Free radical scavenging activity of red ginseng aqueous extracts

This study was performed to investigate the free radical scavenging activity of Panax red ginseng C.A. Meyer aqueous extract on 1,1-dipheny-2-picrylhydrazyl (DPPH), carbon-centered radical, hydroxyl and superoxide radicals using Electron Spin Resonance (ESR) spectrometer and spin-trapping techniques. Two different Red ginseng aqueous extracts prepared by boiling water or room temperature extraction exhibited no significant difference in free radical scavenging activity. Ginseng extracts completely eliminated DPPH radical at 2 mg/ml. About 0.5 mg/ml ginseng extracts quenched 80% carbon-centered free radicals generated from 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH). Hydroxyl radical and superoxide radical were generated by UV irradiation and trapped by 5,5-dimethyl-l-pyrroline-N oxide (DMPO). Ginseng extracts scavenged 40% of hydroxyl radical at 0.1 mg/ml. Two mg/ml ginseng extracts completely scavenged superoxide radical. Ginseng extracts did not scavenge nitric oxide. The ESR data demonstrate that red ginseng aqueous extract is not a strong free radical scavenger.     

Antigenotoxic and free radical scavenging activities of extracts from Moricandia arvensis

This study evaluates genotoxic and antigenotoxic effects of extracts from leaves of Moricandia arvensis, which are used in traditional cooking and medicines. Extracts showed no genotoxicity when tested with the SOS Chromotest using E. coli PQ37 and PQ35 strains, except for the total oligomers flavonoids enriched extract. Petroleum ether and methanol extracts are the most active in reducing nitrofurantoin genotoxicity, whereas methanol and total oligomers flavonoids enriched extracts showed the most important inhibitory effect of H2O2 genotoxicity. In addition, these two extracts showed important free radical scavenging activity toward the DPPH. radical, whereas the chloroform extract exhibited the highest value of TEAC against ABTS+. radical.     

香樟叶不同溶剂提取物清除DPPH自由基的研究

目的研究香樟叶不同溶剂提取物清除1,1-二苯基-2-三硝基苯肼(DPPH)自由基的作用,筛选出香樟叶清除自由基活性的有效部位。方法采用系统溶剂法将香樟叶的乙醇提取物分成石油醚、三氯甲烷、乙酸乙酯、正丁醇和水5种溶剂提取物,采用DPPH自由基体系法测定其抗氧化活性。结果香樟叶的石油醚、三氯甲烷、乙酸乙酯、正丁醇和水溶剂提取物对DPPH的IC50分别为6.003 8、1.329 8、0.398 7、0.346 7、5.087 0mg·mL-1。结论香樟叶不同溶剂提取物均有抗氧化活性,其正丁醇提取物的抗氧化能力最强。     

Cytotoxic and radical scavenging activity of blended herbal extracts

Chinese medicines have been applied to a variety of diseases producing various favorable effects, possibly due to the interactions between individual components. Establishment of an evaluation method for such interactions may facilitate the production of new natural medicines. We investigated here the interaction of the hot water extract of Aconiti Tuber (one of the most prominent Chinese medicines) and that of Scutellariae Radix, Coptidis Rhizoma, Glycyrrhizae Radix, Atractylodesi, Lanceae Rhizoma or Poria, by measuring the superoxide anion (O2-), hydroxyl radical (OH) and nitric oxide (NO) scavenging activity, using ESR spectroscopy. We found that a 1:1 mixture of the hot water extract of one herb and that of another herb (referred to as a combined formula) showed a higher radical scavenging activity and cytotoxic activity than the hot water extract of a 1:1 mixture of two herbs (referred to as a blended formula). Both formulae showed higher cytotoxic activity against human oral tumor cell lines than against normal cells. These data further confirm the medicinal usefulness of combinations of empirical Chinese medicines.     

Free radical scavenging, antioxidant enzymes and wound healing activities of leaves extracts from Clerodendrum infortunatum L

Three successive extracts of Clerodendrum infortunatum L. leaves have been studied for their potential as antioxidants in 1,1-diphenyl-2-picrylhydrazyl (DPPH) model. The scavenging activity of ethanol extract was found to be high when compared to petroleum ether and chloroform extracts. Hence, it was selected to evaluate the beneficial properties using in vitro and in vivo models. The antioxidant and its protective effects against CCl(4) induced oxidative stress in rats were significantly high. Further, to validate the traditional therapeutic claim, wound healing activity of the plant extracts was also carried out. Among the three extracts tested the petroleum ether and ethanol extracts exhibited a significant response. The presence of high antioxidant and pharmacological properties correlates to the total phenolic contents in the plant Clerodendrum infortunatum L.     

