Changes In Antioxidant Levels Research Articles

DETERMINE THE EFFICACY OF CARBOPLATIN WITH VITAMIN C IN DALTON'S LYMPHOMA TUMOR IN MICE MODEL

Carboplatin, a plat inum - containing anticancer drug treatment cau sed a significant increase in the life span of ascites Dalton’s lymphoma tumor bearing mice. However , as compared to carboplatin alone, combination treatment with vitamin C plus carboplatin resulted in better therapeutic efficacy against Dalton's lymphoma tumor. To investigate difference in resistance mechanism to d i a m i n e ( cyclobutane - 1,1 - di carboxylato (2 - ) - O,O’) platinum (CBDCA) and changes in antioxidant levels in liver tissues in relation to different stages of Dalton’s lymphoma tumor growth and the fol lowing carboplatin treatment. The reduction in intracellular accumulation of CBDCA is thought to be an important factor indicating that CBDCA resistant in DLA cell are mutually cross - resistant. Glutathione level increased in liver of tumor bearing compared to normal mice. I ntracellular accumulation of platinum found to be higher in tissue, after carboplatin treatment the platinum accumulation were significantly decre a sed . Antioxidant defense systems such as superoxide dismutase , glutathione peroxidase gluta thione reductase activities and Glutathione – S - transferase activity w ere determined in tissues of carboplatin treatment at different stages of Dalton’s lymphoma tumor gr owth . Resistance mechanism based on reduction of intracellular drug accumulations and i ncreased activity of GST also depend the level of antioxidant enzymes , GST activities are playing significant role in development of resistance in the presences of tumor under various newly developed platinum derivative factor. Anticancer drugs kill suscep tible cells through induction of apoptosis. Alteration of apoptotic pathways in drug –

Improvement in Skin Carotenoid Levels Assessed by Reflectance Spectroscopy

BACKGROUNDCarotenoids have been directly associated with health benefits, including lutein (eye health), lycopene (cardiovascular and prostate health), and beta‐carotene (ultraviolet skin protection). Various biophotonic spectroscopy techniques are accurate and noninvasive methods of detecting skin carotenoid levels and assessing change in antioxidant levels over time.OBJECTIVEWe used Reflectance Spectroscopy to measure skin carotenoid levels following two supplementation regimens.METHODSSixty‐six healthy volunteers were supplemented with: Group A = 15mg/day of mixed carotenoids (9mg beta‐carotene, 4mg lycopene, and 2mg lutein in a proprietary nano‐emulsion); Group B = 18mg/day of natural beta‐carotene; or Group C = placebo containing no carotenoids. Skin carotenoid levels were measured at Baseline and Weeks 8 & 16.RESULTSSkin carotenoid levels were increased 59% and 57% in Group A, and 37% and 36% in Group B at weeks 8 and 16, respectively, compared to Control.CONCLUSIONThese results show, via Reflectance Spectroscopy, that skin carotenoid levels are significantly increased by supplementation with natural beta‐carotene (18mg/d) or a proprietary nano‐emulsion (15mg/d). The magnitude of skin carotenoid increase was greater with the nano‐emulsion, suggesting a possible enhancement of absorption, delivery, deposition, or retention in the body.

Evaluation of the effect of Spirulina against Gamma irradiation induced oxidative stress and tissue injury in rats

