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Free radical scavengers as immuno stimulants in helminth infections

Free radical scavengers as immuno stimulants in helminth infections

Liver histology studies show a significant increase in cellular infiltration and also the collagenous deposition around the parasite in the levamisole treatment group. However, this is not a comprehensive assessment of the total cellular and collagen response in the liver, but only a measure of this response in relation to each parasite. Evidence from the histol­ ogy studies has also shown that a number of parasites in the liver matrix of all treatments were completely free from leukocyte or collagen response, despite high immune responses to other parasites. This suggests that these parasites may have only recently migrated into liver from the peritoneal cavity. Specht and Widmer (1972) after extensive studies on M.corti larvae, suggest that the liver provides the proximity to the blood flow vital for the growth and multiplication of larva. Pollaco et al..(1978) have reported that collagen forma­ tion mediated by T-cells in response to M.corti acts to limit severely the proliferation of parasites in the liver. Various studies reported on the effect of levamisole on the mouse immune system have suggested that levamisole stimulates granulocyte and macrophage function rather than proliferation (Van Ginckel et al.. 1975; Cruchaud, Berney, & Welsher, 1979; Gozzo, and Hanson, 1979). A massive granulocyte response to M.corti infection in mice was also demonstrated by Specht and Widmer, (1972). Levamisole is also capable of stimulating chemotaxis and random movement of granulocytes in mice. (Cruchaud et al..

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Phenolic Acids from Parthenium hysterophorus: Evaluation of Bioconversion Potential as Free Radical Scavengers and Anticancer Agents

Phenolic Acids from Parthenium hysterophorus: Evaluation of Bioconversion Potential as Free Radical Scavengers and Anticancer Agents

sample were recorded to be 130.4 ± 1.2 µg/ml and 9.7 ± 0.98 µg/ml respectively. GC-MS analysis of phenolic acids extract clearly indicated that the major portion of extract comprises of phenolic acids viz. ferulic, p-cou- maric, vanillic and gallic acid, which have an ability to scavenge free radicals and donate hydrogen atoms or electron. Ferulic acid in particular, is reported to possess high antioxidant activity, making it a potent therapeutic agent [14]. Hence, the high antioxidant activity shown by the extract could be attributed to ferulic acid which was detected to be major phenolic acid component in it.

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 FLAVONOIDS FROM RHYNCHOSIA PSEUDO-CAJAN AS SUITABLE ALPHA-GLUCOSIDASE INHIBITORS AND FREE RADICAL SCAVENGERS

 FLAVONOIDS FROM RHYNCHOSIA PSEUDO-CAJAN AS SUITABLE ALPHA-GLUCOSIDASE INHIBITORS AND FREE RADICAL SCAVENGERS

It may be concluded from the present investigation that the isolated flavonoids have moderate to talented activity against α-glucosidase enzyme and DPPH radical; moderate against acetyl cholinesterase; and low activity against lipoxygenase and butyryl cholinesterase enzymes. So, such molecules might serve as possible therapeutic agents for diabetes and suitable antioxidants to rescue the oxidative stress.

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In vivo study of nanoparticles as free radical scavengers for radiation protection

In vivo study of nanoparticles as free radical scavengers for radiation protection

Free radicals are formed through ionizing reactions that are then capable of destroying normal tissues during the exposure to radiation. Nanoparticles are gaining interest in the field of radioprotection. Radioprotecting ability of nanoparticle was evaluated in an in vivo model using albino mice. The aim of the present study is the investigation of the ability of silver nanoparticles (AgNPs), gold nanoparticles (AuNPs) and cerium oxide nanoparticles (CeO 2 NPs) to protect skin tissues of mice against gamma radiation of whole body exposure to 1.2Sv equivalent

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Phytochemical investigations and antioxidant potential of roots of Leea macrophylla (Roxb )

