Protective Role Of Antioxidants Research Articles

Protective effect and antioxidant role of sweetgum (Liquidambar orientalis) oil against carbon tetrachloride-induced hepatotoxicity and oxidative stress in rats

Context: Sweetgum oil (SO) obtained from the Liquidambar orientalis Mill (Hamamelidaceae) tree has been used in Turkish folk medicine for centuries as an antiulcerigenic. Some studies have reported the antibacterial and antioxidant activities of SO; however, its effect on hepatic and oxidative stress complications is still unexplored.Objective: This study investigates the hepatoprotective effect and the antioxidant role of SO against carbon tetrachloride (CCl4) toxicity.Materials and methods: The experiment included control, CCl4, SO, and CCl4 + SO treatment groups. Control and SO group rats were fed a diet without CCl4. CCl4 and CCl4 + SO treatment groups received 0.5 mL/kg CCl4 diluted in olive oil (1:1 dilution) intraperitonally injection twice per week. The CCl4 + SO group also received 1000 mg/kg SO-supplemented feed for 50 d. Blood and tissue samples were used for the determination of hepatic damage serum biomarkers (HDSBs) levels, antioxidant defense system constituents (ADSCs), and malondialdehyde (MDA) contents. In addition, the liver was evaluated for histopathological changes.Results: According to the results, the HDSBs levels of the CCl4 group were significantly (p < 0.05) increased compared with the control, whereas the HDSB levels of the CCl4 + SO group resulted in marked decreases (p < 0.05) compared with the CCl4 group. In addition, the results showed that SO-supplemented diet restored the CCl4-induced MDA and ADS towards to control. Hepatoprotection of SO is further substantiated by the almost normal histologic findings in the CCl4 + SO group against degenerative changes in the CCl4 group.Discussion and conclusion: It was concluded that SO has a hepatoprotective effect and antioxidant capacity against CCl4 toxicity.

45S5Bioglass®-based scaffolds coated with selenium nanoparticles or with poly(lactide-co-glycolide)/selenium particles: Processing, evaluation and antibacterial activity

In the bone tissue engineering field, there is a growing interest in the application of bioactive glass scaffolds (45S5Bioglass®) due to their bone bonding ability, osteoconductivity and osteoinductivity. However, such scaffolds still lack some of the required functionalities to enable the successful formation of new bone, e.g. effective antibacterial properties. A large number of studies suggest that selenium (Se) has significant role in antioxidant protection, enhanced immune surveillance and modulation of cell proliferation. Selenium nanoparticles (SeNp) have also been reported to possess antibacterial as well as antiviral activities. In this investigation, uniform, stable, amorphous SeNp have been synthesized and additionally immobilized within spherical PLGA particles (PLGA/SeNp). These particles were used to coat bioactive glass-based scaffolds synthesized by the foam replica method. Samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and transmission electron microscopy (TEM). SeNp, 45S5Bioglass®/SeNp and 45S5Bioglass®/PLGA/SeNp showed a considerable antibacterial activity against Gram positive bacteria, Staphylococcus aureus and Staphylococcus epidermidis, one of the main causative agents of orthopedic infections. The functionalized Se-coated bioactive glass scaffolds represent a new family of bioactive, antibacterial scaffolds for bone tissue engineering applications.

Vitamin E deficiency in last‐laid eggs limits growth of yellow‐legged gull chicks

