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Query: UNIPROT:P06889 (Mol)
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Oxygen toxicity and related free radical reactions are implicated in numerous pathophysiological conditions, like atherosclerosis, inflammation, gastric ulceration, neuronal degeneration, tumour promotion. The flowers of Matricaria chamomilla, Asteraceae, have been used therapeutically for conditions in which oxidative stress is supposed to be implicated. We considered interesting to investigate the effect of Chamazulene, the active substance of chamomile, on free radical processes. Membrane lipid peroxidation was induced by Fe2+/ascorbate and assessed as the 2-thiobarbituric acid reactive material. The hydroxyl radical scavenging activity was studied as the competition of Chamazulene with DMSO for HO. generated by Fe3+/ascorbate. Finally, the interaction of Chamazulene with the N-centered stable free radical DPPH was estimated photometrically (517 nm). It was found that Chamazulene inhibited lipid peroxidation in a concentration and time dependent manner presenting an IC50 of 18 microM after 45 min incubation. It could also inhibit the autoxidation of DMSO (33 mM) by 76% at 25 mM, and had a weak capacity to interact with DPPH. In conclusion, Chamazulene presents interesting properties concerning radical processes.
Res Commun Mol Pathol Pharmacol 1996 Jun
PMID:Investigation of the effect of chamazulene on lipid peroxidation and free radical processes. 882 32

A North American ginseng extract (NAGE) containing known principle ginsenosides for Panax quinquefolius was assayed for metal chelation, affinity to scavenge DPPH-stable free radical, and peroxyl (LOO*) and hydroxyl (*OH) free radicals for the purpose of characterizing mechanisms of antioxidant activity. Dissociation constants (Kd) for NAGE to bind transition metals were in the order of Fe2+ > Cu2+ > Fe3+ and corresponded to the affinity to inhibit metal induced lipid peroxidation. In a metal-free linoleic acid emulsion, NAGE exhibited a significant (p < or = 0.05) concentration (0.01-10 mg/mL) dependent mitigation of lipid oxidation as assessed by the ammonium thiocyanate method. Similar results were obtained when NAGE was incubated in a methyl linoleate emulsion containing haemoglobin catalyst and assessed by an oxygen electrode. NAGE also showed strong DPPH radical scavenging activity up to a concentration of 1.6 mg/mL (r2 = 0.996). Similar results were obtained for scavenging of both site-specific and non site-specific *OH, using the deoxyribose assay method. Moreover, NAGE effectively inhibited the non site-specific DNA strand breakage caused by Fenton agents, and suppressed the Fenton induced oxidation of a 66 Kd soluble protein obtained from mouse brain over a concentration range of 2-40 mg/mL. These results indicate that NAGE exhibits effective antioxidant activity in both lipid and aqueous mediums by both chelation of metal ions and scavenging of free radicals.
Mol Cell Biochem 2000 Jan
PMID:Antioxidant properties of a North American ginseng extract. 1072 26

Irradiation causes a variety of lesions in important biomolecules of the cell through generation of free radicals leading to genomic instability. DNA strand breaks, acentric fragments, or defective kinetochores are manifested as micronuclei after the first cell division. Chemicals that can trap free radicals may reduce the deleterious effects of ionizing radiation. Mangiferin (MGN), a glucosylxanthone derived from Mangifera indica (mango), was investigated for its ability to reduce the frequency of radiation-induced micronucleated binucleate cells (MNBNCs) in cultured human peripheral blood lymphocytes (HPBLs). HPBL cultures were pretreated with 0, 5, 10, 20, 50, and 100 microg/ml of MGN for 30 min before exposure to 3 Gy of (60)Co gamma-radiation. The maximum decline in radiation-induced micronuclei was observed at a concentration of 50 microg/ml MGN; thereafter, a nonsignificant elevation in MNBNC frequency was observed at 100 microg/ml MGN. Since the lowest MNBNC frequency was observed for 50 microg/ml MGN, dose-response studies were undertaken using this concentration. Irradiation of HPBLs with 0, 1, 2, 3, or 4 Gy of gamma-radiation caused a dose-dependent elevation in the MNBNC frequency, while treatment of HPBLs with 50 microg/ml MGN 30 min before radiation resulted in significant declines in these frequencies. MGN alone did not alter the proliferation index. Irradiation caused a dose-dependent decline in the proliferation index, while treatment of HPBLs with 50 micro/ml MGN significantly elevated the proliferation index in irradiated cells. MGN treatment reduced hydrogen peroxide-induced lipid peroxidation in HPBLs in a concentration-dependent fashion. In cell-free studies, MGN inhibited the induction of (.)OH (hydroxyl), O(2) (.-) (superoxide), DPPH (1,1-diphenyl-2-picrylhydrazyl), and ABTS(.+) (2,2-azino-bis-3-ethyl benzothiazoline-6-sulphonic acid) radicals in a dose-dependent manner. The results of this study indicate that MGN possesses radioprotective properties by suppressing the effects of free radicals.
Environ Mol Mutagen 2005 Jul
PMID:Effect of mangiferin on radiation-induced micronucleus formation in cultured human peripheral blood lymphocytes. 1579 88

