Antioxidative and anti-glycation activity of garcinol from Garcinia indica fruit rind

Garcinol, a polyisoprenylated benzophenone derivative, was purified from Garcinia indica fruit rind, and its antioxidative activity, chelating activity, free radical scavenging activity, and anti-glycation activity were studied. Garcinol exhibited moderate antioxidative activity in the micellar linoleic acid peroxidation system and also exhibited chelating activity at almost the same level as citrate. It also showed nearly 3 times greater DPPH (1, 1-diphenyl-2-picrylhydrazyl) free radical scavenging activity than DL-alpha-tocopherol by weight in aqueous ethanol solution. In a phenazine methosulfate/NADH-nitroblue tetrazolium system, garcinol exhibited superoxide anion scavenging activity and suppressed protein glycation in a bovine serum albumin/fructose system. Thus, garcinol might be beneficial as a potent antioxidant and a glycation inhibitor under specified conditions.     

Free radical scavenging activity of grape seed extract and antioxidants by electron spin resonance spectrometry in an H(2)O(2)/NaOH/DMSO system.

The scavenging effects of grape seed extract (GSE) on free radicals formed in an H(2)O(2)/NaOH/DMSO system were examined using a spin-trapping electron spin resonance (ESR) method and compared with other natural antioxidants, ascorbic acid, dl-alpha-tocopherol, and beta-carotene. GSE reduced greatly the ESR signal intensity of superoxide radical-5,5-dimethyl-1-pyrroline-N-oxide (DMPO) adducts. GSE also exhibited weak scavenging activity on hydroxyl radical and a little scavenging activity on methyl radical. Ascorbic acid exhibited strong superoxide and hydroxyl radical scavenging activities, but it increased the amount of methyl radical at high concentration. dl-alpha-Tocopherol reduced the amount of superoxide anion, especially the amount of methyl radical. However, it slightly reduced the amount of hydroxyl radical. beta-Carotene reduced the amount of hydroxyl radical and methyl radical, but it also slightly reduced superoxide anion. In the case of combination use of beta-carotene and dl-alpha-tocopherol, all radical species were suppressed. Combination of GSE and dl-alpha-tocopherol also could reduce all radical species. beta-Carotene and dl-alpha-tocopherol could reduce the methyl radical formation induced by ascorbic acid.     

Evaluation of free radical scavenging activities of antioxidants with an H(2)O(2)/NaOH/DMSO system by electron spin resonance.

An H(2)O(2)/NaOH/DMSO system has been developed for the formation of three free radicals, and the application of the system was examined with the antioxidants ascorbic acid and tocopherol. Superoxide anion, hydroxyl radical,and methyl radical are simultaneously generated in this system. The scavenging activity of ascorbic acid and tocopherol for these radicals was estimated by 5, 5'-dimethyl-1-pyrroline-N-oxide spin trapping electron spin resonance. Both water-soluble and oil-soluble antioxidants could be evaluated by using this system. Ascorbic acid specifically inhibited the superoxide anion and hydroxyl radical, whereas tocopherol suppressed the methyl radical.     

Comparative study of polyphenol scavenging activities assessed by different methods

The effect of procyanidin solutions on superoxide anion radicals was studied with an enzymatic method and their EC(50) values were determined. A comparative study of the results suggested that the free radical scavenger potential of these phenolic compounds closely depends on their chemical and stereochemical structures. Oligomeric procyanidins were isolated in different fractions from grapes and wines by low- and high-pressure liquid chromatography. These compounds were found to be efficient free radical scavengers even for the weak concentrations in wines. Their activity in grapes or wines was much stronger than that of other commercially available natural antioxidants (such as ascorbic acid and gallic acid). The effect of tannins isolated from grapes on different radicals was analyzed according to three distinct methods: an enzymatic method for superoxide anion radicals (O(2)(*)(-)), a chemical method for the stable 1,1-diphenyl-2-picrylhydrazyl radical (DPPH(*)), and an immunochemical method to study the scavenging activity of seed procyanidins on DNA lesions induced by the radical HO(*).     

