Reduction Of Oxidative Damage And Inflammatory Response In The Diaphragm Muscle Of Mdx Mice Using Iron Chelator Deferoxamine.

Oxidative stress and inflammatory processes strongly contribute to pathogenesis in Duchenne muscular dystrophy (DMD). Based on evidence that excess iron may increase oxidative stress and contribute to the inflammatory response, we investigated whether deferoxamine (DFX), a potent iron chelating agent, reduces oxidative stress and inflammation in the diaphragm (DIA) muscle of mdx mice (an experimental model of DMD). Fourteen-day-old mdx mice received daily intraperitoneal injections of DFX at a dose of 150 mg/kg body weight, diluted in saline, for 14 days. C57BL/10 and control mdx mice received daily intraperitoneal injections of saline only, for 14 days. Grip strength was evaluated as a functional measure, and blood samples were collected for biochemical assessment of muscle fiber degeneration. In addition, the DIA muscle was removed and processed for histopathology and Western blotting analysis. In mdx mice, DFX reduced muscle damage and loss of muscle strength. DFX treatment also resulted in a significant reduction of dystrophic inflammatory processes, as indicated by decreases in the inflammatory area and in NF-κB levels. DFX significantly decreased oxidative damage, as shown by lower levels of 4-hydroxynonenal and a reduction in dihydroethidium staining in the DIA muscle of mdx mice. The results of the present study suggest that DFX may be useful in therapeutic strategies to ameliorate dystrophic muscle pathology, possibly via mechanisms involving oxidative and inflammatory pathways.

Photocatalytic Degradation Of Ofloxacin And Evaluation Of The Residual Antimicrobial Activity.

Ofloxacin is an antimicrobial agent frequently found in significant concentrations in wastewater and surface water. Its continuous introduction into the environment is a potential risk to non-target organisms or to human health. In this study, ofloxacin degradation by UV/TiO2 and UV/TiO2/H2O2, antimicrobial activity (E. coli) of samples subjected to these processes, and by-products formed were evaluated. For UV/TiO2, the degradation efficiency was 89.3% in 60 min of reaction when 128 mg L(-1) TiO2 were used. The addition of 1.68 mmol L(-1) hydrogen peroxide increased degradation to 97.8%. For UV/TiO2, increasing the catalyst concentration from 4 to 128 mg L(-1) led to an increase in degradation efficiency. For both processes, the antimicrobial activity was considerably reduced throughout the reaction time. The structures of two by-products are presented: m/z 291 (9-fluoro-3-methyl-10-(methyleneamino)-7-oxo-2,3-dihydro-7H-[1,4]oxazino[2,3,4-ij]quinoline-6-carboxylic acid) and m/z 157 ((Z)-2-formyl-3-((2-oxoethyl)imino)propanoic acid).

Interaction between staining and degradation of a composite resin in contact with colored foods

Composite resins might be susceptible to degradation and staining when in contact with some foods and drinks. This study evaluated color alteration and changes in microhardness of a microhybrid composite after immersion in different colored foods and determined whether there was a correlation between these two variables. Eighty composite disks were randomly divided into 8 experimental groups (n = 10): kept dry; deionized water; orange juice; passion fruit juice; grape juice; ketchup; mustard and soy sauce. The disks were individually immersed in their respective test substance at 37 ºC, for a period of 28 days. Superficial analysis of the disk specimens was performed by taking microhardness measurements (Vickers, 50 g load for 45 seconds) and color alterations were determined with a spectrophotometer (CINTRA 10- using a CIEL*a*b* system, 400-700 nm wavelength, illuminant d65 and standard observer of 2º) at the following times: baseline (before immersion), 1, 7, 14, 21 and 28 days. Results were analyzed by ANOVA and Tukey's test (p < 0.05). Both variables were also submitted to Pearson's correlation test (p < 0.05). The passion fruit group underwent the greatest microhardness change, while the mustard group suffered the greatest color alteration. Significant positive correlation was found between the two variables for the groups deionized water, grape juice, soy sauce and ketchup. Not all color alteration could be associated with surface degradation.

