Effects of cigarette smoke extract on cell proliferation and growth of cultured human skin fibroblasts

Objective To study the effect of cigarette smoke extract(CSE)on the proliferation and growth of primarily cultured skin fibroblasts.Methods Fibroblasts were isolated from the foreskin of healthy young adults,and subjected to primary culture.After 5～15 passages,these fibroblasts were exposed to various concentrations of CSE for various durations.MTT assay was used to detect the viability of fibro- blasts after exposure.The morphological and structural changes of these cells were observed by microscopy.β-galactosidase staining was performed on fibroblasts treated with CSE during several passages.Growth curves were drawn with MTT method for fibroblasts exposed to low concentration of CSE during 5 passages.The content of reactive oxygen species(ROS)in cell plasma,and activities of superoxide dismutase(SOD)in cells were determined by spectrophotometric method.Results The fibroblasts displayed typical morpho- logical changes after exposed to CSE for 24 h.The viability of fibroblasts declined with the increase of CSE concentration and treatment time.β-galactosidase was detected more frequently in fibroblasts exposed to CSE during 5 passages than in those without any treatment.After CSE treatment,the content of ROS signifi- cantly increased,while the activities of SOD decreased(both P0.05).Conclusions These findings suggest that CSE could injure cultured fibroblasts and inhibit the growth and proliferation of them.Furthermore, long-term action of CSE at low concentration could accelerate the senescence of primarily cultured fibro- blasts,and oxidative damage may be involved in the CSE injury to cells.