Lipid peroxidation activity

Inflammatory cell phenomenon are also contributors to lipid peroxidation. Activated neutrophils may adhere to damaged endothelium and amplify traumatic, ischaemic or ischaemia-reperfiision injury. Many cyclooxygenase products of the metabolism of atachidonic acid modulate the inflammatory responses of cells. Macrophages, neutrophils and microglia are important sources of reactive oxygen at the injury site. When activated, they produce a respiratory burst that is traced to activated nicotinamide adenine dinucleotide (NADPH/NADH) oxidase. 

Kuno, A., Sugiyama, Y., Katsuta, K., Sakai, H. and Takasugi, H. (1992). Studies on cerebral protective agents. Novel 4-arylpyrimidine derivatives with anti-anoxic and anti-lipid peroxidation activities. Chem. Pharm. Bull. 40, 2423-2431. 

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... 

Plasma malondialdehyde-like material, an indicator of lipid peroxidation, is increased in conditions of ischaemia, such as stroke [83, 84] and myocardial infarction [85]. Mitochondria extracted from hearts of vitamin-E-deficient rabbits showed a decreased mitochondrial function and an increased formation of oxygen radicals associated with a reduced superoxide dismutase activity. This was partially reversed by addition of vitamin E in vitro [86]. Measurement of in vitro susceptibility to lipid peroxidation in cardiac muscle from vitamin-E-deficient mice showed a highly significant negative correlation between the concentration of vitamin E and in vitro lipid peroxidation. The results indicate that short-term vitamin E deficiency may expose cardiac muscle to peroxidation injuries [ 87 ]. In rats, treatment for 2 days with isoprenaline increased lipid peroxide activity, as measured by malondialdehyde levels, in the myocardium. Vitamin-E-deficient animals were even more sensitive to this effect, and pretreatment with a-tocopheryl acetate for 2 weeks prevented the effect induced by isoprenaline. The authors [88] propose that free-radical-mediated increases in lipid peroxide activity may have a role in catecholamine-induced heart disease. 

Anuradha, C. and Ravikumar, P. 1998. Anti-lipid peroxidative activity of seeds of fenugreek (Trigonella foenum graecum). Med. Sci. Res. 26, 317-321. 

Both NADPH-linked and ascorbate-induced lipid peroxidation activities induced in vitro were lowered 5.5% and 26%, respectively, in Carworth Farms rats following oral administration of 1,400 mg/kg/day of benzene for 3 days, followed by intraperitoneal injection of phenobarbital. It is concluded that benzene alters hepatic drug metabolism and lipid peroxidation. The decrease in lipid peroxidation could be due to the antioxidant property of the metabolites (Pawar and Mungikar 1975). 

P. striata Asthenia lsoverbascoside Antioxidant Inhibition of FeSOrinduced lipid peroxidation Active [80]... 

Following the action of extraordinary stimulants (hypoxic hypoxia, hypoxia + hyperoxia, hypodynamia + hyperthermia), animals demonstrate an accumulation of malonic dialdehyde with a simultaneous fall of antiradical activity of the liver tissue. A preliminary introduction to rats of acetylene amine 3,4,5-tris(morpho-linopropynyl)-l-methylpyrazole 103 and also of tocopherol antioxidant and gutumine antihypoxant averts activation of the lipid peroxidation processes. The inhibition of peroxidation with this agent is mediated by stabilization of ly-zosomal and mitochondrial membranes. Unsaturated amines prevent destruction of the organelle membranes provoked by UV irradiation and incubation at 37°C (pH4.7)(78MIl). 

The acetylene aminopyrazole 103 was capable of inhibiting the processes of lipid peroxidation both in the enzymatic and nonenzymatic peroxidation system (76MI2). Finally, 4-[3-(l-methyl-l//-pyrazol-3-yl)-prop-2-ynyl]morpholine hydrochloride 104 was patented as a compound with high hypoxic activity (93MIP1). 

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. 

SEERAM N P and NAIR M G (2002) Inhibition of lipid peroxidation and structure-activity-related studies of the dietary constituents autocyanins, autocyanidins, and catechins, JAgric Food Chem, 50, 5308-12. 

Results obtained in in vivo and ex vivo experiments are of various types. Some studies have found positive effects of the consumption of carotenoids or foods containing carotenoids on the markers of in vivo oxidative stress, even in smokers. Other studies demonstrated no effects of carotenoid ingestion on oxidative stress biomarkers of lipid peroxidation. " It should be noted that for studies using food, the activity observed may also be partly due to other antioxidant molecules in the food (phenols, antioxidant vitamins) or to the combination of actions of all the antioxidants in the food. 

Fukuzawa, K. et ah. Rate constants for quenching singlet oxygen and activities for inhibiting lipid peroxidation of carotenoids and alpha-tocopherol in liposomes. Lipids, 33, 751, 1998. 

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... 

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