Cumene Hydroperoxide-induced Lipid Peroxidation Research Articles

Time-dependent effects of perfluorinated compounds on viability in cerebellar granule neurons: Dependence on carbon chain length and functional group attached

The toxicity of long chained perfluoroalkyl acids (PFAAs) has previously been reported to be related to the length of the perfluorinated carbon chain and functional group attached. In the present study, we compared the cytotoxicity of six PFAAs, using primary cultures of rat cerebellar granule neurons (CGNs). Two perfluoroalkyl sulfonic acids (PFSAs, chain length C6 and C8) and four perfluoroalkyl carboxylic acids (PFCAs, chain length C8–C11) were studied. These PFAAs have been detected in human blood and the brain tissue of mammals. The cell viability trypan blue and MTT assays were used to determine toxicity potencies (based on LC50 values) after 24h exposure (in descending order): perfluoroundecanoic acid (PFUnDA)≥perfluorodecanoic acid (PFDA)>perfluorooctanesulfonic acid potassium salt (PFOS)>perfluorononanoic acid (PFNA)>perfluorooctanoic acid (PFOA)>perfluorohexanesulfonic acid potassium salt (PFHxS). Concentrations of the six PFAAs that produced equipotent effects after 24h exposure were used to further explore the dynamics of viability changes during this period. Therefore viability was assessed at 10, 30, 60, 90, 120 and 180min as well as 6, 12, 18 and 24h. A difference in the onset of reduction in viability was observed, occurring relatively quickly (30–60min) for PFOS, PFDA and PFUnDA, and much slower (12–24h) for PFHxS, PFOA and PFNA. A slight protective effect of vitamin E against PFOA, PFNA and PFOS-induced reduction in viability indicated a possible involvement of oxidative stress. PFOA and PFOS did not induce lipid peroxidation on their own, but significantly accelerated cumene hydroperoxide-induced lipid peroxidation. When distribution of the six PFAAs in the CGN-membrane was investigated using NanoSIMS50 imaging, two distinct patterns appeared. Whereas PFHxS, PFOS and PFUnDA aggregated in large hotspots, PFOA, PFNA and PFDA showed a more dispersed distribution pattern. In conclusion, the toxicity of the investigated PFAAs increased with increasing carbon chain length. For molecules with a similar chain length, a sulfonate functional group led to greater toxicity than a carboxyl group.

In vitro study of lipid peroxidation and free radical scavenging activity of cow urine

This study represents a comprehensive analysis and scientific validation of our ancient knowledge about the ethnopharmacological aspects of cow urine by measuring the lipid peroxidation, radical scavenging, and level of reduced glutathione and catalase activity. Graded doses of cow urine were administered orally to experimentally treated rats. Results of liver and plasma from experimentally treated rats indicated that cow urine reduced the levels of thiobarbituric acid reactive substance significantly in all the treatments (P < 0.01). In vitro experiments with the liver of control and experimentally treated rats were also carried out against cumene hydroperoxide-induced lipid peroxidation. On LCMS analysis, the antioxidant component of cow urine was identified as uric acid (m/z 169.07). The results demonstrate that the cow urine-mediated induction of antioxidant level controls oxidative damage, even after minimal processing, and thus is indicative of its potential as a viable substitute of synthetic antioxidants.

A Search for Hepatoprotective Activity of Fruit Extract of Mangifera indica L. Against Oxidative Stress Cytotoxicity

Mango (Mangifera indica L.) and their components are commonly used in folk medicine for many curative effects. The protective effects of different concentrations of aqueous extract of Mangifera indica L. fruit (Mango Extract) (20, 50 and 100 microg/ml) and also gallic acid (100 microM) as a pure compound in the extract were examined against oxidative stress toxicity induced by cumene hydroperoxide (CHP) in isolated rat hepatocytes. The extracts and gallic acid (100 microM) protected the hepatocyte against all oxidative stress markers including cell lysis, ROS generation, lipid peroxidation, glutathione depletion, mitochondrial membrane potential decrease, lysosomal membrane oxidative damage and cellular proteolysis. Mango Extracts (20, 50 and 100 microg/ml) were more effective than gallic acid (100 microM) in protecting hepatocytes against CHP induced lipid peroxidation. On the other hand gallic acid (100 microM) acted more effective than Mango Extracts (20, 50 and 100 microg/ml) at preventing lysosomal membrane damage. In addition H(2)O(2) scavenging effect of all extracts were determined in hepatocytes and compared with gallic acid (100 microM). There were no significance differences (P<0.05) between all plant extracts and gallic acid (100 microM) in H(2)O(2) scavenging activity. These results suggest a hepatoprotective role for Mango Extract against liver injury associated with oxidative stress.

