High SOD-like Activity Research Articles

Characterization and antioxidant activity of Amazonian woods

The heartwood and sapwood characteristics of 11 Amazonian trees were investigated. Whereas 7 of the specimens had densities greater than 0.7 g/cm3, the heartwood density of ipe amarelo (Tabebuia serratifolia), macaranduba (Manilkara huberi), cumaru-ferro (Dipteryx odorata), and guarita (Astronium lecointei) exceeded 1.0 g/cm3. Jatoba contained small amounts of Klason lignin and α-cellulose, and large amounts of holocellulose and alkali extract, suggesting that it has a high polysaccharide content that can be dissolved in an alkaline medium. The difference in the syringyl/guaiacyl (S/G) ratios of the samples before and after alkali extraction suggests that alkali extracts contain syringyl-type polyphenols. In all of the samples, the heart-wood methanol extracts were larger in volume than the sapwood methanol extracts, and the sapwood alkali extracts were larger in volume than the heartwood alkali extracts. The antioxidant activities of the methanol and alkali extracts were assayed by measuring the levels of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and super oxide dismutase (SOD)-like activity, respectively. The heart-wood methanol extract of jatoba (Hymenaea courbaril) exhibited the highest level of activity (EC50 = 44 mg/l), which exceeded that of α-tocopherol (EC50 = 48 mg/l), and the heartwood alkali extracts of jatoba and ipe amarelo had high SOD-like activity comparable with red wine.

Liposome Modified with Mn−Porphyrin Complex Can Simultaneously Induce Antioxidative Enzyme-like Activity of Both Superoxide Dismutase and Peroxidase

An antioxidative liposome catalysis that mimics both superoxide dismutase (SOD) and peroxidase (POD) activities has been developed by using the liposomes modified with lipophilic Mn-(5,10,15,20-tetrakis[1-hexadecylpyridium-4-yl]-21H,23H-porphyrin) (Mn-HPyP). The SOD- and POD-like activities of the Mn-HPyP-modified liposome were first investigated by varying the type of phospholipid, such as 1,2-distearyl-sn-glycero-3-phosphocholine (DSPC), 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), and 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC). Higher SOD-like activity was obtained in the case of DLPC and DMPC liposomes, in which the ligands were well-dispersed on the membrane in the liquid crystalline phase. The POD-like activity was maximal in the case of DMPC liposome, in which the Mn-HPyP complex was appropriately clustered on the membrane in the gel phase. On the basis of the above results, the co-induction of the SOD and POD activities to eliminate the superoxide and also hydrogen peroxide as a one-pot reaction was finally performed by using the Mn-HPyP-modified DMPC liposome, resulting in an increase in the efficiency of the elimination of both superoxide and hydrogen peroxide.

Antioxidant Contents and Antioxidative Properties of Traditional Rye Breads

The purpose of this research was to find out the effect of flour extraction rate on the antioxidative properties of traditional rye bread and then to compare the bioactive compounds content and antioxidant properties of rye breads with commercial wheat roll. Four types of rye flour with different extraction rates of 100 (whole meal dark flour), 95 (brown flour), 90 (brown flour), and 70% (light flour) originated from Warko rye cultivar were used for traditional bread baking with sourdough fermentation. Four types of the respective rye breads were analyzed for their potentially beneficial components, including tocopherols and tocotrienols, total phenolics and flavonoids, reduced glutathione, and inositol hexaphosphates. Moreover, the phenolic acids profile was provided. The Trolox equivalent antioxidant capacity (TEAC) of the breads was evaluated using free radical scavenging activities of 80% methanol extracts against ABTS*+ radical cation (ABTS radical cation decolorization method) whereas radical scavenging activity (RSA) was determined against 2,2-diphenyl-1-picrylhydrazyl radical (DPPH*). The superoxide dismutase-like activity (SOD-like activity) was evaluated as free radical scavenging activities of PBS extracts against superoxide anion radicals (O2*-). The results were compared to whole meal rye bread as well as to wheat roll taken as representative example of wheat based bakery product. The studies showed that flour extraction rates strongly affected the content of bioactive compounds and antioxidative properties of traditionally baked rye breads. The incorporation of the rye flours with extraction rates from 100 down to 70% in the formulation caused decrease in tocopherol (T), tocotrienol (T3), inositol hexaphosphate (IP6), and phenolic compound (TPC) contents in rye breads. No changes in reduced glutathione (GSH) contents were noted between each type of rye bread. A significant decrease in Trolox equivalent antioxidant capacity and radical DDPH scavenging activity was also found in bread formulated on flour with an extraction rate of 70% in comparison to the breads formulated on flour with extraction rates from 100 to 90%. The highest SOD-like activity was noted for rye bread formulated on flour with an extraction rate of 70%. The four types of rye breads showed better antioxidative properties and higher antioxidant contents when compared to wheat roll with one exception made to tocopherols and tocotrienols.

