NB

Fish collagen is known to have moisture-retaining and antioxidant ability. We examined the protective activity of fish collagen hydrolysates derived from tilapia (Oreochromisniloticus) skin, which were dispersed in aqueous phase at the concentration of 72 g/L (Fish Collagen ) UVA-irradiation in three-dimensional (3D) human skin tissue models. Fish Collagen was administered subcutaneously at doses of 2.5–10% in the medium of 3D-skin models and incubated for 72 h. Fish Collagen was demonstrated by its autofluorescence to permeate upwardly into the epidermis. Then the surfaces of 3D-skin models were exposed to 15-time repetition of UVA by 4 J/cm 2 for 4 days (sum: 60 J/cm 2 ). UVA-caused epidermal surface roughness and disruption of vertical dermal layer were detected by scanning elec-tron microscopy. DNA strand cleavages and pycnosis/karyorrhexis indicative of apoptosis were observed in vertical cross-sections of UVA-irradiated 3D-skin models visualized with Hoechst 33342 stain. However, these skin damages were appreciably repressed by Fish Collagen dose-dependently, and 10% Fish Collagen served a sufficiently protective function for 3D-skin models against UVA. These suggest that Fish Collagen was permeated upwardly into the 3D-skin models, which resulted in strengthened collagen fibrils and preserved keratinocytes agaiUVA.