Lipid oxidation in unfractionated serum and plasma

Schnitzer, Edit; Pinchuk, Ilya; Bor, A.; Fainaru, M; Samuni, Amram; Lichtenberg, Dov

doi:10.1016/s0009-3084(98)00021-8

Cited by 98 publications

(70 citation statements)

References 29 publications

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“…In vitro antiatherogenic activity was evaluated by the human plasma oxidation inhibition assay according to Schnitzer et al (1998) with minor modifications using a Spectrophotometer Lambda 25 (Perkin-Elmer, Norwalk, USA) equipped with an 8 position thermostated sample changer. Aliquots of raw and roasted pumpkin seed extracts (0.020 to 0.030 µL) were placed in UV-transparent disposable cuvettes (Brand, Wertheim, Germany) and dried under a stream of nitrogen.…”

Section: In Vitro Anti-atherogenic Activitymentioning

confidence: 99%

In vitro health beneficial activities of Pumpkin seeds from Cucurbita moschata cultivated in Lemnos

Sakka

Karantonis

2015

IJFS

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Pumpkin seeds are commonly consumed in Greece. Although Cucurbita moschata is locally grown in Lemnos and is traditionally used in pumpkin pies, the seeds are currently discarded after consumption of the fruit flesh. The aim of the present study was to investigate the nutritional functionality of pumpkin seeds from Cucurbita moschata grown in Lemnos. Cucurbita moschatas' seeds, raw or roasted, were appropriately extracted and the results are presented for raw versus (vs) roasted seed extracts. The phenolic content was expressed as µg gallic acid/g of seeds according to Folin-Ciocalteau assay (370.3 ± 19.1 vs 551.0 ± 22.0). Antioxidant capacity was expressed as equivalent amount for 50% scavenging in mg of seeds for DPPH (50.03 ± 5.91 vs 25.82 ± 6.77) and ABTS (17.85 ± 0.77 vs 12.77 ± 0.76) assays, and as µmol of trolox/g of seeds for FRAP (1.19 ± 0.05 vs 2.50 ± 0.23) and CUPRAC (2.13 ±0.11 vs 3.25 ± 0.06) assays. Anti-inflammatory/antithrombotic and anti-diabetic activities were expressed as mg of seeds for 50% inhibition of platelet activating factor (0.62 vs 0.15) and as µg of seeds for 25% inhibition of alpha-glycosidase (40.0 vs 61.0) activities respectively. Moreover, anti-atherogenic activity was expressed as the % increase in lag time of human plasma oxidation (62.7 versus 163.2) Raw and roasted pumpkin seed extracts exert anti-oxidant, anti-thrombotic/anti-inflammatory, antiatherogenic and antidiabetic activities. Cucurbita moschata seeds may represent a novel opportunity for development of functional foods, with a local interest in Lemnos that would contribute also to the regional public health improvement.

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Section: In Vitro Anti-atherogenic Activitymentioning

confidence: 99%

In vitro health beneficial activities of Pumpkin seeds from Cucurbita moschata cultivated in Lemnos

Sakka

Karantonis

2015

IJFS

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“…The oxidation of plasma lipoproteins was determined by the method of Schnitzer et al (1998). Reaction mixure (2 ml) contained 20 μl of plasma, CuCl 2 ·2H 2 O (100 μmol/l), phosphate buffer (3.3 × 10 -3 mol/l, pH 7.4).…”

Section: Oxidation Of Plasma Lipoproteinsmentioning

confidence: 99%

Influence of pyridoxylidene aminoguanidine on biomarkers of the oxidative stress and selected metabolic parameters of rats with diabetes mellitus

Országhová¹,

Liptáková²,

Muchová³

et al. 2009

gpb

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Abstract. Oxidative damage is considered to play an important role in the pathogenesis of several diseases, such as diabetes mellitus (DM), atherosclerosis, cardiovascular complications and chronic renal failure. DM is associated with the oxidative stress and formation of advanced glycation end products (AGEs). Different drugs inhibit oxidative stress and formation of advanced glycation end products. Aminoguanidine (AG) has been proposed as a drug of potential benefit in prophylaxis of the complications of DM. Recent reports show a pro-oxidant activity of AG. Therefore we examined the effect of structural analogue of AG, its Schiff base with pyridoxal -pyridoxylidene aminoguanidine (PAG) on the level of selected markers of oxidative stress. We found that PAG decreased total damage to DNA in controls as well as in diabetic group of rats. However, we also found that PAG supplementation increases susceptibility of lipoproteins to oxidation and formation of conjugated dienes in both, diabetic as well as control animals. Its administration to diabetic rats decreases antioxidant capacity of plasma. Therefore, it is necessary to search for other structural modifications of AG that would combine its higher anti-diabetic activity with less toxicity.

