-inflammatory activity. Additionally it has been indicated to inhibit adjuvant-induced arthritis and immuno-inflammation (Matsuda et al., 1990; Matsuda et al.,1991; Matsuda et al., 1992a; Matsuda et al., 1992b; Kubo et al., 1990).

Comments

Uva ursi is used in a wide variety of therapeutic complaints and the only one that has any clinical validation is for urinary complaints, especially cystitis, although there is much more support needed to validate this use. Other purpored herbal medicine uses include prostate problems, bronchitis, dysentery, dysmenorrhea, dysuria, hepatits, hemorrhoids, rhumatism, ulcers, diabetes, dysentery, fever and gonorrhea (McKenna et al., 2002).

Scientific Support

Larsson et al. (1993) performed a randomized, double-blind, placebo-controlled clinical study on the prophylactic effect of an uva-ursi extract (UVA-E, Medic Herb AB, Sweden) on recurrent cystitis. For one month, the 57 women enrolled in the study were administered UVA-E (three tablets t.i.d) or placebo. Routine gynecological and bacteriological examinations were performed at 6 and 12 months. The study found that 23% of the women who were given the placebo had recurrences, vs. none in the UVA-E group, and this was a significant statistically. No side effects were noted in either group, and voiding patterns remained similar between groups.

Safety / Dosage

Uva Ursi is normally recommended in the approximate dosage of 10 g cut or powdered herb (corresponding to 400-700 mg arbutin in 150 mL (0.75 cup) water consumed as a tea or cold maceration. In Europe, uva ursi is used in the forms of infusions, cold macerates, or solid formulations. Assuming the extract of the herb is standardized to at least 6% hydroquinone derivatives, the usual recommendation is 1 g three to six times daily. The efficacy of uva ursi is said to depend on having an alkaline urine, and without this the uva ursi is not bioavailable (McKenna et al., 2002).

In the normal recommended dosages, uva ursi has showed no adverse effects. Excessive use of extracts can cause the urine to turn green, but is harmless, and may also cause vomiting and diarrhea due to the tannin content. One case of bull’s eye maculopathy has been reported in a women with long-term ingestion of uva ursi. As uva ursi is a known inhibitor of melanin synthesis, it may be capable of producing ocular damage (Wang and DelPriore, 2004).

References

1.Kubo M, Ito M, Nakata H, Matsuda H. Pharmacological studies on leaf of Arctostaphylos uva-ursi (L.) Spreng. I. Combined effect of 50% methanolic extract from Arctostaphylos uva-ursi (L.) Spreng. (bearberry leaf) and prednisolone on immuno-inflammation. Yakugaku Zasshi. 1990 Jan;110(1):59-67.

2.Larsson, B., A. Jonasson and S. Fianu. Prophylactic effect of uva-e in women with recurrent cystitis: A preliminary report. Current Therapeutic Research 53:441-443.

3.McKenna, D.; K. Jones and K. Hughes. Botanical Medicines: The Desk Reference for Major Herbal Supplements. 2nd Ed. 2002 Haworth Press: Binghamton, NY. 1138 pp.

4.Matsuda H, Nakamura S, Tanaka T, Kubo M. Pharmacological studies on leaf of Arctostaphylos uva-ursi (L.) Spreng. V. Effect of water extract from Arctostaphylos uva-ursi (L.) Spreng. (bearberry leaf) on the antiallergic and antiinflammatory activities of dexamethasone ointment. Yakugaku Zasshi. 1992a Sep;112(9):673-7.

5.Matsuda H, Nakamura S, Shiomoto H, Tanaka T, Kubo M. Pharmacological studies on leaf of Arctostaphylos uva-ursi (L.) Spreng. IV. Effect of 50% methanolic extract from Arctostaphylos uva-ursi (L.) Spreng. (bearberry leaf) on melanin synthesis. Yakugaku Zasshi. 1992b Apr;112(4):276-82.

6.Matsuda H, Tanaka T, Kubo M. Pharmacological studies on leaf of Arctostaphylos uva-ursi (L.) Spreng. III. Combined effect of arbutin and indomethacin on immuno-inflammation. Yakugaku Zasshi. 1991 Apr-May;111(4-5):253-8.

7.Matsuda H, Nakata H, Tanaka T, Kubo M. Pharmacological study on Arctostaphylos uva-ursi (L.) Spreng. II. Combined effects of arbutin and prednisolone or dexamethazone on immuno-inflammation. Yakugaku Zasshi. 1990 Jan;110(1):68-76.

8.Wang L, Del Priore LV. Bull's-eye maculopathy secondary to herbal toxicity from uva ursi. Am J Ophthalmol. 2004 Jun;137(6):1135-7.

EDITOR'S NOTE: This monograph can be found in The Health Professional's Guide to Dietary Supplements (Lippincott, Williams & Wilkins) by Shawn M. Talbott, PhD and Kerry Hughes, MS