**2.5 Assay of mitochondrial membrane potentials**

Mitochondrial membrane potentials were measured using a DePsipherTM kit. MH7A cells were untreated and treated with resveratrol (100 M) in the absence and presence of sirtinol (10 M) for 24 h. After washing with cold phosphate-buffered saline (PBS), cells were incubated in a DePsipherTM solution at 37°C for 20 min. Then, cells were washed with 1 ml of a reaction buffer containing a stabilizer solution. The fluorescent signals were observed with a laser scanning microscopes (LSM 510, Carl Zeiss Co., Ltd, Germany) equipped with an epifluorescence device using a fluorescein long-pass filter (fluorescein and rhodamine) at an absorbance of 590 nm for red aggregations and at an absorbance of 530 nm for green aggregations.
