Lipid peroxide determination

The TBA test is perhaps the most widely used method for determining lipid peroxidation. The representative adduct of lipid peroxidation, malondialdehyde, forms a 1 2 adduct with TBA that can be measured by spectroscopy or fluorometry. The general procedure, of which there are numerous variations, simply involves heating a small quantity of the test substance for a defined period of time in an aqueous acidic solution of TBA, and then measuring the absorbance (535 nm) of the red color which is produced in the TBA reaction. It should be considered as an index of oxidative stress that represents primarily lipid peroxidation. ... 

Wold, J.P. 2001. A rapid and non-destructive fluorescence method to determine lipid peroxidation in foods, 21stNordic Lipid Symposium, Lipidforum, Bergen, June 5-8, 2001. 

Selley et al. (1992) have recently employed gas chromatography combined with mass spectrometric detection to determine levels of the cytotoxic monounsaturated aldehyde 4-hydroxy-/7 t-2-nonenal in the blood plasma of healthy human subjects, and patients with rheumatoid and osteoarthritis. Intriguingly, this lipid peroxidation end-product is present at a concentration ofc. lx 10 mol/dm in healthy and osteoarthritic human plasma samples (but significantly elevated in those collected from rheumatoid arthritis patients). Although at least some of this could originate from the oxidative degradation of PUFAs invm, there may be a relationship existing between these levels and the frequency of thermally/... 

Mouse peritoneal macrophages that have been activated to produce nitric oxide by 7-interferon and lipopolysac-charide were shown to oxidize LDL less readily than unactivated macrophages. Inhibition of nitric oxide synthesis in the same model was shown to enhance LDL oxidation (Jessup etal., 1992 Yates a al., 1992). It has recently been demonstrated that nitric oxide is able to inhibit lipid peroxidation directly within LDL (Ho etal., 1993c). Nitric oxide probably reacts with the propagating peroxyl radicals thus terminating the chain of lipid peroxidation. The rate constant for the reaction between nitric oxide and peroxyl radicals has recently been determined to be 1-3 X10 M" s (Padmaja and Huie, 1993). This... 

One technique to assess lipid peroxidation utilizes second-derivative spectrophotometric analysis of cyclohexane or ethanol-reconstituted extracts to determine the cis-trans and trans-trans isomeric forms of conjugated dienes and oxodiene species within synovial fluid. Using this method, a rise in the synovial fluid concentration of conjugated oxodienes, hydroxydienes and hydroperoxy-dienes was found to follow joint exercise (Merry et al., 1991). 

Hepatic reperfusion injury is not a phenomenon connected solely to liver transplantation but also to situations of prolonged hypoperfusion of the host s own liver. Examples of this occurrence are hypovolemic shock and acute cardiovascular injur) (heart attack). As a result of such cessation and then reintroduction of blood flow, the liver is damaged such that centrilobular necrosis occurs and elevated levels of liver enzymes in the serum can be detected. Particularly because of the involvement of other organs, the interpretation of the role of free radicals in ischaemic hepatitis from this clinical data is very difficult. The involvement of free radicals in the overall phenomenon of hypovolemic shock has been discussed recently by Redl et al. (1993). More specifically. Poll (1993) has reported preliminary data on markers of free-radical production during ischaemic hepatitis. These markers mostly concerned indices of lipid peroxidation in the serum and also in the erythrocytes of affected subjects, and a correlation was seen with the extent of liver injury. The mechanisms of free-radical damage in this model will be difficult to determine in the clinical setting, but the similarity to the situation with transplanted liver surest that the above discussion of the role of XO activation, Kupffer cell activation and induction of an acute inflammatory response would be also relevant here. It will be important to establish whether oxidative stress is important in the pathogenesis of ischaemic hepatitis and in the problems of liver transplantation discussed above, since it would surest that antioxidant therapy could be of real benefit. 

Esterbauer, H., Zollner, H. and Schaur, KJ. (1990). Aldehydes formed by lipid peroxidation mechanisms of formation, occurrence and determination. In Lipid Oxidation (ed. C. Vigo-Pelfrey) pp. 239-283. CRC Press, Boca Raton, FL. 

Probucol, another di-r-butyl phenol, is an anti-atherosclerotic agent that can suppress the oxidation of low-density lipoprotein (LDL) in addition to lowering cholesterol levels. The antioxidant activity of probucol was measured, using EPR, with oxidation of methyl linoleate that was encapsulated in liposomal membranes or dissolved in hexane. Probucol suppressed ffee-radical-mediated oxidation. Its antioxidant activity was 17-fold less than that of tocopherol. This difference was less in liposomes than in hexane solution. Probucol suppressed the oxidation of LDL as efficiently as tocopherol. This work implies that physical factors as well as chemical reactivity are important in determining overall lipid peroxidation inhibition activity (Gotoh et al., 1992). 

