Effect of the Phytotherapeutic Agent Eviprostat on Inflammatory Changes and Cytokine Production in a Rat Model of Nonbacterial Prostatitis

Abstract

To examine the effect of the phytotherapeutic agent Eviprostat on the stromal-to-epithelial (S/E) ratio, level of macrophage infiltration, expression of the macrophage inhibitory cytokine-1 (Mic1) gene, and tumor necrosis factor-alpha (TNF-α) and interleukin-8 (IL-8) concentrations in prostate tissues in a rat model of nonbacterial prostatitis (NBP). Ten-month old Wistar rats were divided into 4 groups of 10: (1) NBP non-mixed feed (prostatitis control group); (2) NBP Eviprostat (0.1%) mixed feed (prostatitis Eviprostat group); (3) non-NBP non-mixed feed (nonprostatitis control group); and (4) non-NBP Eviprostat mixed-feed (nonprostatitis Eviprostat group). NBP was induced by castration followed by daily subcutaneous injection of 17β-estradiol for 30 days. Ventral prostate lobes were histopathologically examined with Masson's trichrome staining or immunostaining with antimacrophage antibody. Mic1 mRNA levels were quantified by real-time reverse transcriptase polymerase chain reaction. Tissue concentrations of TNF-α and IL-8 were determined by enzyme-linked immunosorbent assay. Stroma was the most abundant in prostatitis control rats. The mean S/E ratio in prostatitis Eviprostat rats was significantly lower than in prostatitis control rats (P < .0001). The high levels of macrophage infiltration found in prostatitis control rats were significantly reduced in prostatitis Eviprostat rats (P < .0001). The up-regulation of the Mic1 gene observed in prostatitis control rat prostates was significantly suppressed in prostatitis Eviprostat rats (P < .0001). A marked suppression of TNF-α and IL-8 secretion was also observed in prostatitis Eviprostat rats (P < .05). Eviprostat significantly suppressed the S/E ratio, level of macrophage infiltration, Mic1 gene expression, and proinflammatory cytokines/chemokines in the prostate in a rat NBP model.