A modulating effect of epigallocatechin gallate (EGCG), a tea catechin, on the bladder of rats exposed to water avoidance stress.

AIMS: To examine the effect of epigallocatechin gallate (EGCG), a green tea catechin, on the bladder of rats exposed to water avoidance stress (WAS). METHODS: Twenty female Sprague-Dawley rats were divided into four groups of five. The first group was exposed to WAS for7 days. The second group was pretreated with EGCG 1 mg/kg intraperitoneally (IP) for 7 days before exposure to WAS. The treatment was continued till the end of the experiment. The third group was placed on the platform in a container without water for 2 hr daily for 7 days (Sham WAS). The fourth group was pretreated with saline I.P. for 7 days before being exposed to sham WAS. PRIMARY OUTCOME: Bladder wall evaluation for signs of inflammation and total and activated mast cell counts. Secondary outcome: fecal pellet output and micturition frequency at baseline, day 1 and day 7. RESULTS: Bladder walls from rats exposed to WAS revealed significantly higher inflammation score, total and degranulated mast cell counts compared to the sham WAS group. EGCG administration had an obvious protective effect on the bladder mucosa, as the inflammation score, total and degranulated mast cell counts were all significantly lower than in the WAS group. In the WAS group, fecal pellet output and micturition frequency increased above baseline throughout the experiment. Comparison of sham WAS group versus sham WAS with saline revealed no statistically significant difference in any parameter. CONCLUSIONS: EGCG given at 1 mg/kg I.P to rats has a significant protective effect against bladder degenerative changes following WAS.