Many antioxidants have been investigated as hepato-protectors against ionizing radiation induced injury since they reduce the oxidative effect of the reactive oxygen species on normal cells . Spirulina is a potent scavenger of a variety of free radicals. The aim of this study was to investigate the radio-protective effect of Spirulina algae a gainst oxidative stress and tissue injury caused by gamma radiation. Rats were irradiated at two doses of 2 and 4Gy from cesium-137 source. Ten days prior to irradiation, animals received Spirulina daily (300mg/kg body weight i.p.). In the irradiated animal group, the oxidative stress markers malondialdehyde (MDA) was significantly increased in the liver, while a marked decrease in hepatic contents of DNA, and glutathione (GSH).The level of cholesterol, triglyceride (TG), low density lipoprotein (LDL), as well as activitiy of aspartate aminotransferase (AST), alkaline phosphatase (ALP), and gamma-glutamyl transferase (GGT), were significantly increased in sera of the irradiated rats. This was coupled with a decreased serum level of high-density lipoprotein (HDL) and total serum protein by irradiation. The administration of Spirulina alone daily for 10 days caused a significant decrease in MDA and produced significant elevation of liver GSH. Moreover, a significant decrease occurred in cholesterol, and TG level with no change in serum LDL or HDL levels in serum. Treatment of rats with Spirulina for 10 days before acute irradiation significantly abolished radiation induced elevation in liver MDA level and significantly maintained hepatic GSH content and CAT activity close to the control values. Pre-irradiation treatment of rats with Spirulina showed a significantly higher hepatic DNA content compared to that of irradiated rats. The level of cholesterol, TG, HDL, LDL as well as the activity of AST, ALT, and GGT in serum was significantly ameliorated when Spirulina was injected before irradiation. In conclusion, the increase in oxidative stress markers and the concomitant change in antioxidant levels indicate the role of oxidative stress in radiation-induced tissue damage. It was concluded that administration of Spirulina algae possess a radio protective capacity against ionizing-radiation induced oxidative stress and organ injury.

Effects of the interaction between ozone and carbon dioxide on gas exchange, photosystem II and antioxidants in rice leaves

To understand the interactive effects of O3 and CO2 on rice leaves; gas exchange, chlorophyll (Chl) fluorescence, ascorbic acid and glutathione were examined under acute (5 h), combined exposures of O3 (0, 0.1, or 0.3 cm3 m-3, expressed as O0, O0.1, or O0.3, respectively), and CO2 (400 or 800 cm3 m-3, expressed as C400 or C800, respectively) in natural-light gas-exposure chambers. The net photosynthetic rate (P N), maximum (Fv/Fm) and operating (Fq'/Fm') quantum efficiencies of photosystem II (PSII) in young (8th) leaves decreased during O3 exposure. However, these were ameliorated by C800 and fully recovered within 3 d in clean air (O0 + C400) except for the O0.3 + C400 plants. The maximum PSII efficiency at 1,500 μmol m-2 s-1 PPFD (Fv'/Fm') for the O0.3 + C400 plants decreased for all measurement times, likely because leaves with severely inhibited P N also had a severely damaged PSII. The P N of the flag (16th) leaves at heading decreased under O3 exposure, but the decline was smaller and the recovery was faster than that of the 8th leaves. The Fq'/Fm' of the flag leaves in the O0.3 + C400 and O0.3 + C800 plants decreased just after gas exposure, but the Fv/Fm was not affected. These effects indicate that elevated CO2 interactively ameliorated the inhibition of photosynthesis induced by O3 exposure. However, changes in antioxidant levels did not explain the above interaction.

The effects of 1-year treatment with a haemodiafiltration with on-line regeneration of ultrafiltrate (HFR) dialysis on biomarkers of oxidative stress in patients with chronic renal failure

In the last few years haemodiafiltration with on-line regeneration of ultrafiltrate (HFR) has been shown to have a positive impact on inflammation and oxidative stress biomarkers, but its effect on antioxidant levels and on oxidative damage to biomolecules in the long-term is still unknown. This is a randomised clinical study over 12 months involving 40 patients on haemodialysis, comparing the effect of HFR (n=25) dialysis with haemodialysis with polysulfone (HD-PS, n=15) on oxidative stress. Total antioxidant capacity, enzymatic antioxidant [superoxide dismutase (SOD), catalase and glutathione peroxidase], non-enzymatic (GSH) and biomarkers of oxidative stress (TBARs, carbonyl groups and 8-OH-dG) were evaluated. The antioxidant activity decreased in the lymphocytes of patients dialysed with HFR, with a significant decrease in the enzyme SOD. In the oxidative stress biomarkers, an increase was seen in the levels of 8-OH-dG in patients on HD-PS dialysis but not in those treated with HFR. Throughout the year the changes in antioxidant levels and biomarkers of oxidative damage in patients dialysed with HFR were generally more modest and fluctuated less than those dialysed with HD-PS. Our study indicates that, in general, long-term dialysis with HFR does not modified antioxidant parameters or increases the oxidative damage to biomolecules. The HFR showed to be a biocompatible technique for long-term dialysis.

