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1.
Probiotic bacteria synthesize extracellular polysaccharides (EPSs) with commercially significant physiological and therapeutic activities. This important class of biomolecules is also characterized by their ability to remove reactive oxygen species (ROS) that are formed in the intestine by various metabolic reactions; hence, they exhibit antioxidant activities. Our probiotic bacterium, Bacillus coagulans RK-02, produces an EPS during the exponential and stationary growth phases when grown in a glucose mineral salts medium. The time course of EPS synthesis was studied with respect to biomass growth. The antioxidant and free radical scavenging potential of isolated EPS were studied by various methods, including the beta-carotene-linoleic acid model system, a superoxide radical scavenging assay using the PMS-NADH-nitroblue tetrazolium system, the 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, a hydroxyl radical scavenging assay using the ascorbic acid-Cu(2+)-cytochrome c system and an in vitro microsome peroxidation inhibition study using a thiobarbituric acid assay. The antioxidant activities were compared to known antioxidants vitamin C and E, which were used as reference standards. The results showed that the EPS, which is a heteropolymer composed of four monosaccharides, produced by B. coagulans RK-02 had significant antioxidant and free radical scavenging activities.  相似文献   

2.
Nine modification conditions were designed to sulfate exopolysaccharides (EPS) produced by Enterobacter cloacae Z0206 by chlorosulfonic acid-pyridine (CSA-Pyr) method according to the orthogonal test and focusing on three affecting factors such as the ratio of CSA to Pyr, reaction temperature and reaction time. And nine sulfated derivatives with various degrees of substitution (DS) were obtained. Their antioxidant activities were evaluated in vitro, by scavenging abilities on superoxide radical and hydroxyl radical. The results indicated that sulfated derivatives of EPS showed noticeable effects on scavenging superoxide radical and hydroxyl radical compared with native one, and sulfated derivative with moderate DS of 0.60 showed highest antioxidant activities. The optimum sulfated conditions of EPS were the ratio of CSA to Pyr of 1:2, the reaction time of 2h and reaction temperature of 70 °C.  相似文献   

3.
Wu JH  Xu C  Shan CY  Tan RX 《Life sciences》2006,78(6):622-630
Through a combination of anion-exchange and repeated gel chromatographies, APS-1 was isolated from fresh leaves of Aloe vera L. var. chinensis (Haw.) Berger (an edible and medicinal plant widely cultivated and consumed in China) as a principal polysaccharide composed of mannose and glucose (ca. 18:5) with its molecular weight around 2.1 x 10(5). In a dose-dependent manner, APS-1 was demonstrated to be free radical scavenging in superoxide and hydroxyl radical assays, inhibitory to the copper-mediated oxidation of human low density lipoprotein (LDL), and protective against hydrogen peroxide (H(2)O(2))-induced lesion to rat PC12 cell (pheochromocytoma cell line). The result suggested that APS-1 could be of considerable preventive and therapeutic significance to some free radical associated health problems such as coronary heart ailments, Parkinson's and Alzheimer's diseases. Furthermore, the finding shed as well fresh light helpful for a better understanding of the health-benefiting potential of the edible plant consumed by the Chinese people for a couple of centuries.  相似文献   

4.
A xanthone derivative, named gaboxanthone (1), has been isolated from the seed shells of Symphonia globulifera, together with known compounds, symphonin (2), globuliferin (3), guttiferone A (4), sistosterol, oleanolic acid and methyl citrate. The structure of the compound was assigned as 5,10-dihydroxy-8,9-dimethoxy-2,2-dimethyl-12-(3-methylbut-2-enyl) pyrano [3,2-b]xanthen-6(2H)-one, by means of spectroscopic analysis. The anti-plasmodial and antioxidant activities of the phenolic compounds were evaluated, respectively, in culture against W2 strain of Plasmodium falciparum and using the free radical scavenging activity of the DPPH radical, respectively. Compounds 1-4 were found to be active against the Plasmodium parasites (IC(50) of 3.53, 1.29, 3.86 and 3.17 microM, respectively). Guttiferone A (4) showed a potent free radical scavenging activity compared to the well-known antioxidant caffeic acid.  相似文献   

