Protective Effects of Berberine against Low-Density Lipoprotein (LDL) Oxidation and Oxidized LDL-Induced Cytotoxicity on Endothelial Cells

2007 ◽  
Vol 55 (25) ◽  
pp. 10437-10445 ◽  
Author(s):  
Yih-Shou Hsieh ◽  
Wu-Hsien Kuo ◽  
Ta-Wei Lin ◽  
Horng-Rong Chang ◽  
Teseng-His Lin ◽  
...  
2009 ◽  
Vol 420 (2) ◽  
pp. 277-281 ◽  
Author(s):  
Markus K. Muellner ◽  
Sabine M. Schreier ◽  
Hilde Laggner ◽  
Marcela Hermann ◽  
Harald Esterbauer ◽  
...  

LOOHs (lipid hydroperoxides) in oxLDL [oxidized LDL (low-density lipoprotein)] are potentially atherogenic compounds. Recently, H2S was identified as the third endogenous gasotransmitter in the vasculature. H2O2 is known to be destroyed by H2S. Assuming that H2S may also react with LOOHs, the results show that H2S can destroy LOOHs in oxLDL. The ability of LOOH-enriched LDL to induce HO-1 (haem oxygenase 1) in endothelial cells was abolished by H2S pretreatment. HPLC analysis showed that 9-HPODE [(9S)-hydroperoxy-(10E,12Z)-octadecadienoic acid], a compound found in oxLDL, was reduced to 9-HODE [(9S)-hydroxy-(10E,12Z)-octadecadienoic acid] in the presence of H2S. Thus H2S may act as an antiatherogenic agent by reducing LOOHs to the less reactive LOHs and could abrogate the pathobiological activity of oxLDL.


1996 ◽  
Vol 42 (4) ◽  
pp. 498-506 ◽  
Author(s):  
I Jialal ◽  
S Devaraj

Abstract Cardiovascular disease is the leading cause of mortality in westernized populations. An increased concentration of plasma low-density lipoprotein (LDL) cholesterol constitutes a major risk factor for atherosclerosis. Several lines of evidence support a role for oxidatively modified LDL in atherosclerosis and for its in vivo existence. Antioxidants have been shown to decrease atherosclerotic lesion formation in animal models and decrease LDL oxidation; the evaluation of LDL oxidation in vivo is therefore very important. However, there is a paucity of methods for direct measurement of LDL oxidation. Of the direct methods currently available, the preferred ones seem to be the measurement of F2-isoprostanes, autoantibodies to epitopes on oxidized LDL, and the assessment of antioxidant status. Of the indirect measures, the most uniformly accepted procedure is examining the oxidative susceptibility of isolated LDL by monitoring conjugated diene formation.


Metabolism ◽  
2000 ◽  
Vol 49 (4) ◽  
pp. 479-485 ◽  
Author(s):  
Mitsunobu Kawamura ◽  
Shigeru Miyazaki ◽  
Tamio Teramoto ◽  
Keiko Ashidate ◽  
Hisako Thoda ◽  
...  

2020 ◽  
Vol 11 (2) ◽  
pp. 1881-1890 ◽  
Author(s):  
Yue-Hua Jiang ◽  
Xiao Li ◽  
Weipin Niu ◽  
DongLi Wang ◽  
Bo Wu ◽  
...  

β-sitosterol is shown to demonstrate endothelial protective effects, which inhibited apoptosis, increased cell migration, and improved mitochondrial function of human aortic endothelial cells.


2005 ◽  
Vol 35 (3) ◽  
pp. 531-545 ◽  
Author(s):  
B Löhrke ◽  
T Viergutz ◽  
B Krüger

The role of endogenously oxidized low density lipoprotein (oxLDL) in follicular steroidogenic regulation is unknown. Information may be important in order to elucidate ovulatory dysregulation in disordered lipid metabolism. To obtain specific data, we studied the effect of polar phospholipids (PL) isolated from oxLDL with different endogenous levels of lipohydroperoxides (LHP) on the thecal expression of mRNA encoding steroidogenic enzymes and cyclooxygenase 2 (COX-2), and on the thecal production of superoxide and progesterone. Large (preovulatory) bovine follicles were used and analyses of thecal fragments from single follicles were performed by radioimmunoassays, chemiluminescence assays and quantitative RT-PCR. Basal concentration of mRNA for several lipoprotein receptors exceeded by about 10-times the basal level of mRNA encoding steroidogenic enzymes, suggesting that preovulatory theca receptors may favour uptake of oxLDL. PL (5–11 pmol phosphorus/ml) decreased (up to 0.5-times the control) progesterone synthesis, production of superoxide and levels of P450 cholesterol side chain cleavage (P450 scc), 3β-hydroxysteroid dehydrogenase and COX-2 mRNA. Abundance of COX-2 transcripts in thecal tissue incubated with forskolin depended on the progesterone/17β-oestradiol ratio of the follicle fluid, i.e. the previous microenvironment in vivo. PL effects were mimicked by the platelet-activating factor (PAF). WEB 2086, a PAF receptor blocker, did not always abolish these responses, suggesting that the effects were not mediated solely by this receptor. PAF interfered dose-dependently with LH-induced responses, indicating interference with LH signalling. PL from mildly oxidized LDL (0.5 nmol/ml LHP) tended to exert greater effects than PL from oxLDL containing 1.5 nmol/ml LHP. In consideration of the known physiologic role of progesterone, COX-2 and possibly superoxide, these results provide evidence for a potential of PL from oxLDL to induce ovulatory dysregulation and suggest that the extent of the LDL oxidation seems to be important for interfering with thecal responses to the preovulatory LH surge.


