Abstract: Objective To study the biological changes and the collagen synthesis of the primary cultured skin fibroblast treated with Cigarette Smoke Extract (CSE). Methods The morphological changes of fibroblasts after 24 hours' treatment with CSE were observed with invert microscope. The inhibitory effect at different concentrations of CSE on fibroblast activities was determined by the tetrazolium dye colorimetric test (MTT Test). The growth curves of fibroblasts treated with CSE were drawn with MTT method. Cell aging was observed with β-galactosidase, which was the biological marker of senescence. Flow cytometry (FCM) was used to estimate cell cycle phases after the fibroblasts were treated at different concentrations of CSE and different time. The mRNA expression of type Ⅰ procollagen was detected by RT-PCR. Results After the treatment, the fibroblasts displayed morphological changes and the growth of fibroblasts was apparently slowed down by CSE. The positive β-galactosidase staining was observed in the treated fibroblasts, which were affected by CSE for 5 passages. FCM analysis demonstrated that CSE decreased the cells in S phase and increased the cells in G1 and G2 phase. The result of RT-PCR showed that type Ⅰ procollagen was decreased after the treatment with CSE. Conclusion CSE can not only inhibit the growth and proliferation of the skin fibroblasts, but also decrease collagen synthesis of dermal fibroblast which is very important to the skin health.

Key words: cigarette smoke extract, fibroblast, collagen, skin