Atherosclerosis-related
cardiovascular disease is the predominant cause of death worldwide.
Ox-LDL-induced vascular endothelial cell injury is a major factor in the pathogenesis of
atherosclerosis.
Dihydromyricetin (DMY) is a
flavonoid extracted from vine
tea that exerts multiple pharmacological activities, including cardio-protective, anti-
tumor, and anti-oxidative effects. However, it is unreported that DMY shows protective effects on
ox-LDL-induced endothelial cell injury. In this study, we used an
ox-LDL injured human umbilical vein endothelial cell (HUVEC) in vitro model to explore the protective effects and mechanism of DMY. HUVECs were pretreatment with DMY and then exposed to
ox-LDL, the cell viability was measured. Then, the anti-oxidative
enzymes were tested by commercial kits and intracellular
reactive oxygen species (ROS) was measured by flow cytometry, cell apoptosis was determined by
Annexin-V/PI assay and apoptosis-related
proteins were detected by western blot. Our results showed that DMY pretreatment provided cytoprotective effects by suppressing
ox-LDL-induced endothelial cell apoptosis, mitochondrial membrane depolarization,
caspase-3 activation, and modulation of oxidative
enzymes, thereby inhibiting ROS generation. The anti-oxidative and anti-apoptotic effects of DMY were abrogated by the transfection of Nrf2 siRNAs and HO-1 inhibitor ZnPP. Furthermore, DMY might activate the Nrf2/HO-1 pathway through activation of the Akt and ERK1/2 pathways, as shown by the inhibition of Nrf2/HO-1 signaling by the inhibitors
PD98059 or
LY294002 and the transfection of ERK, Akt siRNAs. In this study, DMY protects HUVECs from
ox-LDL-induced oxidative injury by activating Akt and ERK1/2, which subsequently activates Nrf2/HO-1 signaling, thereby up-regulating
antioxidant enzymes and
anti-apoptotic proteins.