scholarly journals Impact of Quercetin Encapsulation with Added Phytosterols on Bilayer Membrane and Photothermal-Alteration of Novel Mixed Soy Lecithin-Based Liposome

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2432
Author(s):  
Sahar Pakbaten Toopkanloo ◽  
Tai Boon Tan ◽  
Faridah Abas ◽  
Fahad A. Alharthi ◽  
Imededdine Arbi Nehdi ◽  
...  
Keyword(s):  
Disease Management ◽  
Encapsulation Efficiency ◽  
Uv Light ◽  
Synergistic Effects ◽  
Bilayer Membrane ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Phospholipid Vesicles ◽  
Combined Effects ◽  
Soy Lecithin ◽  
Trolox Equivalent

This study used highly lipophilic agents with an aim to increase the oxidant inhibitory activity and enhance photothermal stability of a novel mixed soy lecithin (ML)-based liposome by changing the composition of formulation within the membrane. Specifically, the development and optimization of the liposome intended for improving Trolox equivalent antioxidant capacity (TEAC) value and %TEAC loss was carried out by incorporating a natural antioxidant, quercetin (QU). In this context, a focus was set on QU encapsulation in ML-based liposomes and the concentration-dependent solubility of QU was investigated and calculated as encapsulation efficiency (EE). To explore the combined effects of the incorporation of plant sterols on the integrity and entrapment capacity of mixed phospholipid vesicles, conjugation of two types of phytosterols (PSs), namely β-sitosterol (βS) and stigmasterol (ST), to mixed membranes at different ratios was also performed. The EE measurement revealed that QU could be efficiently encapsulated in the stable ML-based liposome using 0.15 and 0.1 g/100 mL of βS and ST, respectively. The aforementioned liposome complex exhibited a considerable TEAC (197.23%) and enhanced TEAC loss (30.81%) when exposed to ultraviolet (UV) light (280–320 nm) over a 6 h duration. It appeared that the presence and type of PSs affect the membrane-integration characteristics as well as photodamage transformation of the ML-based liposome. The association of QU with either βS or ST in the formulation was justified by their synergistic effects on the enhancement of the EE of liposomes. Parallel to this, it was demonstrated that synergistic PS effects could be in effect in the maintenance of membrane order of the ML-based liposome. The findings presented in this study provided useful information for the development and production of stable QU-loaded ML-based liposomes for food and nutraceutical applications and could serve as a potential mixed lipids-based delivery system in the disease management using antioxidant therapy.

scholarly journals Improving Vesicular Integrity and Antioxidant Activity of Novel Mixed Soy Lecithin-Based Liposomes Containing Squalene and Their Stability against UV Light

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5873
Author(s):  
Sahar Pakbaten Toopkanloo ◽  
Tai Boon Tan ◽  
Faridah Abas ◽  
Mohammad Azam ◽  
Imededdine Arbi Nehdi ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Particle Size ◽  
Lipid Bilayers ◽  
Uv Light ◽  
Acyl Chain ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Membrane Composition ◽  
Soy Lecithin ◽  
Optimization Study ◽  
Trolox Equivalent

In order to improve the membrane lipophilicity and the affinity towards the environment of lipid bilayers, squalene (SQ) could be conjugated to phospholipids in the formation of liposomes. The effect of membrane composition and concentrations on the degradation of liposomes prepared via the extrusion method was investigated. Liposomes were prepared using a mixture of SQ, cholesterol (CH) and Tween80 (TW80). Based on the optimal conditions, liposome batches were prepared in the absence and presence of SQ. Their physicochemical and stability behavior were evaluated as a function of liposome constituent. From the optimization study, the liposomal formulation containing 5% (w/w) mixed soy lecithin (ML), 0.5% (w/w) SQ, 0.3% (w/w) CH and 0.75% (w/w) TW80 had optimal physicochemical properties and displayed a unilamellar structure. Liposome prepared using the optimal formulation had a low particle size (158.31 ± 2.96 nm) and acceptable %increase in the particle size (15.09% ± 3.76%) and %trolox equivalent antioxidant capacity (%TEAC) loss (35.69% ± 0.72%) against UV light treatment (280–320 nm) for 6 h. The interesting outcome of this research was the association of naturally occurring substance SQ for size reduction without the extra input of energy or mechanical procedures, and improvement of vesicle stability and antioxidant activity of ML-based liposome. This study also demonstrated that the presence of SQ in the membrane might increase the acyl chain dynamics and decrease the viscosity of the dispersion, thereby limiting long-term stability of the liposome.