Anti-oxidative and anti-ulcerogenic activity of Ipomoea imperati

Ipomoea imperati (Vahl) Griseb., Convolvulaceae, is used in traditional medicine for the treatment of inflammation, swelling and wounds, as well as to treat pains and stomach problems. This work evaluates the anti-oxidative activity by ESR (Electron Spin Resonance spectroscopy) and the preventive and curative actions of I. imperati in gastric ulcer animal model. Ipomoea imperati (200 mg/kg, p.o.) prevented the formation of gastric lesions in 78% (p<0.05) when compared with the negative control tween 80. Lanzoprazole, prevented in 85% the gastric lesions formation induced by ethanol (p<0.05). Therefore, the oral administration of I. imperati one hour before the ulcerogenic agent prevented the ulcer formation, conserving the citoprotection characteristics of the gastric mucosa and assuring the integrity of gastric glands and gastric fossets. The healing activity of I. imperati (200 mg/kg, p.o.) evaluated in chronic ulcer experiments induced by the acetic acid, was 72% (p<0.05). The positive control, ranitidine, healed 78% of the gastric lesions (p<0.05). The histological analysis confirmed the recovery of the mucosal layer and the muscle mucosal layer harmed by the acetic acid. Experiments in vitro with DPPH (2.2-diphenyl-1-picrylhydrazyl) of anti-oxidative activity demonstrated that I. imperati presents an IC50 of 0.73±0.01 mg/mL.

Immune cells and oxidative stress in the endotoxin tolerance mouse model

Sepsis is a systemic inflammatory response that can lead to tissue damage and death. In order to increase our understanding of sepsis, experimental models are needed that produce relevant immune and inflammatory responses during a septic event. We describe a lipopolysaccharide tolerance mouse model to characterize the cellular and molecular alterations of immune cells during sepsis. The model presents a typical lipopolysaccharide tolerance pattern in which tolerance is related to decreased production and secretion of cytokines after a subsequent exposure to a lethal dose of lipopolysaccharide. The initial lipopolysaccharide exposure also altered the expression patterns of cytokines and was followed by an 8- and a 1.5-fold increase in the T helper 1 and 2 cell subpopulations. Behavioral data indicate a decrease in spontaneous activity and an increase in body temperature following exposure to lipopolysaccharide. In contrast, tolerant animals maintained production of reactive oxygen species and nitric oxide when terminally challenged by cecal ligation and puncture (CLP). Survival study after CLP showed protection in tolerant compared to naive animals. Spleen mass increased in tolerant animals followed by increases of B lymphocytes and subpopulation Th1 cells. An increase in the number of stem cells was found in spleen and bone marrow. We also showed that administration of spleen or bone marrow cells from tolerant to naive animals transfers the acquired resistance status. In conclusion, lipopolysaccharide tolerance is a natural reprogramming of the immune system that increases the number of immune cells, particularly T helper 1 cells, and does not reduce oxidative stress.

Electrochemical degradation of the dye reactive orange 16 using electrochemical flow-cell

Electrochemical removals of color and organic load from solutions containing the dye reactive orange 16 (RO16) were performed in an electrochemical flow-cell, using a platinum working electrode. The influence of the process variables flow-rate, such as NaCl concentration, applied potential and solution pH, were studied. The best color removal achieved was 93% (λ = 493 nm) after 60 min at 2.2 V vs. RHE electrolysis, using 1.00 g L-1 NaCl as supporting electrolyte. The rises in the concentration of NaCl and applied potential increased the color removal rate. The best total organic carbon removal (57%) was obtained at 1.8 V, without the separating membrane, indicating that the ideal conditions for the color removal are not necessarily the same as those to remove the total organic carbon. The degradation efficiency decreased with the solution pH decrease.

Photo-fenton degradation of poly(Ethyleneglycol)

Polyethyleneglycol (PEG) was photooxidized in a photo-Fenton system and results compared with the dark reaction. The products were analysed using GPC and HPLC. In the absence of light, PEG samples needed 490 min to reduce their w by 50%, whereas under UV irradiation, only 10 min were necessary. The exponential decay of w with a concomitant increase in polydispersity and number of average chain scission, characterized a random chain scission mechanism. The degradation products of PEG in both systems showed the presence of lower molecular weight products, including smaller ethyleneglycols and formic acid. The mechanism involves consecutive processes, were the larger ethyleneglycols give rise, successively, to smaller ones. This suggests that the mechanism involves successive scissions of the polymer chain. Irradiated samples decomposed faster than those kept in the dark This study proves that the foto-Fenton method associated with UV-light is a good reactant for PEG photodegradation.

