Baicalin and baicalein inhibit transforming growth factor-β1-mediated epithelial-mesenchymal transition in human breast epithelial cells.

Since the epithelial-mesenchymal transition (EMT) is involved in many crucial functions of cancer cells, we set out to identify a natural compound capable of inhibiting EMT processes. TGF-β1 treatment induces EMT among normal mammary epithelial cells (MCF10A cells), as reflected by characteristic morphological changes into the fibroblastic phenotype, reduced expression of E-cadherin. Interestingly, butanol extracts of Scutellaria baicalensis Georgi significantly reduced the TGF-β1-mediated EMT of MCF10A cells. Further analysis revealed that baicalin and baicalein, the major flavones of these butanol extracts, inhibited TGF-β1-mediated EMT by reducing the expression level of the EMT-related transcription factor, Slug via the NF-κB pathway, and subsequently increased migration in MCF10A cells. Finally, both compounds reduced the TGF-β1-mediated EMT, anchorage-independent growth and cell migration of human breast cancer cells (MDA-MB-231 cells). Taken together, these results suggest that baicalin and baicalein of Scutellaria baicalensis Georgi may suppress the EMT of breast epithelial cells and the tumorigenic activity of breast cancer cells. Thus, these compounds could have potential as therapeutic or supplementary agents for the treatment of breast cancer.