['It is well documented that hyperglycemia-induced oxidative stress is an important causative factor of endothelial dysfunction. Cinnamaldehyde (CA) is a key flavor compound in cinnamon essential oil that can enhance the antioxidant defense against reactive oxygen species (ROS) by activating NF-E2-related factor 2 (Nrf2), which has been shown to have a cardiovascular protective effect, but its role in endothelial dysfunction induced by high glucose is unknown.', 'Dissected male C57BL/6J mouse aortic rings and HUVECs were cultured in normal glucose(NG 5.5 mM) or high glucose(HG 30.0 mM) DMEM treatment with or without CA (10 µM).', "Treatment with CA protected the endothelium relaxation, inhibited ROS generation and preserved nitric oxide (NO) levels in the endothelium of mouse aortas treated with high glucose . CA up-regulated Nrf2 expression, promoted its translocation to the nucleus'and increased HO-1, NQO1, Catalase and Gpx1 expression under high glucose condition. The increased level of nitrotyrosine in HUVECs under high glucose was also attenuated by treatment with CA. Dihydroethidium (DHE) and DAF-2DA staining indicated that CA inhibited the ROS generation and preserved the NO levels in HUVECs, but these effects were reversed by Nrf2-siRNA in high glucose conditions."] Does cinnamaldehyde prevent endothelial dysfunction induced by high glucose by activating Nrf2?