Zedoarondiol Attenuates Endothelial Cells Injury Induced by Oxidized Low-Density Lipoprotein via Nrf2 Activation

Background/aims: Zedoarondiol, a sesquiterpene lactone compound, showed an anti-proliferative activity on vascular smooth muscle cells in our previous study. However, whether it has a beneficial effect on endothelial cells injury induced by oxidized low-density lipoprotein (ox-LDL) remains unclear. This study was designed to investigate the protective effect of zedoarondiol on ox-LDL-induced injury of endothelial cells and explored its underlying mechanism.

Methods: The protective effect of zedoarondiol on ox-LDL-induced human umbilical vein endothelial cells (HUVECs) injury were evaluated by Cell Counting Kit-8 (CCK-8) assay and released lactic dehydrogenase (LDH) activity assay. Oxidative stress was determined by malonedialdehyde (MDA) content and superoxide dismutase (SOD) activity. The level of Reactive Oxygen Species (ROS) was measured by dichlorodihydrofluorescin diacetate (DCFH-DA) staining. The culture supernatant was collected for Enzyme linked immune-sorbent assays (ELISA) of interleukine-1β (IL-1β), tumor necrosis factor-α (TNF-α), and monocyte chemoattractant protein-1 (MCP-1). Immunofluorescence staining was used to observe NF-E2-related factor 2 (Nrf2) translocation. Western blotting was performed to determine the expression of IL-1β, TNF-α, MCP-1, Kelch-like ECH associated protein 1 (Keap1), heme oxygenase-1 (HO-1), NAD(P)H: quinone oxidoreductase-1 (NQO1), and Nrf2.

Results: Zedoarondiol attenuated HUVECs injury, up-regulated SOD activity, suppressed formation of MDA and ROS, and secretion and protein expression of IL-1β, TNF-α, and MCP-1 in injured HUVECs induced by ox-LDL. Zedoarondiol induced nuclear Nrf2 translocation from cytoplasm into nucleus and up-regulated expression of HO-1, NQO1, and Nrf2 in nucleus. All-trans-retinoic acid (ATRA), an inhibitor of Nrf2, abolished zedoarondiol-mediated anti-oxidative effect.

Conclusion: Zedoarondiol attenuates ox-LDL-induced endothelial cells injury by inhibiting oxidative stress and inflammation via Nrf2/HO-1 pathway, suggesting that zedoarondiol might be meaningful on prevention and treatment of atherosclerosis.