Butein imparts free radical scavenging, anti-oxidative and proapoptotic properties in the flower extracts of Butea monosperma

The flower of Butea monosperma(Lam.)(Fabaceae)has been used in traditional Indian medicine in the treatment of many ailments including liver disorders.To understand the pharmacological basis of its beneficial effects,the extracts of dried flowers in water,methanol,butanol,ethyl acetate and acetone were evaluated for free radical scavenging and pro-apoptotic activities in cell cultures(human hepatoma Huh-7 cell line and immortalized AML-12 mouse hepatocytes).Butrin and butein-the active constituents of flower extracts-were used as reference molecules.The levels of cell injury markers like lactate dehydrogenase,glutathione and lipid peroxidation and primary antioxidant enzymes glutathione S-transferase and catalase were also measured.The aqueous and butanolic extracts exhibited better 2,2-diphenyl-1-picrylhydrazyl scavenging and cytotoxic activities in hepatoma cells than in immortalized hepatocytes.Interestingly,butein inhibited 2,2-diphenyl-1-picrylhydrazyl radical better than butrin.The aqueous and butanolic extracts were further investigated for hepatoprotection against carbon tertrachloride-induced biochemical changes and cell death.Both extracts,just as butrin and butein,significantly reversed the cellular glutathione levels and lipid peroxidation,and glutathione–S-transferase activity.Lactate dehydrogenase leakage and cell death were also prevented.However,only butein revived the catalase activity.Thus,the butein content of Butea monosperma flower extracts is important for free radical scavenging activity,apoptotic cell death and protection against oxidative injury in hepatic cells.

Study on the Free Radical Scavenging Activity of Sea Cucumber (Paracaudina chinens var.) Gelatin Hydrolysate

Gelatin from the sea cucumber(Paracaudina chinens var.) was hydrolyzed by bromelain and the hydrolysate was found to have a high free radical scavenging activity. The hydrolysate was fractionated through an ultrafiltration membrane with 5 kDa molecular weight cutoff(MWCO). The portion(less than 5 kDa) was further separated by Sephadex G-25. The active peak was col-lected and assayed for free radical scavenging activity. The scavenging rates for superoxide anion radicals(O2·-) and hydroxyl radi-cals(·OH) of the fraction with the highest activity were 29.02% and 75.41%,respectively. A rabbit liver mitochondrial free radical damage model was adopted to study the free radical scavenging activity of the fraction. The results showed that the sea cucumber gelatin hydrolysate can prevent the damage of rabbit liver and mitochondria.

Evaluation of Hydroxyl Radical and Alkyl-oxy Radical Scavenging Activity of Coffee by ESR Spin Trapping Method

We evaluated the hydroxyl and alkyl-oxy radical scavenging activity of instant coffee using an electron spin resonance （ESR） spin-trapping method, which was based the spin-trapping reagent 5-（2,2-dimethy-l,3-propoxycyclophosphoryl）-5-methyl-l-pyrroline N-oxide （CYPMPO）. In this method, very pure hydroxyl and alkyl-oxy radicals were generated by illuminating a phosphate buffer solution containing hydrogen peroxide and 2,2＇-azobis （2-amidinopropane） dihydrochloride with a Hg-Xe arc lamp. The ESR adduct signal was sensitive and very stable. We concluded that instant coffee has high hydroxyl radical and alkyl-oxy radical scavenging activity.

Why Static O-H Bond Parameters Cannot Characterize the Free Radical Scavenging Activity of Phenolic Antioxidants: ab initio Study

The static O-H bond parameters including O-H bond length, O-H charge difference, O-H Mulliken population and O-H bond stretching force constant (k) for 17 phenols were calculated by ab initio method HF/6-31G**. In combination with the O-H bond dissociation enthalpies (BDE) of the phenols determined by experiment, it was found that there were poor correlationships between the static O-H bond parameters and O-H BDE. Considering the good correlationship bt tween O-H BDE and logarithm of free radical scavenging rate constant for phenolic antioxidant, it is reasonable to believe that the ineffectiveness of static O-H bond parameters in characterizing antioxidant activity arises from the fact that they cannot measure the O-H BDE.

Preparation of (±)-5,6,7-Trioxygenated Dihydroflavonols and Evaluation of their Superoxide Radical Scavenging Activity

The synthesis of （±）-5, 6, 7-trioxygenated dihydroflavonols was carried out. All synthetic compounds were passed through superoxide radical scavenging activity in vitro. Compounds 1 e and 1 g exhibited significant bioactivity with the inhibitory rates of 68.1% and 80.9% at 40 μg/mL, respectively.