A search for hepatoprotective activity of aqueous extract of Rhus coriaria L. against oxidative stress cytotoxicity

The protective effects of different concentrations of aqueous extract of Rhus coriaria L. fruit (75 and 100μg/ml) and also gallic acid (100μM) as one of its main components were examined against oxidative stress toxicity induced by cumene hydroperoxide (CHP) in isolated rat hepatocytes. Both extract concentrations and gallic acid (100μM) significantly (P<0.05) protected the hepatocyte against all oxidative stress markers including cell lysis, ROS generation, lipid peroxidation, glutathione depletion, mitochondrial membrane potential decrease, lysosomal membrane oxidative damage and cellular proteolysis. Aqueous extracts of Rhus coriaria L. (75 and 100μg/ml) were more effective than gallic acid (100μM) in protecting hepatocytes against CHP induced lipid peroxidation (P<0.05). On the other hand gallic acid (100μM) acted more effective than aqueous extracts of Rhus coriaria L. (75 and 100μg/ml) at preventing hepatocyte membrane lysis (P<0.05). In addition H2O2 scavenging effect of both extract concentrations (75 and 100μg/ml) were determined in hepatocytes and compared with gallic acid (100μM). Gallic acid (100μM) was more effective than aqueous extracts of Rhus coriaria L. (75 and 100μg/ml) at H2O2 scavenging activity (P<0.05).

Bitter Melon Protects Against Lipid Peroxidation Caused by Immobilization Stress in Albino Rats

In the present study, protective effects of bitter melon (Momordica charantia) extract on lipid peroxidation induced by immobilization stress in rats have been assessed. Graded doses of extract (50, 100, and 150 mg/kg body weight) were administered orally to rats subjected to immobilization stress for two hours for seven consecutive days. Stress was applied by keeping the rats in a cage where no movement was possible. After seven days, rats were killed by decapitation after ether anesthesia. Blood and liver were collected to measure thiobarbituric acid reactive substances, reduced glutathione, and catalase. In vitro effects of M. charantia extract on lipid peroxidation in liver homogenate of normal, control, and rats pretreated with extract were carried out against cumene hydroperoxide-induced lipid peroxidation. Results reveal that in vivo M. charantia inhibited stress-induced lipid peroxidation by increasing the levels of reduced glutathione and activities of catalase. These results were further supported by in vitro results. In vitro inhibition of lipid peroxidation was indicated by low levels of thiobarbituric acid in the liver homogenate from pretreated rats and normal rats when incubated with both cumene hydroperoxide and extract. Inhibition was also noted in the homogenate where the rats were pretreated but the mixture contained no extract. Thus this plant provides protection by strengthening the antioxidants like reduced glutathione and catalase. Inclusion of this plant in the daily diet would be beneficial.

Inhibitory Response of Raphanus sativus on Lipid Peroxidation in Albino Rats

In the present study, inhibitory effect of the methanol extract of Raphanus sativus root on lipid peroxidation has been carried out in normal rats. Graded doses of methanol extract of root of the plant (40, 80 and 120 mg kg−1 body weight) were administered orally for 15 days to experimental treated rats. Distilled water was administered to experimental control rats. At the end of experiment, rats were killed by decapitation after ether anesthesia. Blood and liver were collected to measure thiobarbituric acid reactive substance, reduced glutathione and activity of catalase. Results indicated that the extract of R. sativus root reduced the levels of thiobarbituric acid reactive substance significantly in all experimental treated groups (P < 0.05) as compared to the experimental control group. It also increased the levels of reduced glutathione and increased the activity of catalase. In vitro experiments with the liver of experimental control and experimental treated rats were also carried out against cumene hydroperoxide induced lipid peroxidation. The extract inhibited in vitro cumene hydroperoxide induced lipid peroxidation. R. sativus inhibits lipid peroxidation in vivo and in vitro. It provides protection by strengthening the antioxidants like glutathione and catalase. Inclusion of this plant in every day diet would be beneficial.

