Leonurine Mitigates Experimental Autoimmune Prostatitis by Modulating Macrophage M1 Polarization Through the TLR4/NF-κB Signaling Pathway.

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) constitutes a clinically complex urological condition defined by the persistence of pelvic pain and chronic inflammation. Emerging evidence underscores the critical involvement of macrophage-mediated immune dysregulation, particularly the dominance of pro-inflammatory M1 macrophages, in driving CP/CPPS pathogenesis. Leonurine, a bioactive alkaloid derived from leonuri, exhibits various pharmacological properties and has been shown to regulate macrophage polarization in rheumatoid arthritis. This study aimed to evaluate leonurine's therapeutic efficacy in a murine experimental autoimmune prostatitis (EAP) model, established by subcutaneous injection of complete Freund's adjuvant-emulsified prostate antigens. Leonurine administration in EAP mice markedly reduced prostatic inflammatory responses, mitigated chronic pain, and inhibited the expression of pro-inflammatory cytokines. Likewise, leonurine decreased inducible nitric oxide synthase (iNOS) expression levels, an established marker for M1 macrophage polarization. Leonurine has been found to suppress M1 polarization and decrease the secretion of M1-related cytokines (IL-1β and TNF-α) in immortalized bone marrow-derived macrophages (iBMDMs) under in vitro conditions. Mechanistic investigations demonstrated that leonurine mediates its therapeutic effects by modulating the TLR4/NF-κB signaling pathway in both macrophages and EAP models. Molecular docking and dynamics simulations demonstrated stable binding interactions between leonurine and key proteins involved in the TLR4/NF-κB signaling cascade. As a whole, these findings verify that leonurine relieves experimental autoimmune prostatitis (EAP) by regulating M1 macrophage polarization through the TLR4/NF-κB signaling cascade.