5.
Antioxidant and antiradical activities of L-carnitine   总被引:2,自引:0,他引:2  
Gülçin I 《Life sciences》2006,78(8):803-811
L-carnitine plays an important regulatory role in the mitochondrial transport of long-chain free fatty acids. In this study, the antioxidant activity of L-carnitine was investigated as in vitro. The antioxidant properties of the L-carnitine were evaluated by using different antioxidant assays such as 1, 1-diphenyl-2-picryl-hydrazyl free radical (DPPH.) scavenging, total antioxidant activity, reducing power, superoxide anion radical scavenging, hydrogen peroxide scavenging and metal chelating activities. Total antioxidant activity was measured according to ferric thiocyanate method. alpha-tocopherol and trolox, a water-soluble analogue of tocopherol, were used as the reference antioxidant compounds. At the concentrations of 15, 30 and 45 microg/mL, l-carnitine showed 94.6%, 95.4% and 97.1% inhibition on lipid peroxidation of linoleic acid emulsion, respectively. On the other hand, 45 microg/mL of standard antioxidant such as alpha-tocopherol and trolox indicated an inhibition of 88.8% and 86.2% on peroxidation of linoleic acid emulsion, respectively. In addition, L-carnitine had an effective DPPH. scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, total reducing power and metal chelating on ferrous ions activities. Also, those various antioxidant activities were compared to alpha-tocopherol and trolox as references antioxidants.  相似文献   

6.
A series of some 4-(aza substituted) methylene substituted dihydroxy coumarines were evaluated for their antioxidant and antielastase activities. Different in vitro methodologies such as total reducing power, 1,1-diphenyl-2-picryl-hydrazil (DPPH·) free radical scavenging, ABTS radical scavenging activity were used as antioxidant activity. All the tested compounds exhibited potent free radical scavenging ability and antielastase activites.  相似文献   

7.
Antioxidant properties of a North American ginseng extract   总被引:11,自引:0,他引:11  
A North American ginseng extract (NAGE) containing known principle ginsenosides for Panax quinquefolius was assayed for metal chelation, affinity to scavenge DPPH-stable free radical, and peroxyl (LOO·) and hydroxyl (·OH) free radicals for the purpose of characterizing mechanisms of antioxidant activity. Dissociation constants (Kd) for NAGE to bind transition metals were in the order of Fe2+ > Cu2+ > Fe3+ and corresponded to the affinity to inhibit metal induced lipid peroxidation. In a metal-free linoleic acid emulsion, NAGE exhibited a significant (p 0.05) concentration (0.01-10 mg/mL) dependent mitigation of lipid oxidation as assessed by the ammonium thiocyanate method. Similar results were obtained when NAGE was incubated in a methyl linoleate emulsion containing haemoglobin catalyst and assessed by an oxygen electrode. NAGE also showed strong DPPH radical scavenging activity up to a concentration of 1.6 mg/mL (r2 = 0.996). Similar results were obtained for scavenging of both site-specific and non site-specific ·OH, using the deoxyribose assay method. Moreover, NAGE effectively inhibited the non site-specific DNA strand breakage caused by Fenton agents, and suppressed the Fenton induced oxidation of a 66 Kd soluble protein obtained from mouse brain over a concentration range of 2-40 mg/mL. These results indicate that NAGE exhibits effective antioxidant activity in both lipid and aqueous mediums by both chelation of metal ions and scavenging of free radicals.  相似文献   

