Anti-inflammatory effect and prostate gene expression profiling of steryl ferulate on experimental rats with non-bacterial prostatitis.

Steryl ferulate (SF) is a bioactive mixture extracted from rice bran and shows higher inhibitory activity against inflammation than the corresponding free sterols. In this study, the aim was to investigate the anti-inflammatory effect and prostate gene expression profiling of SF using a Xiaozhiling-induced non-bacterial prostatitis (NBP) rat model. The anti-inflammatory effect was evaluated by prostate weight, prostate index, acid phosphatase, density of lecithin corpuscles (DLC), white blood cell count (WBC), and prostatic histologic section. Prostate gene expression profiling was assessed by a cDNA microarray and validated by quantitative real-time PCR of five selected genes. Pathway analysis and Gene ontology (GO) analysis were applied to determine the roles of these differentially expressed genes involved in these biological pathways or GO terms. SF treatment could significantly inhibit prostate weight, prostate index, total acid phosphatase, prostatic acid phosphatase and WBC, suppress the severity of histological lesion and increase the DLC. Compared with the control group, the SF treatment group contained 238 up-regulated genes and 111 down-regulated genes. GO analysis demonstrated that the most significant expression genes were closely related to the terms of fibrinolysis, inflammatory response, high-density lipoprotein particle, protein-lipid complex, enzyme inhibitor activity, peptidase inhibitor activity and others. Canonical pathway analysis indicated five pathways were significantly regulated, which were associated with inflammation and tumorgenesis. In conclusion, SF may be used as a health supplement to prevent NBP, in that it could inhibit prostate inflammation in NBP patients by affecting the expression of genes in the related GO terms and pathways.