Antioxidant activity of glyceollins derived from soybean elicited with Aspergillus sojae

The extract of soybean exposed to biotic elicitors such as food-grade fungus is known to have antioxidant activity. Glyceollins were major bioactive compounds present in soybean elicited by fungi and shown to have antifungal and anticancer activities. The purpose of present study was to evaluate the antioxidant activities of glyceollins by measuring ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, singlet oxygen quenching, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, hydroxyl radical scavenging activity, and lipid peroxidation inhibition. In addition, the antioxidant potential of glyceollins were measured by a fluorescent probe, 2',7'-dichlorofluorescin diacetate (DCFDA), and dihydroethidium (DHE) in mouse hepatoma hepa1c1c7 cells in which they were insulted with H2O2 to generate reactive oxygen species (ROS). Glyceollins showed a strong reducing power and inhibited lipid peroxidation, with significant scavenging activities of radicals including singlet oxygen, superoxide anion, ABTS, and DPPH. We also found that glyceollins significantly suppressed H2O2-induced ROS production in hepa1c1c7 cells. Therefore, glyceollins deserve further study as natural antioxidants and nutraceuticals.     

Antioxidant activity of a flavonoid-rich extract of Hypericum perforatum L. in vitro

A flavonoid-rich extract of Hypericum perforatum L. (FEHP) was prepared by adsorption on macroporous resin and desorption by ethanol. Total flavonoid content of FEHP was determined by a colorimetric method. The major constituents of FEHP, including rutin, hyperoside, isoquercitrin, avicularin, quercitrin, and quercetin, were determined by HPLC analysis and confirmed by LC-MS. Different antioxidant assays were utilized to evaluate free radical scavenging activity and antioxidant activity of FEHP. FEHP was an effective scavenger in quenching DPPH and superoxide radical with IC50 of 10.63 microg/mL and 54.3 microg/mL, respectively. A linear correlation between concentration of FEHP and reducing power was observed with a coefficient of r2 = 0.9991. Addition of 150 microg of FEHP obviously decreased the peroxidation of linoleic acid during 84 h incubation, but the amount of FEHP over 150 microg did not show statistically significant inhibitory effect of peroxidation of linoliec acid (p > 0.05). FEHP exhibited inhibitory effect of peroxidation of liposome induced both by hydroxyl radical generated with iron-ascorbic acid system and peroxyl radical and showed prominent inhibitory effect of deoxyribose degradation in a concentration-dependent manner in site-specific assay but poor effect in non-site-specific assay, which suggested that chelation of metal ion was the main antioxidant action. According to the results obtained in the present study, the antioxidant mechanism of FEHP might be attributed to its free radical scavenging activity, metal-chelation activity, and reactive oxygen quenching activity.     

Antioxidant activity and phenolic composition of wild, edible, and medicinal fennel from different Mediterranean countries

Fennel (Foeniculum vulgare Mill.) is a typical aromatic plant of the Mediterranean area, long used as a medicinal and spice herb. Fennel is also well-known for its essential oil, which has been extensively studied for many years owing to its commercial importance. In this work, the antioxidant activity and the total phenolic and flavonoid contents, as well as the quantitative determination of individual flavonoids and phenolic acids of wild, edible, and medicinal fennel from different Mediterranean countries, have been determined. The antioxidant activity was measured as the free radical (DPPH), hydroxyl radical, and superoxide anion scavenging activities. Wild fennel was found to exhibit a radical scavenging activity, as well as a total phenolic and total flavonoid content, higher than those of both medicinal and edible fennels.     

Isolation and characterization of antioxidant protein fractions from melinjo (Gnetum gnemon) seeds

