Instrumental color and oxidative stability of light and dark muscles of Nile tilapia / Cor instrumental e estabilidade oxidativa de músculos claros e escuros de tilápia do Nilo

ABSTRACT: The aim of the present study was to compare the color and oxidative stability of light (LM) and dark (DM) muscles of Nile tilapia (Oreochromis niloticus) stored at 4 °C for eight days. Five different trials of LM and DM samples were analyzed for instrumental color attributes (lightness, redness and yellowness), including the surface color stability through ratio of reflectance at 630/580 nm (R630/580), myoglobin concentration, total lipid content, fatty acid profile, metmyoglobin reducing activity (MRA), pH, lipid oxidation and protein oxidation. Results of the present study indicated that DM of Nile tilapia (Oreochromis niloticus) present lower oxidative and color stability during refrigerated storage than LM.

RESUMO: O objetivo do presente estudo foi comparar a estabilidade de cor e oxidativa de músculos claros (LM) e escuros (DM) de tilápia do Nilo (Oreochromis niloticus) armazenados a 4° C por oito dias. Cinco repetições diferentes de amostras de LM e DM foram analisadas quanto aos atributos instrumentais de cor (luminosidade, teor de vermelho e teor de amarelo), incluindo a estabilidade de cor na superfície através da razão de refletâncias nos comprimentos de onda 630 e 580 nm (R630/580), concentração de mioglobina, lipídios totais, perfil de ácidos graxos, atividade de redução da metamioglobina (MRA), pH, oxidação lipídica e oxidação proteica. Os resultados do presente estudo indicam que músculos escuros (DM) de tilápia do Nilo (Oreochromis niloticus) apresentam menor estabilidade oxidativa e de cor durante o armazenamento refrigerado, quando comparados aos músculos claros (LM).

Antioxidant properties of the carotenoid extracts of three Deinococcus­Thermus phylum bacteria, Meiothermus sp. strains RP and TP and Thermus sp. strain YY from Paniphala hot spring, India

BACKGROUND:The purpose of the study was to extract carotenoids from thermophilic bacteria which show efficient antioxidant and protein oxidation inhibition properties, characterize and identify those isolates, extract the carotenoids in different solvents, quantify the carotenoids and perform concentration-dependent and solvent-dependent quantitative assays validated and analysed by appropriate statistical tests. METHODS: Three pigment-forming thermophilic strains were isolated from water sample of Paniphala hot spring, India, and tentatively identified by 16S ribosomal DNA (rDNA) homology. Different concentrations of the carotenoid extracts (100, 80, 40 and 20µg) in three solvents, methanol, DMSO and water, were used to determine the antioxidant activity through five methods: the DPPH (1,1-diphenyl-2-picrylhydrazyl) assay, the ABTS (2,2-azino-bis (3-ethylbenz-thiazoline-6-sulfonic acid)) assay, the hydrogen peroxide assay, TOC (total antioxidant capacity) assay and inhibition of protein oxidation assay. Statistical analysis of mean, standard deviation, ANOVA and Pearson correlationcoefficient was performed in Microsoft Excel statistical package.Results:The isolates were tentatively identified as Meiothermussp. strain RP, Meiothermussp. strain TP and Thermusstrain YY.Meiothermussp. formed red coloured pigment, where as Thermussp. formed yellow coloured pigment. Allof the extracts showed positive results in DPPH assay, ABTS assay and hydrogen peroxide radical scavenging assaywith best results obtained when the extracts were dissolved in water. Total antioxidant capacity assay was also highin all the extracts. Protein oxidation inhibition activity was only seen in extracts of strain YY. One-way ANOVA(analysis of variance) clearly showed that choice of solvent influenced the antioxidant capacity of all of the extracts. CONCLUSIONS: Newer and efficient antioxidative compounds are constantly being searched for, and the carotenoid extracts of RP, TP and YY have been shown to catalyze various types of antioxidative reactions, including proteinoxidation inhibition by YY. Thus, all these extracts have huge potential to be industrially and pharmaceutically useful.