Diarylheptanoids with free radical scavenging and hepatoprotective activity in vitro from Curcuma longa.

Assay-guided fractionation of the EtOAc soluble fraction of the rhizomes of Curcuma longa furnished three DPPH free radical scavenging diarylheptanoids, curcumin (1), demethoxycurcumin (2), and bisdemethoxycurcumin (3). Compounds 1-3 showed the DPPH radical scavenging effects with IC(50) values of 2.8, 39.2, 308.7 microM, respectively. L-Ascorbic acid and resveratrol as positive controls exhibited IC(50) values of 22.5 and 25.0 microM, respectively. Compounds 1-3 showed significant hepatoprotective effects on tacrine-induced cytotoxicity in human liver-derived Hep G2 cells. The EC(50) values of 1-3 are 86.9, 70.7, and 50.2 microM, respectively. Silybin (EC(50) = 69.0 microM) and silychristin (EC(50) = 82.7 microM) were used as positive controls.     

Antioxidant and free radical scavenging activity of isoflavone metabolites

1. Soy isoflavones have been extensively studied because of their possible health-promoting effects. Genistein and daidzein, the major isoflavone aglycones, have received most attention; however, they undergo extensive metabolism in the gut and liver, which might affect their biological properties. 2. The antioxidant activity, free radical-scavenging properties and selected cellular effects of the isoflavone metabolites equol, 8-hydroxydaidzein, O-desmethylangiolensin, and 1,3,5 trihydroxybenzene were investigated in comparison with their parent aglycones, genistein and daidzein. 3. Electron spin resonance spectroscopy indicated that 8-hydroxydaidzein was the most potent scavenger of hydroxyl and superoxide anion radicals. Isoflavone metabolites also exhibited higher antioxidant activity than parent compounds in standard antioxidant (FRAP and TEAC) assays. However, for the suppression of nitric oxide production by activated macrophages, genistein showed the highest potency, followed by equol and daidzein. 4. The metabolism of isoflavones affects their free radical scavenging and antioxidant properties, and their cellular activity, but the effects are complex.     

Antioxidant and free radical scavenging activity of isoflavone metabolites

1. Soy isoflavones have been extensively studied because of their possible health-promoting effects. Genistein and daidzein, the major isoflavone aglycones, have received most attention; however, they undergo extensive metabolism in the gut and liver, which might affect their biological properties. 2. The antioxidant activity, free radical-scavenging properties and selected cellular effects of the isoflavone metabolites equol, 8-hydroxydaidzein, O-desmethylangiolensin, and 1,3,5 trihydroxybenzene were investigated in comparison with their parent aglycones, genistein and daidzein. 3. Electron spin resonance spectroscopy indicated that 8-hydroxydaidzein was the most potent scavenger of hydroxyl and superoxide anion radicals. Isoflavone metabolites also exhibited higher antioxidant activity than parent compounds in standard antioxidant (FRAP and TEAC) assays. However, for the suppression of nitric oxide production by activated macrophages, genistein showed the highest potency, followed by equol and daidzein. 4. The metabolism of isoflavones affects their free radical scavenging and antioxidant properties, and their cellular activity, but the effects are complex.     

基于DPPH自由基清除能力的姜黄提取物抗氧化活性评价

目的建立高通量检测DPPH自由基清除能力的实验方法,对姜黄提取物抗氧化活性进行初步评价。方法通过测定抗坏血酸(维生素C)的DPPH自由基清除率曲线,以IC50值作为评价试样清除DPPH自由基能力的指标,并将此应用于测定姜黄醇提物和水提物清除DPPH自由基的能力。结果测定波长515nm,抗坏血酸DPPH自由基清除能力在62.5～750.0μg/mL线性良好,方法可靠。姜黄醇提物的DPPH自由基清除能力(IC507.78mg/mL)明显强于水提物(IC5014.84mg/mL)。结论建立的DPPH自由基清除测定方法可靠、简便、灵敏,其高通量的快速检测方法可为抗氧化药物筛选提供参考。     

Two acylated flavonoid glycosides from Stachys bombycina, and their free radical scavenging activity

Preparative reversed-phase HPLC analysis of the methanol extract of the aerial parts of Stachys bombycina (Lamiaceae) afforded two acylated flavonoids glycosides, chrysoeriol 7-O-[6-O-acetyl-beta-D-allopyranosyl]-(1 --> 2)-beta-D-glucopyranoside (1) and apigenin 7-O-beta-D-(6-p-coumaroyl)-glucopyranoside (2), the former being a new natural product. The structures of these compounds were elucidated unambiguously by UV spectroscopic analyses using shift reagents, ESIMS, and 1D and 2D NMR spectroscopic techniques. The free radical scavenging activity of 1 and 2 compounds were assessed by DPPH assay, and the RC50 values were 1.25 x 10(-2) and 7.69 x 10(-4) mg/mL, respectively.     