Phytochemical investigations and antioxidant potential of roots of Leea macrophylla (Roxb )

can cause tissue injury. In addition, oxidative stress is now thought to make a significant contribution to all inflammatory diseases (arthritis, vasculitis, glomerulo- nephritis, lupus erythematous, adult respiratory diseases syndrome), ischemic diseases (heart diseases, stroke, intestinal ischema), hemochromatosis, acquired immu- nodeficiency syndrome, emphysema, organ transplan- tation, gastric ulcers, hypertension and preeclampsia, neurological disorder (Alzheimer’s disease, Parkinson’s disease, muscular dystrophy), alcoholism, smoking- related diseases, and many others [5, 6]. Although our body has enzymatic and nonenzymatic endogenous anti- oxidant systems, they are insufficient to protect against free radical damage. Therefore, exogenous antioxidants play an important role in maintaining human health status [1]. There are some synthetic antioxidant com- pounds, such as butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA), commonly used in pro- cessed foods. However it has been suggested that these compounds have some side effects [7–9]. Therefore, the need to find natural and safe sources of antioxidants has notably increased. The medicinal properties of plants have been investigated in recent scientific develop- ments through the world, due to their potent antioxidant activities, no side effects and economic viability. Among natural antioxidants, phenolic antioxidants are in the forefront since all the phenolic classes (simple pheno- lics, phenolic acids, anthocyanins, hydroxycinnamic acid derivatives, and flavonoids) have the structural require- ments of free radical scavengers and antioxidants. So current research is now directed towards finding natu- rally occurring antioxidant of herbal drugs.

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 ANTIOXIDANT AND FREE RADICAL SCAVENGING ACTIVITIES OF DOLICHANDRONE ATROVIRENS USING VARIOUS IN VITRO ASSAY MODELS

 ANTIOXIDANT AND FREE RADICAL SCAVENGING ACTIVITIES OF DOLICHANDRONE ATROVIRENS USING VARIOUS IN VITRO ASSAY MODELS

In the last two decades there has been an explosive interest in the role of oxygen free radicals, more generally known as “reactive oxygen species” (ROS) and of “reactive nitrogen species” (RNS) in experimental and clinical medicine (Halliwell and Gutteridge, 2007). ROS/RNS are known to play a dual role in biological systems, since they can be either harmful or beneficial to living systems (Valko et al., 2004). Beneficial effects of ROS involve physiological roles in cellular responses to noxia, as for example in defense against infectious agents and in the function of a number of cellular signaling systems. One further beneficial example of ROS at low concentrations is the induction of a mitogenic response. In contrast, at high concentrations, ROS can be important mediators of damage to cell structures, including lipids and membranes, proteins and nucleic acids termed as oxidative stress (Poli et al., 2004). Oxidative stress has been implicated in the pathology of many diseases such as inflammation, cancer, diabetes, neurodegenerative disorders and aging.

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Evaluation of Antioxidant Activities of Alpinia galanga (L.) Willd

Evaluation of Antioxidant Activities of Alpinia galanga (L.) Willd

Free radicals and ROS are highly reactive atoms or group of atoms produced constantly in our body during normal metabolic functions or introduced from the environment such as exposure to solar radiation, air pollution, ionizing radiations and smoking. Overproduction of free radicals may results into oxidative stress, which contributes to more than hundred disorders in human including hypertension, atherosclerosis, rheumatoid arthritis, diabetes mellitus, stroke, myocardial infarction, reperfusion injury, gastritis, Parkinson’s disease, haemorrhagic shock, coronary heart diseases,

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Free radical theory of autoimmunity

Free radical theory of autoimmunity

Antioxidants confer protection against oxidative stress by quenching free radicals, chelating redox metals and inter- acting with (and regenerating) other antioxidants within the "antioxidant network". When optimal concentrations are sustained in tissues and biofluids they can function in both the aqueous and membrane domains. The most effi- cient enzymatic antioxidants are superoxide dismutase, catalase and glutathione peroxidase [105]. Non-enzy- matic antioxidants include vitamins C and E, carotenoids, thiols (glutathione, thioredoxin and lipoic acid), natural flavonoids and melatonin [106]. Few antioxidants can regenerate other antioxidants to restore the reduced intra- cellular state via an "antioxidant network". The redox cycles of vitamins E and C have this capacity, driven by the redox potentials of the [Red/Ox] couple [107]. Antioxi- dants attenuate ROS by binding to transition metal-con- taining proteins, transferrin or ceruloplasmin, inhibiting cellular reactions (Vitamin E) and detoxifying ROS and RNS, (GSH, SODs, catalase) [108].