Enhanced Free Radical Scavenging and Inhibition of DPP-4 and ACE Activities by Compounds from Salmon Tissues Digested in Vitro with Gastrointestinal Proteases

Research on marine bioactive peptides has mainly focused on characterization of peptides in hydrolysates prepared with commercial industrial enzymes and the usefulness of such hydrolysates in health and functional foods. However, a relevant question is whether digestion of fish proteins with gastrointestinal proteases per se generates peptides that also can have health promoting properties and can reduce, e.g., diabetes 2, inflammation and hypertension either in relation to gastrointestinal digestion or as alternative to industrial proteases. The aim of the study was to investigate hydrolysates obtained from in vitro sequential digestion of salmon muscle and skin with gastrointestinal proteases including pepsin, pancreatic and pancreatic ＋ mucosal proteases for their ability to scavenge ABTS^＋ radicals and inhibit activity of angiotensin I-converting enzyme （ACE） and dipeptidyl peptidase 4 （DPP-4）. Furthermore, it was the aim to study the inhibitory mechanism and stability towards ACE and DPP-4 activity. Analysis of〈 10 kDa hydrolysates showed that gastrointestinal proteases generated peptides with clear radical scavenging activity and DPP-4 and ACE inhibiting activity as well. Hydrolysates from pepsin digestion exhibited the lowest ECso values for radical scavenging activity and ACE inhibition, whereas ECso increased in hydrolysates after subsequent digestion with pancreatic and mucosal proteases. Interestingly, ECso values for the DPP-4 inhibition were hardly affected by sequential digestion. Inhibition modes for the muscle hydrolysates were both competitive and non-competitive, but prolonged incubation showed that the inhibitory properties were unstable and therefore they were probably digested as competitive substrates by gastrointestinal proteases.

Evaluation of lipid peroxidation inhibition and free radical scavenging abilities of 5,6,7-trimethoxy dihydroflavonols

Four naturally rare 5,6,7-trimethoxy-2,3-cis-dihydroflavonols （3-6） and two 5,6,7-trimethoxy-2,3-trans-dihydroflavonols （7-8） were designed and synthesized. Their antioxidative properties were evaluated by way of examining their scavenging capacities towards DPPH and O2^＊- free radicals, as well as by measuring their inhibitory ability against LPO. Both the 2,3-trans and the 2,3- cis conformers exhibited certain quenching abilities to DPPH and O2^＊- radicals, while most of the synthetic dihydroflavonols demonstrated remarkable inhibition to LPO.

Extraction Storage and Qualitative Analysis of Free Radicals Scavenging Substances from Sweet Potato Leaves

[ Objective ] The research aimed to provide reference for the application of extracts from sweet potato leaves in anti-aging cosmetics. [ Method ] The extraction and storage conditions for free radicals scavenging substances from sweet potato leaves were optimized by orthogonal test and the bioactive components in extracts were investigated by correlation analysis. [ Result] Sweet potato leaves contain the bioactive substances scavenging DPPH free radical and hydroxyl free radical. Extracting solvent species is the most important factor that influencing extraction yield. The optimal extraction and storage conditions are as following： water as solvent, pH 8.0 of extracting liquid, storage at 25 ℃. There is a good positive linear relationship between the content of total phenols in sweet potato leaves and corresponding scavenging rates against both the DPPH free radical and hydroxyl free radical. For the content of total flavones in sweet potato leaves, just a correlation with scavenging rate against hydroxyl free radical shown in test. [ Conclusion] The phenols in ex- tracts could effectively scavenge both the DPPH free radical and hydroxyl free radical, whereas the flavones in extracts can only function on the hydroxyl free radical.

Free radical scavenging activity of Eagle tea and their flavonoids

In this study,an online HPLC-DAD-MS coupled with 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonic acid)diammonium salt(A BTS)assay was employed for evaluating free radical scavenging activity of Eagle tea and their active components.Twenty-three chromatographic peaks were detected,and nineteen components had free radical scavenging activity.Among them,eight compounds were identified as flavonoids(hyperin,isoquercitrin,quercitrin,quercetin,kaempferol),catechins,chlorogenic acid and epicatechin based on MS data and standard chromatographic characters.