Metal complexes with superoxide dismutase-like activity as candidates for anti-prion drug

Various compounds were evaluated for ability to inhibit the formation of the abnormal protease-resistant form of prion protein (PrP-res) in two cell lines infected with different prion strains. Examination of the structure–activity relationships indicated that compounds with copper-selective chelating ability and whose copper complexes have high SOD-like activity are candidates for anti-prion drug.

Structure−Activity Relationship of Cyclic Nitroxides as SOD Mimics and Scavengers of Nitrogen Dioxide and Carbonate Radicals

Synthetic nitroxide antioxidants attenuate oxidative damage in various experimental models. Their protective effect reportedly depends on ring size and ring substituents and is greater for nitroxides having lower oxidation potential. The present study focuses on the kinetics and mechanisms of the reactions of piperidine, pyrrolidine and oxazolidine nitroxides with HO2*/O2*-, *NO2 and CO3*- radicals, which are key intermediates in many inflammatory and degenerative diseases. It is demonstrated that nitroxides are the most efficient scavengers of *NO2 at physiological pH (k = (3-9) x 10(8) M(-1) s(-1)) and among the most effective metal-independent scavengers of CO3*- radicals (k = (2 - 6) x 10(8) M(-1) s(-1)). Their reactivity toward HO2*, though not toward *NO2 and CO3*-, depends on the nature of the ring side-chain and particularly on the ring-size. All nitroxide derivatives react slowly with O2*- and are relatively inefficient SOD mimics at physiological pH. Even piperidine nitroxides, having the highest SOD-like activity, demonstrate a catalytic activity of about 1000-fold lower than that of native SOD at pH 7.4. The present results do not indicate any correlation between the kinetics of HO2*/O2*-, *NO2 and CO3*- removal by nitroxides and their protective activity against biological oxidative stress and emphasize the importance of target-oriented nitroxides, i.e., interaction between the biological target and specific nitroxides.

Determination of glutathione peroxidase and superoxide dismutase-like activities in equine spermatozoa, seminal plasma, and reproductive tissues

To determine glutathione peroxidase (GPX) and superoxide dismutase (SOD)-like activities in spermatozoa, seminal plasma, and reproductive tissues (ie, testis, epididymis, bulbourethral gland, prostate, vesicular gland, and ampulla) in horses. Seminal plasma from 17 stallions, spermatozoa from 5 stallions, and reproductive tissues from 3 stallions. Activity of GPX was determined by use of assays measuring oxidation of NADPH in the presence of exogenous glutathione, cumene hydroperoxide, and glutathione reductase. Activity of SOD-like enzymes was determined by use of the nitroblue tetrazolium assay. Mean GPX and SOD-like activities in seminal plasma were 1.3 +/- 0.1 nmol of NADPH oxidized/min/mg of protein and 29.2 +/- 6.6 U/mg of protein, respectively. Mean GPX activities in spermatozoa separated from seminal plasma by centrifugation and via Percoll gradient were 2.2 +/- 0.3 nmol and 6.1 +/- 1.3 nmol of NADPH oxidized/min/mg of protein, respectively. Mean SOD-like activity of spermatozoa separated by centrifugation was 58.6 +/- 22.3 U/mg of protein; SOD-like activity was not detected in Percoll-separated spermatozoa. Among reproductive tissues, the ampulla and prostate had the highest SOD-like activity, although this was not significantly different from activity in other tissues. Testes and spermatozoa from the cauda epididymis contained significantly more GPX activity than other tissues. Results suggest that although equine seminal plasma contains high SOD-like enzyme activity, spermatozoa have limited GPX and SOD-like activity. Enzymatic antioxidant activity in equine spermatozoa appears to be predominantly derived from seminal plasma adsorbed onto the plasma membrane. Removal of seminal plasma during semen processing may increase oxidative stress in equine-spermatozoa.