The protein from the seeds of melinjo ( Gnetum gnemon ) was purified using a precipitation method and ion exchange chromatographic techniques to identify the potent antioxidant and free radical scavenging activities. Two antioxidant protein fractions were isolated from G. gnemon seed with molecular weights of approximately 30 kDa (Gg-AOPI) and 12 kDa (Gg-AOPII) by SDS-PAGE. The N-terminal amino acid sequence of Gg-AOPII is Gly-Asn-Gly-Lys-Ala-Thr-Val-Ala-Ile-Leu-Val-Lys-Glu-Lys-Val-Glu-Tyr-Gly-Glu-Glu, and the result of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analysis showed that they were distinct from each other; no protein in database matching was found to both Gg-AOPI and Gg-AOPII. The antioxidant or free radical scavenging activities of Gg-AOPs were investigated by employing in vitro assay systems including the inhibition of linoleic acid autoxidation, scavenging effect on α,α-diphenyl-β-picrylhydrazyl free radical (DPPH), 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), reducing power, chelating abilities of metal ions Cu(2+) and Fe(2+), and protections against hydroxyl radical-mediated DNA damages. The result showed that two protein fractions exhibited significant (p < 0.05) antioxidant activities against free radicals such as DPPH, ABTS, and superoxide anion and showed activities similar to those of glutathione (G-SH) and BHT in a linoleic acid emulsion assay system. Moreover, Gg-AOPI and Gg-AOPII also exhibited notable reducing power and strong chelating effect on Fe(2+) and protected hydroxyl radical induced oxidative DNA damage. The data obtained by the in vitro systems obviously established the antioxidant potency of Gg-AOPs.     

Antioxidant activity of extracts from Acacia confusa bark and heartwood.

The antioxidant activity of extracts from bark and heartwood of Acacia confusa was evaluated by various antioxidant assays, including free radical and superoxide radical scavenging assays and lipid peroxidation assay as well as hydroxyl radical-induced DNA strand scission assay. In addition, an ex vivo antioxidant assay using a flow cytometric technique was also employed in this study. The results indicate that both bark and heartwood extracts clearly have strong antioxidant effects. Similar inhibitory activities for each test sample were found for both 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical generation and lipid peroxidation. As for the superoxide radical scavenging activity, the heartwood extract was more effective than the bark extract. Furthermore, the heartwood extract protected PhiX174 supercoiled DNA against strand scission induced by ultraviolet photolysis of H2O2, and it reduced the amounts of intracellular hydrogen peroxide, a reactive oxygen species, when it was co-incubated with human promyelocytic leukemia (HL-60) cells under oxidative stress.     

墨鱼缠卵腺糖蛋白的抗氧化及抑菌活性研究

为了探究墨鱼缠卵腺糖蛋白(CGG)的抗氧化活性及抑菌活性,本试验通过测定CGG的超氧阴离子自由基清除率、DPPH自由基清除率、羟基自由基清除能力、小鼠体内过氧化氢酶(CAT)活性及谷胱甘肽过氧化物酶(GSH-PX)活性等研究CGG体内外抗氧化活性,并通过抑菌试验探讨了CGG的抑菌活性。结果表明,随着CGG浓度的增大,超氧阴离子自由基清除率从17.51%增加至55.84%,DPPH自由基清除率从5.7%增加至19.5%,羟基自由基清除能力从10.38%增加至57.94%;与对照组相比, 低、中、高剂量组小鼠体内的CAT 活性分别提高了21.91%、126.29%、135.63%,GSH-PX活性分别提高了2.04%、24.69%、28.13%。抑菌试验结果表明,当CGG浓度为14 mg·mL^-1时,大肠杆菌(Escherichia coli)、金黄色葡萄球菌(Staphylococcus aureus)、假单胞菌(Pseudomonadaceae)的抑菌圈分别为15.7、13.6、12.5 mm,MIC分别为1.25、7、7 mg·mL^-1,MBC分别为14、28、14 mg·mL^-1。综上表明,CGG具有一定的抗氧化和抑菌活性,但抑菌效果较弱。本研究结果为墨鱼缠卵腺的合理利用提供了一定的理论基础,同时对提高水产资源利用率有一定的参考价值。     

