Association of Spices and Overactive Bladder

The prevalence of overactive bladder (OAB) is higher in spicy diet habit countries such as Korea, Thailand and Hong Kong. It is estimated more than 60% of the population suffered from OAB in these regions. Spicy food may increase the possibility of developing OAB, which is the rationale of this animal study. A new treatment strategy may be changed if the association between spices and OAB can be proved. The cause of OAB includes some proposed pathways such as over-production of nerve growth factor (NGF), Rho-kinase pathway activation. These commonly understood pathways do not seem to have direct connection with spices. But the human response to species may be related. The spices can activate the thermogenesis and the sympathetic nervous system activation may be increased, which followed by more thermogenesis to expand excess energy as heat. Since sympathetic system may be activated, systemic effect of spices should be considered including possible local effect of spices. However the local effect from previous studies revealed that OAB may be treated with direct instillation of ingredients of spices into bladder. Therefore, the real connections between OAB, spices and their ingredients, the systemic and local counteractive effect need to be further investigated. To test this hypothesis, we will examine these commonly found spices and their major ingredients including Capsaicin (Sigma-Aldrich, M2028), Benzyl isothiocyanate (Sigma-Aldrich, W442800), Curcumin (Sigma-Aldrich, C1386), and allyl sulfide (Sigma-Aldrich, A35801) on the bladder function and NGF concentration in urine vs. bladder wall. The activation of Rho-kinase pathway will be also evaluated through immuno-histochemical staining. This study will first set up animal models for in vivo evaluation of diet intake, bladder function and systemic effect. The effect of the species will be evaluated in the second part of the study by ex vivo study of detrusor muscle and protein analysis (receptors and NGF) of bladder wall vs. urine with enzyme –link immune-sorbent assay and western blots. The contraction of isolated muscle strips will be assessed in tissue bath. The electric field stimulation (EFS) will be obtained by stimulating the muscle strips with increasing frequencies, using 0.5, 1, 5, 10, 20, 40, and 60 Hz at 50 V/cm with a pulse width of 0.05msec in 10 sec trains at 1 minute intervals. The Rho-kinase signaling pathway will be evaluated by immuno-histochemical methods The anticipated result is that food spices metabolite in urine will stimulate bladder through receptors on bladder mucosa. These metabolites will act as bladder stimulants and irritates bladder. Low urinary tract symptoms may be found in spices treated rat.We expect to demonstrate certain spices as risk factor of overactive bladder. This information could be useful for the creation of different treatment strategies in overactive bladder in the future.

Project ID:PC9907-2198
External Project ID:NSC99-2314-B182-021