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“…Moreover, the smoking status was not found to affect oxidation parameters by multivariate analysis; (4) most medications have been added during hospitalization, so that most of their effects should have been observed during hospitalization; specifically, statin therapy was found to carry no effect on t max by multivariate analysis; (5) thrombolysis cannot be considered to be a major confounder, as none of the oxidation parameters differed significantly between admission (before thrombolysis) and repeated measurements during hospitalization (after thrombolysis); (6) the putative effect of heparin has been excluded (see Methods) by analysis of the effect of adding heparin to serum samples in vitro. Furthermore, the values of the measured oxidation parameters did not differ significantly between admission (before heparin therapy) and the repeated measurements during hospitalization (during heparin treatment), indicating that heparin treatment cannot explain the differences observed in oxidation parameters at the different time points after MI; (7) the possibility that freezing and thawing of serum samples had a significant effect on the reported results has been excluded by comparing the kinetic parameters of oxidation on paired samples, frozen and unfrozen 14,16 (Methods).…”

Section: Discussionmentioning

confidence: 94%

“…14 The absorbance at 245 nm is attributed to dienic hydroperoxides and 7-ketocholesterol, whereas the absorbance at 268 nm is attributed mostly to dienals and other final products of decomposition of hydroperoxides. 14,15 This method has been shown to correlate strongly with copper-mediated oxidation of LDL, as reported by Schnitzer et al 16 The kinetics of oxidation ( Fig. 1) was analyzed in terms of (1) the maximal rate of accumulation of absorbing products (V max ), (2) the time at which the rate of peroxidation achieved its maximal value (t max )-this parameter is in good correlation with the "lag" preceding oxidation and reflects the resistance of serum lipids to oxidative stress 15 -, and (3) the maximal accumulation of absorbing products (OD max ).…”

Section: Copper-induced Oxidation Of Serum Lipidsmentioning

confidence: 99%

Acute myocardial infarction is associated with increased susceptibility of serum lipids to copper‐induced peroxidation in vitro

Fainaru

Assali

et al. 2002

Clinical Cardiology

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Background: Low‐density lipoprotein (LDL) oxidation in the arterial intima plays a pivotal role in atherogenesis. Under physiologic conditions, several mechanisms protect LDL against oxidation, including hydrolysis of oxidation products by high‐density lipoprotein (HDL)‐associated enzymes. Some of these protective mechanisms are less effective under acute phase conditions. Hypothesis: Conditions of acute phase response, including acute myocardial infarction (MI), may be expected to result in increased susceptibility of serum lipids to oxidation. The present study was undertaken to test this possibility. Methods: Using our previously developed spectroscopic method, we have monitored prospectively the kinetics of copper‐induced oxidation of serum lipids obtained from 15 men during and after acute MI. This was tested within 6 h from the onset of chest pain, on Days 1, 3, and 7 of infarction and 1 year after recovery. Results: The lag phase preceding oxidation of serum lipids was much shorter during the first week after MI when compared with values obtained after recovery (52‐59 vs. 107 min, respectively, p < 0.001). During the first week after MI, we observed no significant correlations between kinetic parameters and serum lipid composition, in contrast both to the correlations previously reported for hyperlipidemic patients and to the similar correlations observed in the present study after recovery. Conclusions: Acute MI is associated with an increased susceptibility of serum lipids to oxidation in vitro. This propensity for oxidation may reflect enhanced in vivo formation of free radicals and/or reduced efficiency of defense mechanisms. Both these possibilities may carry detrimental effects on the course, complications, and prognosis of the patients after acute MI.

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Lipid oxidation in unfractionated serum and plasma

Cited by 98 publications

References 29 publications

In vitro health beneficial activities of Pumpkin seeds from Cucurbita moschata cultivated in Lemnos

In vitro health beneficial activities of Pumpkin seeds from Cucurbita moschata cultivated in Lemnos

Influence of pyridoxylidene aminoguanidine on biomarkers of the oxidative stress and selected metabolic parameters of rats with diabetes mellitus

Acute myocardial infarction is associated with increased susceptibility of serum lipids to copper‐induced peroxidation in vitro

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