TiO2-Photocatalyzed degradation of phenol in saline media in an annular reactor: hydrodynamics, lumped kinetics, intermediates, and acute toxicity

The photocatalytic degradation of phenol in aqueous suspensions of TiO2 under different salt concentrations in an annular reactor has been investigated. In all cases, complete removal of phenol and mineralization degrees above 90% were achieved. The reactor operational parameters were optimized and its hydrodynamics characterized in order to couple mass balance equations with kinetic ones. The photodegradation of the organics followed a Langmuir-Hinshelwood-Hougen-Watson lumped kinetics. From GC/MS analyses, several intermediates formed during oxidation have been identified. The main ones were catechol, hydroquinone, and 3-phenyl-2-propenal, in this order. The formation of negligible concentrations of 4-chlorophenol was observed only in high salinity medium. Acute toxicity was determined by using Artemia sp. as the test organism, which indicated that intermediate products were all less toxic than phenol and a significant abatement of the overall toxicity was accomplished, regardless of the salt concentration.

Development and validation of a simple and rapid capillary zone electrophoresis method for determination of nnrti nevirapine in pharmaceutical formulations

A simple and fast capillary zone electrophoresis (CZE) method has been developed and validated for quantification of a non-nucleoside reverse transcriptase inhibitor (NNRTI) nevirapine, in pharmaceuticals. The analysis was optimized using 10 mmol L-1 sodium phosphate buffer pH 2.5, +25 kV applied voltage, hydrodynamic injection 0.5 psi for 5 s and direct UV detection at 200 µm. Diazepam (50.0 µg mL-1) was used as internal standard. Under these conditions, nevirapine was analyzed in approximately less than 2.5 min. The analytical curve presented a coefficient of correlation of 0.9994. Limits of detection and quantification were 1.4 µg mL-1 and 4.3 µg mL-1, respectively. Intra- and inter-day precision expressed as relative standard deviations were 1.4% and 1.3%, respectively and the mean recovery was 100.81%. The active pharmaceutical ingredient was subjected to hydrolysis (acid, basic and neutral) and oxidative stress conditions. No interference of degradation products and tablet excipients were observed. This method showed to be rapid, simple, precise, accurate and economical for determination of nevirapine in pharmaceuticals and it is suitable for routine quality control analysis since CE offers benefits in terms of quicker method development and significantly reduced operating costs.

Development of a flow through photo-reactor to study degradation of organic compounds by Sequential Injection Analysis (SIA)

This work describes a photo-reactor to perform in line degradation of organic compounds by photo-Fenton reaction using Sequential Injection Analysis (SIA) system. A copper phthalocyanine-3,4',4²,4²¢-tetrasulfonic acid tetrasodium salt dye solution was used as a model compound for the phthalocyanine family, whose pigments have a large use in automotive coatings industry. Based on preliminary tests, 97% of color removal was obtained from a solution containing 20 µmol L-1 of this dye.

Oxidative DNA damage induced by S(IV) in the presence of Cu(II) and Cu(I) complexes

The DNA damage induced by S(IV) in the presence of some Cu(II) complexes in air saturated solution was investigated. The addition of S(IV) to an air saturated solution containing CuII GGA (GGA = glycylglycyl-L-alanine), CuII G3 (G3 = triglycine) or CuII G4 (G4 = tetraglycine) and Ni(II) traces, causes rapid formation of the respective Cu(III) complex, with simultaneous O2 uptake and S(IV) oxidation. SO3•- and HO• were detected by EPR-spin trapping experiments. The DNA strand breaks were attributed to the oxysulfur radicals formed. In the reduction of Cu(II)/BCA (BCA = 4,4' dicarboxy-2-2'-biquinoline) by S(IV), with CuI BCA complex formation, there is the possible formation of carbon centered radical of BCA or peroxyl radical (ROO•) capable of oxidizing DNA bases. The intensity of DNA damage in the presence of these Cu(II) complexes and S(IV) (10-300 µmol L-1) followed the order: CuII BCA ∼ CuII G4 ∼ Cu(II) (added as Cu(NO3)2) > CuII G3 ∼ CuII GGA. Specifically for CuII BCA the damage occurred even at lower S(IV) concentration (0.1 µmol L-1). For the Cu(II) complexes with glycylglycylhistidine, glycylhistidylglycine, glycylhistidyllysine and glycylglycyltyrosylarginine the Cu(III) formation and the DNA damage was not observed.

