Fig. 1. Effects of nicotine treatment on cellular senescence in HGF-1. Senescence-associated b-galactosidase (SA-b-gal) staining in HGF-1 treated nicotine (0, 0.1, 0.5, 1, 2, and 5 mM) for 72 hours. SA-b-gal was used to mark the aging cells; the cytoplasm of positive cells was stained blue. Magnification ×100 and quantification of SA-b-Gal+ cells cultures. Values are mean±standard deviation of three experiments. *Statistically significant difference compared with control group (p<0.05).