The interaction between antioxidant status and cervical cancer: A case control study

To compare the antioxidant status of cervical cancer patients with healthy controls and to assess the antioxidant levels before and after radiotherapy or radiochemotherapy. Antioxidant levels (glutathione, glutathione peroxidase, superoxide dismutase, and malondialdehyde) were measured in 35 patients with cervical cancer and 35 age-matched healthy controls. Blood samples were collected twice (before and after treatment) from cervical cancer patients and once from healthy control subjects. In the patient group, pre-radiotherapy glutathione and glutathione peroxidase levels were significantly lower (P <0.01 and P <0.0001, respectively) than the control group. Pre-radiotherapy levels of superoxide dismutase were significantly higher in cancer patients (P <0.01). In general, no difference was observed between pre- and post-radiotherapy antioxidant levels in cancer patients. However, when post-radiotherapy glutathione levels were analyzed, patients who did not respond to treatment had significantly higher levels than those who did respond (P <0.01). Levels of antioxidants significantly differed between the patients with cervical cancer and the controls, and no change in antioxidant levels was observed after treatment. Moreover, further studies evaluating the predictive value of glutathione levels on treatment response are warranted.

Oxidative pathways as a drug target for the treatment of autism

Importance of the field: Autism is a severe, pervasive developmental disorder, the aetiology of which is poorly understood. Current pharmacological treatment options for autism are often focused on addressing comorbid behavioural problems, rather than core features of the disorder. Investigation of a new treatment approach is needed.Areas covered in this review: Recent research has indicated a possible role of abnormalities in oxidative homeostasis in the pathophysiology of autism, based on reports that a range of oxidative biomarkers are significantly altered in people with autism. This article reviews the current findings on oxidative stress in autism, including genetic links to oxidative pathways, changes in antioxidant levels and other oxidative stress markers. We conducted a search of the literature up to June 2010, using Medline, Pubmed, PsycINFO, CINAHL PLUS and BIOSIS Previews.What the reader will gain: This review provides an overview of the current understanding of the role of oxidative stress in autism. This will assist in highlighting areas of future therapeutic targets and potential underlying pathophysiology of this disorder.Take home message: Abnormalities in oxidative homeostasis may play a role in the pathophysiology of autism. Antioxidant treatment may form a potential therapeutic pathway for this complex disorder.

The effects of engineered nanoparticles on survival, reproduction, and behaviour of freshwater snail, Physa acuta (Draparnaud, 1805)

Increasing uses of engineered nanoparticles (ENPs) in commercial products and industrial applications has eventually resulted to their releases into atmospheric, terrestrial, and aquatic environments. However, knowledge gaps in ENPs toxicity, fate, and behaviour currently limit our ability to quantify risk assessment of materials with nanoscale dimensions, and therefore, the extent of the resultant environmental impacts remains unknown. In the present study, we evaluated the effects of γ-alumina, α-alumina, modified TiO 2 (M-TiO 2), and commercial TiO 2 (C-TiO 2) ENPs on the survival, behaviour, and early life stages of the freshwater snail Physa acuta (Draparnaud). The toxicity evaluation was carried out after spiking commercial sand with ENPs concentrations of 0.005, 0.05, or 0.5 g kg −1. Our findings suggest that increases of γ-alumina and α-alumina concentrations at sub-lethal level concentrations caused significant reduction in the embryo growth rate and embryo hatchability. In addition, these ENPs induced observable developmental deformities of the embryos. In addition, toxicity evaluations using acute 96-h and chronic 28-d tests showed exposure duration may be a significant factor in ENPs-induced toxicity. Therefore, long-term exposure of aquatic organisms to ENPs – potentially can alter certain ecological populations at different trophic levels – and may compromise the entire aquatic ecological functionality. The percentage hatchlings in test chambers containing 0.5 g kg −1 γ-alumina and α-alumina concentration was 50% less to those observed in the controls. Our results suggest the embryonic growth and hatchability tests are useful endpoints in chronic sediment toxicity tests for determining the toxic thresholds of ENPs in sediment environment. Although no snail mortalities were observed during the static 96-h test containing sediment spiked with different concentrations of M-TiO 2, C-TiO 2, γ-alumina and α-alumina – the antioxidant enzymatic assay results indicated a significant change in antioxidant levels which altered peroxidation at 0.05 or 0.5 g kg −1concentrations for both γ-alumina and α-alumina.

