The healing and anti-scar effects of astragaloside IV on the wound repair in vitro and in vivo

Astragaloside IV is the chief ingredient of Radix Astragali, which has been used in the Traditional Chinese Medicine as a major component of many polyherbal formulations for the repair and regeneration of injured organ and tissues. This study is to investigate the influence of astragaloside IV on both of the wound healing and scar formation.For the in vitro evaluation, the influence of the astragaloside IV in the wound scratch test of keratinocytes and the secretion of transforming growth factor-β1, a key factor contributing to scar formation were determined. With the rat skin excision model, the in vivo regulation of astragaloside IV on wound closure, angiogenesis and collagen disposition were also evaluated.Astragaloside IV was shown to significantly promote the migration of keratinocytes in wound scratching assay. The superior effect of Astragaloside IV was observed at 100 μmol/L, in which the recover rates was increased with 2 and 3 folds after 48 h and 96 h respectively than that of blank control (P<0.01). Animal skin closure measurement showed that astragaloside IV could stimulate the wound healing, e.g. with 21% recover in contrast to the 8% of blank control at the 6th day. Biomechanic and Masson's trichrome stain analysis indicated that astragaloside IV may improve the strength of the repaired skin and promoted the angiogenesis and collagen synthesis. Meanwhile, the picrosirius-sirus red stain and Elisa test definitely showed the anti-scar effects of astragaloside IV by decreasing the levels of collagen I/III and TGF-β1 secretion by firbroblasts with a dose-dependent manner (25-100 μmol/L).Astragaloside IV was shown a promising natural product with both healing and anti-scar effects for wound treatment. These results give the evidence for the application of astragaloside IV in the treatment of injury.