3,4-dihydroxyphenylacetic acid, a microbiota-derived metabolite of quercetin, protects against pancreatic β-cells dysfunction induced by high cholesterol

© 2015 Elsevier Inc. Cholesterol plays an important role in inducing pancreatic β-cell dysfunction, characterized by an impaired insulin secretory response to glucose, representing a hallmark of the transition from pre-diabetes to diabetes. 3,4 dihydroxyphenylacetic acid (ES) is a scarcely studied microbiota-derived metabolite of quercetin with antioxidant properties. The aim of this study was to determine the protective effect of ES against apoptosis, mitochondrial dysfunction and oxidative stress induced by cholesterol in Min6 pancreatic β-cells. Cholesterol decreased viability, induced apoptosis and mitochondrial dysfunction by reducing complex I activity, mitochondrial membrane potential, ATP levels and oxygen consumption. Cholesterol promoted oxidative stress by increasing cellular and mitochondrial reactive oxygen species and lipid peroxidation and decreasing antioxidant enzyme activities; in addition, it slightly increased Nrf2 translocation to the nucleus. These events resulted