9, 10-Dihydrophenanthrene derivatives from Pholidota yunnanensis and scavenging activity on DPPH free radical

Three new 9,10-dihydrophenanthrene derivatives named phoyunnanins A-C, together with six known 9,10-dihydrophenanthrene constituents, 4,4',7,7'-tetrahydroxy-2,2'-dimethoxy-9,9',10,10'-tetrahydro-1,1'-biphenanthrene (4), lusianthridin (5), eulophiol (6), 2,4,7-trihydroxy-9,10-dihydrophenanthrene (7) and imbricatin (8), were isolated from the 60% ethanolic extract of air-dried whole plant of Pholidota yunnanensis Rolfe. The structures of phoyunnanins A-C were established as 6-[2'-(3',3'-dihydroxy-5'-methoxybibenzy)]-4,7-dihydroxy-2-methoxy-9,10-dihydrophenanthrene (1), 6-[6'-(trans-3',3'-dihydroxy-5'-methoxystilbeny)]-4,7-dihydroxy-2-methoxy-9,10-dihydrophenanthrene (2) and 4,4',7,7'-tetrahydroxy-2,2'-dimethoxy-9,9',10,10'-tetrahydro-1,6'-biphenanthrene (3), respectively, on the basis of the spectroscopic analysis. All eight compounds (1-8) were found to show the DPPH free radical scavenging activity with EC₅₀ from 8.8 to 55.9 μM.     

黄皮酰胺抗脂质过氧化及对氧自由基清除作用

黄皮酰胺是一种生物碱,可抑制铁-半胱氨酸体系引起的大鼠脑,心,肝和睾丸微粒体脂质过氧化,电子自旋共振法研究表明,黄皮酰可清除由佛波醇豆蔻酸乙酸酸酯(PMA)刺激人多形核白细胞(PML)所产生的氧自由基,自旋探针测氧法结果表明,对PMA刺激PML时的氧消耗无影响,在Fenton反应体系中,对羟自由基的清除率为36.6％,在黄嘌呤-黄嘌呤氧化酶和光照核黄素体系中,对超氧阴离子的清除作用分别为21.2％和16.2％。结果提示黄皮酰胺对氧自由基的直接捕捉作用是其抗脂质过氧化作用的机理之一。     

马齿苋提取物体外清除自由基活性的研究

目的:研究马齿苋全草提取物体外的抗氧化活性。方法:选取1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picryl-hydrazine,DPPH)自由基、羟基自由基、超氧阴离子自由基,以及还原能力体系对马齿苋提取物进行抗氧化活性测定。与阳性对照药没食子酸和维生素C作比较。结果:马齿苋提取物清除DPPH自由基、羟基自由基和超氧阴离子自由基的能力在低浓度时弱于阳性对照药没食子酸和维生素C,但随着浓度的增加,其清除活性均明显优于阳性对照药。在0~200μg/ml浓度范围内,马齿苋提取物的还原能力弱于2,6-二叔丁基对甲酚。结论:马齿苋提取物具有较好的清除自由基能力,但还原能力相对较弱。马齿苋可能是有效的外源性天然有机抗氧化剂。     

羊栖菜中清除自由基活性物质的研究

目的 通过不同溶剂对羊栖菜的有效成分进行提取和体外活性检测,以期筛选出具有一定开发潜力的自由基清除荆.方法 采用DPPH(二苯代苦味酰自由基)体系、超氧阴离子体系对不同提取物进行清除自由基活性测定,并与海带、紫菜的提取物及抗坏血酸(Vit C)和荼多酚作活性对照.结果 不同溶剂对羊栖菜的提取率不同,各种提取物之间的清除自由基活性存在一定差异.结论 0.5%Na2CO3溶液提取率最高,且提取物清除自由基的能力最强,以DPPH体系作为检测系统时测量结果较为稳定,效果也较明显.     