8.
A novel water-soluble polysaccharide pMTPS-3, obtained from Melia toosendan Sieb. Et Zucc fruit by hot-water extraction and ethanol precipitation, was fractionated by DEAE-52 cellulose anion-exchange and Sephadex G-100 gel filtration chromatography. Its primary structural features and molecular weight were characterized by Fourier infrared spectrometry (FTIR), gel permeation chromatography (GPC) and gas chromatography (GC). And the antioxidant activities of pMTPS-3 in vitro were evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay, superoxide radical scavenging assay and hydroxyl radical scavenging assay. The results suggested that pMTPS-3 was a heteropolysaccharide, composed of arabinose, glucose, mannose, and galactose in the molar ratio of 17.3:28.3:41.6:12.6 with molecular weight 26 100 Da. The purified pMTPS-3 was revealed to have notable scavenging activity against DPPH radical in a concentration-dependent manner and present a moderate inhibition of superoxide radicals with an IC50 (5.6 mg/ml), and potent inhibiting power for hydroxyl radical compared with crude polysaccharide. Further, it exhibited strong inhibition effect in vitro on the growth of human gastric cancer BGC-823 cells. It is strongly evidenced that pMTPS-3 purified from the crude polysaccharides of Melia toosendan Sieb. Et Zucc could be explored as a potential antioxidant and therapeutics.  相似文献   

9.
Phenylpropanoid glycosides, 1'-O-benzyl-alpha-L-rhamnopyranosyl-(1'-->6')-beta-D-glucopyranoside (1) and alpha-L-xylopyranosyl-(4'-->2')-(3-O-beta-D-glucopyranosyl)-1'-O-E-caffeoyl-beta-D-glucopyranoside (2), together with the known derivatives, 1,6-di-O-caffeoyl-beta-D-glucopyranoside (3), 1-O-(E)-caffeoyl-beta-D-glucopyranoside (4) and 1-O-(E)-feruloyl-beta-D-glucopyranoside (5), were isolated from leaves of Coussarea hydrangeifolia. Their structures were determined by IR, HRESIMS, and 1D and 2D NMR experiments, and their antioxidant activities, evaluated by assaying the free radical scavenging capacity using the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical as substrate. The antioxidant activities of 3 and 4 (IC50 values of 15.0 and 19.2 microM, respectively) were comparable to that of the standard positive control caffeic acid, whilst 2 and 5 were only weakly active and 1 was inactive.  相似文献   

10.
Xu R  Shang N  Li P 《Anaerobe》2011,17(5):226-231
The aim of the study was to purify the exopolysaccharides (EPS) produced from Bifidobacterium animalis RH, which was isolated from the feces of Bama centenarians in Guangxi of China, and evaluate their antioxidant activities in vitro and in vivo. 2 fractions, a neutral EPS fraction (EPSa) and an acidic EPS fraction (EPSb), were obtained and compared for antioxidative activity. In vitro, they both showed remarkable inhibition effect on lipid peroxidation and strong DPPH radical scavenging activity, hydroxyl radical scavenging activity, superoxide radical scavenging activity, in which the last two were measured by the electron spin resonance (ESR). In vivo, EPSa and EPSb were orally administrated for 30 days in a d-galactose induced aged mice model. As results, they both could significantly increase the activities of SOD, CAT and total antioxidant capacity (TAOC) in serums and glutathione GST in livers. They also could inhibit significantly the formation of MDA in serums and livers, and reduce the activity of MAO and lipofuscin accumulation in mice brain. Moreover, EPSb exhibited much higher antioxidant activities than EPSa in vitro and in vivo. The results suggested that EPS fractions of Bifidobacterium animalis RH had direct and potent antioxidant activities.  相似文献   

11.
Divergent literature data are found concerning the effect of lactate on free radical production during exercise. To clarify this point, we tested the pro- or antioxidant effect of lactate ion in vitro at different concentrations using three methods: 1) electron paramagnetic resonance (EPR) was used to study the scavenging ability of lactate toward the superoxide aion (O(2)(-).) and hydroxyl radical (.OH); 2) linoleic acid micelles were employed to investigate the lipid radical scavenging capacity of lactate; and 3) primary rat hepatocyte culture was used to study the inhibition of membrane lipid peroxidation by lactate. EPR experiments exhibited scavenging activities of lactate toward both O(2)(-). and.OH; lactate was also able to inhibit lipid peroxidation of hepatocyte culture. Both effects of lactate were concentration dependent. However, no inhibition of lipid peroxidation by lactate was observed in the micelle model. These results suggested that lactate ion may prevent lipid peroxidation by scavenging free radicals such as O(2)(-). and.OH but not lipid radicals. Thus lactate ion might be considered as a potential antioxidant agent.  相似文献   

