Isoliquiritigenin reduces experimental autoimmune prostatitis by facilitating Nrf2 activation and suppressing the NLRP3 inflammasome pathway

Chronic prostatitis and chronic pelvic pain syndrome (CP/CPPS) lead to severe irritation and impaired sperm quality in males. However, current therapeutic options often fail to achieve satisfactory effects. Consequently, the investigation of novel treatment strategies or remedies holds substantial clinical importance. As a flavonoid monomer, isoliquiritigenin (ISL) has been shown to possess anti-inflammatory activity, especially in several chronic nonspecific-inflammatory conditions. Thus, an exploration of the possible anti-inflammatory effects of ISL on CP/CPPS, a chronic aseptic inflammation of the prostate, has significant potential. An experimental autoimmune prostatitis (EAP) model was used for the evaluation of the anti-inflammatory effects of ISL. It was found that ISL treatment could reduce the secretion and invasion of pro-inflammatory cytokines in prostate tissue. In EAP mice, ISL treatment also reduced oxidative stress (OS) and activation of the NLRP3 inflammasome. In vitro, ISL upregulated the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and inhibited NLRP3 inflammasome activation in RAW264.7 macrophages exposed to lipopolysaccharide (LPS). Treatment with ISL treatment relieved prostate inflammation and pelvic pain in EAP mice. Both in vivo and in vitro, ISL treatment activated Nrf2/HO-1 signaling, which in turn inhibited oxidative stress and activation of the NLRP3 inflammasome. Blockade of Nrf2/HO-1 signaling abolished the inhibitory effects of ISL on oxidative stress and NLRP3 inflammasome activation. Isoliquiritigenin reduced experimental autoimmune prostatitis by facilitating Nrf2 activation and suppressing the NLRP3 inflammasome pathway.