Abstract:

Objective To investigate the effect of Guizhi fuling pills on the treatment of chronic non-bacterial prostatitis （CNP） in rat models and explore its possible mechanism.Methods Fifteen male Sprague-Dawley rats were divided into the physiological saline, model and drug treatment groups （n = 5 for each group）. After accustomed to the feeding, 50 μl of physiological saline was injected into the bilateral ventral lobes of the prostate in the physiological saline group. In both model and drug treatment groups, 50 μl of 5% formalin was injected into the bilateral ventral lobes of the prostate to establish the rat models of prostatitis. In the drug treatment group, 0.5 g /（kg·d） of Guizhi fuling pills suspension was administered to the stomach at 2 days before inducing prostatitis. At 30 days after drug administration, the bladder pressure was measured and the bladder and prostate tissues were collected. The relative expression levels of nerve growth factor （NGF）, P2X2 receptor, transient receptor potential channel A1 （TRPA1）, tumor necrosis factor-α （TNF-α）, inducible nitric oxide synthase （iNOS）, cyclooxygenase 2 （COX2） and estrogen receptor （ER） mRNA were measured by fluorescence real-time quantitative PCR. Histological examination was carried out.Results Compared with the physiological saline group, the micturition interval was shorter, the frequency of non-voiding contraction during each cycle was increased, the maximum voiding pressure was lower and the amount of residual urine was less in the model group （all P < 0.05）. In the drug treatment group, all these parameters were significantly improved compared with those in the model group （all P < 0.05）. The mast cells and lymphocytes infiltrating into the matrix and acini of irregular shape could be seen in the prostate tissue of rats in the model group, whereas no such changes were found in the drug treatment group. Compared with the physiological saline group, the relative expression levels of NGF, P2X2 and TRPA1 mRNA in the bladder mucosa, and TNF-α, iNOS and COX2 mRNA in the ventral lobes of the prostate were significantly up-regulated in the model group （all P < 0.05）. The expression levels of these genes in the drug treatment group were considerably down-regulated than those in the model group （all P < 0.05）. In addition, the relative expression of ERβ mRNA and the ERβ/ERα ratio in the model group were significantly lower, whereas the relative expression of ERα was remarkably higher than those in the physiological saline group （all P < 0.05）. However, the relative expression of ERβ mRNA and the ERβ/ERα ratio in the drug treatment group were significantly higher, whereas the relative expression of ERα was remarkably lower compared those in the model group （all P < 0.05）. In the physiological saline and drug treatment groups, the epithelial nuclei and ventral lobe cells of the prostate were positive for ERβ staining, and the staining intensity was weakened in the model group.Conclusion Guizhi fuling pills can mitigate the prostatitis and alleviate bladder overactivity induced by CNP probably by activating the ERβ and increasing the ERβ/ERα ratio in the prostate.

Key words: Prostate, Inflammation, Estrogen receptor, Guizhi fuling pills