Predominant effects of Polypodium leucotomos on membrane integrity, lipid peroxidation, and expression of elastin and matrixmetalloproteinase-1 in ultraviolet radiation exposed fibroblasts, and keratinocytes

Background: Polypodium leucotomos has been reported to have antioxidant, anti-inflammatory and photoprotective properties. Exposure of skin to ultraviolet (UV) radiation can Lead to deposition of excessive etastotic material, reduction in collagen, and increased expression of matrix metalloproteinases (MMPs). Objective: The goal of this research was to determine the effects of P leucotomos in the absence or presence of UVA or UVB radiation on membrane damage, Lipid peroxidation, and expression of elastin and MMP-1 in fibroblasts and keratinocytes, respectively. Methods: Fibroblasts and keratinocytes, respectively, were irradiated by a single exposure to UVA (0.6, 1.8 or 3.6 J) or UVB radiation (0.75, 2.5 or 7.5 mJ), and then incubated with, or without, P leucotomos (0.01, 0.1 and 1%) and examined for membrane damage, lipid peroxidation, expression of elastin (protein levels) and MMP-1 (protein Levels or MMP-1 promoter activity). Results: UV radiation did not significantly alter membrane integrity, lipid peroxidation or MMP-1 expression, but increased elastin expression. P leucotomos significantly improved membrane integrity, inhibited lipid peroxidation, increased elastin expression, and inhibited MMP-1 expression in both fibroblasts, and keratinocytes. The effects of P leucotomos predominated in the presence of UVA or UVB in both fibroblasts and keratinocytes, respectively, with the exception of inhibition of MMP-1 protein Levels in fibroblasts only in combination with UV radiation. Conclusion: Lower concentration of P leucotomos (Lower than 0.1%), may be beneficial in preventing photoaging by improving membrane integrity and inhibiting MMP-1, without increasing elastin expression. Higher concentration (greater than 0.1%) of P leucotomos may reverse the loss of normal elastic fibers associated with intrinsic aging. (C) 2003 Japanese Society for Investigative Dermatology. Published by Elsevier Science Ireland Ltd. ALL rights reserved.