Cytoprotective effects of grape seed extract on human gingival fibroblasts in relation to its antioxidant potential

Cytoprotective effects of short-term treatment with grape seed extract (GSE) upon human gingival fibroblasts (hGFs) were evaluated in relation to its antioxidant properties and compared with those of a water-soluble analog of vitamin E: trolox (Tx). GSE and Tx showed comparable antioxidant potential in vitro against di(phenyl)-(2,4,6-trinitrophenyl)iminoazanium (DPPH; a stable radical), hydroxyl radical (•OH), singlet oxygen (1O2), and hydrogen peroxide (H2O2). Pretreatment or concomitant treatment with GSE for 1 min protected hGFs from oxidative stressors, including H2O2, acid-electrolyzed water (AEW), and 1O2, and attenuated the intracellular formation of reactive oxygen species induced by H2O2 and AEW. Tx also reduced the H2O2- and AEW-induced intracellular formation of reactive oxygen species, but showed no cytoprotective effects on hGFs exposed to H2O2, AEW, or 1O2. These results suggest that the cytoprotective effects of GSE are likely exerted independently of its antioxidant potential.