Defense System Responses Research Articles

The influence of simulated global ocean acidification on the toxic effects of carbon nanoparticles on polychaetes

Ocean acidification events are recognized as important drivers of change in biological systems. Particularly, the impacts of acidification are more severe in estuarine systems than in surface ocean due to their shallowness, low buffering capacity, low salinity and high organic matter from land drainage. Moreover, because they are transitional areas, estuaries can be seriously impacted by a vast number of anthropogenic activities and in the last decades, carbon nanomaterials (CNMs) are considered as emerging contaminants in these ecosystems. Considering all these evidences, chronic experiment was carried out, trying to understand the possible alteration on the chemical behaviour of two different CNMs (functionalized and pristine) in predicted climate change scenarios and consequently, how these alterations could modify the sensitivity of one the most common marine and estuarine organisms (the polychaeta Hediste diversicolor) assessing a set of biomarkers related to polychaetes oxidative status as well as the metabolic performance and neurotoxicity. Our results demonstrated that all enzymes worked together to counteract seawater acidification and CNMs, however oxidative stress in the exposed polychaetes to both CNMs, especially under ocean acidification conditions, was enhanced. In fact, although the antioxidant enzymes tried to cope as compensatory response of cellular defense systems against oxidative stress, the synergistic interactive effects of pH and functionalized CNMs indicated that acidified pH significantly increased the oxidative damage (in terms of lipid peroxidation) in the cotaminated organisms. Different responses were observed in organisms submitted to pristine CNMs under pH control, where the lipid peroxidation did not increase along with the increasing exposure concentrations. The present results further demonstrated neurotoxicity caused by both CNMs, especially noticeable at acidified conditions. The mechanism of enhanced toxicity could be attributed to slighter aggregation and more suspended NMs in acidified seawater (as demonstrated by the DLS analysis). Therefore, ocean acidification may cause a higher risk of CNMs to marine ecosystems.

Kombine Tuz ve Nikel Stresinin Limon Otu (Melissa officinalis)'nun ROS Üretimi ve Antioksidan Enzim Aktiviteleri Üzerine Etkisi

Plants acclimation to stress is a complex process and this complexity increase with simultaneous subjection to two or more abiotic stress. Salinity and excess accumulation of nickel are growth and development restricted abiotic stress agents. The aim of the present study was to determine the antioxidant defense system responses of Melissa officinalis (lemon balm) to salinity, nickel and their combinations. Growth, leaf osmotic potential, chlorophyll fluorescence, relative water content (RWC), lipid peroxidation, H2O2 and proline content and antioxidant enzyme activities were determined under these stress conditions. Growth and leaf osmotic potential negatively affected due to the combined effect of salt and nickel. All three stress treatments did not show any significant change on RWC and chlorophyll fluorescence in lemon balm. H2O2 content and lipid peroxidation of combined stress had greater than salt and nickel alone. Total activities of ascorbate peroxidase (APX) and glutathione reductase (GR) were increased with salt, nickel and their combinations. Moreover, the reduction in superoxide dismutase (SOD), peroxidase (POX) and catalase (CAT) activities resulted in higher lipid peroxidation and H2O2 content under the combined stress. To the best of our knowledge, this is the first study conducted on the activities of antioxidant defense enzymes of lemon balm under salinity and nickel combinations.

Evaluation of proline content and enzymatic defense mechanism in response to drought stress in rice