Phenolic Content and Biomolecule Oxidation Protective Activity of Globularia alypum Extracts

ABSTRACT The protective activity of methanolic (Met E) and aqueous (Aq E) extracts of Globularia alypum L. (G. alypum) against DNA, lipid and protein oxidative damage was investigated. Moreover, the scavenging, chelating, and reducing power activities of the extracts were also evaluated. Phytochemical analysis was performed to determine phenolic compounds. Results showed that Met E and Aq E were rich in phenolic compounds, and were able to scavenge DPPH˙ with IC50 values of 48.61 µg/mL and 51.97 µg/mL, respectively. In addition, both extracts were able to chelate ferrous ions. At 300 μg/mL, the chelating activity was 97.53% and 91.02%, respectively. The reducing power of these extracts was also remarkable and concentration dependent. At 100 µg/mL, both extracts inhibited lipid peroxidatin by only 42.45% and 4.03%. However, the DNA oxidation damage was inhibited dose-dependently in the presence of G. alypum extracts. At 1 mg/mL, both extracts suppressed DNA cleavage by 83%-84%. The protein oxidation was also inhibited by G. alypum extracts. At 1 mg/mL, Aq E and Met E protected BSA fragmentation by 77%-99%. The overall results suggest that G. alypum extracts exerted antioxidant activity and protect biomolecules against oxidative damage; hence it may serve as a potential source of natural antioxidants.

Influence of peanut skin extract on shelf-life of sheep patties

Objective: To evaluate the phenolic profile and antioxidant activity in vitro of peanut skin extract (PSE) and effect of PSE on characteristics of sheep patties during storage. Methods: PSE phenolic profile was evaluated in LC–MS analysis and by total phenolic content, 1,1-diphenyl-2-picrylhydrazyl radical scavenging capacity and ferric reducing/antioxidant power. Patties elaborated with sheep meat were packaged in modified at-mosphere and storage at (2 ± 1) ?C. The analyses were performed every 5 days for 20 days on microbial counts, physico-chemical properties, lipid oxidation, protein stability and sensory characteristics. Results: The major group of phenolic compounds in PSE was the proanthocyanidins followed by other flavonoids, which are related to potential phenolic content and anti-oxidant activity. The addition of PSE and butyl hydroxytoluene (BHT) reduced the mi-crobial counts during the storage time, caused reduction on the loss of redness and sensory properties over time. The lipid and protein oxidation in sheep patties was effectively inhibited by PSE and BHT. Conclusions: The present results showed the potential application of PSE as a natural alternative to replace synthetic antioxidants (BHT) for increasing the quality and extending the shelf-life of sheep patties.

Influence of peanut skin extract on shelf-life of sheep patties

Objective To evaluate the phenolic profile and antioxidant activity in vitro of peanut skin extract (PSE) and effect of PSE on characteristics of sheep patties during storage. Methods PSE phenolic profile was evaluated in LC–MS analysis and by total phenolic content, 1,1-diphenyl-2-picrylhydrazyl radical scavenging capacity and ferric reducing/antioxidant power. Patties elaborated with sheep meat were packaged in modified atmosphere and storage at (2 ± 1) °C. The analyses were performed every 5 days for 20 days on microbial counts, physico-chemical properties, lipid oxidation, protein stability and sensory characteristics. Results The major group of phenolic compounds in PSE was the proanthocyanidins followed by other flavonoids, which are related to potential phenolic content and antioxidant activity. The addition of PSE and butyl hydroxytoluene (BHT) reduced the microbial counts during the storage time, caused reduction on the loss of redness and sensory properties over time. The lipid and protein oxidation in sheep patties was effectively inhibited by PSE and BHT. Conclusions The present results showed the potential application of PSE as a natural alternative to replace synthetic antioxidants (BHT) for increasing the quality and extending the shelf-life of sheep patties.

Can occupational exposure to antineoplastic drugs increase levels of an inflammatory trigger.

Background: Antineoplastic drugs (AND) are known to cause collateral damage to normal cells by oxidative stress. This study was conducted to check for oxidative stress in occupational exposure to these drugs using advanced oxidation protein products (AOPP). Methods: Cross-sectional comparison of serum AOPP levels of 33 nurses occupationally exposed and serum AOPP levels of 30 nurses not exposed using modified AOPP method. Results: Serum AOPP levels were significantly increased (p<0.001) in the exposed group (16.66±3.31) compared to the unexposed group (12.87±2.62). Conclusion: This study highlights oxidative stress in the form of protein oxidation occurring in nurses exposed to AND.

Loss of Erythrocyte Deformability under Oxidative Stress is caused by Protein Oxidation with Consequent Degradation Rather than by Lipid Peroxidation.