Theoretical Study of the Radical Scavenging Activity of Shikonin and Its Derivatives

A series of shikonin derivatives have been designed and their radical scavenging activity has been characterized by the B3LYP/6-31 ＋G（d） approach. The hydrogen bond properties of the studied structures were investigated using the atoms in molecules （AIM） theory. The calculated results reveal that the hydrogen bond is important for good scavenging activity. The introduction of electron-drawing （electron-donating） groups increases （decreases） the scavenging activities of radical and radical cations of shikonin derivatives. Shikonin derivatives appear to be good candidates for the single-electron-transfer mechanism, particularly for -N（CH3）2 derivative. Taking this system as an example, we present an efficient method for the investigation of radical scavenging activity from theoretical point of view. With the current work, we hope to highlight the radical scavenging activity of hydroxynaphtho- quinones derivatives and stimulate the interest for further studies and exploitation in pharmaceutical industry.

SUPEROXIDE RADICAL SCAVENGING AND CYTOTOXIC EFFECTS OF DIFFERENT MARINE SPECIES FROM TURKEY'S COASTS

In this study,acetone extracts of thirteen different species distributed in Turkey Coasts including tunicates,sea anemones,sponges and corals were investigated for their superoxide(SO)radical scavenging and cytotoxic activities.VWhile SO radical scavenging activity was tested using alkaline DMSO method,cytotoxic activity was tested by MTT assay against Hep-2 cancer cell line.As a result of bioactivity studies,Paramuricea clavata extract showed

MOLECULAR UNDERSTANDING OF NATURAL POLYPHENOLS: FREE RADICAL SCAVENGING AND INTERACTION WITH BIOMEMBRANES

Quantum calculations(mainly DFT)and molecular dynamics are increasingly effective tools to evaluate the physical chemical properties of natural and bio-inspired compounds.Free Radical Scavenging Capacity.Thermodynamic parameters(mainly bond dissociation enthalpies(BDE)of the O-H phenolic bond)allowed an accurate prediction of the antioxidant capacities of

Free Radical-Scavenging Properties and Antioxidant Activity of Fractions from Cranberry Products

Lipid peroxidation inhibition capacity and antiradical activity were evaluated in HPLC fractions of different polarity obtained from two cranberry juices and three extracts isolated from frozen cranberries and pomace containing antho-cyanins, water-soluble and apolar phenolic compounds, respectively. Compounds with close polarities were collected to obtain between three and four fractions from each juice or extract. The cranberry phenols are good free radi-cal-scavengers, but they were less efficient at inhibiting the lipid peroxidation. Of all the samples tested, the intermediate polarity fraction of extract rich in apolar phenolic compounds of fruit presented the highest antiradical activity while the most hydrophobic fractions of the anthocyanin-rich extract from fruit and pomace appeared to be the most efficient at inhibiting the lipid peroxidation. The antioxidant or pro-oxidant activity of fractions increased with the con-centration. The phenol polarity and the technological process to manufacture cranberry juice can influence the antioxidant and antiradical activities of fractions.

Component Analysis and Free Radicals Scavenging Activity of Physalis alkekengi L. Polysaccharide

A crude polysaccharide was extracted from Physalis alkekengi L. fruit. HPLC was used for the component analysis of the polysaccharide. The results indicate that Physalis alkekengi L. polysaccharide（PAP） was composed of rhamnose, xylose, arabinose, galactose, and glucose. Free radicals scavenging activity of PAP was studied through 3 free radicals scavenging tests. PAP exhibited high scavenging effects on OH and DPPH radicals, and both the scavenging rates were about 80%. The scavenging rate of O2^- radical was about 22%.

Effects of Chuanxiongqin hydrochloride on increasing the fluidity of brain cell membrane and scavenging free radicals in model rats with ischemia/reperfusion injury

