Increase of SIRT1 enzymatic activity by combined administration of resveratrol and equol. Fluorimetric SIRT1 activity assay to determine the effect achieved in HUVEC by the combined exposure to equol and resveratrol. Representative data of at least 3 experiments each performed in triplicate. (*= P < 0.05, **= P < 0.01). AFU: arbitrary fluorescence units; C: control; E: equol; R: resveratrol; E+R: equol + resveratrol.