Lipid Peroxidation In Liposomes Research Articles

Arsenic, Mercury, Lead and Iron Induced Lipid Peroxidation in Phospholipids Liposomes and Protective Effect of Fumaric Acid

Arsenic, Mercury, Lead and Iron Induced Lipid Peroxidation in Phospholipids Liposomes and Protective Effect of Fumaric Acid

Mechanism of lipid peroxidation of liposomes by cold atmospheric pressure plasma jet irradiation

Mechanism of lipid peroxidation of liposomes by cold atmospheric pressure plasma jet irradiation

Physicochemical properties and composition of the liposome lipids from lecithin depending on conditions that lead to the formation of liposome lipids

The effects of the composition and physicochemical properties of lecithin lipids, ultrasound exposure and centrifugation time on the composition and physicochemical properties of liposomes formed from lecithin were studied. It was found that the intensity of lipid peroxidation of liposomes is interrelated by the reversal correlation with the phospholipids share in the total lipid composition of lecithin and the direct correlation with the relative content of cardiolipin in the lecithin phospholipid composition. It was shown that ultrasound exposure and centrifugation produce stage changes in the composition and properties of the liposome lipids. Decreases in the levels of medium pH and the intensity of lipid peroxidation of liposomes were observed under centrifugal conditions. It was found that the stage changes in the ability of liposome lipids for oxidation depending on the time of ultrasound exposure and centrifugation are due to the relative changes in the sum share of the acid minor fractions in the composition of their phospholipids.

FLASH irradiation does not induce lipid peroxidation in lipids micelles and liposomes

FLASH radiotherapy (FLASH-RT) enables the delivery of ultra-high dose rate (UHDR) radiation to a tumor, increasing the mean dose rate from 0.1 Gy· s−1of conventional radiotherapy (CONV-RT) to 100 Gy· s−1and above. Animal models have demonstrated that FLASH-RT preserves healthy tissues while yielding similar tumor growth delay as conventional irradiation. Despite the promise of FLASH-RT, the physico-chemical and biological mechanisms underlying the FLASH effect are still under investigation. Two mutually non-exclusive hypothesis have been proposed that could explain the FLASH effect: 1) a reduction in radical diffusion due to a higher recombination rate of primary radicals and, 2) a reduction in tissue oxygenation levels able to alter downstream responses to FLASH-RT. In this respect, lipid peroxidation is a chemical reaction consuming oxygen, which might be involved in the FLASH effect. Here we used linoleic acid micelles and phosphatidylcholine (PC) liposomes as a proxy for cell membrane to investigate the lipid peroxidation yield after irradiation with electrons in FLASH and CONV modalities. With this system, we measured significant differences in concentrations of lipid peroxidation endproducts between both modalities of irradiation. The lipid micelles and PC liposomes exhibited enhanced and linear dose-dependent levels of lipid peroxidation with CONV, while FLASH did not induce lipid peroxidation. Lowering the oxygen content from 21 to 4% resulted in a diminution of the lipid peroxidation yield in CONV, but not its complete suppression. The lipid peroxidation yield dropped rapidly when the dose per pulse was increased from 0.008 Gy·pulse−1to 10 Gy·pulse−1, with no lipid peroxidation occurring above 0.2 Gy·pulse−1. Our results are the first to identify the lack of lipid peroxidation after FLASH-RT, and point to lipids as potentially critical target in rationalizing possible mechanisms underlying the FLASH effect across multiple normal tissue sites.

