Abstract
The aim of our study was to evaluate the potential benefits of an oral supplement containing porcine placenta extract (PPE) on skin parameters related to cutaneous physiology and aging. PPEs were administered orally to hairless mice for 12 wk. The effects of oral PPE administration on skin water-holding capacity and Transepidermal Water Loss (TEWL) were similar to those of oral collagen (HYCPU2) administered as a positive control. Magnified photographs and replica images showed a reduction in UVB-induced wrinkle formation after collagen and PPE treatments. PPE treatments ameliorated the thicker skin surface that results from UVB exposure, based on a histological examination of skin tissue. The groups that were orally administered PPE (0.05%, OL; 0.1%, OH group) showed significantly reduced Matrix Metaloproteinase-2 (MMP-2) mRNA expression levels compared with the UVB control (Con), by 33.5% and 35.2%, respectively. The mRNA expression of another collagen-degrading protein, MMP-9, was also significantly lower in the groups that received oral administration of PPE (especially in the OH group) than in the control group. Additionally, oral administration of PPE significantly upregulated tissue inhibitor of metalloproteinase-1 (TIMP-1) and -2 mRNA expression levels compared with expression levels in the control group (p<0.05). This indicates that orally administered PPE activated the expression of Timp-1 and -2, inhibitors of MMP, which is responsible for collagen degradation in skin. Taken together, we propose that long-term oral administration of PPE might have a beneficial effect with respect to skin photo-aging.