Effects of calcium ascorbate treatments and storage atmosphere on antioxidant activity and quality of fresh-cut apple slices

Fresh-cut ‘Braeburn’ apple slices were dipped in calcium ascorbate (CaAsc; 0, 2, 6, 12 and 20%, w/w) and stored in air or under modified atmosphere (MA) conditions for up to 28 d at 4 °C. Changes in antioxidant levels were measured using free radical scavenging activity (DPPH), reducing activity (FRAP), ascorbic acid content (AA) and polyphenolic content (by HPLC). Changes in browning, sensory quality and microbial counts were measured to indicate eating quality. CaAsc dips increased the initial levels of AA from 0.19 g kg −1 in the untreated control to 3.8 g kg −1 for the 20% CaAsc treatment. Ascorbic acid content of treated slices during storage decreased by more than 50% in CaAsc concentrations of 6, 12 and 20%. Similar patterns were observed for FRAP and DPPH activities. Untreated or 2% CaAsc treated slices stored in air or MA showed browning, microbial deterioration and poor sensory quality, thus resulting in a short shelf life (<7 d). However, apples dipped in 6 or 12% CaAsc and stored in MA packaging, or dipped in 20% CaAsc and packaged in air or MA had a shelf life of 21–28 d. Total antioxidant activity in these treatments was provided by both exogenous ascorbic acid and endogenous phenolic compounds; the latter varied in composition, but were relatively stable during storage compared with ascorbate in higher CaAsc concentration treatments. Thus, the antioxidant levels (as measured by FRAP and DPPH) were related to shelf life and it appears that an antioxidant activity remaining above 2 g kg −1 (DPPH or FRAP) may be a minimum level to achieve long shelf life in ‘Braeburn’ apple slices.

Accumulation of H2O2and changes in activities of antioxidative enzymes andβ-1,3-glucanase in barley and meadow fescue leaves attacked byBipolaris sorokiniana

The effects of Bipolaris sorokiniana inoculation on accumulation of hydrogen peroxide and changes in the activities of superoxide dismutase (SOD), catalase (CAT), non-specific peroxidase (PX) and β-1,3-glucanase enzymes in leaves of differentially resistant spring barley and meadow fescue were investigated in this study. Hydrogen peroxide accumulated slightly in inoculated barley leaves 24 hours after inoculation, and its accumulation after 48 hours of pathogenesis remained week around sites of infection. In leaves of fescue, which is more resistant to B. sorokiniana, accumulation of H2O2 was faster and stronger in comparison to barley. A slight increase in SOD activity was observed only in infected fescue. Catalase activity in infected barely leaves decreased significantly 48 hours after inoculation, while in fescue-infected plants CAT activity, following a slight decrease, remained similar to the control values. PX activity was considerable lower in inoculated barley leaves after 6 hours, but at 24 and 48 hours after inoculation its activity increased significantly compared to the control. In inoculated fescue leaves activity of PX was higher at 6 and 24 hours compared to the control, while at 48 hours PX activity was strongly inhibited. β-1,3-Glucanase activity in inoculated barley plants did not differ from that of the control, while in infected fescue leaves it increased significantly 48 hours after inoculation. Based on the results, we suggest that the strong accumulation of H2O2, changes in antioxidant levels, together with the significant increase of β-1,3-Glucanase activity in infected fescue leaves, plays an important role in fescue’s greater resistance to B. sorokiniana.

Noninvasive Assessment of the Brain Redox Status after Transient Middle Cerebral Artery Occlusion Using Overhauser-Enhanced Magnetic Resonance Imaging

