Abstract
【Aims】 Biological mechanisms of aging have been attracting attention and several food ingredients have been reported to have suppressive effects on the process of aging. In this study， as a model of aging we used cultured fibroblasts irradiated with ultraviolet. We assayed the production of collagen and gene expression， and analyzed the effects of various food ingredients added to the culture medium.
【Methods】 Cultured fibroblasts were irradiated with ultraviolet A（UVA）350 nm， and resveratrol， epicatechin， collagen peptides and other food ingredients were added to the medium. The secretion of collagen and elastin into the medium and accumulation of collagen bound to the cell surface were assayed by dye staining method， and change of the expression of genes of collagen and genes relevant to aging were analyzed using real-time PCR.
【Results】 Depending on the time of UVA irradiation， secretion of collagen into the medium were decreased， but the addition of collagen peptides recovered the secretion of collagen into medium. By the addition of resveratrol， accumulation of cell-bound collagen was decreased， while secretion of collagen into the medium was increased. Under the condition without irradiation， increase of gene expression was observed in all of Collagen I, II, Elastin and Collagenase by the addition of resveratrol and epicatechin， but in irradiated cells， the increase of gene expression were observed by the addition of collagen tripeptide.
【Conclusion】 It is suggested that collagen tripeptide in the irradiated cells and resveratrol and epicatechin in nonirradiated cells activate the production of collagen and suppress the process of aging in gene expression level.