Mechanistic Studies of Atomic Oxygen Reactions with Polymers and Combined Effects with Vacuum Ultraviolet Light

MRS Bulletin ◽  
2010 ◽  
Vol 35 (1) ◽  
pp. 35-40 ◽  
Author(s):  
Masahito Tagawa ◽  
Timothy K. Minton
Keyword(s):  
Atomic Oxygen ◽  
Vacuum Ultraviolet ◽  
Uv Light ◽  
Synergistic Effects ◽  
Low Earth Orbit ◽  
Point Of View ◽  
Experimental Results ◽  
Space Environment ◽  
Combined Effects ◽  
The Individual

AbstractThis article focuses on mechanistic aspects of hyperthermal atomic oxygen reactions with polymers, which are the major contributor to material degradation in low Earth orbit. Due to the importance of well-controlled experiments in the understanding of the reaction mechanisms, ground-based experimental results obtained by a hyperthermal atomic oxygen beam generated by laser detonation facilities are mainly surveyed. Combined effects of atomic oxygen and vacuum ultraviolet (VUV) light on fluorinated polymers are also described. Such combined effects of hyperthermal atomic oxygen and VUV light are important not only from a fundamental point of view but also for engineering purposes (i.e., methodology for ground-based space environmental simulation). The VUV-sensitive polymers, poly(methyl methacrylate), and Teflon fluorinated ethylene-propylene do not show significant synergistic effects. Instead, the effect of combining atomic oxygen and VUV light produces erosion of the polymer that is the sum of the erosion caused by atomic oxygen and UV light acting individually. The experimental results suggest that material erosion in a complicated space environment may be quantitatively predicted if the erosion yields caused by the individual action of atomic oxygen and VUV light are known.

scholarly journals Study on the Synthesis, Antioxidant Properties, and Self-Assembly of Carotenoid–Flavonoid Conjugates

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 636
Author(s):  
Ildikó Línzembold ◽  
Dalma Czett ◽  
Katalin Böddi ◽  
Tibor Kurtán ◽  
Sándor Balázs Király ◽  
...  
Keyword(s):  
Antioxidant Capacity ◽  
Self Assembly ◽  
Uv Light ◽  
Antioxidant Properties ◽  
Hydroxyl Group ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Solvent Ratio ◽  
Protective Effects ◽  
Synergistic Enhancement ◽  
Trolox Equivalent

Flavonoids and carotenoids possess beneficial physiological effects, such as high antioxidant capacity, anticarcinogenic, immunomodulatory, and anti-inflammatory properties, as well as protective effects against UV light. The covalent coupling of hydrophobic carotenoids with hydrophilic flavonoids, such as daidzein and chrysin, was achieved, resulting in new amphipathic structures. 7-Azidohexyl ethers of daidzein and chrysin were prepared in five steps, and their azide-alkyne [4 + 2] cycloaddition with pentynoates of 8′-apo-β-carotenol, zeaxanthin, and capsanthin afforded carotenoid–flavonoid conjugates. The trolox-equivalent antioxidant capacity against ABTS•+ radical cation and self-assembly of the final products were examined. The 1:1 flavonoid–carotenoid hybrids generally showed higher antioxidant activity than their parent flavonoids but lower than that of the corresponding carotenoids. The diflavonoid hybrids of zeaxanthin and capsanthin, however, were found to exhibit a synergistic enhancement in antioxidant capacities. ECD (electronic circular dichroism) and UV-vis analysis of zeaxanthin–flavonoid conjugates revealed that they form different optically active J-aggregates in acetone/water and tetrahydrofuran/water mixtures depending on the solvent ratio and type of the applied aprotic polar solvent, while the capsanthin derivatives showed no self-assembly. The zeaxanthin bis-triazole conjugates with daidzein and with chrysin, differing only in the position of a phenolic hydroxyl group, showed significantly different aggregation profile upon the addition of water.

scholarly journals Self-Crosslinked Ellipsoidal Poly(Tannic Acid) Particles for Bio-Medical Applications

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2429
Author(s):  
Nurettin Sahiner
Keyword(s):  
Tannic Acid ◽  
Hydrolytic Degradation ◽  
Single Step ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Total Phenol Content ◽  
Frap Assay ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Trolox Equivalent ◽  
Free Media

