Lipid peroxidation malondialdehyde

Low intensity laser Helium-neon laser Lipid peroxidation Malondialdehyde... 

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. ... 

Lipid peroxidation Malondialdehyde formation Lipofuscin pigment concentration Superoxide dismutases mitochondrial cytosolic... 

Balb c mice and Wistar rats were used in the experiments. The administration of single doses of 1, 2 and 2 caused mainly necrotic changes in the liver, measured by GPT and histopathology. The extent of necrosis depended on doses and on time of observation (1-4 days after injections). In shorter time interval (2-4 hrs) 1, 2 and 2 caused depletion of hepatic GSH (even up to 10 % of control). 4 and 5 did not generate necrotic changes. Increased GPT activity was observed after 3 doses of fi. Single doses of 4, 5 and fi mostly increased the level of malondialdehyde (MDA-indicator of lipid peroxidation) in the liver. Repeated injections (3-7) of the investigated compounds enhanced the activity of ALA-D or ALA-S in the liver and caused steatosis. 

Figure 14-21. Lipid peroxidation. The reaction is initiated by an existing free radical (X ), by light, or by metal ions. Malondialdehyde is only formed by fatty acids with three or more double bonds and is used as a measure of lipid peroxidation together with ethane from the terminal two carbons ofcoB fatty acids and pentane from the terminal five carbons of cb6 fatty acids.

The chemical adducts formed by reaction of aldehydes with lysine residues form highly immunogenic epitopes, and antibodies have been prepared specific for malondialdehyde- and 4-hydroxynonenal-conjugated LDL (Gonen et al., 1987 Yla-Herttuala et al., 1989 Jurgens et al., 1990). These antibodies cross-react with material in atherosclerotic lesions but not normal tissue, thus supporting the central role of lipid peroxidation in the patho nesis of atherosclerosis (Yla-Herttuala et al., 1989, 1991). 

There is some support for a role for free radicals in the pathogenesis of ischaemic colitis from animal studies. Murthy and Qi (1992) used a spin trap to demonstrate increased production of free radicals up to 60 min after reperfusion, whereas Douglas etal. (1989) demonstrated increases in malondialdehyde and conjugated dienes (presumptive measures of lipid peroxidation) in a rat model of ischaemic colitis. There is no data relating to human ischaemic colitis. 

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

The occupation of all available coordination sites by phytate suppresses other iron-mediated processes, such as lipid peroxidation ( 0). Figure 6 demonstrates that 0.24 mM phytate prevents the peroxidation of arachidonic acid driven by ascorbic acid and iron, whereas substantial amounts of malondialdehyde arise in the presence of free iron or of an iron-ADP chelate. 

Ekstrom T, Stahl A, Sigvardsson K, et al. 1986. Lipid peroxidation in vivo monitored as ethane exhalation and malondialdehyde excretion in urine after oral administration of chloroform. Acta Pharmacol Toxicol 58 289-296. 

The amount of TBA reactant can be converted into moles of malondialdehyde by the extinction coefficient of 155 mM cm ozone (22), and the yield of this reaction, or ratio of malondialdehyde/ozone taken-up, is shown in Figure 9. Notice that the yield for ozone-treated linolenic acid varies with time of reaction from about 3% to over 30%. These results differ from those for lipid peroxidation reactions which also give rise to malondialdehyde but have yields of 2-5% (23). 

Lipid peroxidation activity. Solubilized green tea, administered orally to rats for 5 weeks, reduced lipid peroxidation products. The treatment produced increased activity of glutathione (GSFf) peroxidase and GSH reductase, increased content of reduced GSH, a marked decrease in lipid hydroperoxides and malondialdehyde in the liver, an increase in the concentration of vitamin A by about 40%. A minor change in the measured parameters was observed in the blood... 

Malondialdehyde content MDA Oxidative stress parameter Lipid peroxidation inducers Liver tissue 6-15... 

Dose-dependent increase in cytotoxicity by isolated brown cells Hepatopancreas had 513 mg/kg DW (vs. <50 in controls) accumulations accompanied by a significant increase in hydroperoxide and malondialdehyde contents in microsomal membranes and alterations in lipid peroxidation rates... 

The aim of the present study was to evaluate the effect of LLLT on oxidative markers in serum and tissue biopsies of healing ulcers before and after the 8th session of an LLLT course of chronic leg ulcer treatment. Oxidative damage was assessed in terms of lipid peroxidation reflected by serum malondialdehyde (MDA) level, protein oxidation was measured in terms of tissue protein carbonyls (PCb), and DNA damage was measured in terms of DNA fragmentation. Antioxidative activity was estimated by measuring activity of SOD, GPX and CAT enzymes. 

Antioxidant activity was also tested in a liver microsome system. In this study, mice were treated by oral intubation (2 times/wk) with 0.2 ml olive oil alone or containing CLA (0.1 ml), linoleic acid (0.1 ml), or dl-a-tocopherol (lOmg). Four weeks after the first treatment, liver microsomes were prepared and subsequently subjected to oxidative stress using a non-enzymatic iron-dependent lipid peroxidation system. Microsomal lipid peroxidation was measured as thiobarbituric acid-reactive substance (TBARS) production using malondialdehyde as the standard. It was found that pretreatment of mice with CLA or dl-a-tocopherol significantly decreased TBARS formation in mouse liver microsomes (p < 0.05) (Sword, J. T. and M. W. Pariza, University of Wisconsin, unpublished data). 

Picaud, J. C., Steghens, J. P., Auxenfans, C., Barbieux, A., Laborie, S., and Claris, O. (2004), Lipid peroxidation assessment by malondialdehyde measurement in parenteral nutrition solutions for newborn infants A pilot study, Acta Paediatr., 93, 241-245. 

Impairment of membrane-bound Na,K-ATPase, which is responsible for maintaining and restoring membrane potential, and an increased level of malondialdehyde (MDA), which is a known as an index of lipid peroxidation, are seen after unilateral focal cerebral ischemia in the mouse. Pretreatment with EGb (100 mg/kg/day, p.o. for 10 days) preserves the Na,K-ATPase activity during cerebral ischemia and prevents the increased MDA levels caused by cerebral... 

Lipid peroxidation/oxidative stress (Fig. 7.36). Lipid peroxidation products (e.g., malondialdehyde) have been detected, and GSH is depleted seemingly by oxidation rather than conjugation, and prior depletion of GSH increases the toxicity. NADPH is... 

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