Aims: Loss of erythrocyte deformability under oxidative stress is poorly understood. The present study aimed to determine which of the detrimental effects of oxidant stress, namely, lipid peroxidation or protein degradation, is responsible for loss of erythrocyte deformability. Methodology: Different natural and synthetic antioxidants were tested for their protective effects on erythrocyte deformability, lipid peroxidation and protein degradation after exposure to H2O2. Antioxidants used included -Tocopherol (vitamin E), Butylated Hydroxytoluene (BHT), vitamin C, PNU-101033E, carbon monoxide (CO) and selected flavonoids and herbal extracts. Results: Exposure of human erythrocytes in vitro to H2O2 caused loss of deformability, lipid peroxidation and protein degradation. Pre-incubation of erythrocytes with vitamin E, BHT, vitamin C, PNU-101033E, the flavonoids rutin and morin and herbal extracts of Ferula hermonis, Hibiscus sabdariffa, Teucrium polium, prevented lipid peroxidation caused by H2O2 but did not prevent loss of erythrocyte deformability, nor protein degradation. CO, the flavonoid quercetin and herbal extracts of Nigella sativa and Allium sativum prevented both lipid peroxidation and protein degradation, but also prevented loss of erythrocyte deformability. The flavonoid 3,5,7-trihydroxy-4’-methoxy flavone-7-rutinoside prevented both protein degradation and loss of deformability, with no effect on lipid peroxidation. Vitamin C, unexpectedly, caused a significant increase in loss of erythrocyte deformability induced by H2O2 in parallel to the increased rate of protein degradation. Conclusion: These results suggest that protein degradation rather than lipid peroxidation is responsible for loss of erythrocyte deformability under oxidative stress. Also that lipid peroxidation and protein degradation occur by independent mechanisms. This study should initiate a search for potential drugs that can prevent protein oxidation as well as lipid peroxidation, thereby acting in the prevention of adverse hemorheological consequences in disease states associated with oxidative stress. Caution should be exercised in the therapeutic use of vitamin C, especially under oxidant stress.

Oxidative stability of refrigerated fish pates containing loquat seed extract / Estabilidade oxidativa de patês de pescado contendo extrato de semente de nêspera armazenados refrigerados

This study investigated the effects of hydroethanolic E. japonica seed extracts (EJSE) as inhibitors of lipid and protein oxidation on fish pates subjected to refrigerated storage. Five fish pate formulations were developed. These formulations included two control pates (water-control and ascorbic acid-control) and three pates with added EJSE (0.1, 0.2 and 0.4g of seed 100g-1 product, equivalent to 3.4, 6.8 or 13.6mg phenolic compounds kg-1 product), which were then stored under refrigeration for 35 days. Conjugated dienes (CD) and peroxide (PV) values increased along with the storage time; however, these values decreased and were similar among all samples at the end of 35 days of analysis (P<0.05). However, the thiobarbituric acid reactive substances levels (TBARS) did not change along the storage and were not affected by the EJSE. Additionally, there was a linear increase in the protein carbonyl content of fish pates over the storage period (P<0.05), but no effect of EJSE on protein oxidation. The results show that, at the concentrations evaluated, hydroethanolic E. japonica seed extract was unable to inhibit or reduce lipid and protein oxidation in fish pates, but the observed phenolic content emphasizes the need for further studies on the wastes of this fruit.

Este trabalho investigou os efeitos do extrato hidroetanólico de semente de E. japonica (EJSE) como inibidor da oxidação lipídica e proteica em patês a base de pescado armazenados refrigerados. Foram desenvolvidas cinco formulações de patê de pescado. Estas formulações incluíram dois patês controles (controle-água e controle-ácido ascórbico) e três adicionados de EJSE (0,1; 0,2 e 0,4g de semente 100g-1 de produto, equivalente a 3,4; 6,8 ou 13,6mg compostos fenólicos kg-1 de produto) que foram armazenados refrigerados durante 35 dias. Os valores de dienos conjugados (CD) e peróxidos (PV) aumentaram ao longo do armazenamento, contudo, CD e PV diminuíram de maneira semelhante em todas as amostras aos 35 dias de análise (P<0,05). No entanto, o conteúdo de substâncias reativas ao ácido tiobarbitúrico (TBARS) não se modificou ao longo do armazenamento e não foi afetado pelo EJSE. Também houve aumento linear no conteúdo de proteínas carboniladas dos patês de pescado ao longo do armazenamento (P<0,05), sem efeito do EJSE na oxidação proteica. Os resultados mostram que, nas concentrações avaliadas, o extrato hidroetanólico de semente de E. japonica não foi capaz de inibir ou reduzir as oxidações lipídicas e proteicas em patês de pescado, mas seu conteúdo fenólico enfatiza para a necessidade de aprofundar as pesquisas com o resíduo desta fruta.

