益智的抗氧化作用

本文探讨了益智(Alpinia oxyphylla Miquel)超临界CO2提取物及其渣的水提物、正丙醇提取物和乙酸乙酯提取物的抗氧化作用,测定了总酚含量、黄酮含量、抗氧化力、还原能力、DPPH清除率.结果表明,益智超临界CO2提取物和正丙醇提取物的总酚含量最高,均为5.53%,乙酸乙酯提取物的总酚含量为4.04%,水提物总酚含量最低,为O.89%.抗氧化力与酚含量相关(R2=0.703).四种提取物中黄酮含量顺序为:乙酸乙酯提取物(6.29%)＞丙醇提取物(5.81%)＞水提取物(4.85%)＞超临界CO2提取物(4.70%).在还原能力、清除DPPH自由基和羟自由基方面,乙酸乙酯提取物表现出了很强的抗氧化能力,呈现剂量依赖关系.     

罗汉果不同溶剂提取物抗氧化及清除活性氧自由基作用

以水、甲醇、乙醇和乙酸乙酯为溶剂,对罗汉果干果进行提取,分别采用磷钼酸铵体系、邻苯三酚自氧化体系、Fenton反应体系和卵黄脂质过氧化体系测定各种提取物的总抗氧化性能、超氧阴离子自由基和羟基自由基清除性能及其抗脂质过氧化作用。结果表明,四种溶剂提取物均具较强的抗氧化性和活性氧自由基清除性能,其能力的大小顺序为:乙酸乙酯提取物>水提物>甲醇提取物>乙醇提取物。     

Evaluation of free radical scavenging activity of Butea monosperma Lam

In the present study, ethyl acetate, butanol and aqueous fractions derived from total methanol extract of Butea monosperma flowers were evaluated for radical scavenging activities using different in vitro models like reducing power assay, scavenging of 2,2 diphenyl-1-picrylhydrazyl (DPPH) radical, nitric oxide radical, superoxide anion radical, hydroxyl radical and inhibition of erythrocyte hemolysis using 2, 2' azo-bis (amidinopropane) dihydrochloride (AAPH). Methanol extract along with its ethyl acetate and butanol fractions showed potent free radical scavenging activity, whereas aqueous fraction was found to be devoid of any radical scavenging properties. The observed activity could be due to the higher phenolic content in the extracts (16.1, 25.29, and 17.74% w/w in methanol extract, ethyl acetate and butanol fractions respectively). HPTLC fingerprint profile of the ethyl acetate and butanol fractions were developed which would serve as reference standard for quality control of the extracts.     

Antioxidant activities of extracts and fractions from Lysimachia foenum-graecum Hance

The antioxidant activities of water extract, methanol extract, ethyl acetate, and n-BuOH fractions of methanol extract from Lysimachia foenum-graecum Hance were investigated in this study. Various methods, such as the total antioxidant capacity measured by phosphomolybdenum method, scavenging activities towards 1,1-diphenyl-2-picryhydrazyl (DPPH) radical, superoxide anion radical, and hydroxyl radical, were established in in vitro systems. The amounts of total phenolics and total flavonoids in the extracts and fractions were also determined by spectrophotometric methods. The results showed that all the extracts and fractions exhibited antioxidant and radical-scavenging activities at different magnitudes of potency. The decreasing order of antioxidant and radical-scavenging activities among the extracts assayed through all the four methods were found to be ethyl acetate fraction>n-BuOH fraction>methanol extract>water extract. This similar order of the amounts of total phenolics and total flavonoids shows that the extent of antioxidant and radical-scavenging activities is in accordance with the amounts of phenolics and flavonoids present in extracts and fractions. The extracts of L. foenum-graecum Hance might be valuable antioxidant natural sources and seemed to be applicable in both healthy medicine and food industry.     