12.
In this study, di(2,6-dimethylphenol) (Di-DMP), di(2,6-diisopropylphenol) (Di-DIP, dipropofol) and di(2,6-di-t-butylphenol) (Di-DTP) were synthesized by the reaction of monomeric phenol derivatives with catalytic CuCl(OH). TMEDA and Na2S2O4. Their antioxidant capacity and radical scavenging activity were examined using different in vitro methodologies such as 1,1-diphenyl-2-picryl-hydrazyl (DPPH*) free radical scavenging, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activity, total antioxidant activity by ferric thiocyanate, total reducing power by potassium ferricyanide reduction method, superoxide anion radical scavenging, hydrogen peroxide scavenging and ferrous ions chelating activities.  相似文献   

13.
Free radical scavenging and antioxidant activities of a standardized extract of Hypericum perforatum (SHP) were examined for inhibition of lipid peroxidation, for hydroxyl radical scavenging activity and interaction with 1,1-diphenyl-2-picrylhydrazyl stable free radical (DPPH). Concentrations between 1 and 50 microg/ml of SHP effectively inhibited lipid peroxidation of rat brain cortex mitochondria induced by Fe2+/ascorbate or NADPH system. The results showed that SHP scavenged DPPH radical in a dose-dependent manner and also presented inhibitory effects on the activity of xanthine oxidase. In contrast, hydroxyl radical scavenging occurs at high doses. The protective effect of the standardized extract against H2O2-induced oxidative damage on the pheochromocytoma cell line PC 12 was investigated by measuring cell viability via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), lactate dehydrogenase (LDH) assays, caspase-3-enzyme activity and accumulation of reactive oxygen species [2',7'-dichlorofluorescin (DCF) assay]. Following 8-h cell exposure to H2O2 (300 microM), a marked reduction in cell survival was observed, which was significantly prevented by SHP (pre-incubated for 24 h) at 1-100 microg/ml. In a separate experiment, different concentrations of the standardized extract (0.1-100 microg/ml) also attenuated the increase in caspase-3 activity and suppressed the H2O2 -induced reactive oxygen species generation. Taken together, these results suggest that SHP shows relevant antioxidant activity both in vitro and in a cell system, by means of inhibiting free radical generation and lipid peroxidation.  相似文献   

14.
Gülçin I 《Amino acids》2007,32(3):431-438
Summary. Phenolic compounds are interesting because of their antioxidant properties. In the present study, the antioxidant properties of L-tyrosine as a monophenolic and L-Dopa as a diphenolic amino acid were investigated by using different antioxidant assays: (i) 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH) scavenging; (ii) 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation decolorization assay; (iii) total antioxidant activity by ferric thiocyanate method; (iv) ferric ions (Fe3+) reducing power; (v) superoxide anion radical (O2 •−) scavenging; (vi) hydrogen peroxide (H2O2) scavenging, and (vii) ferrous ions (Fe2+) chelating activities. Butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), α-tocopherol and trolox, a water-soluble analogue of tocopherol, were used as the reference antioxidant compounds. At the same concentration (20 μg/mL), L-tyrosine and L-Dopa showed 30.6 and 67.9% inhibition of lipid peroxidation of linoleic acid emulsion, respectively. On the other hand, BHA, BHT, α-tocopherol and trolox indicated inhibitions of 74.4, 71.2, 54.7 and 20.1% on the peroxidation of linoleic acid emulsion, respectively, at the above-mentioned concentration. In addition, L-tyrosine and L-Dopa had an effect on DPPH radical scavenging, ABTS radical scavenging, superoxide anion radical scavenging, H2O2 scavenging, total ferric ions reducing power and metal chelating on ferrous ions activities.  相似文献   