Blood orange juice is a typical Italian product whose red color is primarily associated with anthocyanin pigments. Two orange-based products are present on the market: pasteurized pure juice with 40 days of shelf life, and sterilized beverage containing minimum 12% of concentrated fruit juice. The aim of the present paper is to verify the relationships between the antioxidant properties and the anthocyanins content in a sampling of pasteurized and sterilized commercial red orange juices. The anthocyanins composition was determined by HPLC-MS/MS, while the antioxidant activity was evaluated by the Briggs-Rauscher reaction, selected in order to acquire information at acid pH values, by three radical scavenging assays (DMPD, 2-2'-azinobis-(3-ethylenbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), DPPH), and by FRAP assay to monitor the ferric reducing power. Results showed that antioxidant activity, particularly when measured by ABTS method, is positively related to the content of anthocyanins and that the reduction of anthocyanins content, typical of commercial long-shelf life juices, leads to a remarkable loss of antioxidant power.
Mol Nutr Food Res 2005 Dec
PMID:Antioxidant activity of pasteurized and sterilized commercial red orange juices. 1625 88

Present study was undertaken to evaluate the radioprotective ability of total polyphenols extracted from edible portion (epicarp and mesocarp) of apple. Prior administration of apple polyphenols to murine thymocytes significantly countered radiation induced DNA damage (evaluated by alkaline halo assay) and cell death (trypan blue exclusion method) in a dose dependent manner maximally at a concentration of 2 and 0.2 mg/ml respectively. Apple polyphenols in a dose dependent fashion inhibited both radiation or Fenton reaction mediated 2-deoxyribose (2-DR) degradation indicating its ability to scavenge hydroxyl radicals and this activity was found to be unaltered in presence of simulated gastric juice. Similarly apple polyphenols in a dose dependent fashion scavenged DPPH radicals (maximum 69% at 1 mg/ml), superoxide anions (maximum 88% at 2 mg/ml), reduced Fe(3 +) to Fe(2 +) (maximum at 1 mg/ml) and inhibited Fenton reaction mediated lipid peroxidation (maximum 66% at 1.5 mg/ml) further establishing its antioxidative properties. Studies carried out with plasmid DNA revealed the ability of apple polyphenols to inhibit radiation induced single as well as double strand breaks. The results clearly indicate that apple polyphenols have significant potential to protect cellular system from radiation induced damage and ability to scavenge free radicals might be playing an important role in its radioprotective manifestation.
Mol Cell Biochem 2006 Aug
PMID:Radioprotective properties of apple polyphenols: an in vitro study. 1653 97

Hippophae rhamnoides or seabuckthorn is used extensively in Indian and Tibetan traditional medicine for the treatment of circulatory disorders, ischemic heart disease, hepatic injury, and neoplasia. In the present study, we have evaluated the radioprotective potential of REC-1001, a fraction isolated from the berries of H. rhamnoides. Chemical analysis of the extract indicated that REC-1001 was approximately 68% by weight polyphenols, and contained kaempferol, isorhamnetin, and quercetin. The effect of REC-1001 on modulating radiation-induced DNA damage was determined in murine thymocytes by measuring nonspecific nuclear DNA damage at the whole genome level using the alkaline halo assay and by measuring sequence/gene-specific DNA damage both in nuclear DNA (beta-globin gene) and in mitochondrial DNA using a quantitative polymerase chain reaction. Treatment with 10 Gy resulted in a significant amount of DNA damage in the halo assay and reductions in the amplification of both the beta-globin gene and mitochondrial DNA. REC-1001 dose-dependently reduced the amount of damage detected in each assay, with the maximum protective effects observed at the highest REC-1001 dose evaluated (250 micro g/ml). Studies measuring the nicking of naked plasmid DNA further established the radioprotective effect of REC-1001. To elucidate possible mechanisms of action, the antioxidant properties and the free-radical scavenging activities of REC-1001 were evaluated. REC-1001 dose-dependently scavenged radiation-induced hydroxyl radicals, chemically-generated superoxide anions, stabilized DPPH radicals, and reduced Fe(3+) to Fe(2+). The results of the study indicate that the REC-1001 extract of H. rhamnoides protects mitochondrial and genomic DNA from radiation-induced damage. The polyphenols/flavonoids present in the extract might be responsible for the free radical scavenging and DNA protection afforded by REC-1001.
Environ Mol Mutagen 2006 Dec
PMID:Protection from radiation-induced mitochondrial and genomic DNA damage by an extract of Hippophae rhamnoides. 1694 57