Determination of Free Radicals, H202 and Lipid PeroxidE 122... 

DETERMINATION OF FREE RADICALS, H202 AND LIPID PEROXIDE... 

Experiment 3. Determination of free radicals, H202 and lipid peroxidation. 

Observations Table 2 shows the levels of free radicals determined by luminol chemiluminescence, H202 levels, and membrane lipid peroxidation determined by conjugated dienes. Total free radicals significantly increased by 1.4 fold, hydrogen peroxide significantly decreased 1.3 fold, and lipid peroxidation increased significantly 1.5 fold. 

The determination of F2-isoprostanes, oxidation products of arachidonic acid, has been proposed as a more reliable index of oxidative stress in vivo, overcoming many of the methodological problems associated with other markers. The isoprostanes have emerged as a most effective method of quantifying the potential of antioxidants to inhibit lipid peroxidation. However, one drawback of this method is that quantification of F2-iP requires sophisticated techniques, in particular GC/MS and HPLC/MS... 

Maiorino M, Roveri A, Ursini F and Gregolin C. 1985. Enzymatic determination of membrane lipid peroxidation. J Free Radic Biol Med l(3) 203-207. 

The effects of flavonoids on in vitro and in vivo lipid peroxidation have been thoroughly studied [123]. Torel et al. [124] found that the inhibitory effects of flavonoids on autoxidation of linoleic acid increased in the order fustin < catechin < quercetin < rutin = luteolin < kaempferol < morin. Robak and Gryglewski [109] determined /50 values for the inhibition of ascorbate-stimulated lipid peroxidation of boiled rat liver microsomes. All the flavonoids studied were very effective inhibitors of lipid peroxidation in model system, with I50 values changing from 1.4 pmol l-1 for myricetin to 71.9 pmol I 1 for rutin. However, as seen below, these /50 values differed significantly from those determined in other in vitro systems. Terao et al. [125] described the protective effect of epicatechin, epicatechin gallate, and quercetin on lipid peroxidation of phospholipid bilayers. 

Crebelli, R., Andreoli, C., Carere, A., Conti, L., Crochi, B., Cotta-Ramusino, M., Benigni, R. Toxicology of halogenated aliphatic hydrocarbons Structural and molecular determinants for the disturbance of chromosome segregation and the induction of lipid peroxidation. Chem. Biol. Interact. 1995, 98, 113-129. 

Lipid peroxidation was measured by determining malondialdehyde (MDA) spectrophotometrically by the thiobarbituric acid method (30). 

Figure 6. Effect of ADP and phytate on iron-mediated OH formation (A) and lipid peroxidation (B). The mean and standard deviation of 3 determinations are shown.

Hassoun et al. (1993) examined the effects of various pesticides on lipid peroxidation and DNA single strand breakage in the hepatic cells of female Sprague-Dawley rats. Animals were dosed orally once with endrin at 4.5 mg/kg, lindane at 30 mg/kg, chlordane at 120 mg/kg, or DDT (dichlorodiphenyl trichloro-ethane) at 40 mg/kg, or vehicle only (com oil, control). At 6, 12, and 24 hours post-dosing, 4 animals from each group were sacrificed, their livers removed, and prepared for lipid peroxidation assay. Lipid peroxidation was measured calorimetrically by determining the amount of thiobarbituric acid reactive substances (TBARS) formed. Exposure to endrin resulted in a 14.5% increase in hepatic mitochondrial... 

The content of the products of lipid peroxidation (LPO) was determined after 1 h of incubation of the cells in a buffer A at 37 °C. Aliquot of cell suspension (100 pg protein) was treated with heptane/isopropyl alcohol mixture at the ratio of 1 1. The content of Schiff bases in heptane phase was analyzed on fluorimeter RF-510, Shimadzu (Japan) at iexit = 360 nm and Xgms = 420 nm (Kolesova et al., 1984). The content of diene conjugates was determined by spectrophotometry (Gavrilov et al., 1988) at the wavelength of X = 245 nm using spectrophotometer Scinco (Germany). 

Kolesova OE, Markin AA, Fedorova TN (1984) Pereoxide oxidation of lipids and the methods for determination of lipid peroxidation produce in the biological mediums. Russian Laboratomoe Delo. 9 540-546. 

Phenylchalcogenyl-l-naphthols with sulfur (91), selenium (92), and tellurium (93) were prepared, as was the methylene analog (90), and their oxidation potentials determined by CV vs. SCE. All were irreversible, and only the Te compound 93 (1.00 V) differed significantly from the other three ( 1.25 V) (Table 9). It is likely that the naphthol moiety is controlling the oxidation potential of 90-92. Interestingly, only 93 showed significant ability to inhibit lipid peroxidation in a... 

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