Antioxidant activity of Glossogyne tenuifolia

Glossogyne tenuifolia is a native traditional anti-inflammatory herb in Taiwan. It has previously been shown that the ethanol extract of G. tenuifolia (GT) inhibited the LPS-induced inflammatory mediator release from murine macrophage cell line and human whole blood. In the present work, the ethanol extracts of G. tenuifolia and its major constituent, luteolin-7-glucoside, were shown to be scavengers of 1,1-diphenyl-2-picrylhydrazyl, superoxide, and hydroxyl radicals. Moreover, copper-induced low-density lipoprotein oxidation was suppressed by GT and luteolin-7-glucoside as measured by decreased formation of malondialdehyde and conjugated diene as well as reduced electrophoretic mobility. GT and luteolin-7-glucoside were also against N-formyl-methionyl-leucyl-phenylalanine-induced reactive oxygen species (ROS) production in human polymorphonuclear neutrophils and peripheral blood mononuclear cells. In summary, these data indicated that GT is a potential ROS scavenger and may prevent atherosclerosis via inhibiting LDL oxidation or ROS production in human leukocytes. Moreover, luteolin-7-glucoside may serve as the active principal of GT.     

Comparison of the radical scavenging potential of polar and lipidic fractions of olive oil and other vegetable oils under normal conditions and after thermal treatment

The antioxidant activity (IC(50)) of extra virgin olive oil (EVOO), commercial olive oil, and other vegetable oils (soybean, sunflower, and corn oil) was determined by UV-vis and by electron paramagnetic resonance (EPR) spectroscopy of the stable radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). Also, we studied the antioxidant activity of the methanol soluble phase (methanolic, MF) and the nonsoluble phase (lipidic, LF) of oils by the same methods. Similarly, we studied the effect of heating on the antioxidant activity at 160 and 190 degrees C. Also, the MF, containing the polyphenolic substances, was used for measurements of the radical scavenging capacity toward the most important oxygen free radicals, superoxide anion (O(2)(*)(-)) and hydroxyl (HO(*)) radicals. Results showed that soybean oil and EVOO had the highest antioxidant potential and thermal stability. In the case of soybean oil, the antioxidant capacity is the result of its high content of gamma- and delta-tocopherols (with the highest antioxidant capacity and thermostabilities), whereas in EVOO, the antioxidant potential is the result of the combination of specific antioxidant polyphenols, which are acting additionally as effective stabilizers of alpha-tocopherol. The high content of EVOO in tyrosol, hydrotyrosol, and oleuropein and other polyphenolics with radical scavenging abilities toward superoxide anion and hydroxyl radical suggests that olive oil possesses biological properties that could partially account for the observed beneficial health effects of the Mediterranean diet.     

Phenolic acid, tocopherol and carotenoid compositions, and antioxidant functions of hard red winter wheat bran

An electron spin resonance (ESR) spectrometry study was conducted to examine the free radical scavenging properties of bran extracts of Alliance and Wichita wheat using hydroxyl radical (HO*), 2,2-diphenyl-1-picryhydrazyl radical (DPPH*), and superoxide radical anion (O2*-) and their chelating capacities against Cu2+. Also reported is the radical cation 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS*+) scavenging activity, oxygen radical absorbing capacity (ORAC), and chelating property against Fe2+ of the bran extracts measured by the spectrophotometric methods. Significant radical scavenging and chelating capacities were detected in the bran extracts, along with significant levels of phenolic acids, tocopherols, and carotenoids. Ferulic acid, with a concentration range of 130.60-146.38 microg/g, was the predominant phenolic acid in all of the tested bran samples and accounted for approximately 53-67% of total phenolic acids on a weight basis. Total tocopherol concentration ranged from 1.87 to 2.95 micromol/100 g of bran, whereas total carotenoid level was 0.20-0.33 micromol/100 g of bran. In addition, both wheat variety and growing conditions might significantly alter antioxidant properties and concentrations of beneficial components in wheat bran.     