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Middle Molecular Weight Heparinyl Amino Acid Derivatives (MHADs) Function as  Indirect Radical Scavengers in Vitro

Middle Molecular Weight Heparinyl Amino Acid Derivatives (MHADs) Function as Indirect Radical Scavengers in Vitro

MHADs (excluding MHD and MHP) tended to inhibit free radical-induced reduction of cell viability of HUV-EC, and MHF, MHL, and MHY significantly protected HUV-EC more strongly than HE. For HE to in- duce EC-SOD and remove radicals, it has to first bind to HUV-EC. Originally, the HUV-EC surface is positive- ly charged. HE is a negatively charged proteoglycan and readily binds to HUV-EC [26]. MHF, MHL and MHY were superior to HE in the action on cell viability. These may be strongly negatively charged or likely to bind to HUV-EC compared with HE.

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Evaluation of Antioxidant and Antimicrobial Activity of Madhuca Indica

Evaluation of Antioxidant and Antimicrobial Activity of Madhuca Indica

DPPH radical was used as a substrate to evaluate free radical scavenging activities of extract. It involves reaction of specific antioxidant with a stable free radical 2, 2-diphenyl-1- picryl- hydrazyl (DPPH). As a result, there is reduction of DPPH concentration by antioxidant, which decreases the optical absorbance of DPPH; this is detected by spectrophotometer at 517 nm. BHA and ascorbic acid were used as standards. The scavenging effect of M.indica extract on the DPPH radical was 87.6%, (Fig.1) at a concentration of 500 µg/ml. These results indicated that extract has a noticeable effect on scavenging the free radicals.

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Antioxidant activity of Cassia auriculata Linn flowers

Antioxidant activity of Cassia auriculata Linn flowers

The reductive capability of the CAFE was compared with BHT (Table 1). For the measurements of the reductive ability, we investigated the Fe 3+ -Fe 2+ transformation in the presence of the CAFE. The reducing capacity of a compound may serve as a significant indicator of its potential antioxidant activity. However, the antioxidant activity of antioxidants have been attributed to various mechanism, among which are prevention of chain initiation, binding of transition metal ion catalysts, decomposition of peroxides, prevention of continued hydrogen abstraction, reductive capacity and radi radical scavenging antioxidant activity (Gulcin et al., 2003). The presence of reductants (antioxidants) in the CAFE causes the reduction of Fe 3+ (ferric cyanide complex) to Fe 2+ (ferrous form) (Amarowiz et al., 2004). The reducing power of the CAFE increased with increasing concentration. In this study, yellow colour of the test solution changes to various shades of green and blue depending upon the reducing power of the extract.

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 IN VITRO ANTIOXIDANT AND FREE RADICAL SCAVENGING ACTIVITIES OF VARIOUS SOLVENT EXTRACTS OF MARSDENIA BRUNONIANA

 IN VITRO ANTIOXIDANT AND FREE RADICAL SCAVENGING ACTIVITIES OF VARIOUS SOLVENT EXTRACTS OF MARSDENIA BRUNONIANA

ABTS radical scavenging activity is relatively recent one, which involves a more drastic radical, chemically produced and is often used for screening complex antioxidant mixtures such as plant extracts, beverages and biological fluids. The ability in both the organic and aqueous media and the stability in a wide pH range raised the interest in the use of ABTS・+ for the estimation of antioxidant activity (Nenadis et al., 2004). The extracts showed potent antioxidant activity in ABTS method which is comparable to the standard used. Here, the extracts radical scavenging activity showed a direct role of its phenolic compounds in free radical scavenging. The electron donation ability of natural products can be measured by 2, 2 -diphenyl-1- picrylhydrazyl radical (DPPH) purple-coloured solution bleaching. The method is based on scavenging of DPPH through the addition of a radical species or antioxidant that decolourizes the DPPH solution. The degree of colour change is proportional to the concentration and potency of the antioxidants. A large decrease in the absorbance of the reaction mixture indicates significant free radical scavenging activity of the compound under test (Pratap Chandran et al., 2013).

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Entropy, Free Radical and Life System

Entropy, Free Radical and Life System

Light or heat is needed when CL molecular resolves into CL atomic, namely resolve needs energy. At this moment free radical absorbs energy, and its single electronic has a strong tendency of pairing. Therefore free radical is really active, which can incur looping reaction. In looping reaction, formula (4) and (5) are the most important steps of free radical reaction, which continually produce new free radicals and products that makes the whole process circulate. However, active and low-concentration free radicals have the chance of collision, like formula (6), (7) and (8). When these collisions oc- curred, looping reaction will end. However, there has a small possibility of collision, and (4) and (5) steps are the main parts in the whole looping reaction.

