Fe-induced Lipid Peroxidation Research Articles

Analytical Method Development and Validation for Butylated Hydroxy Toluene by using UV- Visible Spectrophotometric Method

Upon utilizing the Prediction Activity Spectra of Substances (PASS) program, computer-aided predictions were conducted to assess the antioxidant activities. Compounds 1, 3, 4, and 5 underwent evaluation using 1,1-diphenyl-2- picrylhydrazyl (DPPH) and lipid peroxidation assays to confirm the predictions obtained from the PASS program. Notably, compounds 3 and 5 exhibited higher inhibition of the DPPH stable free radical at 10 M compared to the widely recognized standard antioxidant, butylated hydroxytoluene (BHT). Of particular interest, compound 5 demonstrated significant in vitro inhibition of Fe-induced lipid peroxidation in the lipid-rich medium of essential egg yolk (83.99%, IC50 16.07 ± 3.51 μM/mL) in contrast to α-tocopherol (α-ΤΟΗ, 84.6%, IC50 5.6 ± 1.09 μM/mL). Furthermore, the drug-likeness of these BHT analogues was assessed based on Lipinski's "rule-of-five" (RO5), revealing a violation of one parameter (Log P > 5) despite their solubility in protic solvents. The predictive polar surface area (PSA) and absorption percentage (% ABS) data imply a potential capacity for cell membrane penetration. Consequently, these new multipotent antioxidants (MPAOs) hold promise as effective agents for addressing oxidative stress and lipid peroxidation processes.

Investigating the Modulatory Effect of Methanol Extract of Daniellia oliveri (ROLFE) Leaves on Mitochondrial Membrane Permeability Transition (MPT) Pore

Background: Mitochondrial-mediated cell death begins with opening of mitochondrial membrane permeability transition (mPT) pore and medicinal plants contain phytochemicals that modulate the mPT pore.
 Hypothesis and Purpose: We investigated the modulatory effects of crude methanol extract of Daniellia oliveri leaves (CMDO) on mPT pore in vitro.
 Study Design and Methods: Phytochemical screening and antioxidant activities of crude methanol extract of Daniellia oliveri leaves (CMDO) were evaluated according to standard procedures. CMDO was partitioned into chloroform fraction (CFDO), ethyl acetate fraction (EFDO) and methanol fraction (MFDO) by Vacuum liquid chromatography (VLC). Effects of CMDO, CFDO, EFDO and MFDO on mPT pore were assessed by spectrophotometry. Effects of the most potent fraction on mitochondrial ATPase, Fe-induced lipid peroxidation and cytochrome c release were assessed by spectrophotometry. CMDO was subjected to GC-MS analysis to identify the bioactive compounds present.
 Results: CMDO contains phytochemicals and showed appreciable total flavonoid content (0.483±0.02 QE mg/100g), total phenolic content (0.886±0.12 GAE mg/100g), total antioxidant capacity (0.039±0.001 AE mg/100 g), ferric antioxidant reducing power (IC50=350 µg/ml) and 2, 2-diphenyl-1 picrylhydrazyl (DPPH) radical scavenging activity (IC50=166 µg/ml). The maximum induction of mPT pore opening in the absence and presence of calcium, respectively, were as follows: CMDO (10.11 folds, 5.18 folds), CFDO (19.9 folds, 16.3 folds), EFDO (7.5 folds, 23.2 folds), MFDO (22.2 folds, 31.3 folds). The most potent mPT pore-opening fraction (MFDO) enhanced mitochondrial ATPase activity, inhibited Fe-induced lipid peroxidation and caused cytochrome c release. GC-MS analysis of CMDO revealed the presence of bioactive compounds including methyl propanamide, Dibutyl phthalate, saturated and unsaturated fatty acids.
 Conclusion: Methanol fraction (MFDO) of CMDO most potently induced mPT pore opening via enhancement of mitochondrial ATPase activity, which was substantiated by the release of cytochrome c (in vitro). This includes MFDO as a candidate pharmacologic remedy for diseases associated with insufficient apoptosis.

