DPP-IV Inhibition by Solubilized Elastin Peptides from Yellowtail Bulbus Arteriosus Suppresses Ultraviolet-B-Induced Photoaging in Hairless Mice

Skin aging is intrinsic and extrinsic. Intrinsic, or chronological, skin aging is an inevitable process of chronological and physiological alterations. The factors contributing to extrinsic skin aging involve sunlight, nutrients, and stress. Thus, extrinsic aging is thought to be superimposed over intrinsic aging and depends on the intensity and duration of environmental exposure and skin type (e.g., dry skin, oily skin, or eczema). The most significant extrinsic aging factor is UV radiation, which causes cellular senescence in a process known as photoaging. This study aimed to illuminate the mechanism whereby solubilized elastin peptide lotion (EL) from the bulbus arteriosus of yellowtail (Seriola quinqueradiata) prevents skin photoaging in hairless mice. EL reduced wrinkle formation, epidermal skin thickness, and Ki67 (cell growth marker) mRNA expression in skin tissues from ultraviolet B (UVB)-irradiated mice. EL treatment also reduced glyoxalase-1 (key enzyme of glucose metabolism) levels in skin tissue. Although no significant differences in collagen and elastin contents were found in dermal areas, matrix metalloproteinase-12 (wrinkle-related marker) expression was reduced following EL application. Furthermore, skin DPP-IV/CD26 (new senescence marker) levels decreased following EL treatment in photoaging model mice. These results suggest that EL moderates skin damage caused by UVB irradiation by regulating senescence-related molecule expression.