苦菜总黄酮超声波辅助提取及抗氧化能力研究

为开发和利用苦菜中的黄酮资源,采用超声波辅助法提取苦菜总黄酮,通过响应面分析法对苦菜总黄酮超声波辅助提取工艺条件进行优化,并对最佳提取条件下苦菜总黄酮提取液的抗氧化能力进行分析。结果表明,苦菜总黄酮超声泼辅助提取最优工艺参数为:乙醇浓度49%、浸提温度69℃、浸提时间162 min、料液比1∶62(m/v),此条件下苦菜黄酮得率为3.73%±0.03%。最优提取条件下,苦菜总黄酮提取液清除DPPH自由基、羟基自由基、超氧阴离子自由基的IC₅₀分别为0.005 9、0.153、0.024 8 mg·mL^-1,表现出较强的抗氧化能力。本研究结果为苦菜黄酮的开发应用提供了理论基础。     

中性蛋白酶水解鸡骨泥制备短肽工艺优化

为了探究酶法制备鸡骨泥短肽的最佳工艺,该文研究了以中性蛋白酶酶解鸡骨泥时各因素对短肽得率和羟自由基清除率的影响,以及鸡骨泥肽清除超氧阴离子自由基和1,1-二苯基-2-三硝基苯肼自由基(2,2-diphenyl-1-picrylhydrazyl)的能力。试验探究了酶解过程中不同底物浓度、酶浓度、反应温度和反应时间对短肽得率和羟自由基清除率的影响,采用响应曲面优化得到了以短肽得率为目标的中性蛋白酶酶解鸡骨泥的最优工艺,当反应液p H值为7.2,反应温度42℃,反应时间2 h,底物质量分数5%,酶添加量200 mg/g,该条件下制备鸡骨泥肽,测得其短肽得率为56.16%,羟自由基清除率为54.12%。采用该酶解工艺制备鸡骨泥肽,测得其对超氧阴离子自由基最高清除率为56.01%,对DPPH自由基最高清除率为81.57%,说明鸡骨泥肽具有一定的抗氧化活性,研究结果为酶法制备鸡骨泥肽提供参考。     

Purple rice extract and anthocyanidins of the constituents protect against light-induced retinal damage in vitro and in vivo

This study evaluated the protective effects of purple rice ( Oryza sativa L.) bran extract (PRE) and its major anthocyanidins (cyanidin and peonidin) against light-induced retinal damage. In an in vitro experiment, cultured murine photoreceptor cells (661W) were damaged by a 24 h exposure to light. Viability of 661W after light treatment, assessed by the tetrazolium salt (WST-8) assay and Hoechst 33342 nuclear staining, was improved by the addition of PRE, cyanidin, and peonidin. Intracellular radical activation in 661W, evaluated using the reactive oxygen species (ROS) sensitive probe 5-(and 6)-chloromethyl-2,7-dichlorodihydrofluorescein diacetate acetyl ester (CM-H(2)DCFDA), was reduced by PRE and its anthocyanidins. Electron spin resonance (ESR) measurements showed that PRE, peonidin, and cyanidin all exhibited radical scavenging activities against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, superoxide anion radical ((?)O(2)(-)), and hydroxyl radical ((?)OH). In an in vivo mouse experiment, intravitreous injection of PRE significantly suppressed photoreceptor degeneration induced by exposure to light as revealed by histological analysis using hematoxylin-eosin staining. These findings suggest that PRE and its anthocyanidins possess protective effects with antioxidation mechanism in both in vitro and in vivo models of retinal diseases.     

Studies on the antioxidant activity of Echinacea root extract

Methanol extracts of freeze-dried Echinacea (E. angustifolia, E. pallida, and E. purpurea) roots were examined for free radical scavenging capacities and antioxidant activities. Root extracts of E. angustifolia, E. pallida, and E. purpurea were capable of scavenging hydroxyl radical. Similar scavenging activities for each variety were found for both 1,1-diphenyl-2-picrylhydrazyl radical and ABTS radical. Meanwhile, antioxidant activities of all three varieties of Echinacea were found to delay the formation of conjugated diene hydroperoxide induced by the thermal decomposition of 2, 2'-azobis(2-amidinopropane) dihydrochloride and extend the lag phase of peroxidation of soybean liposomes. Echinacea root extracts suppressed the oxidation of human low-density lipoprotein, as evaluated by reduced agarose electrophoretic mobility following oxidative modification by Cu(2+). The mechanisms of antioxidant activity of extracts derived from Echinacea roots included free radical scavenging and transition metal chelating.     

