Anti-oxidant activity and attenuation of bladder hyperactivity by the flavonoid compound kaempferol

Abstract

Objectives: To evaluate the anti-oxidant activity of the flavonoid compound, kaempferol, and to examine its role in the suppression of oxidative stress and attenuation of bladder hyperactivity in a rat model of bladder injury. Methods: The anti-oxidative activity of kaempferol was examined in lipopolysaccharide-treated RAW264.7 macrophages by using flow cytometry. For invivo studies, rats were pretreated with kaempferol or vehicle for 24h. The rat urothelium was injured by the administration of protamine sulfate for 1.5h and irritated by the subsequent infusion of potassium chloride for 4h. Oxidative stress in the bladder tissue was assessed using chemiluminescence assay, and the bladder pressure was determination by cystomertrogram. Results: Kaempferol significantly suppressed lipopolysaccharide-induced reactive oxygen species production in RAW264.7 rat macrophages. Exposure of the rat bladder to sequential infusion of protamine sulfate and potassium chloride induced bladder hyperactivity. Pretreatment with kaempferol, prevented the formation of reactive oxygen species and prolonged the intercontraction interval. Conclusion: Kaempferol suppresses oxidative stress and attenuates bladder hyperactivity caused by potassium chloride after protamine sulfate-induced bladder injury. © 2013 The Japanese Urological Association.