Bird Cherry (Prunus padus) Fruit Extracts Inhibit Lipid Peroxidation in PC Liposomes: Spectroscopic, HPLC, and GC–MS Studies

The antioxidant potential of bird cherry fruit of water, methanol, ethanol, and acetone extracts and their antioxidant efficiency against oxidation of PC liposomes using spectroscopic and chromatographic methods were investigated. The chromatographic methods quantified and specified the presence of phenolic and flavonoid compounds in the investigated extracts. The characteristic peaks in the UV spectrum at 275 nm and 370 nm confirmed the presence of phenols and flavonoids and their derivatives. Their presence was also confirmed by FTIR spectra, which revealed the presence of its functional groups. The total luminescence spectra with maxima at 314–318 nm, 325–355 nm, and 428–435 nm were ascribed to the presence of phenolic acids and tocopherols. The antioxidant properties of extracts and its inhibition properties against lipid peroxidation in PC liposomes were determined by fluorogenic probes DCF-H and C11-BODIPY581/591. The measured antioxidant properties against generated free radicals in aqueous and lipogenic phases revealed differences between extracts depending on their physicochemical properties with the greatest potential for acetone extract and sirup. The presented quantitative analysis indicated that cherry bird extracts possess significant amounts of phenolics and flavonoids, thus having the opportunity to be used as a natural antioxidant agent source with a large potential for application in pharmaceutical and food industries.

Acylserotonins – a new class of plant lipids with antioxidant activity and potential pharmacological applications

During analysis of components of baobab (Adansonia digitata) seed oil, several new fluorescent compounds were detected in HPLC chromatograms that were not found previously in any seed oils investigated so far. After preparative isolation of these compounds, structural analysis by NMR spectroscopy, UHPLC-HR-MS, GC-FID and spectroscopic methods were applied and allowed identification of these substances as series of N-acylserotonins containing saturated C22 to C26 fatty acids with minor contribution of C27 to C30 homologues. The main component was N-lignocerylserotonin and the content of odd carbon-atom-number fatty acids was unusually high among the homologues. The suggested structure of the investigated compounds was additionally confirmed by their chemical synthesis. Synthetic N-acylserotonins showed pronounced inhibition of membrane lipid peroxidation of liposomes prepared from chloroplast lipids, especially when the peroxidation was initiated by a water-soluble azo-initiator, AIPH. Comparative studies of the reaction rate constants of the N-acylserotonins and tocopherols with a stable radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) in solvents of different polarity revealed that N-acylserotonins showed similar activity to δ-tocopherol in this respect. The described compounds have been not reported before either in plants or in animals. This indicates that we have identified a new class of plant lipids with antioxidant properties that could have promising pharmacological activities.

The Relationship between Lipid Peroxidation and Microviscosity in Phosphatidylcholine Liposomes. The Effects of a Plant Antioxidant and a Protein

Abstract—The influence of lipid peroxidation on the structure of biomembranes and liposomes has been studied for many years; however, there are still a number of unexplained issues that require additional study. In particular, there are contradictions in the assessment of the state of the structure of deep-lying membrane lipids during the development of lipid peroxidation. In this work, we carried out targeted studies of changes in the microviscosity of a lipid component by the EPR method using a spin probe (16-doxyl-stearic acid) in the process of initiated lipid peroxidation in liposomes obtained from phosphatidylcholine and phosphatidylcholine with a plant antioxidant additive and encapsulation in a protein shell at two temperatures, physiological (37°C) and elevated (60°C). It has been found that the development of lipid peroxidation in all experiments is accompanied by an increase in the microviscosity of deep-lying layers of lipids, which is directly proportional to the degree of development of the lipid peroxidation. This effect is mainly due to an increase in the relative content of saturated fatty acids in lipids of liposomes, although new structural forms of the oxidized lipids may also make some contribution to it. Using dynamic light scattering and atomic force microscopy it has been shown that lipid peroxidation causes an increase in the average diameter and volume of individual liposomes and an increase in the absolute value of their negative zeta potential. A plant antioxidant and a protein inhibit this process.

Peridinin Is an Exceptionally Potent and Membrane-Embedded Inhibitor of Bilayer Lipid Peroxidation.

