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1.
Several forms of periodontal diseases (PD) are often associated with modified phagocytosing leukocytes and contemporary free radical production. Host antioxidant defenses could benefit from toothpastes used as adjuncts to counteract plaque-associated bacteria. The aim of the present study was to determine possible antioxidant activity (AA) of 12 differently antioxidant-enriched toothpastes, regardless of their efficacy as antimicrobial agents. Toothpastes were enriched alternatively with sodium ascorbyl phosphate, α-tocopherol acetate, pycnogenol, allantoin and methyl salycilate or a mixture of these. AA was tested in a cell-free system with a ABTS-decolorization assay improved by means of a flow injection analysis device. Comet assay, using NCTC 2544 keratinocytes, was performed to test if it was possible to identify any protection against in vitro DNA fragmentation provoked by a challenge with H2O2 in cultures pre-incubated with toothpaste extracts.

Only toothpastes containing sodium ascorbyl phosphate displayed clear AA with I50 values ranging between 50 and 80?mg of toothpaste/ml water. COMET analysis of cells challenged with H2O2 in presence of toothpaste extracts revealed a limited protection exerted by sodium ascorbyl phosphate. The results described herein indicate that toothpastes containing sodium ascorbyl phosphate possess AA. All the data were obtained in systems in vitro and the demonstration of in vivo AA is desirable. These findings could be useful in the treatment and maintenance of some forms of PD and should be considered when arranging new toothpaste formulations.  相似文献   

2.
Gold nanoparticles (AuNPs) exhibit characteristic absorption peaks in the ultraviolet visible region due to their special surface plasmon resonance effect. This characteristic absorption peak would change with the relative colour varying from wine red to orange‐yellow upon sequential addition of ascorbic acid (AA) into the mixture of AuNPs and Ag(I). Similar observations also could be found when the hydrolysis product of sodium l ‐ascorbyl‐2‐phosphate with alkaline phosphatase (ALP) was used as an alternative to AA. Results of structure characterization confirmed that the phenomena were due to the reduction of Ag(I) to Ag(0) on the surface of AuNPs and the formation of core‐shell AuNPs@Ag. Therefore, a colorimetric assay for rapid visual detection of AA and ALP based on redox‐modulated silver deposition on AuNPs has been proposed. Under the optimal experimental conditions, the absorbance variation ΔA522 nm/A370 nm of AuNPs was proportional to the concentration of AA (5–60 μmol/L) and ALP (3–18 U/L) with the corresponding detection limit of 2.44 μmol/L for AA and 0.52 U/L for ALP. The assay showed excellent selectivity towards AA and ALP. Moreover, the assay has been applied to detect AA and ALP activity in real samples with satisfying results.  相似文献   

3.
The antioxidant activity of a provitamin C agent, 2-O-beta-D-glucopyranosyl-L-ascorbic acid (AA-2betaG), was compared to that of 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G) and ascorbic acid (AA) using four in vitro methods, 1,1-diphenyl-picrylhydrazyl (DPPH) radical-scavenging assay, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS(*+))-scavenging assay, oxygen radical absorbance capacity (ORAC) assay, and 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced erythrocyte hemolysis inhibition assay. AA-2betaG slowly and continuously scavenged DPPH radicals and ABTS(*+) in roughly the same reaction profiles as AA-2G, whereas AA quenched these radicals immediately. In the ORAC assay and the hemolysis inhibition assay, AA-2betaG showed similar overall activities to AA-2G and to AA, although the reactivity of AA-2betaG against the peroxyl radical generated in both assays was lower than that of AA-2G and AA. These data indicate that AA-2betaG had roughly the same radical-scavenging properties as AA-2G, and a comprehensive in vitro antioxidant activity of AA-2betaG appeared to be comparable not only to that of AA-2G but also to that of AA.  相似文献   

