Effect of Serenoa repens (Permixon®) on the expression of inflammation-related genes: analysis in primary cell cultures of human prostate carcinoma

Abstract

Abstract Background To analyze the expression at basal level of inflammation-related cytokines and chemokines and the activation status of the NF-κB pathway, together with the proliferation and apoptosis indexes in two widely used in vitro tumor models, the androgen-dependent human Prostate Cancer (PC) cell line LNCaP and the androgen-independent PC3 , and in primary cultures of human PC cells. To assess in these models and primary cultures, the effects of Serenoa repens (LSESr, Permixon®) on proliferation/apoptosis ratio, inflammation-related genes expression and NF-κB pathway activation. Methods The expression of IL-6, CCL-5, CCL-2, COX-1, COX-2, iNOS inflammation-related genes has been evaluated at the mRNA level in two in vitro human PC models (LNCaP and PC3 cell lines) and in 40 independent human prostatic primary cultures obtained from PC patients undergoing radical prostatectomy. Tissue fragments were collected from both PC lesions and normal hyperplastic tissue counterparts for each case. All cultures were treated with two different amounts of Permixon® (44 and 88 μg/ml) for different time points (16, 24, 48 and 72 hours), depending on the cell type and the assay; the expression of inflammation-related genes, cell growth (proliferation/apoptosis ratio) and NF-κB activation has been analyzed in treated and untreated cells by means of semi-quantitative RNA-PCR, cell proliferation and immunofluorescence respectively. Results We detected a significant reduction (p <0.001) in PC and normal cells proliferation due to Permixon ® treatment. This result was related to an increase of the apoptotic activity showed by an increase in the number of anti-caspase-3 fluorescent cells. Almost all the inflammation-related genes (IL-6, CCL-5, CCL-2, COX-2 and iNOS) were expressed at the basal level in in vitro cultured cells and primary cultures and down-regulated by Permixon® treatment. This treatment interfered with NF-kB activation, detecting by the translocation of more than 30% of NF-κB p65 subunit to the nucleus. Conclusions The present study confirms the expression of inflammatory pattern in PC. We showed the effect of Permixon® on down-regulation of inflammatory-related genes in cell lines and in primary cultures. The inhibitory effect of Permixon® on cell growth could be partly associated to the down-regulation of inflammatory-related genes and to the activation of NF-κB pathway in prostate tissue.