Oxidative stress has been implicated in the cell death that occurs after ischemia-reperfusion of the brain, which causes the production of reactive oxygen species and a decrease in antioxidants, leading to mitochondrial dysfunction. However, the invasive methods used to collect much of this evidence are themselves stress inducing, which could skew the results. In this study, we aimed at demonstrating brain redox alterations after ischemia-reperfusion noninvasively, using Overhauser-enhanced magnetic resonance imaging. The reduction rate of 3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine-L-oxyl (methoxycarbonyl-PROXYL), a redox-sensitive contrast agent, was used as an index of the redox status in vivo. No changes were observed in the antioxidant concentration, the mitochondrial complex activity, or in the redox status image intensity after 3 h of reperfusion, following transient middle cerebral artery occlusion; however, after 24 h of reperfusion, the methoxycarbonyl-PROXYL reduction rate, calculated from continuous images, had decreased significantly. Concordantly, biochemical assays showed that the concentration of ascorbic acid in the ischemic hemisphere and the activity of mitochondrial complex II had also decreased. Thus, the noninvasive imaging of the brain redox alterations faithfully reflected changes in antioxidant levels and in mitochondrial complex II activity after ischemia-reperfusion.

Stress hormones and abiotic stresses have different effects on antioxidants in maize lines with different sensitivity

The effect of stress hormones and abiotic stress treatments on reactive oxygen species and on antioxidants was compared in two maize (Zea mays L.) lines (Penjalinan and Z7) having different stress tolerance. Following treatment with abscisic acid, salicylic acid or hydrogen peroxide, the amount of hydrogen peroxide and lipid peroxides increased, while after osmotic stress or cultivation in continuous darkness, the levels were unchanged or decreased. The higher amount of lipid peroxides in Penjalinan indicated its greater sensitivity compared to Z7. The level of the examined antioxidants was increased by nearly all treatments. Glutathione and cysteine contents were higher after salicylic acid, hydrogen peroxide and polyethylene glycol treatments and lower after application of abscisic acid, NaCl and growth in darkness in Z7 than in Penjalinan. The activity of glutathione reductase, ascorbate peroxidase, catalase and glutathione S-transferase was higher after almost all treatments in Z7. The expression of the glutathione synthetase (EC 6.3.2.3) gene was not affected by the treatments, while the level of gamma-glutamylcysteine synthetase (EC 6.3.2.2) and glutathione reductase (EC 1.6.4.2) transcripts increased after most treatments. The two stress hormones and the stress treatments resulted in different changes in antioxidant levels in the two maize lines, which indicates the specific, stress tolerance-dependent response of plants to the various growth regulators and adverse environmental effects that were examined.

DNA Methyltransferases Modulate the Bystander Effect in Mouse Embryonic Stem Cells.

Cells exposed to radiation or other genotoxic agents can induce DNA damage and other stress responses in non-irradiated cells that are either cultured with the irradiated cells or have been exposed to culture medium from irradiated cells. This is called the bystander effect. In a previous study we found that the descendents of bystander cells exposed to Mitomycin C (MMC) are themselves capable of inducing homologous recombination in un-exposed cells. This suggests that MMC induces persistent and transmissible changes in expression in bystander cells. Bystander effects are likely caused by epigenetic mechanisms rather than “classic” mutations, i.e. changes in DNA sequence. One of the epigenetic mechanisms cells employ for changing expression is DNA methylation in which DNA methyltransferases (DNMTs) add a methyl group to the 5 carbon of cytosine. In this study we asked if ionizing radiation can induce transmissible DNA damage in bystander cells by examining if bystander cells exposed to irradiated cells were themselves able to induce damage in naive cells. Furthermore, we asked if this was dependent on DNMT activity in the irradiated cells. We irradiated wild-type (WT) and DNMT triple knockout (DNMT TKO) mouse embryonic stem cells (ESCs) and after two weeks of continuous culture, we collected conditioned medium (CM). CM was then added to cultures of naive WT ESCs (primary bystanders). Three weeks later, CM was collected from the primary bystanders and added to naïve WT cells (secondary bystanders). We assessed DNA damage by evaluating strand breaks using the alkaline Comet assay and sister chromatid exchange (SCE) analysis. As expected, we found that medium from cells irradiated with 5 Gy induced modest damage in bystander cells. The median Olive tail moment was 2.8 in bystander cells exposed to conditioned medium from irradiated cells compared to 1.0 in control bystander cells (p < 0.0001). Homologous recombination was 0.15 chromatid exchanges per chromosome compared to 0.092 in control bystanders (p < 0.0001). We also observed an increase in strand breaks in secondary bystanders of a similar magnitude to that found in primary bystanders, indicating that radiation-induced bystanders are themselves able to induce damage. In contrast to WT cells, the irradiated DNMT TKO cells did not induce strand breaks in bystander cells, as measured by the Comet assay, but did induce HR. Surprisingly, we also observed that un-irradiated DNMT TKO cells induce DNA damage in bystanders, and furthermore that the magnitude of the effect is similar to that induced by irradiated WT cells. These data suggest that methyltransferases have a complex role in bystander effects. Bystander effects may be mediated by free radicals. To see if the DNMT TKO cells had changes in antioxidant levels, glutathione (GSH) and glutathione peroxidase (GPX) activity were determined. There was no significant change in GSH levels between WT and DNMT TKO cells. However, DNMT TKO cells had significantly higher levels of GPX activity (275.4 + 19.8 mU/mg protein) compared to control cells (122.0 + 16.4 mU/mg, p= 0.0001). Taken together, these results show that radiation-induced bystander cells can themselves induce damage in un-irradiated cells and suggest that cells lacking DNA methylation activity can induce bystander effects.