Antioxidant and anti-inflammatory activity of extract obtained from Aspergillus candidus MTCC 2202 broth filtrate

Antioxidant potential of Aspergillus candidus MTCC 2202 broth filtrate extract was studied using different antioxidant models, whereas anti-inflammatory potential was studied using carrageenan-induced rat paw oedema model. The ethyl acetate extract at 1000 microg/ml showed maximum scavenging activity of the stable radical 1,1-diphenyl,2-picryl hydrazyl upto 96.65% (IC50=430.36 microg/ml) and scavenging of the radical cation, 2,2-azinobis-(3-ethylbenzothiazoline-6-sulphonate) upto 92.25% (IC50=606.29 microg/ml) at the same concentration. The extract had good reducing power, however showed moderate inhibition for conjugated dienes and thiobarbituric acid reactive acid substances (59.56 and 51.45%). The total phenolic content of various extracts of A. candidus broth filtrate was measured and a correlation between radical scavenging activities of extracts with total phenolic content was observed. The ethyl acetate extract (125 mg/kg ip) showed significant anti-inflammatory activity in carrageenan-induced rat paw oedema model. The exhibited antioxidant activity of ethyl acetate extract of A. candidus broth filtrate was comparable with BHA and ascorbic acid, while anti-inflammatory activity was comparable with standard diclofenac sodium.     

Free radical scavenging activity,total phenolic content,total antioxidant status,and total oxidant status of endemic Thermopsis turcica

Thermopsis turcica, endemic to Turkey, is in danger of extinction. Studies on this species are very few due to the fact that it was only discovered in 1983 and grows in a small circumscribed area in Turkey. In this study, free radical scavenging activity, total phenolic content, total oxidant status (TOS), and total antioxidant status (TAS) of methanol (TTM) and acetone (TTA) extracts of T. turcica were measured spectroscopically. Free radical scavenging activity was determined according to the elimination of DPPH radicals and total phenol content was determined by the Folin–Ciocalteu reaction. Total oxidant status (TOS) and total antioxidant status (TAS) were measured with commercially available kits. Methanol and acetone extracts of T. turcica were found to have a specific radical scavenging effect. This effect was found to be related to the total phenolic content of the extracts. Since the TTA had a higher phenolic content than the methanol extract, it had a stronger radical scavenging effect. In addition, the total antioxidant capacity of the methanol extract was observed to be higher than that of its acetone counterpart. As a result, due to its antioxidative properties, T. turcica is thought to be a natural source of antioxidants.     

Analysis of antioxidant metabolites by solvent extraction from sclerotia of Inonotus obliquus (Chaga)

Introduction – The sclerotia of Inonotus obliquus (Chaga) are effective therapeutic agents to treat several human malignant tumours and other diseases without unacceptable toxic side‐effects. Objective – To investigate solvent effects on metabolic profiles and antioxidant activities of extracts of Chaga. Methodology – Chaga was extracted by petroleum ether, chloroform, ethyl acetate, acetone, ethanol and water. Solvent effects on metabolites in the extracts were assayed by NMR‐based metabolomic analysis. Antioxidant activities were indicated as capacities for scavenging superoxide anion, DPPH and hydroxyl radicals. Results – Petroleum ether and chloroform extracts contained primarily lanostane‐type triterpenoids (LT), whereas the extracts of ethyl acetate, acetone and ethanol were characterised by the predominant presence of hispidin analogues and LT, and water extracts by polysaccharides and phenolic compounds. The ethyl acetate, acetone, ethanol and water extracts revealed remarkable potential for scavenging the tested radicals, while those of petroleum ether and chloroform did not. Polyphenols are the major contributors for quenching the tested free radicals, while in LT only compounds 16 , 17 and 22 participated in scavenging hydroxyl radicals. Conclusion – Polyphenols in Chaga are the principles for quenching free radicals while polysaccharides and a few LT compounds contribute partially in scavenging DPPH and hydroxyl radicals, respectively. NMR‐based metabolomic analysis is a useful method by which to correlate ¹H‐NMR spectra of Chaga extracts with their antioxidant activities, and this allows the prediction of potentials for scavenging free radicals by ¹H‐NMR spectroscopy. Copyright © 2011 John Wiley & Sons, Ltd.     

