Natural Products Targeting the Androgen Receptor Signaling Pathway: Therapeutic Potential and Mechanisms

The androgen receptor (AR) signaling pathway is the primary driver of prostate cancer initiation and progression, including the development of castration-resistant prostate cancer (CRPC). Because current AR-targeted therapies inevitably encounter drug resistance, novel strategies to suppress AR signaling are urgently needed. Natural products represent a rich and structurally diverse source of bioactive compounds capable of targeting AR at multiple regulatory levels. This review overviews the interactions between natural products and the AR signaling axis through distinct mechanisms, including inhibition of testosterone production and 5α-reductase activity, direct antagonism of AR, and induction of AR degradation. In addition, several compounds disrupt AR nuclear translocation, downregulate AR splice variants, or suppress AR signaling indirectly through epigenetic regulation, microRNA modulation, or interference with co-regulator networks. Preclinical studies provide compelling evidence that these agents can effectively interrupt AR signaling, thereby suppressing prostate cancer growth. However, challenges remain, particularly the limited pharmacokinetic characterization, lack of in vivo validation, and scarcity of clinical studies. Future research should focus on improving bioavailability, exploring synergistic combinations with existing therapies, and advancing well-designed in vivo and clinical investigations. Collectively, these efforts may establish natural products as lead compounds to modulate AR signaling for prostate cancer prevention and treatment.