Finally, the SA-βG activity of HDF from the experimental group was compared with that from the control group HDF long-term incubated with and 12.5μM EGCG significantly delayed the aging process demonstrated by less FDG fluorescence signals in the treated HDF Quantification of the X-Gal positively stained HDF also revealed the lower SA-βG activity in the EGCG-treated HDF as a result of more juvenile cell status (Figure 20) Figure 20 Effects of EGCG on cellular senescence of the middle-aged HDF HDF (PDL35) incubated with and 12.5μM EGCG for long term was evaluated for its cellular senescence status based on the SA-βG activity using FDG and XGal as substrates Fluorescence signals from FDG staining and blue colored products from X-Gal staining were quantified and expressed in the unit of RFU (relative fluorescence unit) and relative area occupied by positive (blue) cells, respectively; *p