Summary Parental phenotype and environment have cascading effects on offspring performance. Such ‘maternal’ effects are often mediated by the size and quality of the eggs in terms of maternal endogenous substances or exogenous components. Maternal effects can function to maximize parental fitness via adaptive allocation of components among sibling eggs. In birds, the often documented variation in concentration of egg dietary antioxidants or other egg compounds with laying order may thus reflect adaptive parental favouritism or maternal physiological constraints. Vitamins are found in the yolk at high concentrations and accomplish important physiological functions. Tocopherols (‘vitamin E’) have major roles in antioxidant protection, but the consequence of variation in their concentration for chick phenotype has never been experimentally investigated under a natural selection regime. In the yellow‐legged gull (Larus michahellis) free‐ranging population we studied, vitamin E concentration and egg size decline from the first to the third (last) egg. Chicks from third eggs are smaller and have lower viability compared to those from sibling eggs. Here, we tested the effect of injecting a physiological dose of vitamin E in the egg yolk on chick body size at hatching by comparison with chicks from sham‐injected eggs. As predicted, chicks from vitamin E injected third eggs were larger than chicks from control third eggs, whereas vitamin E had no effect on chicks from the other eggs. Thus, vitamin E injection disrupted the brood size hierarchy according to laying order normally found in this species. In species that adopt a brood reduction strategy, differential allocation of vitamin E to the eggs can contribute to establish a hierarchy of reproductive value among progeny members functioning to maximize parental fitness. The present results therefore have general implications for the study of the evolution of maternal effects mediated by transfer of potentially limiting maternal antioxidants to the eggs.

Effect of short-term light- and UV-stress on DMSP, DMS, and DMSP lyase activity in Emiliania huxleyi

AME Aquatic Microbial Ecology Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials AME 74:173-185 (2015) - DOI: https://doi.org/10.3354/ame01735 Effect of short-term light- and UV-stress on DMSP, DMS, and DMSP lyase activity in Emiliania huxleyi Louise J. Darroch1,6, Michel Lavoie1, Maurice Levasseur1,*, Isabelle Laurion2, William G. Sunda3, Sonia Michaud4, Michael Scarratt4, Michel Gosselin5, Gitane Caron1 1Québec-Océan and Unité Mixte Internationale Takuvik U. Laval-CNRS, Département de biologie, Université Laval, Québec, Québec G1V 0A6, Canada 2Institut national de la recherche scientifique, Centre Eau, Terre et Environnement, 490 rue de la Couronne, Québec, Québec G1K 9A9, Canada 3Beaufort Laboratory, National Oceanic and Atmospheric Administration, Beaufort, North Carolina 28516, USA 4Maurice Lamontagne Institute, Fisheries and Oceans Canada, 850 Route de la mer, Mont-Joli, Québec G5H 3Z4, Canada 5Institut des sciences de la mer, Université du Québec à Rimouski, 310 allée des Ursulines, Rimouski, Québec G5L 3A1, Canada 6Present address: British Oceanographic Data Centre, Joseph Proudman Building, 6 Brownlow Street, Liverpool L3 5DA, UK *Corresponding author: maurice.levasseur@bio.ulaval.ca ABSTRACT: The ecological conditions and cellular mechanisms which affect the production of dimethylsulfoniopropionate (DMSP) and dimethylsulfide (DMS) in marine ecosystems are still enigmatic. This information is crucial for deriving accurate oceanic ecosystem models for the dynamics of these major players in the Earth’s sulfur cycle and climate. In the present study, we examined the effect of short-term increases in photosynthetically active radiation (PAR) and ultraviolet radiation (UVR) on the production of DMSP and DMS and on DMSP lyase potential activity (DLPA) in an axenic culture of the coccolithophore Emiliania huxleyi (CCMP 1742). Algal cells were subjected to a rapid shift from a low intensity of PAR (50 μE m-2 s-1; low light, LL) to a high intensity of PAR (198 μE m-2 s-1) and elevated UVR conditions (high light, HL), simulating what may occur during upward mixing in the surface mixed layer or during changes in cloud cover. During the 4.5 h exposure to HL, the intracellular DMSP normalized to cell volume increased by ca. 30%, and dissolved DMSP doubled relative to control values. However, the DLPA per unit of cell volume decreased by ~45% compared to the control value. The up-regulation of cellular DMSP concentration is consistent with an antioxidant and/or energy dissipation role for DMSP. The decrease in DLPA may indicate that the DMSP lyase enzyme plays no role in antioxidant protection in this algal species, but rather serves some other cellular function, such as grazing protection. KEY WORDS: DMSP · DMS · DMSP lyase · Light stress · Ultraviolet radiation · Phytoplankton Full text in pdf format Supplementary material PreviousCite this article as: Darroch LJ, Lavoie M, Levasseur M, Laurion I and others (2015) Effect of short-term light- and UV-stress on DMSP, DMS, and DMSP lyase activity in Emiliania huxleyi . Aquat Microb Ecol 74:173-185. https://doi.org/10.3354/ame01735 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AME Vol. 74, No. 2. Online publication date: February 24, 2015 Print ISSN: 0948-3055; Online ISSN: 1616-1564 Copyright © 2015 Inter-Research.