Lipid and protein oxidation in charqui meat and jerked beef

In this study, the changes in the lipid (Lox) and protein oxidation (Pox) were measured quantitatively by TBARS and carbonyl methods, respectively, throughout the salting and drying steps of charqui meat (CH) and jerked beef (JB) preparation and their storage up to 60 days. The experiment was carried out on CH samples treated with brine (20.0%) and JB with same brine solution added with sodium nitrite (0.02%). After 60 days of storage, the carbonyl substances in CH were 2.77nmol mg-1 while in the JB samples, there was 61.0% oxidation inhibition. The TBARS determination revealed a Lox inhibition by approximately 5-fold in the latter samples. These results indicated that in the metmyoglobin molecule, the nitrite kept the Fe in the Fe2+ state in JB samples whereas in CH, the Fe was oxidized to Fe3+, which catalyzed the oxidation reactions more efficiently, leading to the higher development of Lox and Pox.

Electron paramagnetic resonance study of lipid and protein membrane components of erythrocytes oxidized with hydrogen peroxide

Electron paramagnetic resonance (EPR) spectroscopy of spin labels was used to monitor membrane dynamic changes in erythrocytes subjected to oxidative stress with hydrogen peroxide (H2O2). The lipid spin label, 5-doxyl stearic acid, responded to dramatic reductions in membrane fluidity, which was correlated with increases in the protein content of the membrane. Membrane rigidity, associated with the binding of hemoglobin (Hb) to the erythrocyte membrane, was also indicated by a spin-labeled maleimide, 5-MSL, covalently bound to the sulfhydryl groups of membrane proteins. At 2% hematocrit, these alterations in membrane occurred at very low concentrations of H2O2 (50 µM) after only 5 min of incubation at 37°C in azide phosphate buffer, pH 7.4. Lipid peroxidation, suggested by oxidative hemolysis and malondialdehyde formation, started at 300 µM H2O2 (for incubation of 3 h), which is a concentration about six times higher than those detected with the probes. Ascorbic acid and α-tocopherol protected the membrane against lipoperoxidation, but did not prevent the binding of proteins to the erythrocyte membrane. Moreover, the antioxidant (+)-catechin, which also failed to prevent the cross-linking of cytoskeletal proteins with Hb, was very effective in protecting erythrocyte ghosts from lipid peroxidation induced by the Fenton reaction. This study also showed that EPR spectroscopy can be useful to assess the molecular dynamics of red blood cell membranes in both the lipid and protein domains and examine oxidation processes in a system that is so vulnerable to oxidation.

In vitro, antioxidant and scavenging activities of Hibiscus rosa sinensis crude extract.

The objective of this study is to ascertain the potency of , Hibiscus rosa sinensis leaves extract,with 70% ethanol/ water, as potential natural antioxidant.The phytochemical screening identified the bioactive compounds of the dry extract; carbohydrates and/or glycosides, steroids and/or triterpenes, flavonoids and tannins.The total phenolic and the total flavonoids contents reached 48.4 mg catechol equivalent and 24.26 mg quercetin equivalent /g dry weight, respectively.We assayed in vitro total antioxidant capacity and reducing power of H. rosa extract (HRE), using butylated hydroxytoluene (BHT) and ascorbic acid (ASA) as references, respectively.HRE recorded two-fold stronger antioxidant capacity than that of BHT while its reducing power was less than that of ASA, with reaction time and extract concentration dependent manner. In addition we evaluated the scavenging activities of HRE for O2 •−, H2O2 and NO compared to that of butylated hydroxyanisole (BHA). BHA recorded up to (61.6%), (65.8%), and (37.3%), respectively, at 500 μg/ml. Scavenging ability of HRE was very closed to that of BHA, in case of O2 •− ( 60.4%) and NO ( 36.3%) while it was lower in case of H2O2 (48.5%). Finally, we investigate the protection effect of HRE against lipid peroxidation (LPO) and protein oxidation(PO) using Fe+3/ ascorbate oxidizing system. LPO shwed 2.5-fold increase while PO reduced 56% of –SH groups. The co-incubation of Fe+3/ascorbate with Hibiscus extract inhibited lipid and protein oxidative damage nearly with 31%, at 500 μg/ml. So, we can conclude that the in vitro study emphasized HRE effective antioxidant and scavenging activities which may be due to its phenolics and flavonoids contents.

