Whey peptides prevent chronic ultraviolet B adiation-induced skin aging in melanin-possessing male hairless mice

Abstract

Whey proteins or peptides exhibit various actions, including an antioxidant action, an anticancer action, and a protectiveaction against childhood asthma and atopic syndrome. The effects of orally administered whey peptides (WPs) on chronicultraviolet B (UVB) radiation-induced cutaneous changes, including changes in cutaneous thickness, elasticity, wrinkleformation, etc., have not been examined. In this study, we studied the preventive effects of WPs on cutaneous aginginduced by chronic UVB irradiation in melanin-possessing male hairless mice (HRM). UVB (36-180 mJ/cm2) was irradiatedto the dorsal area for 17 wk in HRM, and the measurements of cutaneous thickness and elasticity in UVB irradiated micewere performed every week. WPs (200 and 400 mg/kg, twice daily) were administered orally for 17 wk. WPs inhibited theincrease in cutaneous thickness, wrinkle formation, and melanin granules and the reduction in cutaneous elasticityassociated with photoaging. Furthermore, it has been reported that UVB irradiation-induced skin aging is closelyassociated with the increase in expression of matrix metalloproteinase (MMP), vascular endothelial growth factor (VEGF),Ki-67-, and 8-hydroxy-2#-deoxyguanosine (8-OHdG)-positive cells. WPs also prevented increases in the expression ofMMP-2 and pro-MMP-9, VEGF, and Ki-67- and 8-OHdG-positive cells induced by chronic UVB irradiation. It was found thatWPs prevent type IV collagen degradation, angiogenesis, proliferation, and DNA damage caused by UVB irradiation.Overall, these results demonstrate the considerable benefit ofWPs for protection against solar UV-irradiated skin agingas a supplemental nutrient. © 2014 American Society for Nutrition.