15.
The fractionation of a methanolic extract of Tagetes maxima guided for antioxidant activity resulted in the isolation of three acylated quercetagetin glycosides, quercetagetin-7-O-(6-O-caffeoyl-beta-D-glucopyranoside), quercetagetin-7-O-(6-O-p-coumaroyl-beta-D-glucopyranoside) and quercetagetin-7-O-(6-O-galloyl-beta-D-glucopyranoside), as well as four known flavonoid glycosides. The structural elucidation was accomplished by spectroscopic methods (ESI-MS/MS and NMR). The antioxidant activity of fractions and isolated compounds was determined by checking the scavenging activity against three different radicals: 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH*), hydroxyl (*OH), and superoxide (O2*-). The three isolated compounds exhibited a high radical scavenging activity in comparison with reference compounds.  相似文献   

16.
为了优化草菇子实体多肽的提取工艺和探究其抗氧化活性,以草菇子实体为原料,采用酶解法提取草菇子实体多肽,通过单因素试验得出最佳的酶解工艺,并使用Box-Behnken设计试验组合。结果表明:草菇子实体提取多肽的最佳工艺为料液比1:52 (g/mL)、加酶量7 200 U/g、酶解温度43 ℃,此工艺条件下的多肽得率为67.76%。从1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除能力、铁离子还原能力、超氧阴离子自由基清除能力和羟自由基清除能力4个方面研究其体外抗氧化能力,结果表明,草菇子实体多肽对DPPH自由基清除率为74.11%,超氧阴离子自由基和羟自由基清除率分别在69.64%和91.83%达到稳定,草菇子实体多肽还具有一定的还原力,说明草菇子实体多肽可以作为优质抗氧化肽的良好来源。该研究为草菇多肽的高效制备和抗氧化肽等高附加值产品的研发提供理论依据。  相似文献   

17.
Antioxidant and radical scavenging properties of curcumin   总被引:3,自引:0,他引:3  
Curcumin (diferuoyl methane) is a phenolic compound and a major component of Curcuma longa L. In the present paper, we determined the antioxidant activity of curcumin by employing various in vitro antioxidant assays such as 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH*) scavenging, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activity, N,N-dimethyl-p-phenylenediamine dihydrochloride (DMPD) radical scavenging activity, total antioxidant activity determination by ferric thiocyanate, total reducing ability determination by the Fe(3+)-Fe(2+) transformation method, superoxide anion radical scavenging by the riboflavin/methionine/illuminate system, hydrogen peroxide scavenging and ferrous ions (Fe(2+)) chelating activities. Curcumin inhibited 97.3% lipid peroxidation of linoleic acid emulsion at 15 microg/mL concentration (20 mM). On the other hand, butylated hydroxyanisole (BHA, 123 mM), butylated hydroxytoluene (BHT, 102 mM), alpha-tocopherol (51 mM) and trolox (90 mM) as standard antioxidants indicated inhibition of 95.4, 99.7, 84.6 and 95.6% on peroxidation of linoleic acid emulsion at 45 microg/mL concentration, respectively. In addition, curcumin had an effective DPPH* scavenging, ABTS*(+) scavenging, DMPD*(+) scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, ferric ions (Fe(3+)) reducing power and ferrous ions (Fe(2+)) chelating activities. Also, BHA, BHT, alpha-tocopherol and trolox, were used as the reference antioxidant and radical scavenger compounds. According to the present study, curcumin can be used in the pharmacological and food industry because of these properties.  相似文献   