Glutathione metabolism system under condition of transplantation of muscle tissue in rats

The paper presents the results of determining the amount of reduced glutathione, glutathione reductase and glutathione peroxidase activity at transplantation of muscle tissue taken from rats from the same litter. During the work 2 surgical interventions were carried out: transplantation of muscle tissue taken from the same litter of rats, and operation without replanting. Transplantation was performed on nonlinear white male rats weighing 180–300 g. The animals were taken out of the experiment by passing electric current through the medulla oblongata. For donor transplants males from the same litter were used. In adult donor rats abdominal muscle tissue was extracted and transplanted to homologous tissue of the recipient rat. The same procedure was carried out with femoral muscle tissue. Operation without replanting was used to compare the effects of changes in the number of investigated parameters of the surgical exposure. Tissue not subject to any surgery served as a control. Parameters under study were determined on the first, third and seventh day after transplantation. Glutathione levels in tissues were determined byE. Butler, A. Dyubona, B. Kelly. Determination of glutathione reductase is based on the reduction of NADPH registration. Glutathione peroxidase activity was determined by accumulation of oxidized glutathione. Surgery is known to lead to expression of oxidative stress in the organs operated. Special role in antioxidant protection of the body is given to thiols. Expressed hydrophilic properties provide their high content in water fraction of cells and ability to protect biologically important molecules (enzymes, nucleic acids, hemoglobin) from oxidative damage. Property of thiol compounds is known to inhibit both fermented and not fermented free radical oxidation. For the first time it was found that transplantation of muscle tissue taken from animals from the same litter lead to significant reduction of glutathione in the femoral muscle of the recipient and abdominal muscle tissue of the donor and recipient and to significant increase in glutathione reductase activity in the femoral muscle tissue of the donor and in the abdominal muscle tissue of the donor and recipient.

Role of dietary antioxidants in human metapneumovirus infection

Human metapneumovirus (hMPV) is a major cause of respiratory tract infections in children, elderly and immunocompromised hosts, for which no vaccine or treatment are currently available. Oxidative stress and inflammatory responses represent important pathogenic mechanism(s) of hMPV infection. Here, we explored the potential protective role of dietary antioxidants in hMPV infection. Treatment of airway epithelial cells with resveratrol and quercetin during hMPV infection significantly reduced cellular oxidative damage, inflammatory mediator secretion and viral replication, without affecting viral gene transcription and protein synthesis, indicating that inhibition of viral replication occurred at the level of viral assembly and/or release. Modulation of proinflammatory mediator expression occurred through the inhibition of transcription factor nuclear factor (NF)-κB and interferon regulatory factor (IRF)-3 binding to their cognate site of endogenous gene promoters. Our results indicate the use of dietary antioxidants as an effective treatment approach for modulating hMPV induced lung oxidative damage and inflammation.

Rice bran oil prevents neuroleptic-induced extrapyramidal symptoms in rats: Possible antioxidant mechanisms

Tardive dyskinesia (TD) is one of the serious side effects of long-term antipsychotic treatment. Chronic treatment with neuroleptic leads to the development of abnormal oral movements called vacuous chewing movements (VCMs). The oxidative stress hypothesis of TD is one of the possible pathophysiologic models for TD. Preclinical and clinical studies of this hypothesis indicate that neurotoxic free radical production is likely to be a consequence of antipsychotic medication and is related to occurrence of TD. Oxidative stress is implicated in the pathophysiology of TD. Rats chronically treated with haloperidol orally at a dose of 0.2 mg/kg/day for a period of 5 weeks developed VCMs, which increased in a time-dependent manner as the treatment continued for 5 weeks. Motor coordination impairment started after the 1st week and was maximally impaired after 3 weeks and gradually returned to the 1st week value. Motor activity in an open field or home cage (activity box) not altered. Administration of rice bran oil (antioxidant) by oral tubes at a dose of 0.4 mL/day prevented the induction of haloperidol-elicited VCMs as well impairment of motor coordination. The results are discussed in the context of a protective role of antioxidant of rice bran oil in the prevention of haloperidol-induced extrapyramidal symptoms.

