Abstract 15019: Differential Effects of Omega-3 Fatty Acid Combinations on the Inhibition of Oxidation Of Human Low-density Lipoproteins in vitro

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Samuel Sherratt ◽  
James J Ferguson ◽  
Deepak L Bhatt ◽  
Preston Mason
Keyword(s):  
Docosapentaenoic Acid ◽  
Low Density Lipoproteins ◽  
Oxidative Modification ◽  
Time Dependent ◽  
Ldl Oxidation ◽  
Low Density ◽  
Dependent Manner ◽  
Omega 3 ◽  
Antioxidant Effects

Background: Omega-3 fatty acids (O3FAs) reduce levels of triglyceride but may also have additional atheroprotective benefits. Randomized trials have suggested potential clinical outcome differences among O3FAs formulations. Oxidative modification of low-density lipoproteins (LDL) contributes to endothelial dysfunction, inflammation, and other aspects of atherogenesis. Individual O3FAs have been shown to inhibit LDL oxidation to varying degrees, but the antioxidant effects of combining O3FAs is unknown. Objective: To compare the dose- and time-dependent antioxidant effects of eicosapentaenoic acid (EPA, 20:5) alone and in combination with either docosapentaenoic acid (DPA, 22:5) or docosahexaenoic acid (DHA, 22:6) in human LDL in vitro . Methods: Human LDL was isolated from healthy subjects and adjusted to a final ApoB concentration of 100 μg/mL in physiologic buffer (PBS) before being incubated with O3FAs at 37°C. The EPA levels in the combinations were fixed at either 2.0, 3.0, or 4.5 μM, while the DPA or DHA levels were set at 0, 0.5, 1.0, and 2.0 μM. Oxidation was initiated by copper sulfate (10 μM) and measured over time by formation of malondialdehyde (MDA), a lipid oxidation product. Results: When combined with EPA, both DPA and DHA increased inhibition of oxidation in a dose- and time-dependent manner, with DPA showing a greater effect and more prolonged inhibition. At high levels of EPA (4.5 μM), DPA showed significantly greater antioxidant activity than equimolar DHA; these differences were more apparent with time. After 8 hours, adding 1.0 μM DPA reduced MDA formation by 61% versus vehicle (3.10 ± 0.42 vs. 7.98 ± 0.56, p <0.001), while adding 1.0 μM DHA only reduced MDA formation by 20% (6.40 ± 1.23, p <0.05). When 2 μM DPA or DHA were added, after 10 hours only DPA still had a significant degree of inhibition versus vehicle (37%; 6.65 ± 0.95 vs. 8.21 ± 0.53, p <0.05). Similar trends were observed in combinations containing 2.0 and 3.0 μM EPA. Conclusion: Adding DPA or DHA to EPA provide dose-dependent incremental antioxidant effects, with DPA providing a larger degree and a longer duration of inhibition. These observations highlight potential differences among O3FAs (and their combinations) in novel mechanisms of atheroprotection.

Abstract 15015: Eicosapentaenoic Acid, but Not Docosahexaenoic Acid or a Mixed Omega-3 Fatty Acid Supplement, Inhibits Low-density Lipoprotein Oxidation in a Time-dependent Manner

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Samuel Sherratt ◽  
Peter Libby ◽  
Deepak L Bhatt ◽  
Preston Mason
Keyword(s):  
Antioxidant Activity ◽  
Fatty Acid ◽  
Eicosapentaenoic Acid ◽  
Time Dependent ◽  
Ldl Oxidation ◽  
Gas Chromatography Mass Spectrometry ◽  
Low Density ◽  
Dependent Manner ◽  
Omega 3 ◽  
Omega 3 Fatty Acid

