Effect of Manitoba-Grown Red-Osier Dogwood Extracts on Recovering Caco-2 Cells from H₂O₂-Induced Oxidative Damage

• Main Authors: Runqiang Yang (Author), Qianru Hui (Author), Qian Jiang (Author), Shangxi Liu (Author), Hua Zhang (Author), Jiandong Wu (Author), Francis Lin (Author), Karmin O (Author), Chengbo Yang (Author)
• Format: Book
• Published: MDPI AG, 2019-07-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 2076-3921; 10.3390/antiox8080250
• Keywords: red-osier dogwood; antioxidative effect; H₂O₂; transepithelial resistance (TEER); Caco-2 cells; Therapeutics. Pharmacology; RM1-950
• Source: Antioxidants, Vol 8, Iss 8, p 250 (2019)

Red-osier dogwood, a native species of flowering plant in North America, has been reported to have anti-oxidative properties because of abundant phenolic compounds; this could be promising as a functional food or a feed additive. In the present study, an oxidative damage model using 1.0 mM hydrogen peroxide (H₂O₂) in Caco-2 cells was established to evaluate the antioxidative effects of red-osier dogwood extracts (RDE). The results showed that 1.0 mM H₂O₂ pre-exposure for 3 h significantly decreased cell viability, and increased interleukin 8 (IL-8) secretion and the intracellular reactive oxygen species (ROS) level. Caco-2 cells were treated with 100 µg/mL RDE for 24 h after pre-exposure to H₂O₂. It was found that the decreased cell viability caused by H₂O₂ was significantly restored by a subsequent 100 µg/mL RDE treatment. Furthermore, the IL-8 secretion and ROS level were significantly blocked by RDE, accompanied by the enhanced gene expression of hemeoxygenase-1 (HO-1), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px), and the enhanced protein expression of the nuclear factor (erythroid-derived 2)-like 2 (Nrf-2). Moreover, RDE improved barrier functions in Caco-2 cells. Using RDE reduced the diffusion of fluorescein isothiocyanate (FITC)-dextran and increased the transepithelial resistance (TEER) value. The relative mRNA level of tight junction claudin-1, claudin-3, and occludin was elevated by RDE. These extracts also repaired the integrity of zonula occludens-1 (ZO-1) damaged by H₂O₂ and increased the protein expressions of ZO-1 and claudin-3 in the H₂O₂-pretreated cells. These results illustrated that RDE reduced the ROS level and enhanced the barrier function in oxidative-damaged epithelial cells.