Collagen synthesis on ultraviolet A irradiated human skin fibroblast treated with insulin
Ultraviolet (UV) irradiation from the sun can stimulate premature skin aging because UV irradiation inhibits collagen synthesis, promotes collagen degradation and inhibits fibroblast proliferation. Insulin is capable to stimulate fibroblast genes collagen expression, DNA synthesis, and collagen synthesis. The effect of insulin in reducing collagen synthesis among repeated-UVA irradiation on human skin fibroblast has never been studied. This study aims to investigate the effect of insulin in collagen synthesis among repeated-UVA irradiation on normal human skin fibroblast. To asses the collagen synthesis collagen degradation, collagen deposition and fibroblast proliferationweremeasured. Experimental study was performed among passage 3 of fibroblast which was isolated from a circumcised skin of a 6-year-old boy. Fibroblasts were irradiated with 3 repeated exposurewith total cumulative dose 9000 mJ/cm2 and treated with insulin 0.5; 1; 2 μg/mL and placebo. Cellswere then incubated for 48 hours, collagen degradation, collagen deposition and fibroblast proliferation were read colorimetric by using Spectroscopy 550 nm. The effect of insulin 0.5; 1 and 2 ig/mL in collagen synthesis among repeated-UVA irradiation on normal human skin fibroblast with cumulative dose 9000 mJ/cm2 was not capable to reduce collagen degradation, nor capable to increase collagen and fibroblast proliferation. Insulin dose 0,5 μg/ml-2 μg/ml among repeated-UVA irradiation on normal human skin fibroblast was not capable to increase collagen synthesis. Key words: photoaging-DNA synthesis-proliferasion-aging process-gene expression