Treatment of Interstitial Cystitis with a Quercetin Supplement

Purpose: Interstitial cystitis (IC) is a disorder of unknown etiology with few effective therapies. Oral bioflavonoid therapy utilizing quercetin recently proved to be clinically effective in men with chronic pelvic pain syndrome, a disorder with similarities to IC. We therefore tested in an open-label trial a quercetin-based supplement in patients with clinically proven IC.

Materials and Methods: Twenty-two patients (5 men and 17 women; average age 53.1 years) with classically documented IC received one capsule of Cysta-Q complex (equivalent to 500 mg of quercetin) twice a day for 4 weeks. Symptoms were assessed before and after therapy by the IC problem and symptom indices as well as by global assessment of pain (range 0-10).

Results: Two patients did not complete the study. In the remaining 20 patients, im- provement was seen in all three parameters tested. After 4 weeks of treatment, the mean (:I: SEM) problem index improved from 11.3.:o!: 0.6 to 5.1:1: 0.7 (p = .000001), the mean symptom index improved from 11.9 :I: 0.9 to 4.5 :1:0.5 (p= .000001), and the mean global assessment score improved from 8.2:1: 0.4 to 3.5:1: 0.4 (p = .000001). None of the patients experienced any negative side effects, and all but one patient had at least some improvement in every outcome measure.

Conclusion: Oral therapy with the quercetin supplement Cysta-Q was well tolerated and provided significant symptomatic improvement in patients with IC. Larger, randomized, placebo-controlled trials appear warranted based on these preliminary open-label results.

Key Words: Interstitial cystitis-Quercetin-Bioflavonoid.

Interstitial cystitis (IC) is a potentially debilitating disorder affecting 52 to 67 in 100,000 adult women in the United States (I). Despite this high prevalence and significant impact on quality of life, few effective therapies exist. The symptom complex of IC is similar to that of men with nonbacterial prostatitis or prostatodynia (National Institutes of Health [NIH] category III), prompting some to suggest that they actually represent a spectrum of the same disease (2). These disorders share the features of chronic pelvic pain, urinary frequency, and sexual dysfunction.

Our group recently showed that many men with category III prostatitis respond favorably to treatment with quercetin-based bioflavonoid supplement (3). In double-blind, placebo-controlled prostatitis study, the NIH symptom index improved from 25.1 to 14.6 after 4 weeks of therapy with a dietary supplement containing quercetin. The naturally occurring bioflavonoid quercetin is found in high concentration in red wine, onions, and green tea. It demonstrates activity as an antioxidant, a tyrosine kinase inhibitor, and an anti inflammatory through interference with NF-KB (4,5). Although phytotherapy has proved popular for treatment of a number of prostatic disorders (6), use of such agents has not been reported for IC. We therefore tested in an open-label study the clinical effects of an oral supplement primarily containing quercetin in patients with IC.