1996 ◽  
Vol 320 (2) ◽  
pp. 373-381 ◽  
Author(s):  
Suzanne E. STAIT ◽  
David S. LEAKE

Ascorbate at concentrations of 60–100 µM inhibits the modification of freshly prepared low-density lipoprotein (LDL) by macrophages. With ‘moderately oxidized’ LDL (produced by prolonged storage in a refrigerator), however, ascorbate does not inhibit LDL modification by macrophages and actually modifies the LDL itself in the absence of macrophages [Stait and Leake (1994) FEBS Lett. 341, 263–267]. We have now shown that dehydroascorbate can modify both ‘fresh’ LDL and moderately oxidized LDL in a dose-dependent manner to increase its uptake by macrophages. The modification of moderately oxidized LDL by ascorbate and dehydroascorbate or of ‘fresh’ LDL by dehydroascorbate is dependent on the presence of iron or copper. In ‘fresh’ LDL, ascorbate inhibited conjugated-diene formation by copper. In moderately oxidized LDL, the number of conjugated dienes present was decreased rapidly in the presence of copper and ascorbate. Dehydroascorbate decreased the lag phase and increased the rate of copper-induced conjugated-diene formation in ‘fresh’ LDL (although in some experiments it inhibited the formation of conjugated dienes). The ascorbate-modified moderately oxidized LDL was taken up by macrophages by their scavenger receptors, as the uptake was inhibited by polyinosinic acid or fucoidan. Ascorbate and dehydroascorbate therefore have the potential to increase LDL oxidation under certain conditions, but whether or not they do so in vivo is unknown.


2013 ◽  
Vol 2013 ◽  
pp. 1-18 ◽  
Author(s):  
Cédric Delporte ◽  
Pierre Van Antwerpen ◽  
Luc Vanhamme ◽  
Thierry Roumeguère ◽  
Karim Zouaoui Boudjeltia

Oxidation of low-density lipoprotein (LDL) has a key role in atherogenesis. Among the different models of oxidation that have been studied, the one using myeloperoxidase (MPO) is thought to be more physiopathologically relevant. Apolipoprotein B-100 is the unique protein of LDL and is the major target of MPO. Furthermore, MPO rapidly adsorbs at the surface of LDL, promoting oxidation of amino acid residues and formation of oxidized lipoproteins that are commonly named Mox-LDL. The latter is not recognized by the LDL receptor and is accumulated by macrophages. In the context of atherogenesis, Mox-LDL accumulates in macrophages leading to foam cell formation. Furthermore, Mox-LDL seems to have specific effects and triggers inflammation. Indeed, those oxidized lipoproteins activate endothelial cells and monocytes/macrophages and induce proinflammatory molecules such as TNFαand IL-8. Mox-LDL may also inhibit fibrinolysis mediated via endothelial cells and consecutively increase the risk of thrombus formation. Finally, Mox-LDL has been involved in the physiopathology of several diseases linked to atherosclerosis such as kidney failure and consequent hemodialysis therapy, erectile dysfunction, and sleep restriction. All these issues show that the investigations of MPO-dependent LDL oxidation are of importance to better understand the inflammatory context of atherosclerosis.


2015 ◽  
Vol 129 (12) ◽  
pp. 1195-1206 ◽  
Author(s):  
H.K. Irundika Dias ◽  
Caroline L.R. Brown ◽  
M. Cristina Polidori ◽  
Gregory Y.H. Lip ◽  
Helen R. Griffiths

We have established a novel anti-inflammatory and antioxidant role of statins towards oxidized fats in the “bad” cholesterol low density lipoprotein (LDL) particle from the blood of mid-life adults with high cholesterol. Oxidized LDL-fat levels were also higher in the blood of patients with dementia and caused inflammatory damage to cells that line blood vessels.


Author(s):  
Joaquim Barreto ◽  
Sotirios K. Karathanasis ◽  
Alan Remaley ◽  
Andrei C. Sposito

Atherosclerosis, the underlying cause of cardiovascular disease (CVD), is a worldwide cause of morbidity and mortality. Reducing ApoB-containing lipoproteins—chiefly, LDL (low-density lipoprotein)—has been the main strategy for reducing CVD risk. Although supported by large randomized clinical trials, the persistence of residual cardiovascular risk after effective LDL reduction has sparked an intense search for other novel CVD biomarkers and therapeutic targets. Recently, Lox-1 (lectin-type oxidized LDL receptor 1), an innate immune scavenger receptor, has emerged as a promising target for early diagnosis and CV risk prediction and is also being considered as a treatment target. Lox-1 was first described as a 50 kDa transmembrane protein in endothelial cells responsible for oxLDL (oxidized LDL) recognition, triggering downstream pathways that intensify atherosclerosis via endothelial dysfunction, oxLDL uptake, and apoptosis. Lox-1 is also expressed in platelets, where it enhances platelet activation, adhesion to endothelial cells, and ADP-mediated aggregation, thereby favoring thrombus formation. Lox-1 was also identified in cardiomyocytes, where it was implicated in the development of cardiac fibrosis and myocyte apoptosis, the main determinants of cardiac recovery following an ischemic insult. Together, these findings have revealed that Lox-1 is implicated in all the main steps of atherosclerosis and has encouraged the development of immunoassays for measurement of sLox-1 (serum levels of soluble Lox-1) to be used as a potential CVD biomarker. Finally, the recent development of synthetic Lox-1 inhibitors and neutralizing antibodies with promising results in animal models has made Lox-1 a target for drug development. In this review, we discuss the main findings regarding the role of Lox-1 in the development, diagnosis, and therapeutic strategies for CVD prevention and treatment.


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