Electrochemical and photocatalytic reactions of polycyclic aromatic hydrocarbons investigated by raman spectroscopy

This paper presents the study of photochemical behavior of polycyclic aromatic hydrocarbons (PAHs), potential pollutants in secondary reactions in aerosols, through Raman spectroscopy compared with its electrochemical behavior. The PAHs studied include pyrene, anthracene, phenanthrene and fluorene. These were adsorbed onto TiO2 and irradiated with ultraviolet light (254 nm). Their electrochemical oxidation was studied by in situ Surface-enhanced Raman Scattering (SERS) and led to the formation of carbonyl-containing products. Oxidized intermediates bearing the C=O group were also formed during photodegradation. The joint analysis of the photodegradation data with those produced by electrochemical means - using spectroscopic techniques for the identification and characterization of the products - revealed the formation of identical products for anthracene, but not for pyrene. A reasonable explanation for this difference in results is that photochemical and electrochemical oxidation reactions proceed via different mechanisms. While photocatalytic degradation over TiO2 is initiated by hydroxyl radicals, electrochemical oxidation is initiated by the direct electron transfer from adsorbed PAH to the electrode, generating PAH cation radicals that undergo subsequent reactions.

Effect of n-3 polyunsaturated fatty acids on oxidative stress in rats supplemented with different doses of fish oil

The diet and plasma lipid patterns associated with lipid oxidation susceptibility in rats fed different doses of polyunsaturated fatty acids (n-3 PUFA) from fish oil were evaluated. Wistar rats were assigned into three groups and received diets containing 8% soybean oil (SOY), 4% soybean oil + 4% fish oil (SOY-FISH) and 8% fish oil (FISH) for 21 days. Linoleic, oleic and ?-linolenic acids in SOY diets were substituted by myristic, palmitic, palmitoleic, eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids in SOY-FISH and FISH diets reducing the n-6/n-3 ratio and increasing the peroxidability index (PI). Increased dietary EPA and DHA were observed in SOY-FISH and FISH plasma at the expense of linoleic and arachidonic acid levels. Saturated fatty acids, which were significantly different between the three diets (P < 0.01), were found at the same concentration in the plasma (P = 0.23). No changes were observed in oxidative stress as measured by the concentration of thiobarbituric acid reactive substances (TBARS) expressed in brain homogenates. However, TBARS concentration in the plasma of the SOY-FISH group was higher than the other two groups (P = 0.02). The major differences between these three groups were the n-3 PUFA content (0.4, 1.8 and 3.2 g/100 g diet) and the saturates/polyunsaturates ratio (0.3, 0.5 and 0.8) for SOY, SOY-FISH, and FISH groups, respectively. Thus, n-3 PUFA intake from fish oil only when followed by a decrease in saturated/polyunsaturated fatty acids ratio increased oxidative susceptibility in rats measured by plasma TBARS concentration

Chemical characterization and oxidative stability of the oils from three morphotypes of Mauritia flexuosa L.f, from the Peruvian Amazon

Three morphotypes of aguaje Mauritia flexuosa were tested, classified by the color of their mesocarpium: ""color"", ""shambo"" and ""amarillo"", collected from different areas near the city of Iquitos, Peru. Also, physical-chemical analyses of the mesocarpium were performed, such as the characterization of fatty acids by gas chromatography, determination of beta- carotene y alpha tocopherol by high efficiency liquid chromatography system in normal and reverse phase and the determination of oxidation induction time in the Rancimat apparatus. Proximate, mineral and fatty acid analyses were done on the seeds. The aguaje mesocarpium is rich in oleic oil (""amarillo"": 75.63% +/- 0.31), (beta-carotene (""amarillo"": 342.42ug/g 0.71) and alpha- tocopherol (""color"": 685.81mg/L +/- 1.04), plus the morphotype ""color"" has a superior oxidation induction time compared to other morphotypes with 6.91 +/- 0.01. The aguaje seed contains significant amounts of (06 (linoleic oil) in ""shambo"" with 36.04 +/- 0.09%. The results indicate that these oils, regardless their classification, contain important chemical compounds that give them a special nutritive value.