Relationship between antioxidant properties and GC-MS component composition of extracts from flowers, leaves and fruits of Crataegus Oxycanta

The aim of this study was to perform a comparative investigation of the antioxidant effect of Crataegus oxycanthas’ flowers, leaves, green and ripe fruits probes and to relate the obtained results with the ones of the accomplished qualitative GC-MS analysis of the antioxidant components participating in the studied standardized ethanol extracts. We established that the three extracts have well manifested antioxidant properties in three biological relevant model systems with different mechanism of generation of ROS: Fe-induced lipid peroxidation, UV induced deoxyribose damage and horse-radish peroxidase (HRP)-H2O2 chemiluminescent system. In the UV system the strongest effect is observed for the extract from flowers and leaves (C-50 = 0.109±0.009 mg/ml), followed by the ones from ripe fruits (C-50 = 0.259±0.015 mg/ml) and finally – by green fruits (C-50 = 0.557±0.014 mg/ml). In the Fe-induced lipid peroxidation system the antioxidant effect of the studied samples decreases in the following order: effect of flowers and leaves (C-50 = 0.287±0.018 mg/ml) > effect of green fruits (C-50 = 0.495±0.021 mg/ml) > effect of ripe fruits (C-50 = 0.704±0.035 mg/ml). Similar results were obtained in the HRP-H2O2 system. The generalized results show that the strongest antioxidant effect is observed for the plant extract from flowers and leaves of Crataegus. The GC-MS analyses we carried out indicate that the observed differences are due to the presence of a bigger number of constitutes possessing antioxidant properties in flowers and leaves extracts, compared with the fruits extracts.

Antioxidant and Antiradical Properties of Esculin, and its Effect in A Model of Epirubicin-Induced Bone Marrow Toxicity

To evaluate the effect of esculin, a plant coumarin glucoside, on free radicals and against epirubicin-induced toxicity on bone marrow cells. Antioxidant activity was assessed by a luminol-dependent chemiluminescence method or NBT test in a xanthine-xanthine oxidase system, and two iron-dependent lipid peroxidation systems. In vivo experiments were carried out in epirubicin-treated mice, alone or in a combination with esculin. Genotoxicity of the anthracycline drug was assessed by cytogenetic analysis and an autoradiographic assay. Esculin inactivated superoxide anion radicals in both systems we used. It exerted SOD-mimetic effect and reduced the level of superoxide radicals generated in a xanthine-xanthine oxidase system by 30%. Esculin also showed an antioxidant effect in a model of Fe2+-induced lipid peroxidation. Cytogenetic analysis showed that epirubicin had a marked influence on the structure of metaphase chromosomes of normal bone marrow cells. Inclusion of esculin in the treatment protocol failed to ameliorate the epirubicin-induced antiproliferative effects and genotoxicity in bone marrow cells. In this study the ability of the coumarin glucoside esculin to scavenge superoxide radicals and to decrease Fe-induced lipid peroxidation was documented. However, despite the registered antioxidant effects the tested compound failed to exert cytoprotection in models of anthracycline-induced genotoxicity in bone marrow cells. The results of this study warrant for more precise further evaluation of esculin, employing different test systems and end-points and a wider range of doses to more precisely appraise its potential role as a chemoprotective/resque agent.

Comparison of Antioxidant Properties of Water and Ethanol Extracts Obtained from Dried Boxthorn (<i>Lycium chinensis</i>) Fruit