To study proline content and enzyme defense system in response to drought stress in rice, a randomized complete block design with three replications was conducted in two separate environments (drought stress and non-stress). The rice cultivars used included two commercial cultivars, i.e., Ahlemi Tarom (low-yield and drought tolerant) and Sepidrood (high-yield and sensitive to drought) and three promising lines of fourth generation mutants (high-yield and drought tolerant), namely, No. 4, 94 and 95 tested on a research farm at Gonbad Kavous University in the 2018 crop year. Plant roots were separately sampled in each block at the reproductive stage. The proline content and activity of the enzymes involved in the defense system, including superoxide dismutase, catalase, ascorbate peroxidase and glutathione peroxidase were measured by extracting the enzymes from each root sample. Results indicated that the drought-tolerant mutant lines had lower proline contents. The mutant lines and Ahlemi Tarom and Sepidrood cultivars had the highest to lowest levels of defense enzymes in the oxidative pathway, respectively. Correlation was found between the decrease in proline contents and increase in levels of defense enzymes of the oxidative stress pathway. The mutants possessed reliable genetic storages for tolerance to drought stress and had a significant superiority over the commercial cultivars at P≤0.05.

Evaluation of oxidant/antioxidant status in serum of sheep experimentally envenomated with Hemiscorpius lepturus scorpion venom.

Scorpion envenomation is a main general health problem in developing countries, especially in tropical and subtropical regions. Hemiscorpius lepturus as a member of the Hemiscorpiidae family is cause of the most scorpion sting lethality in Iran. In the present study, the oxidative stress and antioxidant defense in serum of envenomated sheep with the venom of Hemiscorpius lepturus were investigated. Nine sheep were randomly divided into three groups (three in each). Groups A, B and C received 0.10, 0.05 and 0.01 mg kg-1 of H. lepturus venom subcutaneously, respectively. Blood sampling were performed 30 min before envenomation (control) and 30 min, 1, 2, 3 and 6 hr after envenomation and serum levels of total antioxidant capacity (TAC), malonedialdehyde (MDA) and protein carbonyl (PCO) were determined. The TAC was significantly increased at the doses of 0.10 mg kg-1 (at 3 hr) and 0.05 mg kg-1 (at 6 hr) compared to pre-injection time. However, no significant differences were observed in serum levels of MDA and PCO in different groups. It can be concluded that the dose of 0.01 mg kg-1 of venom had no effect on stress factors of serum, but according to increased level of TAC at the doses of 0.05 and 0.10 and no significant changes in serum levels of MDA and PCO, the oxidative damage has been prevented by the antioxidant defense system response.

Accumulation, metabolite and active defence system responses of fluoxetine in zebrafish embryos: Influence of multiwalled carbon nanotubes with different functional groups

Studies on the bioavailability of organic contaminants adsorbed to nanomaterials are increasing. In this study, we investigated the interaction between fluoxetine (FLX) and three multiwalled carbon nanotubes (MWCNTs) with different functional groups in zebrafish (Danio rerio) embryos, focusing on the FLX accumulation, the formation of the metabolite norfluoxetine (NFLX), and the active defence system responses. The accumulation of FLX in zebrafish was intensified by MWCNTs (46–99%), which simultaneously facilitated the formation of the metabolite NFLX by 23–167%. The consistent enhancement revealed that the absorbed FLX is bioavailable in zebrafish. Moreover, the coexisting MWCNTs further promoted the influences of FLX on the active defence system in zebrafish (e.g. antioxidant and metabolic function), eliciting the defence function. The influences of MWCNTs on the bioavailability of FLX in zebrafish could be ordered as OH-MWCNTs > COOH-MWCNTs > pristine MWCNTs. The release of FLX from MWCNTs in biofluids may partially contribute to these significant alterations. In particular, MWCNTs themselves may also modulate the bioavailability of FLX in zebrafish by downregulating the gene expression of membrane ATP-binding cassette transporter (abcb4). These findings demonstrated that MWCNTs increased the bioavailability of FLX in zebrafish, especially the functionalized MWCNTs. The production of metabolites may be a useful bio-endpoint to evaluate the bioavailability of adsorbed contaminants on nanomaterials.