4.
Antioxidant activity of kappa-carrageenan oligosaccharides (OM) and their chemical modification derivatives was investigated employing various established in vitro systems, such as reducing power, iron ion chelation, and total antioxidant activity using beta-carotene-linoleic acid system. The oversulfated (SD), lowly (LAD), and highly acetylated derivatives (HAD) in reducing power assay, the phosphorylated derivative (PD) in metal chelating assay, and oversulfated and phosphorylated derivatives in total antioxidant activity assay exhibited antioxidant activity higher than that of carrageenan oligosaccharides. The results indicated that the chemical modification of carrageenan oligosaccharides can enhance their antioxidant activity in vitro. The protective effects of the carrageenan oligosaccharides and their chemically modified derivatives against H(2)O(2) and UVA (long-wave ultraviolet radiation) induced oxidative damage on rat thymic lymphocyte were investigated by measuring cell viability via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Thymic lymphocyte exposure to H(2)O(2) and UVA, a marked reduction in cell survival was observed, which was significantly prevented by carrageenan oligosaccharides and their derivatives (preincubated for 2h) at 66.7-2000 microg/mL. But both the carrageenan oligosaccharides and their different derivatives showed the similar protective effects on intracellular level. Taken together, these results suggest that carrageenan oligosaccharides and their derivatives show relevant antioxidant activity both in vitro and in a cell system.  相似文献   

5.
采用系统溶剂法对北虫草子实体进行依次提取,制备得氯仿相、乙酸乙酯相和乙醇相三部位,利用化学发光法和H2O2诱导PC12氧化损伤修复模型,对三部位进行体外抗氧化活性和PC12氧化损伤修复作用测定。结果表明,乙酸乙酯相具有较强的抗氧化活性,是清除H2O2自由基和超氧自由基活性最强的部位,IC50值分别为88.5μg/mL和190μg/mL;乙酸乙酯相对由H2O2诱导的PC12细胞氧化损伤的修复作用较强,且呈现明显的浓度依赖性。无论从抗氧化活性,还是从对H2O2氧化损伤的修复作用,乙酸乙酯相均表现出了较强的作用,乙酸乙酯相是抗氧化活性和保护PC12细胞氧化损伤的主要有效部位。  相似文献   

6.
Epidemiological studies indicate that consumption of green-yellow vegetables rich in chlorophyll, vitamin C, vitamin E, and carotenoids reduce the risk of cancer. We sought to examine the antigenotoxic and antioxidant properties of chlorophyll-rich methanol extracts of Angelica keiskei, Oenanthe javanica, and Brassica oleracea (kale). In the Salmonella mutagenicity assay, A. keiskei caused dose-dependent inhibition against three heterocyclic amine mutagens in the presence of S9, O. javanica was antimutagenic only at the highest concentration in the assay (2 mg/plate), and B. oleracea showed no consistent inhibitory activity at non-toxic levels. None of the extracts were effective against three direct-acting mutagens in the absence of S9. Extracts of A. keiskei and, to a lesser extent O. javanica, inhibited two of the major enzymes that play a role in the metabolic activation of heterocyclic amines, based on ethoxyresorufin-O-deethylase and methoxyresorufin-O-demethylase assays in vitro. All three plant extracts were highly effective in assays which measured ferric reducing/antioxidant power, oxygen radical absorbance capacity, and Fe2+/H2O2-mediated DNA nicking. Finally, using the 'comet' assay, all three plant extracts protected against H2O2-induced genotoxic damage in human HCT116 colon cancer cells. These findings provide support for the antigenotoxic and antioxidant properties of chlorophyll-rich extracts of A. keiskei, O. javanica, and B. oleracea, through mechanisms that include inhibition of carcinogen activation and scavenging of reactive oxygen species.  相似文献   