The role of oxidative stress and antioxidants in the pathogenesis of age-related macular degeneration

OBJECTIVE: To investigate the role of oxidant/antioxidant status and protein oxidation in the development of age-related macular degeneration. METHOD: The activities of serum superoxide dismutase and glutathione peroxidase and the levels of serum malondialdehyde, advanced oxidation protein products, glutathione and vitamin C were measured in 25 patients with age-related macular degeneration and 25 control subjects without age-related macular degeneration. RESULT: The malondialdehyde and advanced oxidation protein product levels in the serum were significantly higher in the age-related macular degeneration patient group than in the control group (p<0.05). The superoxide dismutase activity in the serum was significantly lower in the age-related macular degeneration patient group than in the control group (p<0.05). The levels of vitamin C and glutathione and the activity of glutathione peroxidase in the serum were unchanged between groups (p>0.05). CONCLUSION: The results of the present study suggest that decreased effectiveness of the antioxidant defense system and increased oxidative stress may play a role in the pathogenesis of age-related macular degeneration.

Formation of advanced oxidative protein products induced by three uremic toxins / 中华肾脏病杂志

Objective To study whether the uremic toxins accumulated long-term in uremia patients may be involved in oxidation of protein by forming advanced oxidative protein products (AOPPs). Methods Malonylaldehyde (MDA), hippuric acid (HA) and p-cresol were used as the representatives of uremic toxins. Human albumin serum (HSA), plasma specimens from normal or uremia patients were incubated respectively with MDA (10 retool/L), HA (20 mmol/L) and p-cresol (10 retool/L) or PBS (20 retool/L, pH 7.4, as control groups) at 37℃ for 30 minutes or 24 hours, respectively. Those indices such as AOPPs, protein thiol groups (Pt-SH) and dityrosine were used as biomarkers of protein injury. High performance liquid chromatography (HPLC) was employed to identify the aggregation and cross-links of modified proteins. Results AOPPs levels in all groups containing poison compounds were significantly increased by 121.5%(P<0.05) compared to that in control groups. Uremic toxins also resulted in over 14.7% loss in Pt-SH (P< 0.05) and 119.2% increment in dityrosine, respectively (P<0.05). Meanwhile, the formation of HMW-AOPPs in a time-dependent manner was observed by HPLC and cross-linked protein levels were significantly increased by 148.45%～333.3% in comparison with control groups. Conclusion Uremic toxins can directly mediate the damage of proteins by inducing the formation of HMW- AOPPs in a time-dependent manner, which is also one of the mechanism of AOPPs production in vivo besides the activation of the myeloperoxidase-H2O2-Cl pathway.

Increase in the lipid peroxidation and protein oxidation in the venous plasma of women with preterm pemature rupture of membranes / 대한산부인과학회지

OBJECTIVE: This study was performed to investigate the lipid peroxide levels and the protein carbonyl groups content in the venous plasma of pregnant women with preterm premature rupture of membranes (PPROM), non-pregnant, and normal pregnant women. METHODS: Samples of venous blood were obtained from women with non pregnancy (n=20), normal pregnancy between 25 and 37 weeks gestation (n=20), and PPROM before 37 completed weeks gestation (n=20). Lipid peroxide levels in the venous plasma of women of each group were measured by thiobarbituric acid reaction. The basal, amoxacillin and moxalactam-induced protein carbonyl contents in the venous plasma of women of each group were determined by the 2,4-dinitrophenylhydrazine (DNPH) method. RESULTS: 1. Lipid peroxide levels in the venous plasma of PPROM was significantly higher than that of non-pregnant and normal pregnant women (5.66+/-0.43 vs. 3.78+/-0.24 vs. 3.56+/-0.30 nmol/mg protein, p0.05). 5. There were significant positive correlations between lipid peroxide and moxalactam-induced protein carbonyls levels of the venous plasma (p<0.05). There were no significant positive correlations between lipid peroxide and amoxacillin-induced protein carbonyls levels of the venous plasma. CONCLUSION: In the venous plasma of pregnant women with PPROM, the lipid peroxidation and the protein carbonyl formation were increased. And moxalactam-induced protein carbonyl levels were increased in PPROM. These results suggest that oxydative stress was increased in pregnant women with PPROM.