Self-crosslinking of Tannic acid (TA) was accomplished to obtain poly(tannic acid) (p(TA)) particles in single step, surfactant free media using sodium periodate (NaIO4) as an oxidizing agent. Almost monodisperse p(TA) particles with 981 ± 76 nm sizes and −22 ± 4 mV zeta potential value with ellipsoidal shape was obtained. Only slight degradation of p(TA) particles with 6.8 ± 0.2% was observed at pH 7.4 in PBS up to 15 days because of the irreversible covalent formation between TA units, suggesting that hydrolytic degradation is independent from the used amounts of oxidation agents. p(TA) particles were found to be non-hemolytic up to 0.5 mg/mL concentration and found not to affect blood clotting mechanism up to 2 mg/mL concentration. Antioxidant activity of p(TA) particles was investigated by total phenol content (TPC), ferric reducing antioxidant potential (FRAP), trolox equivalent antioxidant capacity (TEAC), total flavanoid content (TFC), and Fe (II) chelating activity. p(TA) particles showed strong antioxidant capability in comparison to TA molecules, except FRAP assay. The antibacterial activity of p(TA) particles was investigated by micro-dilution technique on E. coli as Gram‑negative and S. aureus as Gram-positive bacteria and found that p(TA) particles are more effective on S. aureus with over 50% inhibition at 20 mg/mL concentration attained.

scholarly journals Bacterial cellulose films with ZnO nanoparticles and propolis extracts: Synergistic antimicrobial effect

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Alexandra Mocanu ◽  
Gabriela Isopencu ◽  
Cristina Busuioc ◽  
Oana-Maria Popa ◽  
Paul Dietrich ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Bacterial Cellulose ◽  
Food Packaging ◽  
Antimicrobial Effect ◽  
Gas Chromatography Mass Spectrometry ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Zno Nps ◽  
X Ray ◽  
Cellulose Films ◽  
Trolox Equivalent

AbstractThis study aimed to obtain possible materials for future antimicrobial food packaging applications based on biodegradable bacterial cellulose (BC). BC is a fermentation product obtained by Gluconacetobacter xylinum using food or agricultural wastes as substrate. In this work we investigated the synergistic effect of zinc oxide nanoparticles (ZnO NPs) and propolis extracts deposited on BC. ZnO NPs were generated in the presence of ultrasounds directly on the surface of BC films. The BC-ZnO composites were further impregnated with ethanolic propolis extracts (EEP) with different concentrations.The composition of raw propolis and EEP were previously determined by gas-chromatography mass-spectrometry (GC-MS), while the antioxidant activity was evaluated by TEAC (Trolox equivalent antioxidant capacity). The analysis methods performed on BC-ZnO composites such as scanning electron microscopy (SEM), thermo-gravimetrically analysis (TGA), and energy-dispersive X-ray spectroscopy (EDX) proved that ZnO NPs were formed and embedded in the whole structure of BC films. The BC-ZnO-propolis films were characterized by SEM and X-ray photon spectroscopy (XPS) in order to investigate the surface modifications. The antimicrobial synergistic effect of the BC-ZnO-propolis films were evaluated against Escherichia coli, Bacillus subtilis, and Candida albicans. The experimental results revealed that BC-ZnO had no influence on Gram-negative and eukaryotic cells.

scholarly journals Phenolic Profiles and Antioxidant Activities of 30 Tea Infusions from Green, Black, Oolong, White, Yellow and Dark Teas

Antioxidants ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 215 ◽  
Author(s):  
Cai-Ning Zhao ◽  
Guo-Yi Tang ◽  
Shi-Yu Cao ◽  
Xiao-Yu Xu ◽  
Ren-You Gan ◽  
...  
Keyword(s):  
Antioxidant Activities ◽  
Dry Weight ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Total Phenolic ◽  
Antioxidant Power ◽  
Phenolic Contents ◽  
Tea Infusions ◽  
Phenolic Profiles ◽  
Trolox Equivalent ◽  
Ferric Reducing Antioxidant Power

Tea is among the most consumed drink worldwide, and its strong antioxidant activity is considered as the main contributor to several health benefits, such as cardiovascular protection and anticancer effect. In this study, the antioxidant activities of 30 tea infusions, which were obtained by the mimic of drinking tea of the public, from green, black, oolong, white, yellow and dark teas, were evaluated using ferric-reducing antioxidant power (FRAP) and Trolox equivalent antioxidant capacity (TEAC) assays, ranging from 504.80 ± 17.44 to 4647.47 ± 57.87 µmol Fe2+/g dry weight (DW) and 166.29 ± 24.48 to 2532.41 ± 50.18 µmol Trolox/g DW, respectively. Moreover, their total phenolic contents (TPC) were detected by Folin-Ciocalteu assay and were in the range of 24.77 ± 2.02 to 252.65 ± 4.74 mg gallic acid equivalent (GAE)/g DW. Generally, Dianqing Tea, Lushan Yunwu Tea, and Xihu Longjing Tea showed the strongest antioxidant activities among 30 teas. Furthermore, the phenolic compounds in tea infusions were identified and quantified, with catechins most commonly detected, especially in green tea infusions, which were main contributors to their antioxidant activities. Besides tea polyphenols, considerable content of caffeine also presented in 30 tea infusions.