7.
Recent evidence shows that plant polyphenols exhibit antioxidant and radical scavenging properties. By three separate and complementary methods--DPPH assay, beta-carotene-linoleic acid assay and NBT-reduction assay it was established that a polyphenol-rich extract from the medicinal plant Geranium sanguineum L. with strong anti-influenza virus activity, possessed antioxidant and radical scavenging capacities. For comparative reasons caffeic acid and the synthetic antioxidant BHT were used. Total soluble phenolic constituents of the MeOH extract measured by Folin-Ciocalteu reagent were found as 34.60% (w/w). Further it was demonstrated that the EtOAc fraction, retaining the majority of the in vivo protective effect exhibited a strong O2-scavenging activity while the n-BuOH fraction, containing the majority of the in vitro antiviral activity provoked generation of O2-. The O2- scavenging activity of all three preparations correlated with the rate of the protective effect shown in the murine model of experimental influenza virus infection. The present results are in accordance with our intensive studies on the mode of the protective effect of the plant extract which showed positively that the protection may possibly be attributed to the combination of more than one biological activities and that the use of antioxidants might be an useful approach in the treatment of influenza infection.  相似文献   

8.
9.
Shen Q  Shang N  Li P 《Current microbiology》2011,62(4):1097-1103
Several studies reported the antioxidant activity of bifidobacteria using assays in vitro. In present study, the in vitro and in vivo antioxidant activity of Bifidobacterium animalis 01 was investigated. Culture supernatant, intact cells, and intracellular cell-free extracts of B. animalis 01 were involved in this study. The antioxidant assays in vitro included lipid peroxidation assay, 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, hydroxyl radical ( OH) assay and superoxide anion ( \textO2 - {\text{O}}_{2}^{ - } ) assay. The antioxidant assays in vivo were conducted using mice model. Activities of antioxidative enzymes, malondialdehyde (MDA) content in serums and livers of aging mice were evaluated. Monoamine oxidase (MAO) activity and lipofuscin level in brains of aging mice were also characterized. Results showed that culture supernatant, intact cells and intracellular cell-free extracts of B. animalis 01 could effectively scavenge free radicals, significantly enhance mice’s activities of antioxidative enzymes and reduce mice’s MDA content, lipofuscin level and MAO activity. Our results indicated that B. animalis 01 has the potential to be developed into a dietary antioxidant supplements.  相似文献   

10.
Soybean cotyledons directly exposed to UV-C (190-280 nm) contained a colored pigment in those areas of the epidermis directly exposed to UV-C. Ethanolic extracts from UV-C irradiated cotyledons showed a significant peak at 532 nm at pH=10, but not seen at pH=6, successive changes in pH were accompanied by reversible changes in the spectra. The identity of the pigment isolated from soybean cotyledons was established as apigeninidin by comparing the features of standard of a apigeninidin (from sorghum) previously characterized by FAB-MS, UV, HPLC, 1H NMR, and IR spectroscopy. To characterize antioxidant activity of this compound, its ability to scavenge radical species in vitro was tested. In the concentration range tested (up to 200 microg ml (-1)), apigeninidin did not show any scavenger activity towards hydroxyl radical, quinones or NO. However, ascorbyl radical and lipid radicals were effectively quenched in a dose-dependent manner. Overall, UV-C radiation triggers molecular signals that lead in soybean cotyledons to the synthesis and accumulation of an antioxidant pigment, apigeninidin, that shows scavenger activity against ascorbyl and lipid radicals in in vitro studies.  相似文献   

11.
The objective of this study was to investigate the efficiency of multifunctional poly(ethylene glycol)-based hemoglobin conjugates crosslinked with antioxidant enzymes for their ability to protect an oxygen carrier (hemoglobin) and insulin secreting islets from the combination of hypoxic and free radical stress under simulated transplantation conditions. In this study, RINm5F cells and isolated pancreatic islets were challenged with oxidants (H(2)O(2) or xanthine and xanthine oxidase) and incubated with conjugates (hemoglobin-hemoglobin or superoxide dismutase-catalase-hemoglobin) in normoxia (21% oxygen) or hypoxia (6% or 1% oxygen). Hemoglobin protection, intracellular free radical activity and cell viability in RINm5F cells measured by methemoglobin, dichlorofluorescein-diacetate, and (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay, respectively, showed that cells were better protected by conjugates containing antioxidant enzymes. Insulin secretion from islets and qualitative confocal evaluation of viability showed beta cells were protected by conjugates containing antioxidant enzymes when exposed to induced stress. Our study suggested that antioxidant enzymes play a significant role in hemoglobin protection and thus extended cell protection.  相似文献   

