[Topical application of vitamins, phytosterols and ceramides. Protection against increased expression of interstital collagenase and reduced collagen-I expression after single exposure to UVA irradiation].

Photoaged skin is characterized by a decrease of dermal collagen fibers, resulting from an increased breakdown and a diminished de novo synthesis. The increased breakdown results from an increased expression of matrix metalloproteinases (MMPs). The main building blocks involved in de novo synthesis of collagen fibers are collagen 1A1 and 1A2, the expression of which is reduced in photoaged skin. We studied the effect of topical application of vitamins, phytosterols and ceramides on UV-induced up-regulation of the expression of MMP-1 and on UV-induced down-regulation of COL1A1 and COL1A2. The study was conducted with 10 subjects with healthy skin who were comparatively treated for 10 days with (i) a basic preparation containing jojoba oil, (ii) the basic preparation supplemented with vitamins, (iii) the basic preparation supplemented with phytosterols and ceramides, and (iv) the basic preparation supplemented with vitamins, phytosterols and ceramides. All four preparations inhibited the UV induced up-regulation of MMP-1. Neither the basic product nor that supplemented with vitamins inhibited down-regulation of COL1A1 and COL1A2, but addition of phytosterols and ceramides caused a decreased down-regulation of the expression of these genes. Our results indicate that phytosterols and ceramides are effective in blocking the reduced collagen synthesis after UV irradiation and even stimulating synthesis. They may be useful additions to anti-aging products.