Interactions of herbal extract combinations against free radical scavenging activity

Herbal medicines are often combinations of herbal extracts that are assumed to have additive or synergistic effects. This investigation compared the effect of individual herbal extracts with combinations of extracts on antioxidant activity by 1,1-diphenyl picryl hydrazyl (DPPH) method and showed the additive or synergistic effects by studying interactions between herbal extracts in combination. Curcuma longa Linn. (Zingiberaceae), Bacopa monneira Linn. Penn. (Scrophulariaceae), Zingiber officinale Rosc. (Zingiberaceae) and Emblica officinalis Gaertn. (Euphorbiaceae) were collected and used to prepare the extracts. Effects of the extracts on DPPH scavenging activity were estimated quantitatively by a UV-spectrophotometeric method. Combinations of two herbal extracts of the four active extracts and their interactions were tested by the DPPH method. Each extract significantly scavenges the free radical activity in a dose-dependent manner. The active extracts of Curcuma longa, Bacopa monneira, Zingiber officinale and Emblica officinalis were tested as two-extract combinations. Curcuma longa and Bacopa monneiera, when combined, showed additive effect with a trend towards synergistic effect, whereas Curcuma longa and Emblica officinalis together were additive. The four extracts together were significantly (p?≤?0.01) more effective than the two-by-two combinations and the individual extracts alone. The less predictable nature of the two-way combinations suggests a need for careful characterization of the effects of each individual herb based on their intended use.     

Antimutagenic and antioxidant characteristics of Chukrasia tabularis A Juss extracts

The current study aims to evaluate the antioxidative and antimutagenic activities of methanol extract and different fractions of Chukrasia tabularis leaves. The antioxidative potential was evaluated using 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation and superoxide anion radical-scavenging assay. The antimutagenic potential was evaluated against direct-acting mutagens, 4-nitro-o-phenylenediamine and sodium azide; and S9-dependent mutagen, 2-aminofluorene in TA98 and TA100 strains of Salmonella typhimurium using Ames assay. It has been found that methanol extract and its fractions were more efficient against S9-dependent mutagen in pre-incubation mode of treatment as compared to direct-acting mutagens in both the strains. Methanol extract and its fractions also exhibited strong radical-scavenging potential. High-performance liquid chromatography (HPLC) analysis of methanol extract showed the presence of gallic acid, epicatechin, 7-hydroxycoumarin, and rutin. From the study, it could be concluded that antioxidative and antimutagenic activity of methanol extract and its fractions was related to the synergistic interactions among different chemical compounds.     

In vitro antioxidant and free radical scavenging activities of Garcinia kola seeds

Garcinia kola Heckel – a tropical plant which grows in moist forest, has found wide applications in traditional medicine especially in the West and Central African sub-region. The seeds have been demonstrated to possess numerous bioactivities but research is highly limited on the link between its fractions and the bioactivities. In this work, the methanolic extract of Garcinia kola seeds was subjected to silica gel column chromatography into five fractions ME1–ME5 and the free radical scavenging activities and antioxidant potentials were determined for each fraction using various in vitro models. The ME4 fraction possessed the greatest activities. It was also demonstrated that the ME4 fraction strongly inhibited nitric oxide production in lipopolysaccharide activated macrophage U937 cells. Chromatographic fractionation and spectroscopic analysis of the ME4 fraction revealed the presence of four compounds namely garcinia biflavonoids GB1 and GB2, garcinal and garcinoic acid. These findings show that these four compounds are partly responsible for the great antioxidant potential of Garcinia kola seeds. This gives further evidence to the nutraceutical and pharmaceutical potential of Garcinia kola.     

Comparison of cytotoxicity and radical scavenging activity between tea extracts and Chinese medicines

Three hot water extracts of black tea, green tea and powdered green tea and five Chinese medicines (Shosaiko-tou, Orengedoku-tou, Goshuyu-tou, Choto-san, Keishininjinn-tou) were investigated for their ability to modify nitric oxide (NO) production by lipopolysaccharide (LPS)-stimulated mouse macrophage-like Raw 264.7 cells, and for their cytotoxicity, radical intensity and scavenging activity. All eight materials significantly reduced the extracellular concentration of NO in the LPS-stimulated Raw 264.7 cells. ESR spectroscopy shows that tea extracts, which had higher cytotoxicity, generated higher amounts of radicals, and more efficiently scavenged O2- (generated by hypoxanthine-xanthine oxidase reaction), hydroxyl radical (generated by Fenton reaction) and NO (generated by 1-hydroxyl-2-oxo-3-(N-3-methyl-3-aminopropyl)-3-methyl-1-triazene) than Chinese medicines. Close association between the radical intensity and radical scavenging activity suggests their bimodal (anti-oxidant and pro-oxidant) action. Pretreatment of mice with tea extracts significantly reduced the lethality of Escherichia coli-infection. All tea extracts showed no apparent anti-HIV activity. The present study demonstrates, for the first time, several attractive features of tea extracts in comparison with Chinese medicines, suggesting the possible application of the tea extracts for radical-mediated diseases.