title: Ethanol extract of propolis protects endothelial cells from oxidized low density lipoprotein-induced injury by inhibiting lectin-like oxidized low density lipoprotein receptor-1-mediated oxidative stress.
abstract: Lectin-like oxidized low density lipoprotein receptor-1 (LOX-1), as the primary oxidized low-density lipoprotein (ox-LDL) receptor on endothelial cells, plays a crucial role in endothelial injury, which is a driving force in the initiation and development of atherosclerosis. Our previous studies have shown that ethanol extract of propolis (EEP) promotes reverse cholesterol transport and inhibits atherosclerotic lesion development. However, the protective effects of EEP against ox-LDL-induced injury in endothelial cells and the underlying mechanisms are still unknown. This study was designed to test the hypothesis that EEP attenuates ox-LDL-induced endothelial oxidative injury via modulation of LOX-1-mediated oxidative stress. Our results showed that exposure of human umbilical vein endothelial cells (HUVECs) to ox-LDL (100 mg/L) led to the decrease in cell viability and increase in lactate dehydrogenase (LDH) release, caspase-3 activation, and apoptosis, whereas pretreatment with EEP (7.5, 15 and 30 mg/L) protected against such damages in a dose-dependent manner. In addition, EEP mitigated ox-LDL uptake by HUVECs and attenuated ox-LDL-upregulated LOX-1 expression both at the mRNA and protein levels. Moreover, EEP suppressed the ox-LDL-induced oxidative stress as assessed by decreased nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation, reactive oxygen species (ROS), and malondialdehyde (MDA) generation as well as increased antioxidant enzyme activities. Similar results were observed in the anti-LOX-1 antibody or diphenyleneiodonium (DPI)-pretreated HUVECs. These data indicate that EEP may protect HUVECs from ox-LDL-induced injury and that the mechanism at least partially involves its ability to inhibit endothelial LOX-1 upregulation and subsequent oxidative stress.
authors: College of Basic Medical Sciences, Taishan Medical University, Taian, Shandong 271000, China.
authors: Yongqi
authors: Y
authors: Fang
authors: College of Basic Medical Sciences, Taishan Medical University, Taian, Shandong 271000, China.
authors: Jinguo
authors: J
authors: Li
authors: Affiliated Hospital of Taishan Medical University, Taian, Shandong 271000, China.
authors: Mingde
authors: M
authors: Ding
authors: College of Pharmacy, Taishan Medical University, Taian, Shandong 271000, China.
authors: Xiaoyan
authors: X
authors: Xu
authors: Affiliated Hospital of Taishan Medical University, Taian, Shandong 271000, China.
authors: Jiajun
authors: J
authors: Zhang
authors: Institute of Atherosclerosis, Key Laboratory of Atherosclerosis in Universities of Shandong, Taishan Medical University, Taian, Shandong 271000, China.
authors: Peng
authors: P
authors: Jiao
authors: College of Basic Medical Sciences, Taishan Medical University, Taian, Shandong 271000, China.
authors: Ping
authors: P
authors: Han
authors: College of Basic Medical Sciences, Taishan Medical University, Taian, Shandong 271000, China.
authors: Jiafu
authors: J
authors: Wang
authors: College of Basic Medical Sciences, Taishan Medical University, Taian, Shandong 271000, China yst228@126.com.
authors: Shutong
authors: S
authors: Yao
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D017209:Apoptosis; D053148:Caspase 3 / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D042783:Endothelial Cells / Q000187:drug effects*; D006801:Humans; D008077:Lipoproteins, LDL / Q000378:metabolism*; D018384:Oxidative Stress; D011429:Propolis / Q000494:pharmacology*; D011973:Receptors, LDL / Q000037:antagonists & inhibitors*
chemical_list: D000975:Antioxidants; C573412:LDLR protein, human; D008077:Lipoproteins, LDL; D011973:Receptors, LDL; D011429:Propolis; D053148:Caspase 3
keywords: Ethanol extract of propolis; lectin-like oxidized low-density lipoprotein receptor-1; oxidative stress; oxidized low-density lipoprotein; vascular endothelial cell