Mn 2+, Co 2+, Cu 2+ and Zn 2+complexes with two macrocyclic ligands bearing l-lactate-like functions: potentiometric studies and evaluation of superoxide-scavenging properties of the Mn 2+ complex

Some aerobic organisms devoid of SOD use Mn 2+ chelates to scavenge the O 2 − radical. Since the Mn 2+-bis(lactato)diaquo complex is known as having a high SOD-like activity, we prepared manganese(II) complexes with triazamacrocyclic ligands bearing l-lactate-like functions in order to obtain model compounds able to disproportionate the superoxide radical. Thus, two macrocyclic ligands, N,N′,N″-tris[2( S)-hydroxybutyric acid]-1,4,7-triazacyclononane, L 1 , and N,N′,N″-tris[2( S)-hydroxybutyric acid]-1,5,9-triazacyclododecane, L 2 , were prepared and their capacity to retain the Mn 2+ ion in aqueous solution was determined from potentiometric experiments. The chelating properties in aqueous solution of each ligand towards Co 2+, Cu 2+ and Zn 2+ ions were also determined. L 1 forms complexes with Mn 2+, Co 2+, Cu 2+ and Zn 2+ ions with stability constants of 8.33(5), 15.78(5), 17.65(3) and 14.32(1), respectively. L 2 forms complexes with Cu 2+ and Zn 2+ ions with stability constants of 10.67(1) and 6.98(3), respectively. But the constants related to the Mn 2+ and Co 2+ complexes were too low to be determined by the method used. The stability constants values calculated for L 2 complexes are significantly lower than those for the corresponding complexes of L 1 . Additional spectroscopic measurements were carried out on the Mn 2+– L 1 system. The electronic spectrum of this system showed a pH-dependence that may be consistent with the formation of hydroxo-species as the ESR spectra recorded at 120 K did not show oxidation of the Mn 2+ ion in the pH range studied. The superoxide-scavenging activity of the manganese(II)– L 1 complex was investigated using the cytochrome c assay. The Mn 2+– L 1 system showed an IC 50 value of 1.7 μM which indicates that it appears as a potent SOD mimic.

Determination of SOD-Like activity of Copper(II) complexes with α-Amino acid dithiocarbamates

The SOD-like activity of the copper(II) complexes of five amino acid (Gly, Ala, Ser, Asn, Glu) dithiocarbamates was determined. The concentration of the complexes that inhibit by 50% (IC 50) the reduction of nitroblue tetrazolium by superoxide radical (generated by xanthine oxidase) lies between 1.2 μM (Glu) and 20 μM (Gly). Quantitative structure-activity relationships, QSAR, were established between pIC 50 (-log IC 50) and the molar refraction values of the amino acid substituents, as well as Cu(I) / Cu(II) oxidation potentials (determined by cyclic voltammetry). The high SOD-like activity of the Glu dithiocarbamate complex is interpreted to be due to its distorted geometry based on EPR spectra and conductimetric titration data.

Serum superoxide dismutase in patients with Graves' disease

We studied serum superoxide dismutase (SOD) in patients with Graves' disease. Measurements of immunoreactive Cu, Zn-SOD and SOD-like activities were made by enzyme-linked immunosorbent assay (Ube Industries Ltd) and Nitroblue Tetrazolium method (Wako Ltd), respectively. Serum from patients with untreated Graves' disease had a significantly higher concentration of Cu, Zn-SOD and higher SOD-like activity than those from normal subjects, patients with Graves' disease under treatment over one year, patients with Graves' disease in remission, and patients with untreated Hashimoto's disease. Methimazole treatment produced no significant change in SOD-like activity and Cu, Zn-SOD concentration when patients with Graves' disease had normal thyroid function. These results indicated that oxidative tissue injury existed in patients with Graves' disease with normal thyroid function under treatment; however, we could not clearly establish that thyroid function had a direct connection with oxidative tissue injury.

Requirements for SOD mimics operating in vitro to work also in vivo.

When an efficient SOD mimic operating in vitro is introduced into cells, the following requirements are needed in order that this compound will catalyze O2- dismutation efficiently: it should be non toxic, stable, has a long metabolic half life, does not form ternary complexes with the cell components, its reduced form reacts slowly with molecular oxygen, should be able to cross cell membranes and also to reach lipophilic or hydrophobic regions. Thus, it seems that finding an efficient compound that has high SOD-like activity in vivo will not be easily achieved.