水分胁迫对长序榆幼苗脂质过氧化及抗氧化系统的影响

以盆栽长序榆一年生幼苗为试验材料,分对照、轻度干旱、中度干旱、重度干旱、饱和状态、轻度水涝、中度水涝7个处理,研究不同土壤含水量对长序榆幼苗脂质过氧化及抗氧化系统的影响。结果表明:处理前期,随着处理时间的延长和胁迫程度的加深,长序榆幼苗体内SOD、POD活性上升,脯氨酸和可溶性糖含量逐渐升高,质膜透性变化趋势不明显,MDA含量、.OH等活性氧的含量呈先降低后升高趋势,水涝胁迫下长序榆叶绿素含量、Fo、Fm、Fv/Fm、ETR、同期光合量子产量(Yield)、非光化学荧光淬灭系数(NPQ)都有所上升。到处理后期,超氧阴离子产生速率继续增大,SOD、POD活性开始下降,使活性氧的增加超出了细胞的清除能力,导致活性氧积累增加,使得质膜透性增大,.OH和MDA含量持续升高,Fo、Fm、Fv/Fm、ETR、Yield、NPQ大幅降低。灰色关联度分析表明,在16个指标中,与土壤水关系最密切的是叶绿素b,其次是Fo、Fm、Fv/Fm和ETR。通过隶属函数分析可知,长序榆幼苗更耐涝,对不同土壤含水量的适应程度依次为饱和状态>对照组>轻度水涝>中度水涝>轻度干旱>中度干旱>重度干旱。     

Antioxidant activity of A-type proanthocyanidins from Geranium niveum (Geraniaceae)

Geranium niveum S. Watson (Geraniaceae) is a medicinal herb widely used by the Tarahumara Indians of Mexico. This species is rich in proanthocyanidins and other phenolics. Previous in vitro assays have demonstrated that proanthocyanidins exhibited antiinflammatory, antiviral, antibacterial, enzyme-inhibiting, antioxidant, and radical-scavenging properties. In view of its medicinal use and chemical composition, the aim of the present study was to determine the in vitro antioxidant activity of the extracts and two proanthocyanidins (geranins A and D) from the roots of G. niveum by using seven different assay systems, namely, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), 1,1-diphenyl-2-picrylhydrazyl (DPPH), superoxide anion (O2*-), hydrogen peroxide (H2O2), hydroxyl radical (OH*), hypochlorous acid (HOCl), and singlet oxygen ((1)O2). Two known antioxidants, resveratrol and ascorbic acid, were used as positive controls. The results showed that geranins A and D and the extracts were able to scavenge ABTS, DPPH, O2*-, OH*, and HOCl. The scavenging ability of geranins A and D was similar to that of resveratrol and ascorbic acid in the following assays: ABTS, O2*-, and HOCl. The scavenging capacity of ascorbic acid for DPPH was higher than that of both geranins and resveratrol. On the other hand, the OH* scavenging action of both geranins and resveratrol was similar. The methanol-CHCl3 (1:1) extract had a higher ability to scavenge ABTS, DPPH, and O2*- radicals than the chloroform extract. In turn, the latter was more potent than the methanol-CHCl3 (1:1) extract as OH* or HOCl scavenger agent. Neither geranins A and D nor the extracts were able to scavenge H2O2 and (1)O2. In conclusion, G. niveum roots have proanthocyanidins with powerful radical scavenging in vitro activity. This property may partially explain the wide use of this plant in the Tarahumara indigenous system of medicine for the treatment of gastrointestinal illnesses (other than spasms), pain, and fevers associated with oxidative stress.     

Free radical scavenging activity of chitooligosaccharides by electron spin resonance spectrometry

The radical scavenging effects of chitooligosaccharides (COSs) on hydroxyl radical, superoxide radical, alkyl radical, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical were investigated using a spin-trapping electron spin resonance (ESR) method and compared with the ESR signal intensity. COSs exhibited strong scavenging activity on hydroxyl radical and superoxide radical and weak scavenging activity on alkyl radical and DPPH radical. The radical scavenging activity of COSs increased with increment of concentration, and it was also dependent on molecular weight. These results suggest that the scavenging activity of COSs is dependent on their molecular weights and tested radicals.