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.

Background/Objectives: Elastin-derived peptides (EPs) from food sources may be multifunctional dietary components that support metabolic and vascular health. However, their in vivo physiological actions remain incompletely understood. This study investigated the effects of bonito bulbus arteriosus-derived EPs on glucose metabolism, GLP‑1 elevation and enhanced early-phase insulin secretion, and renal vascular integrity in stroke-prone spontaneously hypertensive rats (SHRSP) with glucose intolerance. Methods: Male SHRSP were administered EPs orally as a single dose (1,000 mg/kg) or 4-week regimen (600 mg/kg/day). Glucose tolerance, plasma GLP‑1 and insulin levels, and blood glucose levels were measured following glucose loading. Renal morphology was assessed histologically. Dpp4, Icam‑1, and Agtr1 expression was quantified in glomerular and leukocyte fractions. Leukocyte oxidative signaling was evaluated by quantifying reactive oxygen species production associated with inducible nitric oxide synthase (iNOS). Age‑matched Wistar-Kyoto rats were included as normotensive controls. Results: A single dose increased plasma GLP‑1 and insulin levels and improved glucose tolerance compared with controls. The 4‑week regimen resulted in sustained improvements in glucose tolerance, without changes in blood pressure, a lower nephrosclerosis incidence, and reduced renal and leukocytic inflammatory marker expression. Dpp4, Icam‑1, and Agtr1 expression was downregulated and leukocyte iNOS‑driven oxidative signaling was reduced. These effects occurred despite the modest DPP‑IV inhibitory activity of EPs. Conclusions: Food-derived EPs exert multi-target physiological actions, including GLP‑1 elevation with enhanced early-phase insulin secretion and leukocyte oxidative and inflammatory response suppression, that improve metabolic and renal vascular outcomes. EPs warrant further investigation as candidate functional food ingredients for metabolic and vascular health.

Background/Objectives: Elastin-derived peptides (EPs) from food sources may be multifunctional dietary components that support metabolic and vascular health. However, their in vivo physiological actions remain incompletely understood. This study investigated the effects of bonito bulbus arteriosus-derived EPs on glucose metabolism, GLP-1 elevation associated with enhanced early-phase insulin secretion, and renal vascular integrity in stroke-prone spontaneously hypertensive rats (SHRSP) with glucose intolerance. Methods: Male SHRSP were administered EPs orally as a single dose (1000 mg/kg) or 4-week regimen (600 mg/kg/day). Glucose tolerance, plasma GLP-1 and insulin levels, and blood glucose levels were measured following glucose loading. Renal morphology was assessed histologically. Dpp4, Icam-1, and Agtr1 expression was quantified in glomerular and leukocyte fractions. Leukocyte oxidative signaling was evaluated by quantifying reactive oxygen species production associated with inducible nitric oxide synthase (iNOS). Age-matched Wistar–Kyoto rats were included as normotensive controls. Results: A single dose increased plasma GLP-1 and insulin levels and improved glucose tolerance compared with controls. The 4-week regimen resulted in sustained improvements in glucose tolerance, without changes in blood pressure, a lower nephrosclerosis incidence, and reduced renal and leukocytic inflammatory marker expression. Dpp4, Icam-1, and Agtr1 expression was downregulated, and leukocyte iNOS-driven oxidative signaling was reduced. These effects occurred despite the modest DPP4 inhibitory activity of EPs. Conclusions: Food-derived EPs may exert multi-target physiological actions, including GLP-1 elevation with enhanced early-phase insulin secretion and leukocyte oxidative and inflammatory response suppression, which potentially improve metabolic and renal vascular outcomes. EPs warrant further exploratory investigation as candidate functional food ingredients for metabolic and vascular health.