Antilipoperoxidant protein dysfunction is associated with many human diseases, suggesting that bilayer lipid peroxidation may contribute broadly to pathogenesis. Small molecule inhibitors of this membrane-localized chemistry could in theory enable better understanding and/or treatment of such diseases, but currently available compounds have important limitations. Many biological questions thus remain unanswered, and clinical trials have largely been disappointing. Enabled by efficient, building block-based syntheses of three atypical carotenoid natural products produced by microorganisms that thrive in environments of extreme oxidative stress, we found that peridinin is a potent inhibitor of nonenzymatic bilayer lipid peroxidation in liposomes and in primary human endothelial cells. We also found that peridinin blocks monocyte-endothelial cell adhesion, a key step in atherogenesis. A series of frontier solid-state NMR experiments with a site-specifically 13C-labeled isotopolog synthesized using the same MIDA boronate building block-based total synthesis approach revealed that peridinin is completely embedded within and physically spans the hydrophobic core of POPC membranes, maximizing its effective molarity at the site of the targeted lipid peroxidation reactions. Alternatively, the widely used carotenoid astaxanthin is significantly less potent and was found to primarily localize extramembranously. Peridinin thus represents a promising and biophysically well-characterized starting point for the development of small molecule antilipoperoxidants that serve as more effective biological probes and/or therapeutics.

Astaxanthin Restrains Nitrative-Oxidative Peroxidation in Mitochondrial-Mimetic Liposomes: A Pre-Apoptosis Model.

Astaxanthin (ASTA) is a ketocarotenoid found in many marine organisms and that affords many benefits to human health. ASTA is particularly effective against radical-mediated lipid peroxidation, and recent findings hypothesize a “mitochondrial-targeted” action of ASTA in cells. Therefore, we examined the protective effects of ASTA against lipid peroxidation in zwitterionic phosphatidylcholine liposomes (PCLs) and anionic phosphatidylcholine: phosphatidylglycerol liposomes (PCPGLs), at different pHs (6.2 to 8.0), which were challenged by oxidizing/nitrating conditions that mimic the regular and preapoptotic redox environment of active mitochondria. Pre-apoptotic conditions were created by oxidized/nitr(osyl)ated cytochrome c and resulted in the highest levels of lipoperoxidation in both PCL and PCPGLs (pH 7.4). ASTA was less protective at acidic conditions, especially in anionic PCPGLs. Our data demonstrated the ability of ASTA to hamper oxidative and nitrative events that lead to cytochrome c-peroxidase apoptosis and lipid peroxidation, although its efficiency changes with pH and lipid composition of membranes.

Antioxidant, Anti-acetylcholinesterase, Anti-inflammatory and DNA Protection Activities of Glaucium grandiflorum var. grandiflorum.

In this study, antioxidant, antiacetylcholinesterase, anti-inflammatory, and DNA protecting activities of the aerial parts of Glaucium grandiflorum var. grandiflorum were evaluated. The lyophilized methanolic extract of the aerial parts of G. grandiflorum var. grandiflorum was investigated for potential in-vitro antioxidant properties in thiobarbituric acid test using the lipid peroxidation of liposomes, ferric ion reducing antioxidant power (FRAP), 1,1-diphenyl-2-picrylhydrazyl,2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonate) free-radicals and hypochlorous acid scavenging assays. The extract demonstrated antioxidant activity in all the assays. The (AChE) inhibition capacity of the lyophilized methanolic extract at 320 μg/mL (80.75 ± 1.59%) was found to be strong and almost equal to the inhibition capacity of the positive control, galantamine (82.23 ± 2.21%) at 25 μg/mL. The significant AChE inhibitory activity suggests that the extract may be beneficial in the treatment of Alzheimer's disease. The extract also showed inhibitory activity against plasmid DNA damage (94%), as well as COX-2 69.05%, which is a target for many anti-inflammatory and cancer-preventive drugs. These results indicate that G. grandiflorum var. grandiflorum methanolic extract is an excellent source of compounds with antioxidant, anti-acetylcholinesterase and anti-inflammatory properties that prevent DNA damage.