Antioxidant properties of methanol extract and its solvent fractions obtained from selected Indian red seaweeds

In vitro antioxidant activities of three selected Indian red seaweeds - viz., Euchema kappaphycus, Gracilaria edulis and Acanthophora spicifera were evaluated. Total phenolic content and reducing power of crude methanol extract were determined. The antioxidant activities of total methanol extract and five different solvent fractions (viz., petroleum ether (PE), ethyl acetate (EA), dichloromethane (DCM), butanol (BuOH) and aqueous) were also evaluated. EA fraction of A. spicifera exhibited higher total antioxidant activity (32.01 mg ascorbic acid equivalent/g extract) among all the fractions. Higher phenolic content (16.26 mg gallic acid equivalent/g extract) was noticed in PE fraction of G. edulis. Reducing power of crude methanol extract increased with increasing concentration of the extract. Reducing power and hydroxyl radical scavenging activity of E. kappaphycus were higher compared to standard antioxidant (alpha-tocopherol). The total phenol content of all the seaweeds was significantly different (P<0.05). In vitro antioxidant activities of methanol extracts of all the three seaweeds exhibited dose dependency; and increased with increasing concentration of the extract.     

Secondary metabolites of ponderosa lemon (Citrus pyriformis) and their antioxidant, anti-inflammatory, and cytotoxic activities

Column chromatography of the dichloromethane fraction from an aqueous methanolic extract of fruit peel of Citrus pyriformis Hassk. (Rutaceae) resulted in the isolation of seven compounds including one coumarin (citropten), two limonoids (limonin and deacetylnomilin), and four sterols (stigmasterol, ergosterol, sitosteryl-3-beta-D-glucoside, and sitosteryl-6'-O-acyl-3-beta-D-glucoside). From the ethyl acetate fraction naringin, hesperidin, and neohesperidin were isolated. The dichloromethane extract of the defatted seeds contained three additional compounds, nomilin, ichangin, and cholesterol. The isolated compounds were identified by MS (EI, CI, and ESI), 1H, 13C, and 2D-NMR spectral data. The limonoids were determined qualitatively by LC-ESI/MS resulting in the identification of 11 limonoid aglycones. The total methanolic extract of the peel and the petroleum ether, dichloromethane, and ethyl acetate fractions were screened for their antioxidant and anti-inflammatory activities. The ethyl acetate fraction exhibited a significant scavenging activity for DPPH free radicals (IC50 = 132.3 microg/mL). The petroleum ether fraction inhibited 5-lipoxygenase with IC50 = 30.6 microg/mL indicating potential anti-inflammatory properties. Limonin has a potent cytotoxic effect against COS7 cells [IC50 = (35.0 +/- 6.1) microM] compared with acteoside as a positive control [IC50 = (144.5 +/- 10.96) microM].     

Chemical Characterization and Multidirectional Biological Effects of Different Solvent Extracts of Arum elongatum: in Vitro and in Silico Approaches

Arum elongatum (Araceae) is widely used traditionally for the treatment of abdominal pain, arterial hypertension, diabetes mellitus, rheumatism and hemorrhoids. This study investigated the antioxidant properties, individual phenolic compounds, total phenolic and total flavonoid contents (HPLC/MS analysis), reducing power and metal chelating effects of four extracts obtained from A. elongatum (ethyl acetate (EA), methanol (MeOH), methanol/water (MeOH/water) and infusion). The inhibitory activity of the extracts were also determined against acetylcholinesterase, butyrylcholinesterase, tyrosinase, amylase and glucosidase enzymes. The MeOH/water extracts contained the highest amount of phenolic contents (28.85 mg GAE/g) while the highest total flavonoid content was obtained with MeOH extract (36.77 mg RE/g). MeOH/water demonstrated highest antioxidant activity against DPPH⋅ radical at 38.90 mg Trolox equivalent per gram. The infusion extract was the most active against ABTS⁺⋅ (133.08 mg TE/g). MeOH/water extract showed the highest reducing abilities with the CUPRAC value of 102.22 mg TE/g and the FRAP value of 68.50 mg TE/g. A strong metal chelating effect was observed with MeOH/water extract (35.72 mg EDTAE/g). The PBD values of the extracts ranged from 1.01 to 2.17 mmol TE/g. EA extract displayed the highest inhibitory activity against AChE (2.32 mg GALAE/g), BChE (3.80 mg GALAE/g), α-amylase (0.56 mmol ACAE/g) and α-glucosidase (9.16 mmol ACAE/g) enzymes. Infusion extract was the most active against tyrosinase enzyme with a value of 83.33 mg KAE/g. A total of 28 compounds were identified from the different extracts. The compounds present in the highest concentration were chlorogenic acids, 4-hydroxybenzoic acid, caffeic acid, p-coumaric acid, ferulic acid, isoquercitrin, delphindin 3,5-diglucoside, kaempferol-3-glucoside and hyperoside. The biological activities of A. elongatum extracts could be due to the presence of compounds such as gallic acid, chlorogenic acids, ellagic acid, epicatechin, catechin, kaempferol, 4-hydroxybenzoic acid, caffeic acid, p-coumaric acid, ferulic acid, quercetin, isoquercitrin, and hyperoside. Extracts of A. elongatum showed promising biological activities which warrants further investigations in an endeavor to develop biopharmaceuticals.     