Background: Eicosapentaenoic acid (EPA), an omega-3 fatty acid (O3FA), reduces oxidation of low-density lipoproteins (LDL) in patients with hypertriglyceridemia, an effect that may contribute to lower cardiovascular (CV) events as reported in the REDUCE-IT trial. By contrast, DHA-containing products have failed to show a reduction in CV events, which may be due, in part, to differences in antioxidant activity. We compared the effects of EPA versus DHA and a mixed O3FA (EPA/DHA) supplement on oxidation of human LDL in vitro . Methods: LDL was isolated from human plasma by isopycnic centrifugation, separated into test samples of 100 μg/mL, and incubated at 37°C for 30 min in the absence (vehicle) or presence of EPA, DHA, or mixed O3FA supplement at equimolar levels (2.5 μM). All samples were then subjected to copper-induced oxidation (20 μM) as measured by formation of malondialdehyde (MDA). The FA content of the O3FA supplement was measured using gas chromatography/mass spectrometry. Results: EPA significantly inhibited LDL oxidation in a time-dependent manner compared with vehicle; after 4 hours, EPA inhibited MDA levels by 96% compared with the vehicle oxidation level (0.51 ± 0.01 vs 11.4 ± 0.4 μM; p <0.001). While DHA exhibited antioxidant activity at 2 hours at a level below EPA (2.5 ± 0.1 vs 11.4 ± 0.4; p <0.001), even this level of activity was lost by 4 hours. The mixed O3FA supplement failed to show any antioxidant activity through 4 hours (11.4 ± 0.5 μM). Fatty acid analysis showed that the O3FA supplement, in addition to EPA and DHA, contained more than 30 other fatty acids, including saturated fats, that may have nullified any potential benefits. Conclusions: These data support potent LDL antioxidant effects of EPA that were sustained over time compared with DHA, which had a weaker, transient effect, or a mixed O3FA supplement, which had no beneficial effect at all. This potent antioxidant mechanism of EPA may contribute to reduced CV risks seen in REDUCE-IT compared with negative findings from trials using DHA-containing formulations.

Antrodia Camphorata in Submerged Culture Protects Low Density Lipoproteins Against Oxidative Modification

2006 ◽  
Vol 34 (02) ◽  
pp. 217-231 ◽  
Author(s):  
Hsin-Ling Yang ◽  
You-Cheng Hseu ◽  
Jing-Yi Chen ◽  
Yi-Jen Yech ◽  
Fung-Jou Lu ◽  
...  
Keyword(s):  
Oxidized Ldl ◽  
Oxidant Stress ◽  
Antioxidant Properties ◽  
Low Density Lipoproteins ◽  
Oxidative Modification ◽  
Low Density ◽  
Dependent Manner ◽  
Antrodia Camphorata ◽  
Concentration Dependent Manner ◽  
Apo B

Antrodia camphorata is well known in Taiwan as a traditional Chinese medicine. In this study, we have investigated the antioxidant properties of a fermented culture broth of Antrodia camphorata (FCBA) and the aqueous extracts of mycelia from Antrodia camphorata (AEMA) on the oxidative modification of human low-density lipoproteins (LDL), as induced by either copper sulfate ( CuSO 4) or 2,2′-azo-bis(2-amidinopropane) hydrochloride (AAPH). Under such oxidant stress, FCBA and AEMA appear to possess antioxidant properties with respect to oxidation of LDL in a time-and concentration-dependent manner, as assessed by inhibition of thiobarbituric acid-reactive substances (TBARS) formation, conjugated diene production, and cholesterol degradation of oxidized LDL. In addition, both FCBA and AEMA exhibited a remarkable ability to rescue the relative electrophoretic mobility and fragmentation of the Apo B moiety of the oxidized LDL. Furthermore, FCBA and AEMA effectively protected the endothelial cells from the damaging effects of the CuSO 4-oxidized LDL. Our findings suggest that the antioxidant properties of Antrodia camphorata may also provide effective protection from atherosclerosis.

scholarly journals Plasma metabolites of quercetin and their antioxidant properties

1998 ◽  
Vol 275 (1) ◽  
pp. R212-R219 ◽  
Author(s):  
Christine Morand ◽  
Vanessa Crespy ◽  
Claudine Manach ◽  
Catherine Besson ◽  
Christian Demigné ◽  
...  
Keyword(s):  
Fruits And Vegetables ◽  
Antioxidant Properties ◽  
Total Antioxidant Status ◽  
Low Density Lipoproteins ◽  
Ldl Oxidation ◽  
Plasma Metabolites ◽  
Low Density ◽  
Very Low Density Lipoproteins

Quercetin is one of the most widely distributed flavonoids present in fruits and vegetables. The present experiments were performed on rats adapted for 3 wk to a semipurified diet supplemented with 0.2% quercetin. The major part of the circulating metabolites of quercetin (91.5%) are glucurono-sulfo conjugates of isorhamnetin (3′-O-methyl quercetin; 89.1 ± 2.1 μM) and of quercetin (14.7 ± 1.7 μM); the minor part (8.5%) is constituted by glucuronides of quercetin and its methoxylated forms (9.6 ± 2.3 μM). Conjugated dienes formation, resulting from Cu2+-catalyzed oxidation of rat very low density lipoproteins + low density lipoproteins (LDL), was effectively inhibited in vitro by conjugated metabolites of quercetin. These metabolites appeared to be four times more potent than trolox in inhibiting LDL oxidation. Moreover, the plasma from rats adapted to a diet containing 0.2% quercetin exhibited a total antioxidant status markedly higher than that of control rats (+60%). This study shows that ubiquitous quercetin is conjugated in vivo, yielding metabolites that exhibit antioxidant properties. Thus the health benefits of flavonoids in foods can be due to the antioxidant properties of their metabolites.