Antioxidant activities of W and E extracts obtained from dried boxthorn (Lycium chinensis) fruit were measured based on DPPH radical scavenging and reducing powers, and their relationships with total phenolics, flavonoid content, and antioxidant activity were investigated. A linear correlation among antioxidant activity, total phenolics, and flavonoid content was observed in concentration-dependent mode. Both extracts showed > 95% DPPH radical-scavenging activity and the higher reducing power of 3200 ppm at the same concentration. The antioxidant potential of both extracts were compared with those of commercial antioxidants such as BHA, BHT, TBHQ, ferulic acid, and α-tocopherol using H2O2 scavenging activity, inhibition of linoleic acid peroxidation, inhibition of hemolysis of rat erythrocyte induced by peroxyl radicals, and inhibition of Fe2+-induced lipid peroxidation using rat brain tissue. In the H2O2 scavenging activity, E extract showed a comparable significant antioxidant power, comparable to commercial antioxidants, and no signifi-cant difference (P > 0.05) was found between W and E extracts on inhibition of the linoleic acid peroxidation. Whereas W extract exhibited a significant power in the hemolysis of rat erythrocytes, none was observed in E extract. In the Fe-induced lipid peroxidation using rat brain tissue, no significant difference (P > 0.05) was found between both ex-tracts, showing a comparable activity with those of synthetic antioxidants. Both W and E extracts of dried boxthorn (Lycium chinensis) fruit may have a potential as natural antioxidants to replace synthetic antioxidants.

Influence of broccoli extract and various essential oils on performance and expression of xenobiotic- and antioxidant enzymes in broiler chickens

The aim of our present study was to examine the regulation of xenobiotic- and antioxidant enzymes by phytogenic feed additives in the intestine and the liver of broilers. A total of 240 male Ross-308 broiler chickens (1 d old) were fed a commercial starter diet for 2 weeks. On day 15, the birds were assigned to six treatment groups of forty birds each. The control (Con) group was fed a diet without any additive for 3 weeks. The diet of group sulforaphane (SFN) contained broccoli extract providing 0.075 g/kg SFN, whereas the diets of the other four groups contained 0.15 g/kg essential oils from turmeric (Cuo), oregano (Oo), thyme and rosemary (Ro). Weight gain and feed conversion were slightly impaired by Cuo and Oo. In the jejunum SFN, Cuo and Ro increased the expression of xenobiotic enzymes (epoxide hydrolases 1 and 2 and aflatoxin B1 aldehyde reductase) and of the antioxidant enzyme haeme oxygenase regulated by an 'antioxidant response element' (ARE) compared to group Con. In contrast to our expectations in the liver, the expression of these enzymes was decreased by all the additives. Nevertheless, all the additives increased the Trolox equivalent antioxidant capacity of the jejunum and the liver and reduced Fe-induced lipid peroxidation in the liver. We conclude that the up-regulation of ARE genes in the small intestine reduces oxidative stress in the organism and represents a novel mechanism by which phytogenic feed additives improve the health of farm animals.

Oxidative damage in human epithelial alveolar cells exposed in vitro to oil fly ash transition metals

Among particulate matter emissions from combustion processes, oil fly ash (OFA) displays a marked oxidative and inflammogenic reactivity, due to the high content of bioavailable transition metals. In the present study, we evaluated the biological effects of an OFA water solution, composed of the transition metals Fe (57.5%), V (32.4%), and Ni (10.1%), in human epithelial alveolar cells (A549 line). The fluorimetric analysis by 2',7'-dichlorofluorescein showed a significant, dose- and time-dependent induction of intracellular reactive oxygen species (ROS) triggered by OFA metal components at subtoxic doses. The metal chelator deferoxamine and the radical scavenger dimethylsulfoxide attenuated the metal-induced generation of ROS. Confocal microscopy observations strengthened these findings and showed an intense cytoplasmic fluorescence with perinuclear thickenings in A549 cells, in the absence of morphological damage. Metal-induced generation of ROS was significantly correlated with a dose- and time-dependent DNA damage, as assessed by single cell gel electrophoresis (comet assay). Catalase was able to decrease dramatically DNA damage. Fluorimetric analyses by diphenyl-1-pyrenylphosphine showed a parallelism between generation of ROS and formation of lipid peroxides. The results obtained in the experiments evaluating the effects of individual metal solutions did not show any significant difference in DNA damage between Fe(III) and V(IV), but highlighted the higher capability of V(IV) to increase ROS in the cytoplasmic compartment. The different behavior of these two elements, confirmed by the weak Fe-induced lipid peroxidation, may be ascribed to the presence of Fe-binding proteins, such as ferritin, in the cytoplasm. Finally, Ni(II) had negligible effects on ROS production. On the whole, the results obtained in this study show the strong capability of transition metals adsorbed to OFA to cause widespread damage to biological macromolecules, and suggest potential health effects resulting from exposure to power plant emissions in industrialized sites.