Protective Role of Osmolytes and Antioxidants during High Temperature Stress in Wheat

Ten wheat genotypes differing thermo tolerance were exposed to gradual increase of high temperature stress from control (25⁰C) to 30⁰C1 h, 35⁰C 1 h, 40⁰C 2 h and 46⁰C 3 h in order to investigate its effect on RWC, chlorophyll, osmolytes accumulation, lipid peroxidation and activity of antioxidants SOD, CAT, GPOX, APX and GR. After exposed to heat stress an increment in proline and GB content was noticed in thermo-tolerant wheat genotypes and at 40⁰C 2 h and 46⁰C 3 h stress treatment the levels dropped in thermo-susceptible genotypes. RWC, chlorophyll ‘b’ content significantly declined with steady increase in lipid peroxidation. Heat stress induces the activity of all five ROS scavenging enzymes. However, heat inactivation of all five antioxidants observed at 46⁰C 3 h stress in all wheat cultivars. Wheat genotypes NIAW-34, AKAW-4627 and NIAW-917 found to be stable. Heat stress increases GB content with higher activity of all five antioxidants could probably ameliorate the adverse effect.

Effects provoked by chronic undernourishment on the fibre type composition and contractility of fast muscles in male and female developing rats.

In this study, we compare the effects of pre- and post-natal food deprivation on the relative proportion of fibre types and contractile responses in the extensor digitorum longus (EDL) muscle of female and male rats at different post-natal ages. EDL muscles from undernourished male (UM) rats showed a higher proportion of Type IIB than IIA fibres and larger normalized twitch responses (with respect to muscle weight) than those of controls (CM). In contrast, EDL muscles from control (CF) and undernourished female rats (UF) showed no significant differences in their fibre type composition and normalized twitch forces at most of the ages analysed. Our data are indicative that the EDL muscles from undernourished males are more susceptible to the effects exerted by low food income than the EDL muscles from female rats. It is proposed that changes in the reactive oxygen species (ROS) concentration and hormonal factors, due to undernutrition, are involved in the alterations observed in the fibre type composition and force production of EDL muscles in undernourished male rats and that estrogens may have an antioxidant protective role on the undernourished EDL muscles in female rats.

Integral assessment of antioxidant status of fruit vegetables

The integral assessment of the antioxidant status of fruited vegetables can be a key when choosing a product suitable for storage. Making the integrated assessment of the antioxidant system of fruited vegetables taking into account the differences in units of measuring the system components is a difficult task. For solving complex multicriteria informal problems, the hierarchy analysis method was used. The method for determining the generalized integral assessment of the antioxidant status of fruited vegetables based on the hierarchy analysis method was proposed. The components of the antioxidant system of protecting fruited vegetables tissues were ranked. The integral assessment showed that among the studied fruits pepper had the highest antioxidant status (ІАО=0.43), squash had the minimum (ІАО=0.12). Due to a powerful system of high antioxidants, cucumbers had higher integrated assessment (ІАО = 0.25) than tomatoes (ІАО =0.20). Low-molecular antioxidants make the main contribution to the antioxidant status of solanaceous vegetables. Enzymatic antioxidants play a leading role in antioxidant protection of tissues in pumpkin vegetables.

Carbamazepine toxic effects in chick cardiomyocyte micromass culture and embryonic stem cell derived cardiomyocyte systems--possible protective role of antioxidants.

The use of carbamazepine (CBZ) during pregnancy increases cardiovascular anomalies. In this study CBZ developmental cardiotoxic effects were evaluated using chick cardiomyocyte micromass (MM) culture and mouse embryonic stem cells derived cardiomyocyte (ESDC) systems. In MM culture, CBZ only inhibited the cardiomyocyte contractile activity, while in ESDC it completely ceased the contractile activity at 200 μM with decreased cell viability and protein content. The antioxidant superoxide dismutase (SOD) supplement in MM and ascorbic acid (AA) in ESDC showed protective effects on CBZ toxicity, but elevated levels of reactive oxygen species (ROS) production were recorded with CBZ treatment only in ESDC. CBZ has also affected cardiac connexin 43 expression in both in vitro systems. Our results indicated CBZ induced ROS stress as mechanism of developmental cardiotoxicity at early stage of cardiogenesis in ESDC system compared to MM system's differentiated cells. These toxic effects can be negated by using antioxidant agent.