Marcadores plasmáticos de estrés oxidante en población mexicana sana de 31 a 60 años de edad / Plasma markers of oxidative stress in healthy 31-60 year old mexican population

Introducción: Patologías como asma, enfermedad pulmonar obstructiva crónica, diabetes mellitus, neuropatías y el síndrome de Alzheimer, entre otros, están asociados al estrés oxidante, condición metabóllca por la cual las personas que sufren estos padecimientos presentan modificaciones y rompimiento de biomoléculas en plasma; es importante conocer sus valores básales en personas sanas para poder interpretarlos adecuadamente. Objetivo: Determinar las concentraciones básales de algunos marcadores de estrés oxidante en adultos sanos (31-60 años). Método: A 67 personas sanas, divididas en tres grupos. Grupo 1 (31-40 años); grupo 2 (41-50 años) y grupo 3 (51-60 años), se les evaluaron los siguientes marcadores de estrés oxidante: Compuestos reactivos al ácido tiobarbitúrico (CRAT), predisposición al daño oxidante, determinación de grupos carbonilo, capacidad antioxidante total de plasma (CATP), y actividad enzimática de paraoxonasa. Los resultados se sometieron a pruebas estadísticas de ANOVA de una vía y post-hoc de Bonferroni, considerando una significancia de 0.05. Resultados: Se encontró un aumento significativo en CRAT en el grupo 2 y en el grupo 3 (8.462 ± 0.571 vs 10.34 ± 1.23µM CRAT, respectivamente). En la predisposición a la lipoperoxidación, el grupo 3 fue el más susceptible al daño, debido a que hubo un incremento en los niveles de CRAT (477.0 ± 16.71 µM) en comparación al grupo 2 (432.3 ± 25.71 µM) y al grupo 1 (320.6 ± 28.95µM). En la determinación de grupos carbonilo no existieron diferencias entre los grupos. La CATP disminuyó en el grupo 2 con respecto al grupo 1 (0.950 ± 0.071 vs 0.69 ± 0.068 unidades, respectivamente). La actividad de paraoxonasa presentó un aumento en el grupo 3 con respecto al grupo 1 (0.119 ± 0.004 vs 0.072 ± 0.007 nmol p-nitrofenol/ mg proteína, respectivamente). Conclusión: Las concentraciones de los marcadores de daño por estrés oxidante se ven modificadas por la edad del individuo. En el proceso natural de envejecimiento, el principal daño es a Iípidos.

Introduction: Patients with asthma, COPD, diabetes mellitus, kidney diseases and Alzheimer syndrome, conditions associated to oxidative stress, have modifications and rupture of certain plasma biomolecules. In order to explain properly this findings, basal values in normal individuals of such biomolecules should be known. Objective: To determine the basal values of some markers of oxidative stress in healthy 31 to 60 year old individuals. Method: Seventy seven healthy volunteers were classified into group 1, 31 to 40 years, group 2, 41 to 50 years and group 3, 51 to 60 years; the following oxidative stress markers were measured: reactive compounds to tiobarbituric acid (TBARs), predisposition to oxidative stress, determination of carbonil groups, total antioxidative capacity of plasma (TACP) and enzymatic activity of paraoxonase. ANOVA and Bonferroni tests were used; a level of 0.05 was considered significant. Results: Croup 2 and 3 showed significant increment in TBARs (8.462 ± 0.571 vs 10.34 ± 1.23µM TBARs, respectively). In the predisposition to lipoper oxidation, group 3 was more susceptible, due to an increase in RCTA levels (477.0 ± 16.71 µM) in comparison to group 2 (432.3 ± 25.71 µM) and 1 (320.6 ± 28.95 µM). There was no difference in the determination of carbonil groups between the groups. TACP is significantly diminished in group 2 in relation to group 1 (0.950 ± 0.071 vs 0.69 ± 0.068 units, respectively). Paraoxonase's activity showed a significant increase in group 3 in relation to group 1 (0.119 ± 0.004 vs 0.072 ± 0.007 nmol p-nitrophenol/mg protein, respectively). Conclusion: Advancing age modifies biomolecular markers of oxidative stress; during the natural aging process, the main damage is to lipids.

Antioxidant status and products of oxidative stress in colorectal cancer / 医学研究生学报

Objective:Colorectal cancer is related to antioxidative ability and oxidative stress level.The aim of the study was to evaluate the oxidative stress in colorectal cancer patients and to investigate the relationship between oxidative stress and colorectal cancer.Methods:A total of 60 subjects(30 colorectal cancer patients,30 normal healthy controls) were examined in the study and estimated the protein oxidation,DNA damage,lipid peroxidation and antioxidants-vitamin C,vitamin E,glutathione(GSH) and antioxidative enzymes in serum,respectively.Results:Statistically significantly higher values of protein carbonyl and advanced oxidation protein products(AOPP) were observed in colorectal cancer patients(P