BACKGROUND: The fluidity of cell membrane can be affected by various factors. Many experiments have confirmed that the ischemia/reperfusion of organic tissue can increase the contents of free radicals, which lead to high rigidity and low fluidity of cell membrane, and the conditions can be changed by Chuanxiongqin. OBJECTIVE: To observe the effect and mechanism of Chuanxiongqin hydrochloride on the fluidity of brain cell membrane in rat models of ischemia/reperfusion. DESIGN: A completely randomized controlled animal trial. SETTINGS: Institute of Brain Sciences; Department of Physiology, Medical College, Datong University. MATERIALS: Twenty male grade Ⅰ Wistar rats of 170-220 g were randomly divided into model group (n =10) and control group (n =10). Chuanxiongqin hydrochloride (molecular mass was 172.2) was purchased from the National Institute for the Control of Pharmaceutical and Biological Products (batch number: 0817-9803); Spin labelers: 5-doxyl-stearlic acid methylester (5DS), 16-doxyl-stearlic acid methylester (16DS), xanthine, xanthine oxidase (XOD) and 5,5-dimeth-1-pyrroline- N-oxide (DMPO) from Sigma Company; Bruker ESP 300 electron paramagnetic resonance (EPR) spectrometer by Bruker Company (Germany). METHODS: The experiments were carried out in the State Key Laboratory of Natural and Biomimetic Drugs, Peking University from June 2001 to July 2002. In the model group, rats were made into models of cerebral ischemia by 30-minute ligation and 2-hour reperfusion of common carotid arteries; The rats in the control group were not made into models. The order parameter (S) and rotational correlation time (τc) were detected with the ESR spectrometer by means of spin labeling. The greater the S and τc, the smaller the fluidity. Meanwhile, the clearance rate of free radicals was detected with ESR spin trapping. The measurement data were compared using the t test. MAIN OUTCOME MEASURES: The S, τc and clearance rates of O2 · and OH· free radicals were compared between the model group and control group. RESULTS: The S and τc in the model group [0.738 4±0.003 5; (8.472±0.027)×10-10 s/circle] were obviously different from those in the control group [0.683 9±0.008 3; (7.945±0.082)×10-10 s/circle, t =5.731, 5.918, P < 0.05], which suggested that ischemia/reperfusion injury decreased the fluidity of brain cell membrane. After adding Chuanxiongqin hydrochloride, there were no obvious differences between the model group [0.688 5±0.030 5; (7.886±0.341)×10-10 s/circle] and control group (P > 0.05), indicating that Chuanxiongqin hydrochloride could recover the fluidity of brain cell membrane after ischemia/reperfusion injury close to the level in the normal control group. Chuanxiongqin hydrochloride could directly scavenge the O2 · and OH· free radicals, and the maximal clearance rates were 83.92% and 44.99% respectively. CONCLUSION: Chuanxiongqin hydrochloride increases the fluidity of membrane of ischemia-injured brain cell by scavenging both O2 ·and OH· free radicals.

Study on Solid Fermentation and Antioxidant Function of Natto

[Objectives]To study the optimum conditions of solid fermentation of natto with antioxidant function as an index.[Methods]Single factor experiment and orthogonal experiment were designed to study the effects of temperature,time,initial pH and inoculum amount on the antioxidant activity of natto solid fermentation.The optimum conditions of natto solid fermentation were determined and the antioxidant ac-tivity of natto extract was compared.[Results]The optimal fermentation conditions were as follows:temperature 32℃,initial pH 7.0,inocu-lation amount 8%,fermentation time 32 h.The hydroxyl radical scavenging rate of natto solid fermentation crude extract was the highest,which was 82.7%.The optimized nato fermentation extract showed stronger scavenging ability for-OH and O,:,and showed obvious dose-effect relationship.ICso was 3.63 and 4.24 mg/mL,respectively,and the scavenging efficiency was 1.3 and 1.9 times higher than that of the unoptimized fermentation extract,respectively.[Conclusions]Natto is rich in nattokinase and other functional factors,and its antioxidant ac-tivity can be improved by optimizing fermentation technology,so that natto products can be widely used,including cosmetic raw materials,nat-to skin care soap,health food and medicine,etc.,and have a broader development prospect.

Peroxynitrite Scavenging Activities of Resveratrol and Piceid

In vitro antioxidant activities of resveratrol and piceid against peroxynitrite（ONOO-） were examined by the inhibition of 3-nitrotyrosine formation.Trolox was used as a positive control.Resveratrol and piceid exhibited high ONOO--scavenging activities in a concentration dependent manner.The antioxidant activities（the concentration of test compound required to yield a 50% inhibition of tyrosine nitration,IC 50） of resveratrol and piceid against ONOO-were（48.34±0.97） and（74.69±1.49） μmol/L,respectively.Compared with that of trolox[（105.40±1.16） μmol/L],their scavenging activities were 2.2-and 1.5-fold higher for resveratrol and piceid.Formation of nitroresveratrol as shown by UV-Vis spectroscopy and liquid chromatography-tandom mass spectrometry（LC-MS/MS） analysis indicates that resveratrol could directly scavenge ONOO-via nitration reaction.Our results demonstrate that foods and medicinal herbs with resveratrol and piceid as stronger ONOO-scavengers are valuable ingredients and have healthy application in preventing humans from peroxynitrite-mediated oxidative damage by scavenging peroxynitrite efficiently.