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IN VITRO ANTIOXIDANT ACTIVITY OF NYMPHAEA RUBRA L  RHIZOME

IN VITRO ANTIOXIDANT ACTIVITY OF NYMPHAEA RUBRA L RHIZOME

The 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical is widely used as a model system to investigate the free radical scavenging activities of several plant extracts. DPPH is stable, nitrogen centered free radical which produces violet colour in methanol solution. It was reduced to a yellow coloured product with, diphenyl picryl hydrazine, with the addition of the extracts. The reduction in the number of DPPH molecules can be calculated with the number of available hydroxyl groups. [16] The DPPH scavenging activity of methanol extract of N. rubra rhizome was found to increase in a concentration dependent manner. The results of DPPH radical scavenging activity of the extract and the standard ascorbic acid were presented in Figure 1. The extract exhibited potent DPPH radical scavenging activity. The IC 50 value of the methanol extract of rhizome (18.26 µg/mL) was lower than standard

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Effects of antioxidants on oxidant induced sister chromatid exchange formation

Effects of antioxidants on oxidant induced sister chromatid exchange formation

determine whether antioxidants inhibit this process. Superoxide dismutase, catalase, and hydroxyl radical scavengers (benzoate, mannitol) protected target Chinese hamster ovary cells from phagocyte-induced sister chromatid exchanges, implicating the involvement of hydroxyl radicals in this chromosomal damage. N-acetylcysteine and beta-carotene were also protective. alpha-Tocopherol (greater than 5 microM) protected target cells exposed to phagocytes but not to enzymatically generated oxidants when the vitamin was added just before the source of oxygen radicals, suggesting, as reported by others, that the principal action of tocopherol in this setting was to inhibit the release of oxidants from phagocytes. On the other hand, cultivation of target cells with supplemental tocopherol protected them from the toxic effects of the enzymatic oxidant-producing system, indicating a role for membrane- associated free radicals in the mechanism of sister chromatid exchange induction. Low concentrations of sodium selenite (0.1-1.0 microM) protected the target cells. However, higher concentrations (10 microM) of selenite had no effect on oxidant-induced sister chromatid exchange formation, and 0.1 mM selenite increased the number of exchanges. Sodium selenite concentrations of 0.1 mM also decreased the intracellular glutathione concentration of target cells during an oxidant stress, and reducing target cell glutathione concentrations with buthionine sulfoximine increased their sensitivity to […]

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The Potential of some Plant Extracts as Radical Scavengers and Dipeptidyl Peptidase-4 Inhibitors

The Potential of some Plant Extracts as Radical Scavengers and Dipeptidyl Peptidase-4 Inhibitors

Seeds, beans, leaves, fruit peel and seeds of five plants (Ferula assa-foetida, Coffea robusta, Olea europaea, Punica granatum and Vitis vinifera, respectively) were extracted with four solvents (distilled water, 80% methanol, 80% acetone and a mixed solvent that included methanol, ethanol, acetone and n- butanol at proportions 7:1:1:1). Such manipulation yielded 20 extracts, which were phytochemically analyzed for total polyphenols (TP) and flavonoids (TF). The DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity (RSA) and DPP-4 (dipeptidyl peptidase-4) relative inhibition activity (RIA) were also assessed for each extract. The results revealed that mixed solvent extract of V. vinifera seeds showed the highest content of TP (194.8 ± 2.5 mg Gallic acid equivalent/g dry mass), while methanol extract of V. vinifera seeds recorded the highest content of TF (75.9 ± 0.3 mg catechin equivalent/g dry mass). The C. robusta bean aqueous extract was remarkable in scoring the highest DPPH RSA (87.2 ± 1.2%), while O. europaea leaf methanol extract had the highest DPP-4 RIA (86.4 ± 0.8%). In conclusion, the importance of natural products as radical scavengers and DPP-4 inhibitors is encouraged, and such biological effects were dependent on the plant species and the solvent of extraction. C. robusta beans are suggested to have a prominent RSA, while O. europaea leaves are recommended to be a target for investigations involved in the development of anti-T2DM therapies.