Noise-induced hearing loss: an occupational medicine perspective.

Up to 30 million workers in the United States are exposed to potentially detrimental levels of noise. Although reliable medications for minimizing or reversing noise-induced hearing loss (NIHL) are not currently available, NIHL is entirely preventable. The purpose of this article is to review the epidemiology and pathophysiology of occupational NIHL. We will focus on at-risk populations and discuss prevention programs. Current prevention programs focus on reducing inner ear damage by minimizing environmental noise production and through the use of personal hearing protective devices. NIHL is the result of a complex interaction between environmental factors and patient factors, both genetic and acquired. The effects of noise exposure are specific to an individual. Trials are currently underway evaluating the role of antioxidants in protection from, and even reversal of, NIHL. Occupational NIHL is the most prevalent occupational disease in the United States. Occupational noise exposures may contribute to temporary or permanent threshold shifts, although even temporary threshold shifts may predispose an individual to eventual permanent hearing loss. Noise prevention programs are paramount in reducing hearing loss as a result of occupational exposures.

Reviewing the Protective Role of Antioxidants in Oxidative Stress Caused by Free Radicals

Reviewing the Protective Role of Antioxidants in Oxidative Stress Caused by Free Radicals

Inoculation of Lens culinaris with Pb-resistant bacteria shows potential for phytostabilization.

Phytoremediation comprises a set of plant and microbe-based technologies for remediation of soil heavy metal contamination. In this work, four Pb-resistant bacteria (Agrobacterium tumefaciens, Rahnella aquatilis, and two Pseudomonas sp.) were selected among a collection of isolates from root nodule of Lens culinaris. They had a high degree of bioaccumulation ability in nutrient medium containing 2 mM Pb, and the maximum Pb accumulation of whole cell was found after 48-h incubation. These Pb-resistant bacteria synthesized plant growth promoting substances such as indole acetic acid and siderophore. The presence of the Pb resistance genes (pbrA) in these bacteria has been confirmed by PCR. L. culinaris cultivated in two experimental soils with different levels of contamination showed that Pb contamination affected plant growth; therefore, it's co-inoculation with the consortium of Pb-resistant bacteria improved plant biomass. The present study demonstrated that lentil accumulated Pb primarily in their roots and poorly in their shoots; in addition, it's co-inoculation in moderately Pb-contaminated soil induced a reduction in Pb accumulation in roots and shoots by 22 and 80 %, respectively. Whereas in highly Pb-contaminated soil, we registered a diminution in concentration of Pb in shoots (66 %) and an augmentation in roots (21 %). The contamination of soil by Pb caused an oxidative stress in lentil plant, inducing modulation in antioxidant enzymes activities, essentially in superoxide dismutase (SOD) and peroxidase (GPOX) activities which were more pronounced in lentil cultivated in highly Pb-contaminated soil, in addition, co-inoculation enhanced these activities, suggesting the protective role of enzymatic antioxidant against Pb-induced plant stress.Thus, the present study demonstrated that co-inoculation of lentil with A. tumefaciens, R. aquatilis, and Pseudomonas sp. formed a symbiotic system useful for phytostabilization of highly and moderately Pb-contaminated soils.

