The combined treatment of resveratrol and equol strongly increased the number of mitochondria in HUVEC cells. (A) Mitotracker fluorescent intensities were analysed to assess the mitochondrial biogenesis. (B) Relative mitochondrial DNA (mtDNA) content was estimated by qRT-PCR. Representative data of at least 3 experiments each performed in triplicate. (*= P < 0.05, **= P < 0.01). C: control; E: equol; R: resveratrol; E+R: equol + resveratrol.