Antioxidant and Anti-Inflammatory Effects of Delphinidin on Glial Cells and Lack of Effect on Secretase Enzyme

Beneficial health effects of anthocyanin extracts such as antioxidation and anti-inflammatory effects have been demonstrated in many studies. However, studies focusing on these effects exerted specifically by delphinidin (anthocyanin extract) are generally poor. The purpose of this study was to explore the in vitro protective functional role of anthocyanin extract, delphinidin, on oxidation- and inflammation-induced injury in C6 neuroglial cells, and to examine its effect on suppression of secretase enzyme, a key factor in Alzheimer's disease development. Cytotoxicity assay results revealed that delphinidin at high concentrations enhanced cell viability of spiked cells. Moreover, in a dose-dependent manner, delphinidin caused glutathione levels to increase in cells, a critical indicator of the cellular redox state, versus cells treated with hydrogen peroxide. Delphinidin decreased the expression of MCP-1 and CINC-1, two major cytokines markers in inflammatory situations versus tumor necrosis factor-α-induced damage. However, delphinidin, even at higher concentrations, did not suppress the secretase enzyme activity, indicating its indirect action in ameliorating the underlying cause of the disease. Our findings suggested that delphinidin could be a promising candidate for the development of therapeutics for the management of diseases associated with oxidative stress and inflammatory expressions such as neurodegenerative diseases.