Effects of antioxidant agents against cyclosporine-induced hepatotoxicity

BackgroundTo investigate the potential protective antioxidant role of ursodeoxycholic acid (UDCA), melatonin, and allopurinol treatment in cyclosporine (CsA)-induced hepatotoxicity. MethodsHepatotoxicity was established in Sprague–Dawley rats by daily administration of CsA. Treatment groups were additionally administered UDCA, melatonin, or allopurinol treatments. Rats that received no CsA and no treatments served as a control group. Liver samples from each group were examined by histopathologic analysis to determine the effects of CsA treatment on liver morphology. Biochemical assays were also used to determine the effect of CsA treatment on liver function, in the presence or absence of UDCA, melatonin, or allopurinol. ResultsCsA treatment induced hepatotoxicity, resulting in sinusoidal dilatation, congestion, infiltration, hydropic degeneration, and loss of glycogen storage in the liver. From a molecular perspective, the CsA treatment increased levels of malondialdehyde (MDA) levels, decreased levels of reduced glutathione and xanthine oxidase, and decreased activities of superoxide dismutase and catalase. The CsA treatment also resulted in decreased serum total antioxidant capacity, whereas alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total bilirubin levels, and total oxidant status were increased. Treatment with UDCA, melatonin, or allopurinol reduced the CsA-induced histopathologic changes, as compared with CsA-treated samples. In addition, UDCA, melatonin, or allopurinol treatment mitigated the CsA-induced effects on glutathione and MDA levels, and on superoxide dismutase and catalase activities, as well as reduced the CsA-mediated perturbations in serum levels of total antioxidant capacity, total oxidant status, and alkaline phosphatase. ConclusionsUDCA, allopurinol, and melatonin may each help to protect against CsA-induced damage to liver tissues, possibly through effects on the antioxidant system.

Nephrotoxicity of Bisphenol A (BPA) -An Updated Review

Bisphenol A (BPA), the highest volume chemical produced in the whole world is widely used in the production of polycarbonate plastics and epoxy resins. Polycarbonate plastics are used especially in the manufacture of consumer products. The exposure of BPA to humans occurs through food contamination from polycarbonate bottles and food and beverage cans. Dust is also a contributor to the total daily exposure of BPA. Thus, BPA has a high potential for human consumption. The U.S. Food and Drug Administration (FDA) recently announced concern about the safety of BPA and the need for more research data. This article reviews toxicity of BPA in general and kidney in particular using clinical and experimental literature. BPA is toxic to aquatic organisms, animals and humans. BPA is cytotoxic and mutagenic and exerts various adverse effects on immune, endocrine, reproductive, developmental and nervous systems in animals and human and exhibits toxicity by all routes of exposure. Metabolism of BPA is much more rapid in humans than in rodents. BPA increases estrogen metabolism in the kidney and upregulates cytochrome p-450 aromatase activity by means of steroidogenesis. BPA acts as biomarker for renal disease and exhibits nephrotoxicity. BPA toxicity with reference to human exposure level and also carcinogenicity are lacking. While focusing on kidney, this review suggests that further research is required to evaluate the molecular mechanism of BPA induced nephrotoxicity. Protective role of antioxidants against BPA induced toxicity / nephrotoxicity is discussed in this literature.

Low intake of dietary antioxidants is associated with oxidative stress in Omani adults newly diagnosed with type 2 diabetes (829.16)

Background: Recent epidemiological studies strongly indicate that low physical activity and a diet low in vegetables and fruits increased risk of type 2 diabetes (T2DM) among adults. Environmental insults induce oxidative stress that has been suggested to occur in the context T2DM pathology. The prevalence of T2DM in the Omani adults’ population is continuously increasing and has been linked to obesity and a sedentary life style. Although the protective role of dietary antioxidants in the pathogenesis of T2DM and oxidative stress has been investigated in Western populations, no study has been carried out in Omani adults with T2DM. Objective: The purpose of this study was to examine the status of dietary antioxidants and oxidative stress Omani adults newly diagnosed with T2DM. Methods: A case‐control study involved 200 Omani adults (100 patients and 100 age‐ and gender‐matched healthy controls). Several parameters were investigated, including dietary intake, physical activity level and biochemical assessments of dietary antioxidants and oxidative stress markers. Results: Among the studied subjects; there was no significant difference in the physical activity level, meanwhile low serum levels of dietary antioxidants, and oxidative stress indices were prevalent in patients with T2DM compared with controls. The oxidative stress insults levels were higher in subjects living in urban areas versus rural areas. Conclusion: Low intake of dietary antioxidants is associated with oxidative stress and collectively increasing the risk of T2DM among high risk groups of the Omani adults’ population.

