Protective Effects of Cranberry on Infection-induced Oxidative Renal Damage in a Vesicoureteral Reflux Rabbit Model / 대한비뇨기과학회지

ABSTRACT

PURPOSE: We evaluated the protective effects of cranberry, which is known as a fruit with anti-oxidative effects, on infection-induced oxidative renal damage with using a rabbit vesico-ureteral reflux (VUR) model. MATERIALS AND METHODS: New Zealand male rabbits were divided into 5 groups (the control group, VUR group, E. coli group, cranberry group and melatonin group). VUR was created and confirmed at 2 weeks after the operation. Infection was induced by intravesical instillation of an E. coli suspension. Cranberry powder was supplied with the feed. Melatonin was injected into the peritoneal cavity. The rabbit kidneys were obtained 3 weeks after the operation. Histopathologic examination was performed to evaluate for inflammation, fibrosis and the tubular change. The oxidative renal damage was evaluated by measuring malondialdehyde (MDA) in the renal tissue. RESULTS: Grossly, the refluxing kidney was larger than the contralateral normal kidney and the refluxing ureter was dilated and tortuous. The microscopic observation of the kidneys from the E. coli group showed apparent periglomerular mononuclear cell infiltration, tubular dilatation and atrophy, and interstitial fibrosis. The kidneys from the reflux group, cranberry group and melatonin group showed mild mononuclear cell infiltration without interstitial fibrosis. The MDA level in the kidneys of the E. coli group was significantly higher than that in the control, cranberry and melatonin groups (p<0.05). The MDA level in the cranberry and melatonin groups didn't significantly differ from that in the sterile group. CONCLUSIONS: This study demonstrates that cranberry has an anti-inflammatory effect due to an anti-oxidative function and it may prevent infection-induced oxidative renal damage. But application of cranberry in children with VUR needs more clinical studies.