Abstract
PURPOSE: To investigate the efficacy of an intravesical instillation of hyaluronic acid (HA) combined with epidermal growth factor (EGF) for the treatment of interstitial cystitis (IC) using a lipopolysaccharide (LPS)-induced IC animal model. METHODS: A total of 24 female Sprague-Dawley rats were randomized to 4 groups: sham control, IC, HA, and treatment (HA/ EGF) groups. A polyethylene-50 tube was placed inside the bladder of each animal. IC was induced by twice-weekly instillations of LPS for 3 weeks, which resulted in chronic injury of the urothelium. Animals in the sham control group only received saline instillation. Treatment solutions of HA and HA/EGF were given on days 0, 7, and 14 after IC induction (400 μL of HA in a concentration of 0.4 mg/0.5 mL and 400 μL of NewEpi, a commercialized HA/EGF mixture containing 2 μg of EGF and 0.4 mg of sodium hyaluronate). Animals were sacrificed on day 21 for further examinations. RESULTS: The HA/EGF group showed visible improvement in hematuria with a significant reduction of red blood cells in the urine compared to the HA group. Histological examination revealed that HA/EGF treatment reversed the abnormalities developed in IC, including infiltration of inflammatory cells, irregular re-epithelialization, and fibrotic tissue. Moreover, HA/ EGF significantly reduced the levels of proinflammation cytokines (tumor necrosis factor-α, interleukin [IL]-6, and IL-1β) and substantially lowered the elevated oxidative stress biomarker malondialdehyde, yet restored the levels of antioxidant enzymes glutathione peroxidase and superoxide dismutase, with superior results than HA treatment. Cystometry studies indicated that HA/EGF significantly prolonged intercontraction interval and increased micturition volume. CONCLUSION: HA/EGF has been demonstrated as a more effective treatment for enhancing the urothelium lining and reducing inflammatory changes to alleviate clinical symptoms associated with IC in rats, compared to HA alone.