Intracellular GSH of Streptococcus thermophilus shows anti-oxidative activity against low-density lipoprotein oxidation in vitro and in a hyperlipidaemic hamster model

2018 ◽  
Vol 9 (1) ◽  
pp. 143-152 ◽  
Author(s):  
S. Kusuhara ◽  
M. Ito ◽  
T. Sato ◽  
W. Yokoi ◽  
Y. Yamamoto ◽  
...  
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Streptococcus Thermophilus ◽  
Oxidative Modification ◽  
Mass Spectrometry Analysis ◽  
Oxidative Activity ◽  
Ldl Oxidation ◽  
Low Density ◽  
Dependent Manner ◽  
Hamster Model

Streptococcus thermophilus YIT 2001 (ST-1), a lactic acid bacterial strain, was shown to have inhibitory effects on the oxidation of low-density lipoprotein (LDL) and the development of aortic fatty lesions in an animal model, and lower the serum levels of malondialdehyde-modified LDL, an oxidative modification product of LDL, in a clinical trial. This study aimed to identify the intracellular active component of ST-1 associated with anti-oxidative activity against LDL oxidation. High-performance liquid chromatography-electrospray ionisation mass spectrometry analysis after fractionation of the cellular extract by reversed-phase chromatography demonstrated that the active fraction contained reduced glutathione (GSH). GSH showed anti-oxidative activity in a dose-dependent manner, while this activity disappeared following thiol derivatisation. ST-1 had the strongest anti-oxidative activity against LDL oxidation and the highest level of intracellular GSH among five strains of S. thermophilus. In addition, the anti-oxidative activity of ST-1 after thiol derivatisation decreased by about half, which was similar to that of three other strains containing poor or no intracellular GSH or thiol components. Moreover, anti-oxidative activity against LDL oxidation was observed in hyperlipidaemic hamsters fed with high GSH ST-1 cells but not in those given low GSH cells. These findings suggest that intracellular GSH in ST-1 may provide beneficial effects via anti-oxidative activity against LDL oxidation and excess oxidative stress in the blood.

scholarly journals Non-oxidative modification of native low-density lipoprotein by oxidized low-density lipoprotein

1996 ◽  
Vol 316 (2) ◽  
pp. 377-380 ◽  
Author(s):  
Min YANG ◽  
David S. LEAKE ◽  
Catherine A. RICE-EVANS
Keyword(s):  
Oxidized Ldl ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Oxidative Modification ◽  
Low Density ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Process Studies

The oxidative modification of low-density lipoprotein (LDL) has been implicated in the pathogenesis of atherosclerosis, although little is known as yet about the precise mechanism of oxidation in vivo. The studies presented here demonstrate that, in the absence of cells or transition metals, oxidized LDL can modify native LDL through co-incubation in vitro such as to increase its net negative charge, in a concentration-dependent manner. The interaction is not inhibited by peroxyl radical scavengers or metal chelators, precluding the possibility that the modification of native LDL by oxidized LDL is through an oxidative process. Studies with radioiodinated oxidized LDL showed no transfer of radioactivity to the native LDL, demonstrating that fragmentation of protein and the transfer of some of the fragments does not account for the modified charge on the native LDL particle. The adjacency of native to oxidized LDL in the arterial wall may be a potential mechanism by which the altered recognition properties of the apolipoprotein B-100 may arise rapidly without oxidation or extensive modification of the native LDL lipid itself.

Antioxidant effects of phyto-and synthetic-estrogens on cupric ion-induced oxidation of human low-density lipoproteins in vitro

Life Sciences ◽  
2002 ◽  
Vol 70 (19) ◽  
pp. 2287-2297 ◽  
Author(s):  
Ted Wilson ◽  
Heather March ◽  
William J Banz ◽  
Yuqing Hou ◽  
Stuart Adler ◽  
...  
Keyword(s):  
Low Density Lipoproteins ◽  
Low Density ◽  
Cupric Ion ◽  
Synthetic Estrogens ◽  
Antioxidant Effects
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