Lipid peroxidation is essential for α-synuclein-induced cell death.

Parkinson's disease is the second most common neurodegenerative disease and its pathogenesis is closely associated with oxidative stress. Deposition of aggregated α-synuclein (α-Syn) occurs in familial and sporadic forms of Parkinson's disease. Here, we studied the effect of oligomeric α-Syn on one of the major markers of oxidative stress, lipid peroxidation, in primary co-cultures of neurons and astrocytes. We found that oligomeric but not monomeric α-Syn significantly increases the rate of production of reactive oxygen species, subsequently inducing lipid peroxidation in both neurons and astrocytes. Pre-incubation of cells with isotope-reinforced polyunsaturated fatty acids (D-PUFAs) completely prevented the effect of oligomeric α-Syn on lipid peroxidation. Inhibition of lipid peroxidation with D-PUFAs further protected cells from cell death induced by oligomeric α-Syn. Thus, lipid peroxidation induced by misfolding of α-Syn may play an important role in the cellular mechanism of neuronal cell loss in Parkinson's disease. We have found that aggregated α-synuclein-induced production of reactive oxygen species (ROS) that subsequently stimulates lipid peroxidation and cell death in neurons and astrocytes. Specific inhibition of lipid peroxidation by incubation with reinforced polyunsaturated fatty acids (D-PUFAs) completely prevented the effect of α-synuclein on lipid peroxidation and cell death

Lipid peroxidation in the serum of hypothyroid patients (In Gorgan-South East of Caspian Sea)

This study was designed to determine if lipid peroxidation can be modified by hypothyroidism. Twenty eight subjects with hypothyroidism and 33 euthyroid subjects participated in this study (2007). Blood samples were collected and serum malondialdehyde, T3, T4 and TSH were measured. An increase in lipid peroxidation (expressed as Malondialdehyde, MDA) and TSH levels and also a decrease in T4 level were observed in the hypothyroid patients when compared with control groups (p<0.001). The level of T3 was not changed when compared with control groups. The results shows that hypothyroidism may not modulate the free-radical-induced oxidative damage and that hypothyroidism may not present some protection against lipid peroxidation. Thus, the enhancedlipid peroxidation may play a role in the free-radical-induced oxidative damage of some tissues in hypothyroidism. These may show that there is an important relation between hypothyroidism and lipid peroxidation. © 2008 Academic Journals Inc

Correlation of Lipid Peroxidation with Glycated Haemoglobin Levels in Diabetes Mellitus

Reactive oxygen species are crucial to normal biological processes; they are potentially dangerous and are commonly referred to as prooxidants. The reactive oxygen intermediates can cause direct cellular injury by including lipid and protein peroxidation and damage to nucleic acid. The polyunsaturated fatty acids present in the cells are vulnerable to free radicals causing lipid peroxidation. Determination of Malondialdehyde (MDA) by using thiobarbituric acid is used as an index of the extent of lipid peroxidation. This study was done to know if lipid peroxidation correlated with the glycated haemoglobin levels. Diabetic status was assessed by estimating fasting blood sugar and glycated haemoglobin level while oxidant stress was evaluated by estimating erythrocyte MDA levels. The lipid peroxidation in erythrocyte lysates was significantly increased in diabetic individuals compared to controls (p<0.001). The result of this study indicates that in diabetic individuals are more prone to oxidative stress and glycated haemoglobin is a marker in evaluating the long term glycemic status in diabetic individuals

Lipid Peroxidation After Intracortical Injection of Ferric Chloride Increases the Incidence of Seizures in Young Rats

Clinical studies have shown that the incidence of early posttraumatic seizures ishigher in children than in adults and it has been proposed that iron-induced lipidperoxidation has an important role in the development of epileptogenic foci. In this study,we examined some of the hypothesized reasons for the difference in the incidence ofearly posttraumatic seizures between young and adult rats. Twelve young and twelveadult rats were randomized into 4 groups. Group 1 and 2 were control groups, eachcomprising of 6 young rats and 6 adult rats respectively and were given intracorticalinjections of normal saline. Group 3 and 4 were injury groups, again comprising 6 youngrats and 6 adult rats respectively and were given intracortical injections of FeCl3. All ratswere observed for 6 hours post injection for the occurrence of seizures and were thenkilled. The injected hemispheres were extirpated and tested for malondialdehyde (MDA)level and superoxide dismutase (SOD) activity as indices of oxidative damage. Resultsshowed that seizures were observed only in Group 3. Increased MDA level and decreasedSOD activity were observed in Group 3 (ANOVA, p&lt;0.001). Increased MDA levels anddecreased SOD activity were significantly higher in rats with seizures (Group 3) than inthose without seizures (independent t-test, p&lt;0.001). We conclude was that differentlevels of lipid peroxidation induced by intracortical ferric chloride injection may accountfor the different seizure incidence between young and adult rat

Turmeric and black pepper spices decrease lipid peroxidation in meat patties during cooking.