Synthesis and evaluation of peptidic metal chelators for neuroprotection in neurodegenerative diseases

A series of novel derivatives of neuropeptides with a metal-chelating moiety was synthesized and examined for various properties related to iron (Fe) chelation and neuroprotective action. All derivatives chelated Fe to form stable Fe complexes in water. Some strongly inhibited Fe-induced lipid peroxidation with an IC(50) value of about 12 microm. In PC12 cell culture, several compounds, at concentrations as low as 1 microm, attenuated serum-free stimulated cell death and improved cell survival by 20-35%. At this concentration, these analogs also protected against 6-hydroxydopamine (6-OHDA)-induced cell death, increasing cell viability by 20-30%. Electron paramagnetic resonance (EPR) studies indicated that besides being good Fe chelators, these analogs act as radical scavengers to directly scavenge hydroxyl radicals. Together, the data indicate that some of the analogs could be further developed as possible neuroprotective agents for treatment of neurodegenerative diseases such as Parkinson's, Alzheimer's, and Huntington's diseases, Friedreich's atxia, amyotrophic, and lateral sclerosis where Fe misregulation has been reported.

Effect of iron overload on spontaneous and xenobiotic-induced lipid peroxidation in vivo.

To study the effect of iron-overload on hepatic lipid peroxidation, two rat models of haemochromatosis were employed: in the first model resembling secondary haemochromatosis, repeated i.p. injections with Fe-dextran led to an accumulation of Fe in Kupffer cells, while in the second model resembling hereditary haemochromatosis, iron was located mainly in periportal hepatocytes after feeding on a diet containing 3.5% Fe-fumarate for 3 weeks. In both models, total hepatic iron content was elevated four- to fivefold over controls. In vivo lipid peroxidation (ethane exhalation) was enhanced only in the second model, indicating that the hepatocytes are the main targets of Fe-induced lipid peroxidation. Low hepatotoxicity was observed in the second model. Additional treatment of the rats with hepatotoxic agents led to different results: with ethanol and bromobenzene, lipid peroxidation was only evident in both models of iron-overload, while paracetamol-induced lipid peroxidation was seen only in Fe-fumarate-fed rats. CCl4-induced lipid peroxidation was strongly enhanced in both models of haemochromatosis. Hepatotoxicity was enhanced by iron overload only in the case of CCl4-treated, Fe-fumarate-fed rats. The activities of phase I and phase II enzymes of xenobiotic metabolism were not markedly altered in livers of iron-overloaded rats. This implies that neither the bioactivation nor the detoxification of the agents studied were affected in experimental haemochromatosis.

Antioxidant Activity of 5-Hydroxytryptophan, 5-Hydroxyindole, and Dopa Against Microsomal Lipid Peroxidation and Its Dependence on Vitamin E

The antioxidant capacity of 5-hydroxy-tryptophan, 5-hydroxy-indole, and DOPA (3,4-dihydroxy-phenylalanine) was tested in the Fe-induced lipid peroxidation of liver microsomes of normal- and vitamin E-deficient rats, using ascorbate as a reductant. Lipid peroxidation was monitored as low-level chemiluminescence, indicative of generation of electronically-excited states arising from the recombination of secondary lipid peroxyl radicals. The lag phase (tau 0) preceding the rise in chemiluminescence intensity was used as indicator of antioxidant efficiency, in the absence (tau 0) and the presence (tau) of these polar compounds. The increase in duration of the lag phase exerted by these hydroxy compounds was expressed and quantified as the relationship: tau-tau 0. The tau-tau 0 values were considerably higher in the presence of vitamin E and almost negligible in the absence of tocopherol. It is postulated that the observed increased protection against lipid peroxidation by the above 5-hydroxy derivatives is displayed in a fashion dependent on the presence of vitamin E and probably involving recovery of the chromanoxyl radical by means of an electron-transfer process.