Inhibition of Lipid Peroxidation by S -nitrosoglutathione and Copper

The antioxidant properties of S -nitrosoglutathione, a nitric oxide-derived product were studied in different experimental systems. By using the crocin bleaching test, S -nitrosoglutathione, in the presence of copper ions, shows an antioxidant capacity about six times higher than that of Trolox c and referable to the interception of peroxyl radicals by nitric oxide. Copper alone shows a modest inhibitory action, which is about seven times lower than that of Trolox c. S -nitrosoglutathione prevents lipid peroxidation induced by the well-known Fe 2+ /ascorbate system (IC 50 =450 w M) and the inhibitory effect is strongly reinforced by the presence of copper ions (IC 50 =6.5 w M). In addition, cumene hydroperoxide-induced lipid peroxidation is markedly decreased by S -nitrosoglutathione, provided that copper ions, maintained reduced by ascorbate, are present. Decomposition of S -nitrosoglutathione through metal catalysis and/or the presence of reducing agents and the consequent release of nitric oxide are of crucial importance for eliciting the antioxidant power. In this way, copper ions and/or reducing species with low antioxidant potency are able to promote the formation of an extremely strong antioxidant species such as nitric oxide.

The reduction of alpha-tocopherolquinone by human NAD(P)H: quinone oxidoreductase: the role of alpha-tocopherolhydroquinone as a cellular antioxidant.

alpha-Tocopherolquinone (TQ), a product of alpha-tocopherol oxidation, can function as an antioxidant after reduction to alpha-tocopherolhydroquinone (TQH2). We examined the ability of human NAD(P)H:quinone oxidoreductase (NQO1) to catalyze the reduction of TQ to TQH2 in cell-free and cellular systems. In reactions with purified human NQO1, TQ was reduced to TQH2. Kinetic parameters for the reduction of TQ by NQO1 (Km = 370 microM; k(cat) = 5.6 x 10(3) min(-1); k(cat)/Km = 15 min(-1) x microM(-1)) indicate that NQO1 can efficiently reduce TQ to TQH2. A comparison of the rate of reduction of TQ and coenzyme Q10 by NQO1 showed that TQ is reduced more efficiently than coenzyme Q10. Experiments with either Chinese hamster ovary (CHO) cells stably transfected with human NQO1 or CHO cell sonicates demonstrated a correlation between NQO1 activity and TQ reduction to TQH2. CHO cells with elevated NQO1 generated and maintained higher levels of TQH2 after treatment with TQ relative to NQO1-deficient CHO cells. TQH2 generated from NQO1-mediated reduction of TQ prevented cumene hydroperoxide-induced lipid peroxidation in rat liver microsomes. In addition, cumene hydroperoxide-induced lipid peroxidation was inhibited more efficiently by TQ in CHO cell lines with elevated NQO1 activity. These data demonstrate that NQO1 can reduce TQ to TQH2 and that TQH2 can function as an efficient antioxidant. This work suggests that one of the physiological functions of NQO1 may be to regenerate antioxidant forms of alpha-tocopherol.

Effects of glucose, Trolox-C, and glutathione disulphide on lipid peroxidation and cell death induced by oxidant stress in rat heart.

The aim was to find effective protection of myocytes against peroxide induced damage in terms of preservation of contractile activity, protection against lipid peroxidation, and protection against cell death. The components of the glutathione redox cycle, the production of malondialdehyde, cell contractions, and enzyme release from myocytes were measured in cultured neonatal rat heart cells before and after administration of cumene hydroperoxide, 80 mumol.litre-1. The protective action was tested of (1) glucose (10 mmol.litre-1) which stimulates the production of NADPH; (2) Trolox-C (0.16 mmol.litre-1) which is a water soluble analogue of alpha tocopherol and a scavenger of free radicals; and (3) GSSG (0.6 mmol.litre-1) which increases the intracellular concentrations of GSH and GSSG. Although the three substances tested were equally effective in reducing the formation of malondialdehyde, exogenous GSSG afforded only slight protection against cumene hydroperoxide induced cell death, whereas glucose and Trolox-C were highly effective protectors. The depressant effect of cumene hydroperoxide on beating frequency was not influenced by preincubation with GSSG, nor by coadministration of glucose, but Trolox-C was able to diminish the negative chronotropic action of cumene hydroperoxide. Effective protection against cumene hydroperoxide induced lipid peroxidation is not associated per se with effective protection against cumene hydroperoxide induced loss of beating frequency and cell death.