Radical scavenging activities of Rio Red grapefruits and Sour orange fruit extracts in different in vitro model systems

Antioxidant fractions from two different citrus species such as Rio Red (Citrus paradise Macf.) and Sour orange (Citrus aurantium L.) were extracted with five different polar solvents using Soxhlet type extractor. The total phenolic content of the extracts was determined by Folin-Ciocalteu method. Ethyl acetate extract of Rio Red and Sour orange was found to contain maximum phenolics. The dried fractions were screened for their antioxidant activity potential using in vitro model systems such as 1,1-diphenyl-2-picryl hydrazyl (DPPH), phosphomolybdenum method and nitroblue tetrazolium (NBT) reduction at different concentrations. The methanol:water (80:20) fraction of Rio Red showed the highest radical scavenging activity 42.5%, 77.8% and 92.1% at 250, 500 and 1000 ppm, respectively, while methanol:water (80:20) fraction of Sour orange showed the lowest radical scavenging activity at all the tested concentrations. All citrus fractions showed good antioxidant capacity by the formation of phosphomolybdenum complex at 200 ppm. In addition, superoxide radical scavenging activity was assayed using non-enzymatic (NADH/phenaxine methosulfate) superoxide generating system. All the extracts showed variable superoxide radical scavenging activity. Moreover, methanol:water (80:20) extract of Rio Red and methanol extract of Sour orange exhibited marked reducing power in potassium ferricyanide reduction method. The data obtained using above in vitro models clearly establish the antioxidant potential of citrus fruit extracts. However, comprehensive studies need to be conducted to ascertain the in vivo bioavailability, safety and efficacy of such extracts in experimental animals. To the best of our knowledge, this is the first report on antioxidant activity of different polar extracts from Rio Red and Sour oranges.     

Enzyme inhibition and radical scavenging activities of aerial parts of Paeonia emodi Wall (Paeoniaceae)

The ethanolic extract derived from aerial parts of an indigenous medicinal plant Paeonia emodi was screened for enzyme inhibition activities against Urease (jack bean and Bacillus pasteurii) and alpha-Chymotrypsin. The extract was also investigated for its radical scavenging activity using DPPH assay. The crude extract was found to possess significant enzyme inhibition activities against jack bean (74%) and Bacillus pasteurii (80%) urease and a moderate activity (54%) against alpha-Chymotrypsin. The extract also displayed excellent (83%) radical scavenging activity. On the basis of these results, the crude extract was subsequently fractionated into n-hexane, chloroform, ethyl acetate, n-butanol and water fractions and tested independently for the aforesaid activities. Significant inhibitory activity against urease enzyme was observed for the ethyl acetate, n-butanol and water fractions while the n-hexane and chloroform fractions were devoid of any such activity. In the alpha-Chymotrypsin enzyme inhibition studies the activity was concentrated into the ethyl acetate fraction. All the fractions displayed potent radical scavenging activity. The crude extract and fractions thereof were also subjected to total phenolic content determination. A correlation between radical scavenging capacities of extracts and total phenolic content was observed in the majority of cases.     

