Fish collagen-containing drink is subcutaneously absorbed and attenuates the UVA-induced tissue-integrity destruction and DNA damages in 3D-human skin tissue model

Abstract

Fish collagen is known to have moisture-retaining and antioxidant ability. We examined the protective activity of fish collagen hydrolysates derived from Nile tilapia (Oreochromis niloticus) skin, which were dispersed in aqueous phase at the concentration of 72 g/L (FishCllgn), against UVA-irradiation in three-dimensional (3D) human skin tissue models. FishCllgn was administered subcutaneously at doses of 2.5–10% in the medium of 3D-skin models and incubated for 72 h. FishCllgn 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/cm2 for 4 days (sum: 60 J/cm2). UVA-caused epidermal surface roughness and disruption of vertical dermal layer were detected by scanning electron 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 FishCllgn dose-dependently, and 10% FishCllgn served a sufficiently protective function for 3D-skin models against UVA. These suggest that FishCllgn was permeated upwardly into the 3D-skin models, which resulted in strengthened collagen fibrils and preserved keratinocytes against UVA.

Keywords

• Fish collagen
• UVA
• Scanning electron microscopy (SEM)
• Hoechst 33342 stain
• 3D-Human skin tissue model