Role of the p -Coumaroyl Moiety in the Antioxidant and Cytoprotective Effects of Flavonoid Glycosides: Comparison of Astragalin and Tiliroside

摘要

The aim of this study was to explore the role of p -coumaroyl in the antioxidant and cytoprotective effects of flavonoid glycosides. The antioxidant effects of astragalin and tiliroside were compared using ferric ion reducing antioxidant power, DPPH? scavenging, ABTS? + scavenging, ?O 2 – scavenging, and Fe 2+ -chelating assays. The results of these assays revealed that astragalin and tiliroside both exhibited dose-dependent activities; however, tiliroside exhibited lower IC 50 values than astragalin. In the Fe 2+ -chelating assay, tiliroside gave a larger shoulder-peak at 510 nm than astragalin, and was also found to be darker in color. Both of these compounds were subsequently evaluated in a Fenton-induced mesenchymal stem cell (MSC) damaged assay, where tiliroside performed more effectively as a cytoprotective agent than astragalin. Tiliroside bearing a 6′′- O - p -coumaroyl moiety exhibits higher antioxidant and cytoprotective effects than astragalin. The 6′′- O - p -coumaroyl moiety of tiliroside not only enhances the possibility of electron-transfer and hydrogen-atom-transfer-based multi-pathways, but also enhances the likelihood of Fe-chelating. The p -coumaroylation of the 6"-OH position could therefore be regarded as a potential approach for improving the antioxidant and cytoprotective effects of flavonoid glycosides in MSC implantation therapy.