The effect of the trolox equivalent antioxidant capacity (TEAC) in plasma on the formation of 4-aminobiphenylhaemoglobin adducts in smokers

Biomarkers ◽  
2002 ◽  
Vol 7 (4) ◽  
pp. 291-298 ◽  
Author(s):  
Jan W. Dallinga ◽  
Guido R. M. M. Haenen ◽  
Aalt Bast ◽  
Frederik-Jan Van Schooten
Keyword(s):  
Antioxidant Capacity ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Trolox Equivalent

scholarly journals Melatonin deprival modifies follicular and corpus luteal growth dynamics in a sheep model

Reproduction ◽  
2014 ◽  
Vol 147 (6) ◽  
pp. 885-895 ◽  
Author(s):  
Maria Elena Manca ◽  
Maria Lucia Manunta ◽  
Antonio Spezzigu ◽  
Laura Torres-Rovira ◽  
Antonio Gonzalez-Bulnes ◽  
...  
Keyword(s):  
Antioxidant Properties ◽  
Growth Dynamics ◽  
Oestrous Cycle ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Corpora Lutea ◽  
Sheep Model ◽  
Ovarian Status ◽  
Trolox Equivalent ◽  
And Function ◽  
Breeding Seasons

This study assessed the effect of melatonin deprival on ovarian status and function in sheep. Experimental procedures were carried out within two consecutive breeding seasons. Animals were divided into two groups: pinealectomised (n=6) and sham-operated (n=6). The completeness of the pineal gland removal was confirmed by the plasma concentration of melatonin. Ovarian status was monitored by ovarian ultrasonography for 1 year to study reproductive seasonality. Follicular and corpus luteal growth dynamics were assessed during an induced oestrous cycle. As the effects of melatonin on the ovary may also be mediated by its antioxidant properties, plasma Trolox equivalent antioxidant capacity (TEAC) was determined monthly for 1 year. Pinealectomy significantly extended the breeding season (310±24.7 vs 217.5±24.7 days in controls;P<0.05). Both pinealectomised and sham-operated ewes showed a well-defined wave-like pattern of follicle dynamics; however, melatonin deficiency caused fewer waves during the oestrous cycle (4.3±0.2 vs 5.2±0.2;P<0.05), because waves were 1 day longer when compared with the controls (7.2±0.3 vs 6.1±0.3;P<0.05). The mean area of the corpora lutea (105.4±5.9 vs 65.4±5.9 mm2;P<0.05) and plasma progesterone levels (7.1±0.7 vs 4.9±0.6 ng/ml;P<0.05) were significantly higher in sham-operated ewes compared with pinealectomised ewes. In addition, TEAC values were significantly lower in pinealectomised ewes compared with control ones. These data suggest that melatonin, besides exerting its well-known role in the synchronisation of seasonal reproductive fluctuations, influences the growth pattern of the follicles and the steroidogenic capacity of the corpus luteum.Free Italian abstractAn Italian translation of this abstract is freely available athttp://www.reproduction-online.org/content/147/6/885/suppl/DC1.

scholarly journals Effect of the French Oak Wood Extract Robuvit on Markers of Oxidative Stress and Activity of Antioxidant Enzymes in Healthy Volunteers: A Pilot Study

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Martina Horvathova ◽  
Zuzana Orszaghova ◽  
Lucia Laubertova ◽  
Magdalena Vavakova ◽  
Peter Sabaka ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Antioxidant Enzymes ◽  
Antioxidant Capacity ◽  
Healthy Volunteers ◽  
Total Antioxidant Capacity ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Total Antioxidant ◽  
Trolox Equivalent ◽  
Markers Of Oxidative Stress

We examinedin vitroantioxidant capacity of polyphenolic extract obtained from the wood of oakQuercus robur(QR), Robuvit, using TEAC (Trolox equivalent antioxidant capacity) method and the effect of its intake on markers of oxidative stress, activity of antioxidant enzymes, and total antioxidant capacity in plasma of 20 healthy volunteers. Markers of oxidative damage to proteins, DNA, and lipids and activities of Cu/Zn-superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were determined in the erythrocytes. We have found anin vitroantioxidant capacity of Robuvit of 6.37 micromole Trolox equivalent/mg of Robuvit. One month intake of Robuvit in daily dose of 300 mg has significantly decreased the serum level of advanced oxidation protein products (AOPP) and lipid peroxides (LP). Significantly increased activities of SOD and CAT as well as total antioxidant capacity of plasma after one month intake of Robuvit have been shown. In conclusion, we have demonstrated for the first time that the intake of Robuvit is associated with decrease of markers of oxidative stress and increase of activity of antioxidant enzymes and total antioxidant capacity of plasmain vivo.

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