Design, synthesis, and biological evaluation of novel chrysin derivatives as poly(ADP-ribose) polymerase 1 (PARP1) inhibitors for the treatment of breast cancer

In this study, we reported the discovery and structure-activity relationship analysis of chrysin derivatives as a new class of inhibitors targeting poly (ADP-ribose) polymerase 1 (PARP1). Among these derivatives, compound 5d emerged as the most effective chrysin-based inhibitor of PARP1, with an IC₅₀ value of 108 nmol·L⁻¹. This compound significantly inhibited the proliferation and migration of breast cancer cell lines HCC-1937 and MDA-MB-436 by inducing DNA damage. Furthermore, 5d induced apoptosis and caused an extended G₁/S-phase in these cell lines. Molecular docking studies revealed that 5d possesses a strong binding affinity toward PARP1. In vivo, in a xenograft model, 5d effectively reduced tumor growth by downregulating PARP1 expression. Overall, compound 5d shows promise as a potential therapeutic agent for the treatment of BRCA wild-type breast cancer.