12.
In this study we compared the antioxidant properties of five different extracts of different composition obtained from Achyrocline satureioides' inflorescences (Compositae), a widely used Brazilian folk medicinal herb. All of the extracts presented significant antioxidant potential identified by TRAP assay, which increased in the presence of human plasma. Characterization of the content of flavonoids in each extract showed that the FDP80 (ethanol 80%) and FFr (enriched flavonoid fraction) extracts contained a higher content of flavonoids. Cytotoxicity of the extracts as determined in Sertoli cell culture showed that FDP80 and FFr were highly toxic at most concentrations tested. The extracts induced a significant increase in lipid peroxidation levels in Sertoli cells. These results suggest that medicinal herb extracts that contain higher flavonoid concentrations and shows higher antioxidant protection in vitro might not always produce the greatest benefit.  相似文献   

13.
This study aims to compare the electron spin resonance (ESR) spectra emitted by human blood loaded with either ascorbyl-6-palmitate (AP), a lipid-soluble derivative of ascorbic acid (AA), or with AA. Whole blood of a healthy male individual was equilibrated with equimolar concentrations of AP and AA of 200, 400, and 800 micromol/l. The intensity of the ESR signal, expressed as the peak-to-peak amplitude, reflects the amount of unpaired spins that are created due to the reducing action of AA and is proportional, in relative terms, to the amount of the ascorbyl radical formed. We found that the blood with AP emitted an ESR signal whose singlet shape, width, and location precisely correlate with the known characteristics of the ascorbyl radical in vitro. The signal magnitude increased linearly with increasing concentrations of AP and was similar to that of AA. We conclude that AP is biologically active, as it generates the ascorbyl radical, an action that also underlies the scavenging process by ascorbic acid. To this end, ascorbyl-6-palmitate might have potential advantages, due to its ability to penetrate biomembranes and to act at the lipid-related molecular target sites.  相似文献   

14.
The Chaga mushroom (Inonotus obliquus) is claimed to have beneficial properties for human health, such as anti-bacterial, anti-allergic, anti-inflammatory and antioxidant activities. The antioxidant effects of the mushroom may be partly explained by protection of cell components against free radicals. We evaluated the effect of aqueous Chaga mushroom extracts for their potential for protecting against oxidative damage to DNA in human lymphocytes. Cells were pretreated with various concentrations (10, 50, 100 and 500 microg/mL) of the extract for 1 h at 37 degrees C. Cells were then treated with 100 microM of H2O2 for 5 min as an oxidative stress. Evaluation of oxidative damage was performed using single-cell gel electrophoresis for DNA fragmentation (Comet assay). Using image analysis, the degree of DNA damage was evaluated as the DNA tail moment. Cells pretreated with Chaga extract showed over 40% reduction in DNA fragmentation compared with the positive control (100 micromol H2O2 treatment). Thus, Chaga mushroom treatment affords cellular protection against endogenous DNA damage produced by H2O2.  相似文献   

