FIGURE 5.

Baicalein increases mitochondrial biogenesis in TAM‐resistant cells. Parental and TAM‐resistant cells were treated with OHT (1 μM), baicalein (25 μM) or OHT (1 μM) combined with baicalein (25 μM) for 48 h. (A) Representative mitochondria in MCF‐7 and MCF‐7TR cells were observed via TEM (× 15 000 magnification; scale bar = 1 μm). White arrowheads indicate mitochondrial damage in MCF‐7 or MCF‐7TR cells and aggregation of mitochondria in MCF‐7TR cells. (B) The percentage of mitochondria with different morphologies was quantified (n = 6 cells). (C) Mitochondrial area was quantified using ImageJ software (n = 30 mitochondria). (D) Cells were treated for 24, 36 or 48 h, and mtDNA levels were assessed according to the relative levels of ND1 and ND5 in comparison with SLCO2B1 and SERPINA1 (n = 3). (E) Mitochondria were stained with MitoTracker Green FM (green fluorescence), and cell nuclei were stained with Hoechst 33342 (blue fluorescence; original magnification 400 × ; scale bars, 50 μm). The ratio of mitochondrial area to nuclear area was calculated (n = 30). (F) MitoTracker Green FM fluorescence was analysed via flow cytometry. Representative histogram overlays and relative MitoTracker Green FM fluorescence intensities. Mean fluorescence intensity values were calculated (n = 3). (G) Western blot analyses of PGC‐1α and Drp1 expression. Results are shown as mean ± SD. *p < 0.05, **p < 0.01, control (PR) vs. control (TR); control vs. OHT; control vs. baicalein (Bai); OHT vs. OHT plus baicalein; baicalein vs. OHT plus baicalein