English

This study was designed to investigate the ability of ethanol fruit extract from Detarium microcarpum to protect erythrocytes against hemolysis and lipid peroxidation. To achieve this objective, hemolytic, anti-hemolytic and lipid peroxidation from cell membrane assays were used. Hemolytic and anti-hemolytic activities (regarding H2O2 induced hemolysis) were assessed by determination of free haemoglobin at 540 nm. Inhibition of lipid peroxidation was measured at 532 nm, using thiobarbituric acid reaction on sodium nitroprusside and ferric sulfate induced liposome peroxidation models. D. microcarpum fruit ethanol extract (100 µg/ml) did not exhibit any hemolytic effect but reduces significantly hemolysis from human and rat erythrocyte with inhibitory percentages more than 50 and 75%, respectively. Furthermore, the extract caused a significant decrease in both ferric sulfate and sodium nitroprusside inducing lipid peroxidation in each rat tissue liposomes investigated. D. microcarpum fruit ethanol extract protects erythrocytes against hemolysis and lipid peroxidation, probably due to its antioxidant potential. Therefore, animal tissues disorders caused by cell membrane lipid damage could be potentially managed/prevented by dietary intake of D. microcarpum fruit pulp. Key words: Detarium microcarpum, anti-hemolytic activity, inhibition of lipid peroxidation

Evaluation of chemical composition, antioxidant and anti-acetylcholinesterase activities of Hypericum neurocalycinum and Hypericum malatyanum

This study was conducted to evaluate the chemical composition, antioxidant and anti-acetylcholinesterase (anti-AChE) activities of methanolic extracts of H. neurocalycinum and H. malatyanum, two endemic species of the Turkish flora. HPLC-DAD analysis indicated that two naphthodianthrones (pseudohypericin and hypericin) together with chlorogenic acid, rutin, hyperoside, isoquercitrin, kaempferol, quercitrin, quercetin, amentoflavone and hyperforin are the main compounds present in the methanol extracts. The extracts were tested in vitro for their antioxidant activities including, inhibition of lipid peroxidation in liposomes, induced by Fe3+/ascorbate system, scavenging effect on DPPH and superoxide anion radicals, and ferric ion reducing antioxidant power (FRAP). H. neurocalycinum demonstrated stronger antioxidant properties than H. malatyanum due to higher activity on scavenging DPPH (EC50=2.49±0.09mg/mL) and superoxide anion radicals (EC50=0.613±0.05mg mg/mL), and inhibition of lipid peroxidation (EC50=2.49±0.09mg/mL). This difference in activity seems to be due to the presence of higher amounts of the antioxidant compounds (flavonoids) such as rutin, quercetin and kaempferol in H. neurocalycinum extract. The antioxidant activities of the extract may be attributed to their reducing capabilities. At 5mg/mL H. neurocalycinum (FRAP value=2.39±0.039mM Fe2+) and H. malatyanum (FRAP value=2.23±0.013mM Fe2+) showed high ability to reduce Fe3+ to Fe2+. The extracts were tested also for their in vitro AChE inhibitory activities. H. neurocalycinum inhibited 72.24±0.39% of AChE activity at a concentration of 5mg/mL. It was concluded that H. neurocalycinum is more effective AChE inhibitor and antioxidant than H. malatyanum.

