ESR1 and benign prostatic hyperplasia: The observed in vivo efficacy of the extract has been attributed in part to the presence of gallic acid in the plant extract as the subsequent in vitro investigation of gallic acid in BPH-1 cell line demonstrated that the polyphenol could inhibit DHT or 17β-estradiol induced BPH-1 cell proliferation and modulated the steroid(s)-regulated androgen and estrogen receptor expressions (41).