Tentative Identification of Phytochemicals and Antioxidant Activities during Fruit-Ripening on Chamaedorea radicalis Mart.

This work aims to determine the phytochemical characterization of the pericarp of Chamaedorea radicalis Mart.fruit as a non-timber product with potential to obtain phytochemicals with potential applications in the industry.Fruit from C.radicalis were grouped in four ripening stages named as S1,S2,S3 and S4,according to maturity;S1 the most unripe stage and S4 the completely ripe stage.Determinations of total phenolic compounds,free radical scavenging activities and total flavonoid contents using spectrophotometric methods were done.Also,the tentative identification of phytochemicals during fruit ripening was done using UPLC-MS-MS.Total phenolic compound(TPC)content ranged from 7.24 to 12.53 mg gallic acid equivalents per gram of fresh weight(mg GAE/g FW).Total flavonoids(TF)contents ranged from 0.163 to 0.23 mg of quercetin equivalents per g FW(mg QE/g FW).Free radical scavenging activity against DPPH and ABTS radicals varied from 40.80 to 53.68 and from 22.29 to 37.76 mmol Trolox equivalents g FW(mmol TE/g FW),respectively.Antioxidant assay in vitro by FRAP(ferric reducing antioxidant power)method showed that S3 was the highest level with antioxidant power while S4 was the lowest with Red ripeness stage showed the lowest contents for all determinations.Mass spectrometry allowed detection of 26 compounds,including phenolics,alkaloids and saponins.Afzelin,Kaempferol 3-neohesperidoside and the four saponins identified were present in all ripeness stages.Preliminary phytochemical identification and the spectrophotometric determinations showed that the pericarp of C.radicalis presented antioxidants and compounds related to alkaloids,phenolics and saponins.The presence and abundance of each phytochemical regarding each ripeness stage should be considered.

Studies on Biologically Active Principles of Huangqi,Root of Astragalus membranaceous,Isolation and Detection of Constituents Scavenging Superoxide Anion

本文使用黄嘌呤-黄嘌呤氧化酶—鲁米诺化学发光体系和化学发光检测法研究了黄芪中各成分的清除超氧阴离子自由基的能力,以药物抑制发光强度50%的浓度(IC_(50))为指标。经研究证明,黄芪总皂甙部分(N)具有较强的活性,IC_(50)为185μg/ml,再经进一步导向分离并鉴定证明,黄芪甙Ⅲ,Ⅳ和Ⅵ的 IC)_(50)分别为80、50和11μg/ml,从而证明黄芪的抗心力衰竭的有效成分可能为黄芪总皂甙部分。

Non-peptidyl low molecular weight radical scavenger IAC attenuates DSS-induced colitis in rats

AIM:To investigate the effects of the free radical scavenger bis(1-hydroxy-2,2,6,6-tetramethyl-4-piperidinyl) decandioate(IAC) in the dextran sodium sulphate(DSS) experimental model of ulcerative colitis.METHODS:Colitis was induced in Sprague Dawley male rats by administration of 5% DSS in drinking water.IAC(30 mg/kg,lipophilic or hydrophilic form) was administered daily(orally or ip) for 6 d until sacrifice.Colonic damage was assessed by means of indirect(Disease Activity Index score) and direct measures(macroscopic and microscopic scores) and myeloperoxidase(MPO)activity.Neutrophil infiltration within the tissue and glutathione S-transferase activity were also investigated.RESULTS:DSS-induced colitis impaired body weight gain and markedly increased all inflammatory parameters.Six-day treatment with lipophilic IAC significantly reduced intestinal damage caused by inflammation,induced a down-regulation in MPO activity(0.72 ± 0.12 and 0.45 ± 0.12 with lipophilic IAC po and ip,respectively,vs 1.10 ± 0.27 in untreated DSS colitis animals) and minimized DSS-induced neutrophil infiltration,while hydrophilic IAC administered orally did not ameliorate DSS-induced damage.CONCLUSION:These results support the hypothesis that reactive oxygen metabolites contribute to inflammation and that the radical scavenger IAC has therapeutic potential in inflammatory bowel disease.