15.
The free radical scavenging capacity of a wide range of plant oil extracts, principally those used in traditional European herbal medicine (with novel therapeutic potential for patients with degenerative disorders of the CNS), has been compared in vitro. The antioxidant capacity of individual plant extracts was determined via three complementary assay procedures, based on: (i) attenuation of the generation of ABTS√+ radical (quantitated colorimetrically), by a metmyoglobin catalyst/hydrogen peroxide system; (ii) inhibition of iodophenol enhanced chemiluminescence by a horseradish peroxidase/perborate/luminol system; (iii) protection of a target enzyme (human brain alanyl aminopeptidase, activity quantitated via fluorimetric assay) against oxidative damage by √OH or O√2 generated by Co60γ radiolysis. In assays (i) and (ii), only three plant extracts (cinnamon, pimento, bay) showed substantial antioxidant activity, although the two assays yielded quantitatively different values of antioxidant activity (Trolox equivalent values of 16–25 M (method ii) and 0.25–2.1 M (method (i)). None of the plant extracts investigated showed significant antioxidant protective activity against √OH or O√2 species in assay (iii). The data obtained thus demonstrate that the apparent antioxidant capacity of putative free radical scavenging agents depends entirely on the assay method utilized and particular free radical species generated. We therefore suggest that antioxidant capacity determined by a single assay method (particularly via competitive assay with ABTS√+) should be interpreted with some caution. This conclusion may be of particular potential importance in clinical chemistry, in view of the current interest in the assessment of the antioxidant status of tissues of patients with a variety of disorders.  相似文献   

16.
6-Hydroxydopamine (6-OHDA) is a dopaminergic neurotoxin putatively involved in the pathogenesis of Parkinson's disease (PD). Its neurotoxicity has been related to the production of reactive oxygen species. In this study we examine the effects of the antioxidants ascorbic acid (AA), glutathione (GSH), cysteine (CySH), and N-acetyl-CySH (NAC) on the autoxidation and neurotoxicity of 6-OHDA. In vitro, the autoxidation of 6-OHDA proceeds rapidly with the formation of H2O2 and with the participation of the H2O2 produced in the reaction. The presence of AA induced a reduction in the consumption of O2 during the autoxidation of 6-OHDA and a negligible presence of the p-quinone, which demonstrates the efficiency of AA to act as a redox cycling agent. The presence of GSH, CySH, and NAC produced a significant reduction in the autoxidation of 6-OHDA. In vivo, the presence of sulfhydryl antioxidants protected against neuronal degeneration in the striatum, which was particularly remarkable in the case of CySH and was attributed to its capacity to remove the H2O2 produced in the autoxidation of 6-OHDA. These results corroborate the involvement of oxidative stress as the major mechanism in the neurotoxicity of 6-OHDA and the putative role of CySH as a scavenger in relation to PD.  相似文献   

17.
The extracts obtained from 28 species of marine algae were evaluated for their antioxidant activity (AA) versus the positive controls butylated hydroxytoluene (BHT), gallic acid (GA), and ascorbic acid (AscA). Most of the tested samples displayed antioxidant activity to various degrees. Among them, the extract of Symphyocladia latiuscula exhibited the strongest AA, which was comparable to BHT, GA, and AscA in radical scavenging activity, as shown in the DPPH (α,α-diphenyl-β-picrylhydrazyl) assay, and higher than those of the positive controls in β-carotene-linoleate assay system. In addition, the ethyl acetate-soluble fraction isolated from the crude extract of S. latiuscula exhibited the highest antioxidant activity in both assay systems. This fraction was further fractionated into seven subfractions (F1-F7) by vacuum liquid chromatography (VLC). F1 and F4 were found to be the most effective subfractions in scavenging DPPH radical assay and in the β-carotene-linoleate assay, respectively. The total phenolic content (TPC) and reducing power (RP) for all of the extracts, fractions, and subfractions (F1–F7) were also determined. The TPC of the 28 extracts ranged from 0.10 to 8.00 gallic acid equivalents (mg/g seaweed dry weight) while the RP ranged from 0.07 to 11.60 ascorbic acid equivalents (mg·g−1 seaweed dry weight). Highly positive relationships between AA and TPC as well as between AA and RP were found for the extracts and fractions, while for the subfractions F1–F7 only weak or no such relations were found. The results obtained from this study indicate that further analysis is needed of those marine algal species that contain the most antioxidant activity in order to identify the active principles.  相似文献   

