Synergistic Action of Flavonoids, Baicalein, and Daidzein in Estrogenic and Neuroprotective Effects: A Development of Potential Health Products and Therapeutic Drugs against Alzheimer’s Disease
Figure 1
Potentiation of estrogenic activities by baicalein and daidzein. (a) The structures of baicalein and daidzein were illustrated. (b) Three repeats of estrogen responsive element (ERE) were tagged with a luciferase report gene to form pERE-Luc (upper panel). This construct was stably transfected into MCF-7 cells to determine the estrogenic activity of flavonoids. After treatment of baicalein (0.1, 1, 10 μM), daidzein (0.5, 5, 50 μM), and estrogen (10 nM) for 48 hours, cultures were collected to determine the luciferase activity. (c) Potentiation effect was investigated by the addition of baicalein and daidzein at 0.1 μM + 5 μM (upper panel) and 1 μM + 5 μM (lower panel) in pERE-Luc stably transfected MCF-7 cells and then performed the same assay as in (b). (d) Cultured MCF-7 cells were serum-starved and then treated with submaximal dose of baicalein (1 μM) and daidzein (5 μM) for 30 min. Phosphorylation of estrogen receptor α (P-ERα) was determined by western blot analysis. Total ERα and GADPH served as a loading control. Quantification of band intensity was performed in lower panel. Data are expressed as Basal, whereas reading of control without drug or time 0 min is set as 1, mean ± SEM, . ***.
