Anti-inflammation properties of resveratrol in the detrusor smooth muscle of the diabetic rat.

Purpose: In this paper, we aimed to prove that resveratrol can inhibit inflammation in the detrusor smooth muscle of diabetic rats, which may provide a new direction for diabetic cystopathy (DCP) treatment.

Methods: We induced a Sprague-Dawley (SD) rat model of type 1 diabetes by intraperitoneal injections of streptozotocin (STZ). Then, we separated the SD rats into four groups: (1) an excipient-treated control group; (2) a resveratrol-treated control group; (3) an excipient-treated streptozotocin (STZ)-injected group; and (4) a resveratrol-treated STZ-injected group. We administered the resveratrol or excipient by intragastric administration. After 12 weeks of diabetes induction, we measured the blood-sugar concentrations and bladder weights, and we took the bladder tissues of each group of rats for hematoxylin-eosin staining to observe the histological changes. We used real-time quantitative polymerase chain reaction (qPCR) and Western blotting to analyze the expression levels of tumor necrosis factor-alpha (TNF-α), nuclear factor kappa B (NF-κB), interleukin (IL)-6, and IL-1β.

Results: The bodyweights of the diabetic rats were appreciably reduced, while the bladder weights and blood-glucose concentrations were substantially increased. Oral resveratrol could not improve the changes in the bodyweights and blood-glucose concentrations, but it had a certain effect on the bladder weights. In a macroscopic evaluation, the bladder walls of the STZ-induced diabetes rats were thickened, and, from the H&E staining, we could see that the bladder tissues of the diabetic rats had inflammatory cell infiltration, edema, and the capillary congestion of the mucosa and lamina propria. After resveratrol treatment, the bladder-wall thickening was reduced, and the tissue damage and inflammation were significantly ameliorated. We could associate all these changes with markedly heightened expressions of TNF-α, IL-1β, IL-6, and NF-κB in the detrusor smooth muscle (DSM) tissues of the diabetic rats. Oral treatment with resveratrol alleviated the expressivity of the inflammatory cytokines in the DSM tissues.

Conclusions: Resveratrol treatment ameliorated the histological changes in the bladder and inhibited the expressions of DSM-tissue inflammatory factors in diabetes rats. Resveratrol may provide a new direction of research for the treatment of diabetic cystopathy.