Ameliorative effect of melatonin against gamma-irradiation-induced oxidative stress and tissue injury

While radiation hazards, due to free radical generation, present an enormous challenge for biological and medical safety, melatonin is a potent scavenger of a variety of free radicals. The aim of this study was to investigate the radioprotective effect of melatonin against oxidative stress and tissue injury induced by gamma radiation. Rats were subjected to two doses of 2 and 4 Gy from cesium-137 source. Four days prior to irradiation, animals received melatonin daily (10 mg/kg body weight i.p.). In the irradiated animals, the oxidative stress markers malondialdehyde (MDA) and protein carbonyl were significantly increased in the liver, while a marked decrease in hepatic contents of DNA, RNA, and glutathione (GSH) as well as activity of glutathione- S-transferase (GST) was demonstrated. In addition, catalase (CAT) activity was increased in the liver 5 days after irradiation. The levels of total lipids, cholesterol, triglyceride (TG), low-density lipoprotein (LDL), urea, and creatinine, as well as activities of aspartate aminotransferase (AST), alkaline phosphatase (ALP), and gamma-glutamyltransferase (GGT), were significantly increased in sera of the irradiated rats. This is coupled with decreased serum levels of high-density lipoprotein (HDL), total protein and albumin, and total globulins by irradiation. The administration of melatonin alone daily for 4 days caused significant decreases in MDA and protein carbonyl content and produced significant elevations of GSH content and GST activity in the liver. Moreover, significant decreases in total lipids, cholesterol, and TG without change in LDL or HDL levels in serum were demonstrated. Treatment with melatonin for 4 days before acute irradiation significantly abolished radiation-induced elevations in MDA and protein carbonyl levels in the liver and significantly maintained hepatic GSH content, GST, and CAT activities close to the control values. Preirradiation treatment with melatonin showed significantly higher hepatic DNA and RNA contents than irradiated rats. The levels of total lipids, cholesterol, TG, HDL, LDL, total proteins, albumin, total globulins, creatinine, and urea, as well as the activities of AST, ALT, and GGT in serum were significantly ameliorated when melatonin was injected before irradiation. In conclusion, the increase in oxidative stress markers and the concomitant change in antioxidant levels indicate the role of oxidative stress in radiation-induced tissue damage. Moreover, melatonin shows a radioprotective impact against ionizing-radiation-induced oxidative stress and organ injury.

Changes in anti-oxidant level in the blood and the brain corresponding to wide-ranging fluctuation of energy metabolism during Syrian hamster hibernation

Changes in anti-oxidant level in the blood and the brain corresponding to wide-ranging fluctuation of energy metabolism during Syrian hamster hibernation

Characterization of Antioxidants and Change of Antioxidant Levels during Storage ofManilkara zapotaL.