The slightly water-soluble flavonoid quercetin (QUE) and its inclusion with either beta-cyclodextrin (betaCD), hydroxypropyl-beta-cyclodextrin (HP-betaCD) or sulfobutyl ether-beta-cyclodextrin (SBE-betaCD) were investigated. The stoichiometric ratios and stability constants describing the extent of formation of the complexes have been determined by phase-solubility measurements; in all cases type-A(L) diagrams have been obtained (soluble 1:1 complexes). The results showed that the inclusion ability of betaCD and its derivatives was the order: SBE-betaCD>HP-betaCD>betaCD. Kinetic studies of DPPH with QUE and CDs complexes were done. The results obtained indicated that the QUE-SBE-betaCD complex was the most reactive form. The scavenging capability of QUE and CDs complexes with DPPH and galvinoxyl was studied using ESR spectroscopy. All complexes showed a higher scavenging capability with both radicals, compare quercetin in water. Beside, these results indicated that the complexes formed maintained the quercetin antioxidant activity.
Spectrochim Acta A Mol Biomol Spectrosc 2007 May
PMID:Complexation of quercetin with three kinds of cyclodextrins: an antioxidant study. 1695 Jun 45

During the early stage of the Maillard reaction pyrazinium radical cations were detected by ESR within the reaction system d-glucose/glycine. The spectra were characterized by completely resolved hyperfine structure. The partial pressure of oxygen and the radical concentrations were measured directly in the reaction mixture by ESR using solutions of the spin probe TEMPOL and of DPPH, respectively. There are quantitative and qualitative relations of the actual concentration of the radical ions to the partial pressure of oxygen, the temperature-time regime and the mechanical mixing of the reaction system. These macroscopic parameters significantly affect both the induction period and the velocity of the time-dependent formation of free radicals. From in situ variations of p(O2) and p(Ar) including the connected mixing effects caused by the passing the gases through the reaction mixture, steric and chemical effects of the stabilization of the radical ions were established. The determination of suitable and relevant conditions for stabilization and subsequent radical reactions contributes to the elucidation of the macroscopically known antioxidant activity of Maillard products.
Spectrochim Acta A Mol Biomol Spectrosc 2007 Aug
PMID:On the time behaviour of the concentration of pyrazinium radical cations in the early stage of the Maillard reaction. 1710 Dec 90

Various pigments were formed in the D-xylose-glycine reaction system. Blue pigments (Blue-M1 and Blue-M2) and red pigments (Red-M1 and Red-M2) were generated in the Maillard reaction. Blue-M2 is presented to have been generated by the reaction between Blue-M1, which involved two pyrrolopyrrole structures as the major blue pigment, and di-D-xyluloseglycine. We identified red pigments as the isomers of addition compounds of D-xyluloseglycine to condensated compound between pyrroropyrrole-2-carbaldehyde and pyrrole-2-carbaldehyde compounds. These pigments have polymerizing activities, suggesting that they are important Maillard reaction intermediates through the formation of melanoidins. Blue-M1 as well as melanoidins effectively suppressed the peroxidation of linoleic acid. The scavenging activity toward Blue-M1 on hydroxyl and DPPH radicals was also as strong as that of melanoidins. Furthermore, Blue-M1 prevents the oxidative cell injury. Therefore, Blue-M1 will be an antioxidant which protects against the oxidative stress in biological systems. Melanoidins induced IFN-gamma mRNA and IL-12 mRNA expressions in spleen cells exposed to allergen and in macrophage-like J774.1 cells, respectively. These findings suggest that melanoidins have suppressive effect on allergic reaction as a novel physiological effect.
Mol Nutr Food Res 2006 Dec
PMID:Chemistry and some biological effects of model melanoidins and pigments as Maillard intermediates. 1713 57

Osteoarthritis is thought to be induced by the aging-related loss of homeostatic balance between degeneration and repair mechanism around cartilage tissue in which inflammatory mediators such as reactive oxygen species, cytokines and prostaglandins are prone to overproduction under undesirable physiological conditions. Phlorotannins are unique polyphenolic compounds bearing dibenzo-1,4-dioxin skeleton which are not found in terrestrial plants but found only in some brown algal species such as Ecklonia and Eisenia families. Phlorotannin-rich extracts of Ecklonia cava including ventol showed significant antioxidant activities such as DPPH radical scavenging, ferric ion reducing power, peroxynitrite scavenging and inhibition of LDL oxidation, indicating their possible antioxidative interference both in onset and downstream consequences of osteoarthritis. Ventol also showed significant down regulation of PGE2 generation in LPS-treated RAW 246.7 cells, and significant inhibition of human recombinant interleukin-1alpha-induced proteoglycan degradation, indicating its beneficial involvement in pathophysiological consequences of osteoarthritis, the mechanism of which needs further investigation. Since ventol showed strong therapeutic potentials in arthritic treatment through several in vitro experiments, it is highly encouraged to perform further mechanistic and efficacy studies.
Res Commun Mol Pathol Pharmacol 2004
PMID:Antioxidant and antiinflammatory activities of ventol, a phlorotannin-rich natural agent derived from Ecklonia cava, and its effect on proteoglycan degradation in cartilage explant culture. 1756 7


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