Objectives The root of Astragalus membranaceus, regarded as a tonic in traditional Korean medicine, has been prescribed for long periods to treat chronic illness by boosting the immune system. Ultraviolet (UV) irradiation causes damage to skin connective tissue by degrading collagen, which is a major structural component of the extracellular matrix. Such damage is considered to be a cause of the wrinkling observed in premature ageing of the skin. This study has investigated the photo-protective effect of A. membranaceus on UVB radiation-induced activation of nuclear factor kappa-B (NF-κB) activity in human dermal fibroblasts.
Methods Hs68 fibroblast cells cultured with various concentrations of A. membranaceus were exposed to UVB (40 mJ/cm2). Activation of NF-κB P65 and expression of matrix metalloproteinase-1 (MMP-1) and type 1 procollagen were measured by Western blotting. Translocation of NF-κB P65 and MMP-1 regulation were also examined by immunocytochemistry.
Key findings Western blotting and immunocytochemistry results showed that A. membranaceus inhibited UVB-induced translocation of NF-κB P65 and MMP-1 expression. The data suggested that A. membranaceus restored type 1 procollagen synthesis by inhibiting NF-κB P65 activity and MMP-1 expression in UVB-exposed human dermal fibroblasts.
Conclusion A. membranaceus is a candidate for use in skin protection from UVB-induced skin inflammation and photoageing.