Abstract: Objective To explore the effects of estradiol benzoate on the proliferation of collagen synthesis and UVA-induced inhibition of collagen synthesis in cultured human skin fibroblasts.Methods The human skin fibroblasts were cultured in various concentrations (2,4,8,16,32,64,128 nmol/L) of estradiol benzoate in vitro.MTT method was used to assess the proliferation of the cells.To investigate the effects of estradiol benzoate on the UVA-induced inhibition of collagen synthesis,the cultured fibroblasts were divided into four groups:blank control,treatment with estradiol benzoate (2,4,8,16 nmol/L,respectively) only,treatment with UVA radiation (10 J/cm²)only,and treatment with both estradioi benzoate and UVA radiation (4 nmol/L estradiol benzoate + 10 J/cm² UVA and 16 nmol/L estradiol benzoate + 10 J/cm² UVA,respectively).After 48 h of culture,total RNA was extracted from the cells,then the mRNA expression of type I andⅢprecollagens was examined by RT-PCR.Results MTT assay showed that estradiol benzoate had no effect on the proliferation of fibroblasts in vitro.The mRNA expression of the two types of precollagen was up-regulated in the group treated with estradiol benzoate only.On the contrary,the synthesis of the two types of precoilagen was significantly inhibited by UVA radiation,while estradiol benzoate could block the inhibition (P<0.05).Conclusion Estradiol benzoate can improve the synthesis of typeⅠandⅢ precollagens in cultured human skin fibroblasts,and block the inhibitory effect of UVA radiation on the precollagen synthesis.

Key words: Estradiol, Ultraviolet rays, Fibroblasts, Collagen typeⅠ, Collagen typeⅢ