Study on Effect and Mechanism of Astragalosides in Promoting Wound Healing

• Main Authors: Zhi-Xiang Li, 李志詳
• Other Authors: Tsu-Chang Chang
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/98731185857205270425

碩士 === 國防醫學院 === 生物化學研究所 === 101 === Astragalus is a widely used in traditional Chinese medicine with a variety of applications. It is traditionally valued for its prominent wound-healing activity, thought clinically proven data and the detailed mechanism is lacking. In this study, the wound-healing activity of the astragalosides, the active components of Astragali Radix, were investigated. It has been known that EGFR (Epidermal growth factor receptor) plays an essential role in regulation of wound healing with complex cell functions. In this study, we found that all of the eight astragalosides studied enhanced EGFR activity in HaCaT cells. Among them, compounds AA and AS VI exhibit the most significant EGFR activation activity. In addition, AA and AS VI also enhanced the ERK, which is the downstream of EGFR, activity in a dose-dependent manner. The effect of these compounds on EGFR and ERK were also confirmed using specific kinase inhibitor for EGFR, AG1478 and for ERK, U0126. Moreover, we showed that AA and AS VI stimulated HaCaT cells proliferation and their activity were suppressed by AG1478 or U0126. Additional experiments also showed that AA and AS VI promoted human dermal fibroblast (HDF) proliferation. Further studies in animal model demonstrated that AA and AS VI accelerated wound healing and promoted angiogenesis. Furthermore, histological examination indicated increased collagen synthesis and anti-inflammatory activities in mice skin tissues treated with these compounds. In summary, we found that astragalosides, AA and AS VI, significantly increased skin cell proliferation and wound healing through EGFR-ERK signaling pathway. Using animal model, we further showed that the AA- or AS VI-enhanced wound healing may be resulted from increased angiogenesis, collagen synthesis and anti-inflammatory activities in the healing skin tissues.