18.
Nine derivatives of three natural diarylheptanoids, curcumin, demethoxycurcumin and bisdemethoxycurcumin, were prepared. Their antioxidant, free radical scavenging, nitric oxide (NO) inhibitory and cytotoxic activities were evaluated and compared with those of the respective natural compounds. Curcumin (1), demethoxycurcumin (2), demethyldemethoxy-curcumin (C3), diacetyldemethoxycurcumin (AC2) and triacetyldemethylcurcumin (AC5) exhibited higher antioxidant activity than quercetin while products from demethylation of 1 and 2 exhibited higher free radical scavenging activity. Compounds AC2 and AC5 were found to be most active in inhibiting breast cancer cells (MCF-7) proliferation with IC50 values of 6.7 and 3.6 microM, respectively. The activity of AC2 is almost doubled and of AC5 almost tripled as compared to curcumin. Their selectivity towards different cell lines is also more noticeable. Compounds AC2 and AC5 also showed increased activity against a human prostate cancer cell line (DU-145) and non-small lung cancer cell line (NCI-H460) with IC50 values of 20.4, 16.3 and 18.3, 10.7 microM, respectively.  相似文献   

19.
Silymarin, a known standardized extract obtained from seeds of Silybum marianum is widely used in treatment of several diseases of varying origin. In the present paper, we clarified the antioxidant activity of silymarin by employing various in vitro antioxidant assay such as 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH(.)) scavenging, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activity, total antioxidant activity determination by ferric thiocyanate, total reducing ability determination by Fe3+ - Fe2+ transformation method and Cuprac assay, superoxide anion radical scavenging by riboflavin/methionine/illuminate system, hydrogen peroxide scavenging and ferrous ions (Fe2+) chelating activities. Silymarin inhibited 82.7% lipid peroxidation of linoleic acid emulsion at 30 microg/mL concentration; butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), alpha-tocopherol and trolox indicated inhibition of 83.3, 82.1, 68.1 and 81.3% on peroxidation of linoleic acid emulsion at the same concentration, respectively. In addition, silymarin had an effective DPPH(.) scavenging, ABTS(.)+ scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, ferric ions (Fe3+) reducing power by Fe3+-Fe2+ transformation, cupric ions (Cu2+) reducing ability by Cuprac method, and ferrous ions (Fe2+) chelating activities. Also, BHA, BHT, alpha-tocopherol and trolox, were used as the reference antioxidant and radical scavenger compounds. Moreover, this study, which clarifies antioxidant mechanism of silymarin, brings new information on the antioxidant properties of silymarin. According to the present study, silymarin had effective in vitro antioxidant and radical scavenging activity. It could be used in the pharmacological and food industry because of its antioxidant properties.  相似文献   

20.
The study explored on the commonly available weed plant Commelina nudiflora which has potential in-vitro antioxidant and antimicrobial activity. The different polar solvents such as ethanol, chloroform, dichloromethane, hexane and aqueous were used for the soxhlet extraction. The extracts were identified pharmacologically as important bioactive compounds and their potential free radical scavenging activities, and antimicrobial properties were studied. C. nudiflora extracts were monitored on their in-vitro antioxidant ability by DPPH and ABTS radical scavenging assay. Aqueous extract shows significant free radical scavenging activity of 63.4 mg/GAE and 49.10 mg/g in DPPH and ABTS respectively. Furthermore, the aqueous crude extract was used in antibacterial studies, which shows the highest inhibitory activity against Pseudomonas aeruginosa, Escherichia coli and Salmonella typhi. Among all the extracts, aqueous extract of C. nudiflora has significant control over free radical scavenging activity and inhibition of the growth of food pathogenic bacteria. Also, the aqueous extract contains abundance of phenolics and flavonoids higher than other extracts. This study explored weed plant C. nudiflora as a potential source of antioxidant and antibacterial efficacy and identified various therapeutic value bioactive compounds from GC–MS analysis.Abbreviations: ABTS, 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid), DPPH, 2,2-diphenyl-1-picrylhydrazyl, GAE, gallic acid equivalent, GC–MS, gas chromatography and mass spectrometry  相似文献   

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