Z-Ligustilide protects vascular endothelial cells from oxidative stress and rescues high fat diet-induced atherosclerosis by activating multiple NRF2 downstream genes

Background and aims: Oxidative stress-induced endothelial dysfunction is considered to exert a vital role in the development of atherosclerotic coronary heart disease (CHD). NRF2 is a key transcriptional factor against oxidative stress through activation of multiple ARE-mediated genes. Z-Lig is derived from the Ligusticum species with antitumor, anti-inflammation and neuroprotection activities. However, the antioxidant potentials of Z-Lig on endothelial dysfunction and atherosclerosis have not been well elucidated. Therefore, in the present work, we appraise the cytoprotective property and anti-atherosclerosis effect of Z-Lig. Methods: Potential NRF2 activators were screened and verified by luciferase reporter gene assay. The protein and mRNA levels of NRF2 and ARE-mediated genes, and GSH/GSSG level in EA.hy926 cells treated with Z-Lig were detected. The cytoprotective property of Z-Lig was appraised in tert-butyl hydroperoxide (t-BHP)-evoked oxidative stress model. Cell viability and reactive oxygen species (ROS) levels in EA.hy926 cells were determined. An atherosclerosis model induced by HFD was used to determine the anti-atherosclerosis effect of Z-Lig in HFD-fed Ldlr-deficient mice. Results: In vitro, 100 µM Z-Lig upregulated expressions of NRF2 and ARE-driven genes, promoted accumulation of nuclear NRF2 and unbound NRF2- KEAP1 complex in EA.hy926 cells. Furthermore, Z-Lig alleviated oxidative stress and cell injury caused by t-BHP via stimulating NRF2/ARE pathway. In vivo, intervention with 20 mg/kg Z-Lig markedly restrained atherosclerosis progression, including attenuating HFD-induced atherosclerotic plaque formation, alleviating lipid peroxidation and increasing antioxidant enzyme activity in aortas of HFD-fed Ldlr −/− mice. The chemopreventive effects of Z-Lig might be associated with the activation of NRF2 and ARE-driven genes. Conclusions: The present study suggested that Z-Lig is an effective NRF2 activator, which can protect vascular endothelial cells from oxidative stress and rescue HFD- induced atherosclerosis.