皱环球盖菇不同极性萃取物抗氧化活性比较及成分分析

为考察皱环球盖菇子实体的抗氧化活性,利用溶剂萃取法得到皱环球盖菇子实体二氯甲烷、乙酸乙酯、正丁醇和水4种不同极性萃取物,选用二苯基三硝基苯肼自由基(DPPH)法、羟基自由基法和还原力法对4种萃取物进行体外抗氧化活性分析。结果表明,乙酸乙酯萃取物显示了最强的抗氧化活性;通过超高效液相色谱串联三重四级杆飞行时间质谱法(UPLC-Triple-TOF/MS)分析了皱环球盖菇乙酸乙酯萃取物中化学组成,从中鉴定出9种化合物,多数为核苷类物质,具有很好的抗氧化活性。研究结果为皱环球盖菇的开发提供了理论依据和技术支持。     

河南产景天三七抗氧化活性研究

用清除二苯代苦味酰基(DPPH)自由基、2,2′-连氨-(3-乙基苯并噻唑啉-6-磺酸)二氨盐(ABTS)自由基和铁离子还原/抗氧化能力(FRAP)测定法对洛阳和信阳产景天三七(Sedum aizoon)体外总抗氧化活性进行评价,并与阳性对照丁基羟基茴香醚(BHA)、没食子酸丙酯(PG)和二丁基羟基甲苯(BHT)比较。发现洛阳和信阳景天三七有较好的体外抗氧化活性。洛阳和信阳产乙酸乙酯部位活性最强,正丁醇部位活性次之。在6个提取部位中,信阳产景天三七乙酸乙酯部位活性最强,其清除DPPH、ABTS自由基能力强于阳性对照BHA和BHT,还原Fe3+的能力大于阳性对照BHT,洛阳产景天三七乙酸乙酯部位和正丁醇部位活性次之。     

桦褐孔菌提取物抗氧化活性研究

以乙酸乙酯和甲醇为提取剂,采用索氏提取法,剩余残渣采用热水浸提,最终得到桦褐孔菌不同极性提取物,对其DPPH自由基、羟基自由基及超氧阴离子自由基清除活性作用进行了研究,确定桦褐孔菌的抗氧化能力,为深入研究和开发桦褐孔菌功能性食品奠定理论基础。实验结果表明桦褐孔菌具有较好的抗氧化活性,其中乙酸乙酯提取物的DPPH自由基清除率、羟基自由基清除率和超氧阴离子自由基清除率均高于其他两组分及BHT,桦褐孔菌提取物有望成为功能性食品组分中合成抗氧化剂的天然替代品。     

菹草提取物总黄酮、总酚酸和抗氧化活性含量研究

研究菹草提取物的有效成分,测定其总黄酮含量及总酚酸含量,并确定它的乙酸乙酯和石油醚部位的抗氧化活性成分。采用紫外可见分光光度法,以芦丁和没食子酸作为控制材料,测定菹草的石油醚部位及乙酸乙酯部位中总黄酮和总酚酸含量;采用清除DPPH自由基能力测定法、测定总还原能力铁氰化钾法和水杨酸捕捉羟基自由基法来对菹草各组分提取物的抗氧化能力进行研究。菹草中有一定量的黄酮类化合物和酚酸类化合物存在,不同溶剂提取的部位所含有的总黄酮和总酚酸含量是有差异的,石油醚部位的总黄酮含量要高于乙酸乙酯部位的总黄酮含量,并且总酚酸的含量亦是如此;石油醚部位和乙酸乙酯部位的提取物具有清除DPPH、羟基自由基和还原Fe^3+的能力,各部位清除DPPH、羟基自由基的能力和还原Fe^3+的能力随着样品浓度的增大而增大,且乙酸乙酯部位的测定结果均低于石油醚部位。     

Antioxidant activity of leaf extracts from Bauhinia monandra

Bauhinia monandra Kurz. is used in Brazil for the treatment of diabetes. Since this activity may be correlated with the presence of antioxidant compounds, leaf extracts of B. monandra were evaluated for their radical scavenging capacity (RSC). An ethanolic extract was taken up in aqueous methanol and partitioned with hexane, chloroform, ethyl acetate to yield three organic extracts together with remaining aqueous extract. The RSC was determined spectrophotometrically using 1,1-diphenylpicrylhydrazyl free radical (DPPH). The chloroform and ethyl acetate extracts were the most appropriate as sources of antioxidant compounds as shown by their inhibition concentration (IC50) and inhibition percentage (IP) values. The antioxidant activity of such extracts was attributed to the presence of three compounds of different polarities (flavonoids and steroids). The chloroform and ethyl acetate extracts exhibited an IC50 of approximately 2 mg/g DPPH and IP values in the range of 60-65%. The results indicate that the extracts of B. monandra have a very potent antioxidant activity, compared with the pure catechins used as positive controls and with other plant extracts.     

