α-Lipoic acid can not prevent effet on cell viability, collagen synthesis inhibition, collagen degradation induction in ultraviolet A irradiated human fibroblast cell

Abstract

Ultraviolet A (UVA) irradiation on human skin can generate free radical and stimulate matrix metalloproteinase
production resulting in collagen degradation and transforming growth factor beta (TGF-β) inhibition. It causes synthesis
collagen inhibition and induces cell death. α-Lipoic acid (ALA) is an universal antioxidant and a powerful scavenger
of free radicals. In this study we investigated the effect of ALA on viability, collagen synthesis and degradation in
UVA irradiated human fibroblasts. Normal human skin fibroblasts cell culture were irradiated with UVA for three
times with each dose of 3000 mJ/cm2 UVA. α-Lipoic acid in various concentration was added to the culture
following UVA irradiation and incubated for 48 hours. The cell viability was determined by MTT-assay while collagen
synthesis and degradation were determined by Sirius red binding assay. The difference of cell viability and collagen
synthesis and degradation between fibroblasts cell after and without UVA irradiation were analyzed using paired-t
test with 95% confidence interval (p<0.05). The results showed that UVA irradiation decreased cell viability,
inhibited collagen synthesis and induced collagen degradation in fibroblasts cell. However, ALA was not sufficient to
increase viability, to increase collagen synthesis and to inhibit collagen degradation in fibroblasts cell due to UVA
irradiation. In conclusion, ALA can not prevent UVA irradiation effect on human skin fibroblasts cell.
Key words: UVA – irradiation - human skin fibroblasts – antioxidants – α-lipoic acid