Androgen-independent effects of Serenoa repens extract (Prostasan®) on prostatic epithelial cell proliferation and inflammation.

Extracts from Serenoa repens are widely used for the treatment of benign prostatic hyperplasia (BPH) and traditionally for prostatitis. In the present study we evaluated the biological effects of Serenoa repens extract (Prostasan®) on prostate cells beyond its known antiandrogenic actions. Prostasan® inhibited epidermal growth factor (EGF) and lipopolysaccharide (LPS) induced proliferation of the prostatic epithelial, androgen independent cell line PC-3. At effective concentrations of 50 µg/mL, Prostasan® partly displaced EGF from EGF receptor (EGFR) but fully blocked EGF-induced cell proliferation of PC-3 cells. Similarly, Prostasan® inhibited LPS-induced proliferation of PC-3 cells without affecting LPS activation of the NFĸB pathway via toll-like receptor-4 (TLR-4). Additionally, Prostasan® reduced the constitutive secretion of monocyte chemotactic protein-1 (MCP-1), the LPS-induced secretion of IL-12 and inhibited MCP-1 and granulocyte-macrophage colony-stimulating factor (GM-CSF) production in the presence of LPS on PC-3 cells. Taken together, our results suggest that S. repens extracts, in addition to other reported effects on BPH development and prostatitis, inhibits EGF-dependent growth and proinflammatory responses of the prostate epithelial cells.