The protective role of antioxidants in the defence against ROS/RNS-mediated environmental pollution.

Overproduction of reactive oxygen and nitrogen species can result from exposure to environmental pollutants, such as ionising and nonionising radiation, ultraviolet radiation, elevated concentrations of ozone, nitrogen oxides, sulphur dioxide, cigarette smoke, asbestos, particulate matter, pesticides, dioxins and furans, polycyclic aromatic hydrocarbons, and many other compounds present in the environment. It appears that increased oxidative/nitrosative stress is often neglected mechanism by which environmental pollutants affect human health. Oxidation of and oxidative damage to cellular components and biomolecules have been suggested to be involved in the aetiology of several chronic diseases, including cancer, cardiovascular disease, cataracts, age-related macular degeneration, and aging. Several studies have demonstrated that the human body can alleviate oxidative stress using exogenous antioxidants. However, not all dietary antioxidant supplements display protective effects, for example, β-carotene for lung cancer prevention in smokers or tocopherols for photooxidative stress. In this review, we explore the increases in oxidative stress caused by exposure to environmental pollutants and the protective effects of antioxidants.

Levels of salivary antioxidant vitamins and lipid peroxidation in patients with oral lichen planus and healthy individuals.

Oral lichen planus (OLP) is a chronic inflammatory mucosal disease of unknown etiology. Many studies have implicated the protective role of antioxidants in such diseases. The aim of this study was to compare salivary total antioxidant capacity (TAC and malondialdehyde (MDA) and antioxidant vitamin (vitamin s A, C and E) levels in patients with erosive OLP and healthy individuals. Thirty six patients with OLP (14 males, 22 females) and 36 control subjects (15 males, 21 females), matched for age and sex were enrolled in this case control study. The salivary levels of MDA, TAC, and antioxidant vitamin levels were measured in both case and control groups. The salivary level of MDA was significantly higher (p<0.001) in patients than in controls. In patients with OLP, the TAC of saliva was significantly lower than that in healthy subjects (p<0.001). Compared with controls, the levels of salivary antioxidant vitamins were significantly decreased in patients with OLP (p<0.001). In addition, a positive correlation was found between the decrease in the salivary amount of vitamin C and that in vitamin E in patients and controls. In addition to the lower salivary levels of antioxidant vitamins and the lower TAC, the higher level of MDA in patients with OLP suggests that free radicals and the resulting oxidative damage may be important in the pathogenesis of OLP lesions.

Higher sensitivity of pad2-1 and vtc2-1 mutants to cadmium is related to lower subcellular glutathione rather than ascorbate contents

Cadmium (Cd) interferes with ascorbate and glutathione metabolism as it induces the production of reactive oxygen species (ROS), binds to glutathione due to its high affinity to thiol groups, and induces the production of phytochelatins (PCs) which use glutathione as a precursor. In this study, changes in the compartment specific distribution of ascorbate and glutathione were monitored over a time period of 14 days in Cd-treated (50 and 100 μM) Arabidopsis Col-0 plants, and two mutant lines deficient in glutathione (pad2-1) and ascorbate (vtc2-1). Both mutants showed higher sensitivity to Cd than Col-0 plants. Strongly reduced compartment specific glutathione, rather than decreased ascorbate contents, could be correlated with the development of symptoms in these mutants suggesting that higher sensitivity to Cd is related to low glutathione contents rather than low ascorbate contents. On the subcellular level it became obvious that long-term treatment of wildtype plants with Cd induced the depletion of glutathione and ascorbate contents in all cell compartments except chloroplasts indicating an important protective role for antioxidants in chloroplasts against Cd. Additionally, we could observe an immediate decrease of glutathione and ascorbate in all cell compartments 12 h after Cd treatment indicating that glutathione and ascorbate are either withdrawn from or not redistributed into other organelles after their production in chloroplasts, cytosol (production centers for glutathione) and mitochondria (production center for ascorbate). The obtained data is discussed in respect to recently proposed stress models involving antioxidants in the protection of plants against environmental stress conditions.Electronic supplementary materialThe online version of this article (doi:10.1007/s00709-013-0576-x) contains supplementary material, which is available to authorized users.