Spices are rich in natural antioxidants and have been shown to be potent inhibitors of lipid peroxidation during cooking of meat. Turmeric contains unique conjugated curcuminoids with strong antioxidant activity. Piperine, one of the main constituents of black pepper, is known to increase the bioavailability of curcuminoids in mouse and human studies when consumed with turmeric. We investigated whether adding black pepper to turmeric powder may further inhibit lipid peroxidation when added to meat patties prior to cooking. The addition of black pepper to turmeric significantly decreased the lipid peroxidation in hamburger meat. When investigating the antioxidant activity of the main chemical markers, we determined that piperine did not exhibit any antioxidant activity. Therefore, we conclude that other black pepper ingredients are responsible for the increased antioxidant activity of combining black pepper with turmeric powder

Physiological antioxidant system and oxidative stress in stomach cancer patients with normal renal and hepatic function

Role of free radicals has been proposed in the pathogenesis of many diseases. Gastric cancer is a common disease worldwide, and leading cause of cancer death in India. Severe oxidative stress produces reactive oxygen species (ROS) and induces uncontrolled lipid peroxidation. Albumin, uric acid (UA) and Bilirubin are important physiological antioxidants. We aimed to evaluate and assess the role of oxidative stress (OS) and physiological antioxidant system in stomach cancer patients. Lipid peroxidation measured as plasma Thio Barbituric Acid Reactive substances (TBARS), was found to be elevated significantly (p=0.001) in stomach cancer compared to controls along with a decrease in plasma physiological antioxidant system. The documented results were due to increased lipid peroxidation and involvement of physiological antioxidants in scavenging free radicals but not because of impaired hepatic and renal functions

Studies on ferrous ion-induced lipid peroxidation of rat liver mitochondria. I. Effect of inorganic phosphate

Effect of inorganic phosphate on ferrous ion- and ascorbate-induced lipid. peroxidations of isolated rat liver mitochondria was investigated. As a result it has been shown that phosphate accelerates the ferrous ion.induced lipid peroxidation; namely, phos. phate shortens the induction lag period of the lipid peroxidation reaction but the malondialdehyde after onset of its production is yielded at the same rate in various concentrations of phosphate. On the other hand, phosphate inhibits ascorbate.induced lipid peroxidation. There are stoichiometric interactions between the concentration of phos. phate and the induction period. Oxygen uptake by mitochondria was observed in the presence of both ferrous ion and phosphate at initial step of the reaction without being accompanied by malondialdehyde production, and afterwards there occurred malondialdehyde production with rapid rate of the oxygen uptake. Possible mechanisms and interactions among ferrous ion, ascorbate and phosphate were discussed.</p

Plasma total antioxidant capacity and peroxidation biomarkers in psoriasis

Systemic biomarkers of oxidative stress can be relevant for assessment of psoriasis severity, for prediction of the outcome of therapy and of the development of comorbidities. In this review we aimed to evaluate the relationship between plasma total antioxidant capacity (TAC) and peroxidation biomarkers, as well as their association with dyslipidemia and systemic inflammation in psoriasis. The review of 59 case–control comparisons (from 41 studies) and 17 interventions (from 13 studies) suggests that peroxidation markers are more sensitive than TAC in the evaluation of oxidative stress in psoriasis. Although few studies investigated the effect of treatment on oxidative stress, it seems that biological drugs could be the better choice in the treatment of psoriasis. However, considering the limitations of TAC and plasma peroxidation markers, this review suggests that new methods should be developed in order to evaluate systemic oxidative stress in psoriasis

OXIDATIVE CHANGES OF LIPIDS, PROTEINS AND ANTIOXIDANTS IN YOGURT DURING THE SHELF LIFE

Background: Oxidation processes in milk and yogurt during the shelf life can result in an alteration of protein and lipid constituents. Therefore, the antioxidant properties of yogurt in standard conditions of preservation were evaluated. Results: Total phenols, free radical scavenger activity, degree of lipid peroxidation and protein oxidation were determined in plain and skim yogurts with or without fruit puree. After production, plain, skim, plain berries and skim berries yogurts were compared during the shelf life up to 9 weeks. All types of yogurts revealed a basal antioxidant activity that was higher when a fruit puree was present but gradually decreased during the shelf life. However, after five-eight weeks, antioxidant activity increased again. Both in plain and berries yogurts lipid peroxidation increased until the seventh week of shelf life and after decreased, while protein oxidation of all yogurts was similar either in the absence or presence of berries and increased during shelf life. Conclusion: During the shelf life, a different behavior between lipid and protein oxidation takes place and the presence of berries determines a protection only against lipid peroxidation

Studies on the hyperplasia ('regeneration') of the rat liver following partial hepatectomy. Changes in lipid peroxidation and general biochemical aspects

Using the experimental model of partial hepatectomy in the rat, we have examined the relationship between cell division and lipid peroxidation activity. In rats entrained to a regime of 12 h light/12 h dark and with a fixed 8 h feeding period in the dark phase, partial hepatectomy is followed by a rapid regeneration of liver mass with cycles of synchronized cell division at 24 h intervals. The latter phenomenon is indicated in this study by pulses of thymidine kinase activity having maxima at 24 h, 48 h and 72 h after partial hepatectomy. Microsomes prepared from regenerating livers show changes in lipid peroxidation activity (induced by NADPH/ADP/iron or by ascorbate/iron), which is significantly decreased relative to that in microsomes from sham-operated controls, again at 24 h, 48 h and 72 h after the operation. This phenomenon has been investigated with regard to possible underlying changes in the content of microsomal fatty acids, the microsomal enzymes NADPH:cytochrome c reductase and cytochrome P-450, and the physiological microsomal antioxidant alpha-tocopherol. The cycles of decreased lipid peroxidation activity are apparently due, at least in part, to changes in microsomal alpha-tocopherol content that are closely associated in time with thymidine kinase activity