PSVI-11 Antioxidative effects of red-osier dogwood extract on H2O2-treated human intestinal epithelial Caco-2 cells

Abstract

Abstract Red-osier dogwood is a species of flowering plant native in North America. Its extract may exhibit the anti-oxidative and anti-bacterial properties because it contains plenty of phenolic compounds, polysaccharides, and bioactive peptides. Hence, red-osier dogwood extract (RDE) could be a potential alternative to antibiotics. In the present study, an in vitro oxidative damage model via using Caco-2 cells was established to evaluate the antioxidative effects of RDE. The results showed that 1 mM H2O2 significantly decreased the cell viability, and increased interleukin 8 (IL-8) secretion and reactive oxygen species (ROS) production (P < 0.05). The mRNA abundance of tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6) and IL-8 also increased in cells treated by H2O2. Caco-2 cells exposed to H2O2 for 6 h were then treated with 100 µg/mL RDE for 24 h. The IL-8 secretion and ROS production induced by H2O2 was significantly blocked by RDE (P < 0.05). RDE reduced the leakage of Fluorescein isothiocyanate (FITC)-dextran, and increased transepithelial resistance (TEER) value compared with the control (H2O2 treatment). Moreover, RDE increased Zonula occludens-1 (ZO-1) and β-actin staining in the cells and tight junction proteins expression including ZO-1, claudin 1, claudin 3 and occludin. These results suggested that RDE enhanced barrier functions and reduced ROS production in the epithelial cells under H2O2-induced oxidative damage.