Antioxidants found in fruits and vegetables play an important role via their protective effects against the onset of aging-related chronic diseases. Our previous research has indicated that unripe ciku fruits (Manilkara zapota L.) are an excellent source of antioxidants, with over 3000 mg of L-ascorbic acid equivalent antioxidant capacity (AEAC) per 100 g of fresh sample. In this study, 24 antioxidants in an extract of ciku king were characterized through a free radical spiking test. Their chemical structures were proposed using high-performance liquid chromatography-mass spectrometry (HPLC-MS) and tandem MS (HPLC/MSn). The antioxidant capacity of ciku king fruits was mainly attributed to polyphenolics with basic blocks of gallocatechin or catechin or both. The changes of total antioxidant capacity (TAC) and total phenolics content (TPC) of ciku king fruits with storage time were also investigated. It was found that the TAC and TPC decreased significantly as the fruits gradually changed from the unripe to the overripe stage. The best time for one to consume ciku king fruits at a flavorful stage with high amounts of antioxidants with AEAC values ranging from 600 to 1200 mg per 100 g fresh sample is suggested. The change of the content of major antioxidant peaks was also consistent with changes of antioxidant levels during storage.

Changes of anti-oxidant levels in human blood cells during early post-renal transplant period

Changes of anti-oxidant levels in human blood cells during early post-renal transplant period

Changes in antioxidant levels in Oryza sativa L. roots subjected to NaCl-salinity stress

Imposition of NaCl-salinity stress induced oxidative reactions in root tissue of rice seedlings. A uniform accumulation of proline was marked with the increasing NaCl concentrations. Both peroxide content and lipid peroxidation level (MDA) increased with the salt treatment from the control. CAT, GPx and SOD activities decreased with the increasing NaCl concentrations suggesting a possible oxidative damage to root tissue.

Seasonal changes in antioxidant level of Scots pine (Pinus sylvestris L.) needles exposed to industrial pollution. II. Enzymatic scavengers activities

The involvement of enzymic antioxidant system, superoxide dismutase, guaiacol peroxidase, ascorbate peroxidase in defense reaction to environmental stress evoked by air and soil pollution, was seasonally studied on three populations of Scots pine (Pinus sylvestris L.) growing on experimental areas close two industrial objects in Poland. The first of them (Luboon) is localised near a phosphate fertiliser factory, the second (Glogow) near a copper foundry, and control stand is placed in Kornik. Glogow is the most polluted site, where in 1998 monthly mean daily concentrations was: SO2 - 17 µg·m−3, NOx- 12 µg·m−3 and dust containing heavy metals (Cu, Pb, Cd) - 29 µg·m−3. Trees in Lubon were influenced for many years by high concentration of SO2 and fluor compounds. Few years ago emissions were markedly reduced, but changes in the soil (low pH and high concentration of aluminium ions) still influence the growth of trees. In needles of two populations: 3 (Russia) and 8 (Poland), from the polluted sites Glogow and Lubon, activities of superoxide dismutase (SOD) and guaiacol peroxidase (PO) were significantly higher compared to Kornik. However, in one population (16 - Slovakia), such dependance was not evident. Activity of ascorbate peroxidase (AP) measured in winter was also higher in needles from polluted sites. The results indicated that the sensitivity of free radical scavenging system in Scots pine needles differs among populations.

Changes in rat plasma-free fatty acid composition under oxidative stress induced by carbon tetrachloride: decrease of polyunsaturated fatty acids and increase of palmitoleic acid.

In order to measure the changes in antioxidant levels and the composition of plasma-free fatty acids resulting from oxidative stress, male Fisher rats were given a twice weekly subcutaneous injection of a 50% solution of carbon tetrachloride (CCl4) in corn oil for a period of 2 to 13 weeks. The dosage was 1.3 ml/kg of body weight. This treatment significantly suppressed the gain of body weight compared with control rats receiving the same dosage of corn oil. Liver weight of the two groups was similar while necrosis and hyperplasia of hepatocytes and liver fibrosis were observed in CCl4 treated rats. Increased levels of plasma glutamate-oxalacetate transaminase and glutamate-pyruvate transaminase were indicative that hepatocyte necrosis was induced by CCl4. Increased oxidative stress in CCl4 treated rats was indicated by a significant decrease of liver ascorbate and a decrease in the plasma ratio of polyunsaturated fatty acids (PUFA) to total free fatty acids. Interestingly, a significant increase of palmitoleic acid was observed in CCl4 treated rats, which may compensate for the loss of PUFA. The possibility of using the plasma composition of PUFA and palmitoleic acid as a marker of oxidative stress is discussed.