Growth inhibitory efficacy of the nutritional herb Psoralea corylifolia in a model of triple‑negative breast cancer

Abstract

. Triple‑negative breast cancer (TNBC) lacks the expression of estrogen receptor‑ α (ER‑ α ), progesterone receptor (PR) and amplified human epidermal growth factor receptor‑2 (HER‑2). Current treatments involve chemo‑ therapy and molecular targeted therapy. These options lead to dose‑limiting systemic toxicity and acquired tumor resis‑ tance. Moreover, no drug is yet available for the secondary prevention of TNBC. Such limitations underscore a need to investigate non‑toxic testable alternatives for the secondary prevention/treatment of TNBC. The Chinese nutritional herb, Psoralea corylifolia (PC), has been shown to be effective against the MCF‑7 cell line, a cellular model for ER‑ α ‑positive breast cancer. The present study aimed to investigate the growth inhibitory effects of PC against TNBC using the MDA‑MB‑231 cell line. Anchorage‑independent colony forma‑ tion, cell cycle progression, cellular apoptosis, RB signaling and caspase‑3/7 activity assays were performed to determine the quantitative parameters for the efficacy of PC. Treatment with PC induced a 3.5‑fold increase in the G 1 : S + G 2 /M ratio, an 11‑fold increase in the apoptotic cell number and a 149‑fold increase in caspase‑3/7 activity. PC treatment also decreased cyclin D1, CDK4/6 and p‑RB expression levels. On the whole, the data of the present study identify mechanistic leads for PC as a naturally occurring testable alternative, and validate a mechanistic approach to prioritize efficacious nontoxic herbal extracts as nutritional supplements for the secondary preven‑ tion/therapy of TNBC.