Structural characterization of β-carotene-incorporated nanovesicles produced with non-purified phospholipids

The technical feasibility of obtaining β-carotene-incorporated phospholipid nanovesicles using non-purified soybean lecithins was studied. For this purpose, three lecithin-types were evaluated. Nanovesicles were characterized by average hydrodynamic diameter, particle size distribution, polydispersity index, ζ-potential, transmission electron microscopy, membrane microviscosity, small angle X-ray scattering and capacity of lipid peroxidation inhibition. In general, the β-carotene incorporation did not promote a significant increase on average hydrodynamic diameter, but vesicles produced from lecithins containing triglycerides showed lower polydispersity. The lecithin-type used to produce nanovesicles did not influence the β-carotene loading capacity, but significantly influenced the microviscosity of liposomal membrane and lipid peroxidation inhibition capacity. Non-enzymatically modified lecithin (containing or not triglycerides) showed similar efficiency and peroxidation inhibition capacity considering β-carotene incorporation. Therefore, low-cost non-purified lecithin can be employed for production of liposomal systems as an encapsulating and/or delivery system to be used in food products.

Protection by beta-Hydroxybutyric acid against insulin glycation, lipid peroxidation and microglial cell apoptosis.

BackgroundDiabetes mellitus is characterized jointly by hyperglycemia and hyperinsulinemia that make insulin more prone to be glycated and evolve insulin advanced glycation end products (Insulin- AGE). Here, we report the effect of beta-hydroxy butyrate (BHB) (the predominant ketone body) on the formation of insulin-AGE, insulin glycation derived liposomal lipid peroxidation and insulin-AGE toxicity in microglial cells.MethodsThe inhibitory effect of BHB was monitored as a result of insulin incubation in the presence of glucose or fructose using AGE-dependent fluorescence, Tyr fluorescence as well as anilinonaphthalenesulfonate (ANS) andthioflavin T (ThT) binding, and circular dichroism (CD) investigations. To study lipid peroxidation induced by insulin glycation, thiobarbituric acid (TBA) assay and thiobarbituric acid reactive substance (TBARS) monitoring were used. The effect of insulin–AGE on microglial viability was investigated by 3-(4, 5 dimethylthiazol-2-yl)—2, 5-diphenyltetrazoliumbromide (MTT) cell assay and Annexin V/propidium iodide (PI) staining.ResultsHere we are reporting the inhibitory effect of BHB on insulin glycation and generation of insulin-AGE as a possible explanation for insulin resistance. Moreover, the protective effect of BHB on consequential glycation derived liposomal lipid peroxidation as a causative event in microglial apoptosis is reported.ConclusionThe reduced insulin fibril formation, structural inertia to glycation involved conformational changes, anti-lipid peroxidation effect, and increasing microglia viability indicated the protective effect of BHB that disclose insight on the possible preventive effect of BHB on Alzheimer’s disease.

Insulin glycation coupled with liposomal lipid peroxidation and microglial cell death

Type 2 diabetes is characterized jointly by hyperglycemia and hyperinsulinemia, which make insulin prone to glycation then fibrillation.

Semiquinone glucoside derivative (SQGD) isolated from Bacillus sp. INM-1 protects against gamma radiation-induced oxidative stress

In the present study, radioprotective potential of Semiquinone glucoside derivative (SQGD) isolated from radioresistant bacterium Bacillus sp. INM-1 was evaluated. γ-Radiation induced protein carbonylation, plasmid DNA damage, enzyme functional impairment, lipid peroxidation, HO radicals generation and their protection by SQGD was assessed. As a result of SQGD treatment, significant inhibition (p<0.05) in protein carbonylation was observed with BSA. SQGD treatment was found to restore supercoiled (∼70±3.21%) form of irradiated plasmid DNA against γ-irradiation. SQGD protects enzymes (EcoR1 and BamH1) against radiation-induced dysfunctioning. SQGD significantly inhibited (p<0.05) lipid peroxidation in liposomes, brain and liver homogenate. Higher HO• radicals-averting activity of SQGD was observed in the serum and liver homogenate of C57BL/6 mice against H2O2-induced oxidative stress. In conclusion, SQGD demonstrates excellent radical-scavenging activity towards bio-macromolecules in irradiated environment and can be developed as an ideal radioprotector against radiation-induced oxidative stress in future.

Membrane lipid peroxidation by the peroxidase-like activity of magnetite nanoparticles.