Antioxidant Activities of Some Extracts of Thymus zygis

The antioxidant activities of methanol and ethyl ether extracts obtained from Thymus zygis, collected during the flowering or non-flowering period, were evaluated and compared. To investigate this potential, extracts were tested on their capacity to react with diphenyl-picrylhydrazyl (DPPH) in a homogeneous medium, and to inhibit Fe²⁺/ascorbate-induced membrane lipid peroxidation, as estimated by the formation of thiobar-bituric acid-reactive substances (TBARS). Although methanol extracts reduce DPPH radicals more efficiently than ethyl ether extracts, suggesting a potent radical scavenger activity, the ethyl ether extracts were found to be most active in inhibiting lipid peroxidation in sarcoplasmic reticulum (SR) membranes. In addition, both extracts present peroxyl and superoxide radical scavenging activities. Peroxyl radicals were generated by the water soluble 2, 2A-azobis(2-amidinopropane) dihydrochloride (AAPH) azoinitiator, and the scavenging activities of the extracts were measured by the inhibition of cis-parinaric acid (PnA) fluorescence decay in SR. Superoxide radicals were generated either by an enzymatic or a non-enzymatic system, and the scavenger ability was evaluated by the inhibition of nitrob-lue tetrazolium reduction. Methanolic extracts are more potent as scavengers of peroxyl and super oxide radicals than the ethyl ether extracts. Apparently, there is a relationship between antioxidant potency and the total phenolic groups content in each extract.     

Enzyme inhibition and radical scavenging activities of aerial parts of Paeonia emodi Wall. (Paeoniaceae)

The ethanolic extract derived from aerial parts of an indigenous medicinal plant Paeonia emodi was screened for enzyme inhibition activities against Urease (jack bean and Bacillus pasteurii) and α-Chymotrypsin. The extract was also investigated for its radical scavenging activity using DPPH assay. The crude extract was found to possess significant enzyme inhibition activities against jack bean (74%) and Bacillus pasteurii (80%) urease and a moderate activity (54%) against α-Chymotrypsin. The extract also displayed excellent (83%) radical scavenging activity. On the basis of these results, the crude extract was subsequently fractionated into n-hexane, chloroform, ethyl acetate, n-butanol and water fractions and tested independently for the aforesaid activities. Significant inhibitory activity against urease enzyme was observed for the ethyl acetate, n-butanol and water fractions while the n-hexane and chloroform fractions were devoid of any such activity. In the α-Chymotrypsin enzyme inhibition studies the activity was concentrated into the ethyl acetate fraction. All the fractions displayed potent radical scavenging activity. The crude extract and fractions thereof were also subjected to total phenolic content determination. A correlation between radical scavenging capacities of extracts and total phenolic content was observed in the majority of cases.     

Composition and biological activities of different extracts of Salvia jurisicii,a rare and endemic Macedonian species

This is the first report on the phenolic composition and biological activities of endemic species Salvia jurisicii Ko?anin (Lamiaceae) originating from Macedonia. Aerial parts of S. jurisicii were extracted with dichloromethane, ethyl acetate, methanol, ethanol and water. All extracts were tested spectrophotometrically for total phenolic and flavonoid contents, while their phenolic composition was analyzed using HPLC-DAD. The antioxidant activity of extracts was studied using 2,2-dyphenyl-1-picrylhydrazyl, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), ferric reducing ability of plasma and ß-carotene bleaching assays. Being the most frequently used solvents for extraction of bioactive ingredients from medicinal plants, water and ethanol extracts were chosen for further testing of antimicrobial, cytotoxic and antineurodegenerative activities. More polar solvent extracts showed higher total phenolic content and lower flavonoid content. Ethanol and methanol extracts, followed by water extract exhibited the strongest antioxidant activity. Extracts showed antimicrobial activity against certain bacteria and micromycetes. The cytotoxicity assay showed slight toxicity to HCT-116 cell line. In the antineurodegenerative assays, the extracts performed lower inhibition of acetylcholinesterase and tyrosinase than standards. According to the results of this study, it can be inferred that more polar extracts of S. jurisicii were quantitatively richer in total phenolics, showing stronger antioxidant activity. Ethanol extract showed stronger biological activities comparing to water extract.