Estrogen-like Activity of Scrophularia buergeriana Root Extracts in MCF-7 Cells

Background/Objectives: Estrogen deficiency-related menopause is associated with various physical and psychological symptoms. Although hormone replacement therapy (HRT) effectively alleviates these symptoms, its long-term use is associated with several side effects such as an increased risk of breast cancer and cardiovascular disease. Consequently, there is a growing interest in some plant-derived phytoestrogens that are considered safer alternatives to estrogen. Recent studies on Scrophularia buergeriana confirmed their anti-inflammatory and antioxidant properties; however, their effects on menopausal health remain unclear. Therefore, the aim of this study was to investigate the estrogen-like effects of S. buergeriana root (SB-R) extract, a potential phytoestrogen. Methods: Briefly, the MCF-7 cell line, a widely used in vitro model for assessing estrogen-like activity, was treated with SB-R extract and 17β-estradiol (E2; positive control) in the presence or absence of ICI 182,780 (Fulvestrant), an estrogen receptor antagonist. An E-screen assay and flow cytometry were performed to assess the effects of the treatments on cell proliferation and the cell cycle, respectively. Additionally, Western blotting and immunofluorescence assays were performed to elucidate the potential mechanisms underlying the estrogen-like effects of SB-R. Result: Treatment with SB-R extract promoted MCF-7 cell proliferation in a manner similar to E2. However, ICI 182,780 co-treatment inhibited the SB-R extract-induced increase in MCF-7 cell proliferation. Additionally, SB-R extract promoted cell cycle progression by increasing the proportion of cells in the S and G2/M phases. Moreover, Western blotting and immunofluorescence assays showed that SB-R extract increased the expression of estrogen receptor alpha (ERα). Furthermore, SB-R treatment activated downstream signaling pathways by enhancing AKT and ERK phosphorylation and upregulated the expression of cell cycle regulators, including cyclin D1, cyclin dependent kinase 4 (CDK4), cyclin E1, and cyclin dependent kinase 2 (CDK2). Conclusions: SB-R exhibits estrogen-like activity by activating ERα-mediated AKT and ERK pathways and thereby increasing the expression of proteins involved in cell cycle regulation. This makes it a promising phytoestrogen candidate and a safer alternative to conventional hormonal therapy for alleviating menopausal symptoms.