Chitooligosaccharides attenuate UVB-induced damages in human dermal fibroblasts.

As a continuation of our research on chitooligosaccharides (COS), this study focused on the protective effect of COS of various molecular weights (1-3, 3-5, and 5-10 kDa) on cellular damage caused by ultraviolet B (UVB)-induced oxidative stress in human dermal fibroblast cells. The results show that the protective effect of COS on UVB-stressed human fibroblasts was dependent on molecular weight. COS suppressed UVB irradiation-induced reactive oxygen species generation and DNA damage, accompanied by the downregulation of matrix metalloproteinase (MMP)-1 and MMP-13. In a comparative analysis, COS (3-5 kDa) exhibited the most potent protective effect on UVB-stressed fibroblasts. The presence of COS (3-5 kDa) attenuated UVB-induced collagenolytic MMP production and collagen degradation. The photoprotective activity of COS (3-5 kDa) was confirmed by transcriptional phosphorylation of mitogen-activated protein kinase-responsive signaling pathways.