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Preventing Radiobleaching of Cyanine Fluorophores Enhances Stability of Nuclear/NIRF Multimodality Imaging Agents

Preventing Radiobleaching of Cyanine Fluorophores Enhances Stability of Nuclear/NIRF Multimodality Imaging Agents

(GA), ethanol (EtOH), and ascorbic acid (AA) (Fig. 3A-C). All scavengers provided some degree of radioprotection, which in the case of GA and EtOH was both concentration and exposure time dependent. Only AA was able to preserve completely 800CW fluorescence after longer radiation exposure, in a much wider range of concentrations (0.001–10 % (w/v)). NIRF images in Fig. S4 reiterate the strong radioprotective effect of relatively low AA concentrations, 0.1 % (w/v), which were able to

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NON CHOLESTEROL LOWERING DOSE OF ATORVASTATIN AMELIORATES DIABETIC VENTRICULAR MYOCYTE DYSFUNCTION IN MICE

NON CHOLESTEROL LOWERING DOSE OF ATORVASTATIN AMELIORATES DIABETIC VENTRICULAR MYOCYTE DYSFUNCTION IN MICE

. Many of these pleiotropic effects are mediated by antagonism of isoprenoid mediated activation of small GTP-binding proteins, such as Rac 1. Nicotinamide adenine dinucleotid phosphate (NADPH) oxidase which is regulated by the small GTP-binding protein Rac 1 is a main source of ROS in myocardium. Statins inhibit cardiac hypertrophy through an antioxidant mechanism involving inhibition Rac1 geranylgeranylation [16,19,24,25] . Further, atorvastatin (ATV) has free-radical scavenging ability via its metabolites [26] . Among various statins, ATV is the most widely used statin for the treatment of hypercholesterolemia. This study was designed to investigate whether ATV has beneficial effect on diabetes-induced cardiomyocyte dysfunction independently of cholesterol-lowering effect. Although a large number of groups have investigated the cardioprotective effects of ATV, independent of its hypolipidemic effect [13,19,27-30] , it’s effect on diabetes-induced cardiac myocyte dysfunction has not been investigated at a single cell level after in vivo treatment.

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Mechanistic Study of Pollutant Degradation

Mechanistic Study of Pollutant Degradation

molecules and thus enhances the Fenton degradation efficiency. However, in the cases where the pollutant has coordination ability to Fe 2+ , the presence of CMCD competes with the pollutant for Fe 2+ binding and results in reduced degradation. This result illustrates the potential of CMCD in protecting certain classes of compounds from being degraded or attacked. The protection effect may be useful in organic synthesis to keep certain compounds or certain groups of a compound intact. On the other hand, effective formation of metal-cyclodextrin-guest complexes can be used to selectively react the guest molecule with hydroxyl radical. In general, the role the cyclodextrin plays depends on the properties and interactions of all species coexisting in the solution. Therefore thorough study of the solution must be conducted in order to make a good prediction of the effect of cyclodextrin.

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Oxygen free radicals in ischemic acute renal failure in the rat

Oxygen free radicals in ischemic acute renal failure in the rat

During renal ischemia, ATP is degraded to hypoxanthine. When xanthine oxidase converts hypoxanthine to xanthine in the presence of molecular oxygen, superoxide radical (O-2) is generated. We studied the role of O-2 and its reduction product OH X in mediating renal injury after ischemia. Male Sprague-Dawley rats underwent right nephrectomy followed by 60 min of occlusion of the left renal artery. The O-2 scavenger superoxide dismutase (SOD) was given 8 min before clamping and before release of the renal artery clamp. Control rats received 5% dextrose instead. Plasma creatinine was lower in SOD treated rats: 1.5, 1.0, and 0.8 mg/dl vs. 2.5, 2.5, and 2.1 mg/dl at 24, 48, and 72 h postischemia. 24 h after ischemia inulin clearance was higher in SOD treated rats than in controls (399 vs. 185 microliter/min). Renal blood flow, measured after ischemia plus 15 min of reflow, was also greater in SOD treated than in control rats. Furthermore, tubular injury, judged histologically in perfusion fixed specimens, was less in SOD treated rats. Rats given SOD inactivated by prior incubation with diethyldithiocarbamate had plasma creatinine values no different from those of control rats. The OH X scavenger dimethylthiourea (DMTU) was given before renal artery occlusion. DMTU treated rats had lower plasma creatinine than did controls: 1.7, 1.7, and 1.3 mg/dl vs. 3.2, 2.2, and 2.4 […]

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