scholarly journals Allicin Decreases Lipopolysaccharide-Induced Oxidative Stress and Inflammation in Human Umbilical Vein Endothelial Cells through Suppression of Mitochondrial Dysfunction and Activation of Nrf2

2017 ◽  
Vol 41 (6) ◽  
pp. 2255-2267 ◽  
Author(s):  
Min Zhang ◽  
Huichao Pan ◽  
Yinjie Xu ◽  
Xueting Wang ◽  
Zhaohui Qiu ◽  
...  

Background: Allicin, a major component of garlic, is regarded as a cardioprotective agent and is associated with increased endothelial function. Methods: The effects of allicin on lipopolysaccharide (LPS)-induced vascular oxidative stress and inflammation in cultured human umbilical vein endothelial cells (HUVECs) and the mechanisms underlying these effects were studied. The protective effects were measured using cell viability, a lactate dehydrogenase (LDH) assay and cell apoptosis as indicators, and the anti-oxidative activity was determined by measuring reactive oxygen species (ROS) generation, oxidative products and endogenous antioxidant enzyme activities. HUVEC mitochondrial function was assessed by determining mitochondrial membrane potential (MMP) collapse, cytochrome c production and mitochondrial ATP release. To investigate the potential underlying mechanisms, we also measured the expression of dynamic mitochondrial proteins using western blotting. Furthermore, we evaluated the Nrf2 antioxidant signaling pathway using an enzyme-linked immunosorbent assay (ELISA). Results: Our results demonstrated that allicin enhanced HUVEC proliferation, which was suppressed by LPS exposure, and LDH release. Allicin ameliorated LPS-induced apoptosis, suppressed ROS overproduction, reduced lipid peroxidation and decreased the endogenous antioxidant enzyme activities in HUVECs. These protective effects were associated with the inhibition of mitochondrial dysfunction as indicated by decreases in the MMP collapse, cytochrome c synthesis and mitochondrial ATP release. In addition, allicin attenuated the LPS-induced inflammatory responses, including endothelial cell adhesion and TNF-α and IL-8 production. Furthermore, allicin increased the expression of LXRα in a dose-dependent manner. Allicin-induced attenuation of inflammation was inhibited by LXRα siRNA treatment. Finally, allicin activated NF-E2-related factor 2 (Nrf2), which controls the defense against oxidative stress and inflammation. Conclusions: Taken together, the present data suggest that allicin attenuated the LPS-induced vascular injury process, which may be closely related to the oxidative stress and inflammatory response in HUVECs. Allicin modulated Nrf2 activation and protected the cells against LPS-induced vascular injury. Our findings suggest that allicin attenuated the LPS-induced inflammatory response in blood vessels.

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Ping Lin ◽  
Qian Ren ◽  
Qin Wang ◽  
Jiali Wu

Objective. This research is aimed at determining the vascular health characteristics of carotenoids by evaluating their effect on excessive inflammatory response in endothelial and monocyte cells, the main factors of atherosclerosis. Methods. Human umbilical vein endothelial cells (HUVECs) or U937 monocytes were treated with escalating concentrations (0.1, 0.5, and 1 μM) of five most common carotenoids in human plasma, i.e., α-carotene, β-carotene, β-cryptoxanthin, lutein, and lycopene prior to stimulation with 2 mM fructose. We examined the monocyte adhesion to endothelial cells (ECs) and relevant endothelial adhesion molecules. Chemokine and proinflammatory cytokine production as well as intracellular oxidative stress were also assessed in fructose-stimulated ECs and monocytes. Results. Carotenoids repressed monocyte adhesion to fructose-stimulated ECs dose dependently via decreasing primarily the expression of endothelial VCAM-1. In ECs and monocytes, three carotenoids, i.e., β-cryptoxanthin, lutein, and lycopene, suppressed the fructose-induced expression of chemokines MCP-1, M-CSF, and CXCL-10 and inflammatory cytokines TNF-α and IL-1β, with CXCL-10 being the most repressed inflammatory mediator. β-Cryptoxanthin, lutein, and lycopene dramatically downregulated the fructose-induced CXCL-10 expression in vascular cells. The reduction in the inflammatory response was associated with a slight but significant decrease of intracellular oxidative stress. Conclusions. Our results show that carotenoids have a variety of anti-inflammatory and antiatherosclerosis activities, which can help prevent or reduce fructose-induced inflammatory vascular diseases.


2016 ◽  
Vol 39 (3) ◽  
pp. 847-859 ◽  
Author(s):  
Jie Li ◽  
Junfeng Li ◽  
Tingting Wei ◽  
Junhua Li

Background/Aims: To investigate the effects of miR-137 on high glucose (HG)-induced vascular injury, and to establish the mechanism underlying these effects. Methods: Human umbilical vein endothelial cells (HUVECs) were transfected with miR-137 inhibitor or mimic, and then treated with normal or high glucose. Cell viability and apoptosis were detected by using the Cell Counting Kit-8 (CCK-8) assay and flow cytometry, respectively. Reactive oxygen species (ROS), malondialdehyde (MDA), and superoxide dismutase (SOD) were detected by fluorescent probe (DCFH-DA), thiobarbituric acid reaction, and the nitroblue tetrazolium assay, respectively. The mRNA and protein expressions of AMPKα1 were determined by qRT-PCR and Western blotting. Results: Down-regulation of miR-137 dramatically reverted HG-induced decreases in cell viability and SOD levels and increases in apoptosis, ROS and MDA levels. Moreover, bioinformatics analysis predicted that the AMPKα1 was a potential target gene of miR-137. Luciferase reporter assay demonstrated that miR-137 could directly target AMPKα1. AMPKα1 overexpression had the similar effect as miR-137 inhibition. Down-regulation of AMPKα1 in HUVECs transfected with miR-137 inhibitor partially reversed the protective effect of miR-137 inhibition on HG-induced oxidative stress in HUVECs. Conclusion: Down-regulation of miR-137 ameliorates HG-induced injury in HUVECs by overexpression of AMPKα1, leading to increasing cellular reductive reactions and decreasing oxidative stress. These results provide further evidence for protective effect of miR-137 inhibition on HG-induced vascular injury.


2011 ◽  
Vol 89 (6) ◽  
pp. 445-453 ◽  
Author(s):  
Tao Chen ◽  
Zai-pei Guo ◽  
Xiao-yan Jiao ◽  
Yu-hong Zhang ◽  
Jing-yi Li ◽  
...  

Peoniflorin (PF), extracted from the root of Paeonia lactiflora Pall., has been reported to have anti-inflammation and antioxidant effects in several animal models. Herein, we investigated the protective effects of PF against hydrogen peroxide (H2O2)-induced oxidative damage in human umbilical vein endothelial cells (HUVECs). HUVECs were treated by H2O2 (240 µmol/L) with or without PF. PF significantly increased the percent cell viability of HUVECs injured by H2O2 using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. By flow cytometric analysis, PF markedly attenuated H2O2-induced apoptosis and intracellular reactive oxygen species production. In addition, PF also displayed a dose-dependent reduction of lactate dehydrogenase leakage, malondialdehyde formation, and caspase-3 proteolytic activities in H2O2-treated cells, which was accompanied with a restoration of the activities of endogenous antioxidants, including total superoxide dismutase and glutathione peroxidase. Finally, Western blot data revealed that H2O2 upregulated phosphorylation of extracellular signal-regulated kinase 1/2 in HUVECs, which was almost completely reversed by PF. Taken together, our data provide the first evidence that PF has a protective ability against oxidative damage in HUVECs. PF may be a candidate medicine for the treatment of vascular diseases associated with oxidative stress.


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