Potassium humate improves physio-biochemical attributes, defense systems activities and water-use efficiencies of eggplant under partial root-zone drying

Abstract Partial root-zone drying (PRD) applied in an alternate strategy (PRDalt) can regulate plant physiological and antioxidative defense system responses, and it is considered as an irrigation water-saving method. The current study was carried out using pot experiments to elucidate the potential role of potassium humate (KH) in integration with PRDalt in regulating eggplant physiological and defense systems responses, and irrigation water-saving. PRDalt significantly reduced the plant growth and yield, leaf photosynthetic gas exchange, leaf relative water content (RWC) and membrane stability index (MSI), while significantly increased leaf and root contents of malondialdehyde (MDA), hydrogen peroxide (H2O2), and leaf and root activities of enzymatic and non-enzymatic antioxidants compared to Full irrigation (control; FI). Integrative application of PRDalt + KH increased water-use efficiencies; WUEfw (calculated as g fruits L−1 applied water) by 97.9% and WUEpt (calculated by dividing the net photosynthetic rate by transpiration rate) by 20.3% compared to the controls. It also further increased leaf and root activities of enzymatic and non-enzymatic antioxidants, while controlled the contents of MDA and H2O2, and maintained plant growth and yield, leaf photosynthetic gas exchange, RWC and MSI at the same levels in plants of FI. Results of this study recommend using the integrative strategy of PRDalt + KH to confer the same eggplant growth and yield of the FI control and save about 50% of irrigation water.

Dose- and age-specific antioxidant responses of the mysid crustacean Neomysis awatschensis to metal exposure

Waterborne metals can adversely affect an organism’s innate defenses through oxidative stress. In the present study, the marine mysid Neomysis awatchensis was exposed to sublethal concentrations (1/10 and 1/5 of the median LC50s) of As, Cd, Cu, Pb, and Zn for 48 or 96 h at the juvenile and adult developmental stages, and the dose- and age-specific antioxidant defense system responses were characterized. Metal accumulation and modulation of four key antioxidant biomarkers, malondialdehyde (MDA), glutathione (GSH), superoxide dismutase, and catalase, were measured in juvenile and adult mysids. Based on LC50, level of metal toxicity was dependent on metal concentration, developmental stage, and the exposure duration. Intracellular MDA content was increased in the As-, Cu-, Pb-, and Zn-exposed juvenile mysids after exposure for 48 and/or 96 h, while increases in MDA content were observed in adult mysids following Cu and Zn exposure. Interestingly, GSH content was differentially modulated, where intracellular GSH levels decreased in juvenile mysids following Cd, Cu, Pb, and Zn exposure, but significantly increased in metal-exposed adult mysids, except for Pb exposure. The catalase and superoxide dismutase activities displayed similar stage-specific increases or decreases as also observed for the different GSH levels, suggesting that the susceptibility to and defense against metal-induced oxidative stress differed based on stage. Modulations in MDA and GSH content and enzymatic activity of the antioxidant defense system indicate that mysid antioxidant defense system factors are intimately connected during control of oxidative imbalances with different capacities at different developmental stages.

The offensive posture of NATO's missile defence system

A compelling case can be made to develop a NATO's missile defence system in response to the advancement of missile technology and the danger of nuclear weapons. However, this development also undermines Russia's retaliatory capacity, and consequently heightens the offensive potential of nuclear weapons. This article explores the offence/defence posture of NATO's missile defence plans in terms of both capabilities and strategy. It is argued that NATO is incrementally increasing the strength and reach of its missile defence components, while rejecting any international treaty to regulate and limit their future expansion. This corresponds with a strategy of achieving invulnerability through counterforce and utilising NATO as an ‘insurance policy’ against Russia, to be activated when conflicts arise. We conclude that NATO has the capacity to distinguish between an offensive and defensive posture by discriminating between potential targets, but it has displayed no intention to do so.

Vehicle pollution toxicity induced changes in physiology, defence system and biochemical characteristics of Calotropis procera L.

