Two phenolic antioxidants in Suoyang enhance viability of •OH-damaged mesenchymal stem cells: comparison and mechanistic chemistry.

As two reference antioxidants in Suoyang, epicatechin and luteolin-7-O-β-D-glucoside can enhance the viability of •OH-damaged MSCs. Such a beneficial effect may be from their antioxidant effects, including direct-antioxidant and indirect-antioxidant (i.e., Fe2+-binding) processes. In the direct-antioxidant process, proton (H+), one electron (e), or even hydrogen-atom (•H) transfer may occur to fulfill radical-scavenging (especially •OH-scavenging); in this aspect, epicatechin is superior to luteolin-7-O-β-D-glucoside due to the presence of more phenolic -OHs. The additional -OHs can also be responsible for the better cytoprotective effect. In terms of indirect-antioxidant potential, however, epicatechin is inferior to luteolin-7-O-β-D-glucoside due to the absence of a hydroxyl-keto moiety. These findings will provide new information about medicinal psammophytes for MSC transplantation.