DL-3-n-butylphthalide prevents oxidative stress and atherosclerosis by targeting Keap-1 and inhibiting Keap-1/Nrf-2 interaction

Atherosclerosis is the common pathophysiological foundation of ischaemic stroke and myocardial ischaemia. Oxidative stress is intricately related to the progress of atherosclerosis. DL-3-n-butylphthalide (NBP) is a synthesized raceme of L-3-n-butylphthalide that is first isolated from celery. As a neuroprotective agent, NBP also exhibits potent antioxidative activity. Our research aimed to evaluate the effect of NBP on atherosclerosis and to explore the underlying antioxidative mechanisms and targets. Firstly, we detected the protective effect of NBP on ApoE^-/- model of atherosclerosis. NBP showed high efficiency as a therapeutic agent against the formation of atherosclerotic plaques and oxidative events in HFD-treated ApoE^-/- mice. We have also evaluated the effect of NBP on oxidized-LDL (oxLDL)-induced oxidative damage and Keap-1/ Nrf-2 interaction by utilizing rat aortic endothelial cells (ECs) and mouse primary peritoneal macrophages (MPMs). Furthermore, we investigated the possibility that NBP improves oxLDL-stimulated oxidative stress in a Keap-1- dependent way in ECs by siRNA technique. Using molecular dynamics (MD) simulation, we detected that Keap-1, a negative adaptor of Nrf-2, may be one of the target protein of NBP. Our studies show that amelioration of oxidative stress by NBP may provide a potential therapeutic strategy for atherosclerosis or cardio-cerebrovascular events from atherosclerosis.