Uva ursi, also called bearberry, refers to the plant Arctostaphylos uvaursi, the leaves of which are used in herbal medicine.
Uses and Benefits:
Uva ursi has long been used
Uva ursi, also called bearberry, refers to the plant Arctostaphylos uvaursi, the leaves of which are used in herbal medicine.
Uses and Benefits:
Uva ursi has long been used as a urinary antiseptic for mild urinary tract infections (UTls) or inflammation, and as an herbal diuretic. The herb is a common ingredient in a number of "bladder and kidney" teas and products, which are popular in European countries. Uva ursi also has been employed for centuries as an astringent or hemostatic for diarrhea and hemorrhages, probably due to its high tannin content.
Key constituents of the leaf include hydroquinone glycosides (4-15%) such as arbutin, polyphenols such as tannins (10-20%), flavonoids, and triterpenes Arbutin is most likely hydrolyzed to hydroquinone in the gastrointestinal tract, which is eliminated in the urine in small amounts. Uva ursi extracts, arbutin, and hydroquinone all have antimicrobial activity. In a series of European experiments, hydroquinone was found to be the most active constituent of uva ursi, which has antimicrobial activity in vitro against typical urinary pathogens in an alkaline urine environment (pH of 8), but not in an acidic urine (pH of 6). In rats with experimentally induced pyelonephritis, 25 mg/kg doses of a uva ursi extract were reported to have significant antibacterial and nephroprotective activity.
Monopreparations of uva ursi have not been evaluated in clinical trials. However, a combination herbal product (UVA-E) was evaluated in one randomized, double-blind, placebocontrolled trial for UTls. This extract product (containing uva ursi as an antiseptic and dandelion as a mild diuretic) or a placebo was given to healthy women with recurrent cystitis. Treatment for month significantly reduced recurrence during the 1-year follow-up period, with no cystitis in the herbal group (0 of 30) versus 23% recurrence in the placebo group (5 of 27; P < 0.05). Another combination herbal preparation (containing uva ursi, hops, and peppermint) was used to treat patients suffering from frequent and painful urination. 3 Of 915 patients treated for 6 weeks, success was reported in 70%; however, this study was not controlled. No studies have evaluated uva ursi's potential diuretic effects in humans.
There are no reported side effects from uva ursi products. The high tannin content (10-20%) may cause Gl upset, and oxidation of hydroquinone may turn the urine a green-brown color.
Side Effects and Interactions:
The high tannin content of the herb could precipitate alkaloid drugs, and bind iron or other metal ions. Foods or drugs that produce an acidic urine could presumably reduce the urinary antimicrobial effects of uva ursi, while alkanization of the urine would enhance