We report that Fe3O4 nanoparticles are able to catalyse lipid peroxidation in liposomes at acidic but not neutral pH. The oxidation is dependent on either pre-existing lipid peroxides or hydrogen peroxide as a substrate. This is the first evidence for metal oxide nanoparticles as peroxidase mimetics oxidising biomolecules in a relevant environment.

Effects of Different Phases of Cigarette Smoke on Lipid Peroxidation and Membrane Structure in Liposomes

This paper discloses for the first time the effects of the gas phase (GP) and the tar of cigarette smoke on lipid peroxidation (LPO) and on the structure of different lipid regions in liposomes. The LPO development was analysed in terms of the total unsaturation of lipids (double-bond, DB, content) and the formation of dienic conjugates (DC), ketodienes (KD), and malonic dialdehyde (MDA). As expected, the exposure of liposomes to either the GP or the tar led to a significant decrease in the DB content. However, the formation of oxidation products revealed different dynamics: MDA generation was inhibited, while the formation of DC and KD increased during the first few hours of the LPO development followed by its inhibition. The smoke constituents exhibited opposite effects on the structure of the lipid bilayer of liposomes: the GP markedly enhanced the microviscosity of liposomal membranes, whereas the tar caused a drastic lowering of microviscosity.

The modified action of triphenyllead chloride on UVB-induced effects in albumin and lipids

Previously we have shown a toxic effect of the organometallic compound triphenyllead (TPhPb) on cells. In the present study we evaluated the destructive effect of TPhPb on model systems – serum albumin and liposome membranes – alone and under UVB irradiation. UVB irradiation of bovine serum albumin results in protein SS bond reduction, free SH and CO group formation and decrease in fluorescence intensity of tryptophans. Triphenyllead chloride alone and under UVB irradiation did not induce protein oxidation, measured as formation of carbonyl groups, in serum albumin; however, it decreased the content of SH groups in both cases (alone and under UVB radiation) in a dose-dependent manner. It was found that triphenyllead chloride alone did not induce lipid peroxidation of liposomes but increased their fluidity. However, under UVB irradiation TPhPb dramatically enhances the pro-oxidant action of UVB in a manner dependent on concentration and intensity of radiation, and these effects were suppressed by Trolox. These results suggest that the toxicity of TPhPb under UVB irradiation is due to formation of radical forms of the compound and its disordered effects on the membrane structure.

Secondary metabolites from two endemic Stachys cretica subspecies and their antioxidant properties

The genus Stachys is one of the largest genera of the Lamiaceae family including about 300 species growing wild in the tropical regions of both hemispheres and represented by more than 80 species in the Flora of Turkey. We aimed to elucidate the structure of major phenylethanoid glycosides and flavonoids present in two endemic subspecies namely Stachys cretica ssp. lesbiaca and S. cretica ssp. trapezuntica and evaluate their antioxidant activities through several biochemical assays including inhibition of lipid peroxidation in soybean phosphatidylcholine liposomes induced with Fe3+/ascorbate, scavenging effect on DPPH· and superoxide radicals, reducing power and ABTS radical cation decolorization. Succesive coloumn chromatography of the ethyl acetate subfraction of two subspecies led to isolation of acteoside, leucosceptoside A, martynoside as major phenylethanoid glycosides and isoscutellarein-7–0-[6'''-acetyl-allosyl(1→2)]glucopyranoside, 3'-hydroxy-4'-0-methylisoscu- tellarein-7–0-[6'''-acetylallosyl(1→2)]glucopyranoside and 4'-0-methylisoscutellarein-7–0-[6'''-acetyl-allosyl(1→2)]glucopyranoside as flavonoids. The antioxidant activities of the compounds were compared to that of quercetin as a typical example of a naturally occurring flavonol. All isolated metabolites showed moderate antioxidant activity. Among the tested compounds acteoside was found to be the most active.