Studies on cumene hydroperoxide-induced lipid peroxidation in the isolated perfused rat heart

In the isolated, perfused rat heart, lipid peroxidation, induced by cumene hydroperoxide (Cum OOH), is accompanied by the release of malondialdehyde (MDA). Using a modified perfusion technique resulting in the separate collection of coronary and interstitial effluent, it can be shown that upon Cum OOH (0.5 mM) perfusion there is an immediate release of MDA in the coronary effluent and a delayed release in the interstitial fluid, indicating the susceptibility and coronary vascular tissue towards free radical-induced lipid peroxidation. Perfusion with Cum OOH leads to an initial increase of the coronary flow and a depressed contractility followed by a cardiac arrest concomitantly with the onset of MDA release in the interstitial fluid. Finally, during prolonged perfusion the coronary flow diminishes and contracture of the heart muscle ('stone heart') develops. These phenomena resemble those occurring during the 'calcium paradox'. Although the contractility diminishes immediately after the perfusion with Cum OOH the tissue ATP level and energy charge (formula; see text) remain constant. From the moment of cardiac arrest the ATP and creatine phosphate levels gradually decrease and the energy charge drops simultaneously with the appearance of MDA in the interstitial fluid. In contrast to the calcium paradox there is no simultaneous increase in the myocardial AMP level. Various mitochondrial enzymes (cytochrome c oxidase, monoamine oxidase, carnitinepalmitoyltransferase I and palmitoyl CoA synthetase) were tested and not affected by Cum OOH perfusion. During the development of contracture after 20 min of Cum OOH perfusion massive contraction band necrosis of cardiac tissue occurs. However, overall protein release is lower when compared with the protein release during the calcium paradox.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of cumene hydroperoxide- and NADPH/Fe 3+/ADP-induced lipid peroxidation in heart and liver submitochondrial particles : Mechanisms of protection by succinate

The NADPH/Fe 3+/ADP system stimulates lipid peroxidation both in rat liver and bovine heart submitochondrial particles, while cumene hydroperoxide is active only in rat liver submitochondrial particles. The lack of a peroxidizing effect of cumene hydroperoxide in heart submitochondrial particles was related to the absence of cytochrome P-450. When ubiquinones are extracted from rat liver and bovine heart submitochondrial particles, succinate can still partially protect the cumene hydroperoxide-induced lipid peroxidation but not the peroxidation induced by NADPH/Fe 3+/ADP. The protective effect of succinate in lipid peroxidation was referred either to the reduction of ubiquinones that can act as antioxidants in the NADPH/Fe 3+/ADP system, or to the reduction of cytochrome P-450 that acts as a peroxidase in the cumene hydroperoxide system.

The effect of diethyldithiocarbamate on the lipid peroxidation of rat-liver microsomes and intact hepatocytes

The role of the oxygen radicals in lipid peroxidation, induced by ADP/Fe 3+ or cumene hydroperoxide was investigated by administering diethyldithiocarbamate, an inhibitor of Superoxide dismutase, to hepatocytes or rats. Intact rat-liver hepatocytes perform a delayed ADP/Fe 3+-induced lipid peroxidation after pretreatment with diethyldithiocarbamate. The cumene hydroperoxide-induced lipid peroxidation is unchanged. Hepatocytes, isolated from a rat administered with diethyldithiocarbamate in vivo, exhibit the same pattern, a delayed iron-induced lipid peroxidation and an unchanged cumene hydroperoxide-induced lipid peroxidation. Liver microsomes isolated from liver of a rat administered with diethyldithiocarbamate do not perform lipid peroxidation with NADPH/ADP/Fe 3+, but do undergo lipid peroxidation with cumene hydroperoxide. It can be concluded that besides the inhibition of Superoxide dimutase, diethyldithiocarbamate inhibits directly the microsomal lipid peroxidation. Although this inhibition hampers the conclusion, evidence is obtained that Superoxide dismutase is probably involved in the protection against lipid peroxidation of the mitochondria, but not of the microsomes.

Cumene hydroperoxide-induced lipid peroxidation in the isolated rat heart: A process leading to calcium paradox-like phenomena: J.F. Koster, R.G. Slee and [formula omitted]. Department of Biochemistry I, Medical Faculty, Erasmus University Rotterdam, The Netherlands

Cumene hydroperoxide-induced lipid peroxidation in the isolated rat heart: A process leading to calcium paradox-like phenomena: J.F. Koster, R.G. Slee and [formula omitted]. Department of Biochemistry I, Medical Faculty, Erasmus University Rotterdam, The Netherlands