18.
An optical antigenotoxicity assay using genetically engineered red fluorescent bacteria is presented. Exposure of Escherichia coli RS4U to genotoxicants [mitomycin C (MMC), nalidixic acid (NA) and hydrogen peroxide (HP)] resulted in phenotypic red fluorescence proportional to the concentration of the inducer. Except for tannic acid (TA), co-treatment of the genotoxicant-activated bacteria with ascorbic acid (AA) and aqueous plant extracts (Mangifera indica, Psidium guajava and Syzygium cumini) afforded protection against all three genotoxicants. TA was effective in suppressing the genotoxic effect of MMC and HP. The antigenotoxic effect is seen as inhibition of the genotoxicant-triggered red fluorescence. The IC50 of the plant extracts and AA varied with the genotoxicant used. Rec assay verified the antigenotoxic activity of the plant extracts. Folin-Ciocalteu test, FeCl3 test and DPPH assay confirmed the presence of polyphenolic compounds and hydrolyzable tannins in the plant extracts and the antioxidant capacity of the plant samples.  相似文献   

19.
Excretory-secretory (E-S) products obtained during in vitro Schistosoma mansoni miracidium-to-sporocyst transformation were found to contain a 108-kDa polypeptide capable of scavenging both exogenously produced and M-line Biomphalaria glabrata hemocyte-derived superoxide (O2-) anions. Separation of crude transformation E-S products using HPLC and ion exchange chromatography resulted in the separation of two isoforms of the 108-kDa molecule. Using an in vitro phagocytosis assay, both isoforms were found to be capable of reducing O2- production by phagocytically stimulated M-line B. glabrata hemocytes without cell loss and without a concomitant reduction in phagocytosis. Although parasite antioxidant molecules appear to play a role in the evasion of host oxidative defense systems in several parasite-vertebrate systems, no previous reports of a parasite antioxidant capability against the potential of oxidative killing by invertebrate defense systems has been reported. In conjunction with the previously confirmed production of O2- by B. glabrata hemocytes and reports of reactive oxygen metabolite production by hemocytes from several molluscan species, these results indicate that reactive forms of oxygen and parasite antioxidant systems may play an important role in the determination of compatibility in the trematode-mollusc relationship.  相似文献   

20.
This study aimed to evaluate the antioxidant activities of a cultured medicinal fungus--Armillariella mellea (Vahl. ex Fr.) Karst. (AM). Three antioxidant assay systems, namely cytochrome c, xanthine oxidase inhibition and FeCl2-ascorbic acid stimulated lipid peroxidation in rat tissue homogenate tests, were used. Total flavonoid and phenol contents of AM extracts were also analyzed. Results showed that both aqueous (AM-H2O) and ethanolic (AM-EtOH) extracts of solid state cultured AM showed antioxidant activities in a concentration-dependent manner. At concentrations 1-100 microg/ml, the free radical scavenging activity was 73.7-92.1% for AM-H2O, and 60.0-90.8% for AM-EtOH. These extracts also showed an inhibitory effect on xanthine oxidase activity, but with a lesser potency (IC50 - 9.17 microg/ml for AM-H2O and 7.48 microg/ml for AM-EtOH). In general, AM-H2O showed a stronger anti-lipid peroxidation activity on different rat's tissues than AM-EtOH. However, both AM extracts displayed a weak inhibitory effect on lipid peroxidation in plasma. Interestingly, the anti-lipid peroxidation activity of AM-H2O (IC50 - 6.66 microg/ml) in brain homogenate was as good as alpha-tocopherol (IC50 - 5.42 microg/ml). AM-H2O (80.0 mg/g) possessed a significant higher concentration of total flavonoids than AM-EtOH (30.0 mg/g), whereas no difference was noted in the total phenol content between these two extracts. These results conclude that AM extracts possess potent free radical scavenging and anti-lipid peroxidation activities, especially the AM-H20 in the brain homogenate.  相似文献   

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