Phosphatidylserine prevents UV-induced decrease of type I procollagen and increase of MMP-1 in dermal fibroblasts and human skin in vivo

In an effort to find topical agents that prevent or retard cutaneous aging, seven functional lipids were screened for their procollagen-upregulating and matrix metalloproteinase (MMP)-1-downregulating activities in human dermal fibroblasts by Western blotting. The preventive effect on ultraviolet (UV)-induced decrease of procollagen was demonstrated in phosphatidylserine (PS), lysophosphatidylserine (LPS), lysophosphatidic acid (LPA), N-acetyl phytosphingosine (NAPS), and tetraacetyl phytosphingosine (TAPS). Furthermore, PS, LPS, and LPA upregulated procollagen expression in unirradiated basal conditions. The inhibitory effect on UV-induced MMP-1 expression was seen in NAPS, TAPS, LPA, PS, lysophosphatidylglycerol, and LPS. PS was chosen as the most suitable candidate anti-aging chemical for the subsequent in vivo studies. We investigated the effects of PS on acute UV response and chronologic skin aging by topically applying it to young skin before UV irradiation and to aged human skin, respectively. Real-time PCR and Western blot revealed that in the young skin, PS treatment prevented UV-induced reduction in procollagen expression and inhibited UV-induced MMP-1 expression. PS also blocked UV-induced IL-6 and COX-2 gene expression in cultured fibroblasts dose-dependently. In the aged skin, PS caused increased procollagen transcription and procollagen immunostaining in the upper dermis, and a significant decrease in MMP-1 expression at both mRNA and protein levels. These results indicate that topical PS has anti-skin-aging properties and point to the potential use of PS as a therapeutic agent in the prevention and treatment of cutaneous aging.