Involvement of Increased Expression of Estrogen Receptor Β in the Anti- Inflammatory Effects of Dutasteride in a Rat Model of Non-bacterial Prostatic Inflammation

Hypothesis / aims of study There is increasing evidence showing that prostatic inflammation is associated with the development of histological benign prostatic hyperplasia (BPH) and male lower urinary tract symptoms (LUTS) [1]. It has also been reported that dutasteride, which inhibits 5α-reductase, might have anti-inflammatory effects in the prostate of patients with lower urinary tract symptoms. In addition, it is shown that estrogen receptor β (ERβ) can be upregulated in prostatic tissues from patients treated with dutasteride [2]. Furthermore, ERβ agonists reportedly upregulate the expression of ERβ with anti-inflammatory effects. Therefore, there might be a possibility that the anti-inflammatory effect of dutasteride is associated with modulation of ERβ pathways during the treatment of BPH/LUTS. Therefore, in order to clarify mechanisms underlying the anti-inflammatory effect of dutasteride, we evaluated the expression of proinflammatory cytokines such as IL18 and IL1, and ERs such as ERα and ERβ in the prostate using a rat model with formalin-induced prostatic inflammation.