ABSTRACTThe present study aims to examine the physiological, biochemical and defence system responses of Calotropis procera to vehicle exhaust pollution. We selected various sample sites along two major roads in the Punjab province of Pakistan, i.e. Faisalabad to Sargodha road (FSR) and Pindi Bhattian to Lillah motorway (M-2). Traffic density at all sites and plant responses (i.e. chlorophyll a, chlorophyll b, total chlorophyll and carotenoid contents, transpiration rate, stomatal conductance, photosynthetic rate, sub-stomatal CO2 concentration, water use efficiency, total free amino acids, total soluble proteins and total antioxidant activity) were measured. Levels of carbon (C) and nitrogen (N) and four metals of most possible concern – i.e. lead (Pb), zinc (Zn), cadmium (Cd) and nickel (Ni) – were also examined in all samples. We found their considerable deposition in all the samples along roads. Inhibitory effects of roadside pollutants were noted for photosynthetic pigments, stomatal conductance, transpiration rate, photosynthetic rate and total soluble proteins, whereas stimulatory effects were noted for sub-stomatal CO2 concentration, free amino acids and total antioxidant activity. The stimulation of antioxidant enzymes activity revealed stress and mitigation of reactive oxygen species. The present study clearly signifies that C. procera has great potential to endure the stress caused by roadside pollutants.

The protective role of multixenobiotic resistance (MXR)-mediated ATP-binding cassette (ABC) transporters in biocides-exposed rotifer Brachionus koreanus

P-glycoprotein (P-gp) and multidrug resistance-associated protein (MRP) are ATP-binding cassette (ABC) transporters that confer multixenobiotic resistance (MXR) via their efflux activity, which enables a variety of xenobiotics to be expelled from cells. MXR has been proposed as the first line of defense against xenobiotics. In this study, the protective roles of P-gp and MRP in the rotifer Brachionus koreanus were examined in response to four biocides (alachlor, chlorpyrifos, endosulfan, and molinate) using fluorescent substrates and inhibitors specific to P-gp and MRP. Exposure of rotifers to the four biocides resulted in increased P-gp and MRP activity. Moreover, the rotifers became more sensitive to the biocides with a reduced tendency in survival and slower population growth rates, when P-gp or MRP was inhibited. These findings suggest that P-gp and MRP are involved in the defense system in response to biocide exposure. Furthermore, the transcriptional levels of the genes encoding P-gp and MRP were examined to uncover the mechanism by which MXR is regulated. Our results demonstrate a crucial role of the MXR efflux system in the defense response to biocides, thereby providing a better understanding of rotifer defense mechanisms on the molecular level.

Ultrasonication of in vitro potato single node explants: Activation and recovery of antioxidant defence system and growth responses

The ability to use sound or ultrasound (US) to modify plant growth in vitro, and if possible, to improve yield or productivity, would benefit horticultural scientists. In this study, potato (Solanum tuberosum L. cv. Desirée) in vitro node segments with a single leaf were exposed to US (35 kHz, 70 W, for 20 min). Morphological, physiological and biochemical parameters were measured. Treatment with US 24 h after ultrasonication temporarily accelerated shoot growth but inhibited the development and growth of roots due to a decrease in the level of AA directly after ultrasonication. At the end of the subculture period, i.e., 4 weeks after US treatment, shoot length increased 20% more than control shoots after 4 weeks, while shoot fresh weight was 24% higher than that of control shoots, representing the long-term after-effect of the US treatment. The antioxidant defence system was induced, partly by intensive plantlet growth and development from node segments, and partly by abiotic stress caused by the US treatment. Immediately (0 h) or 24 h after ultrasonication, superoxide dismutase, ascorbate peroxidase, and glutathione reductase activity increased significantly, as did the concentration of low molecular weight antioxidants (GSSG, GSH, AA, TCPa). However, there was no glutathione peroxidase activity, most likely due to the lack of selenium in the basal in vitro growth medium. Therefore, the glutathione-S-transferase path of the ascorbate-glutathione pathway was induced both by metabolic processes and by abiotic stresses and took part in the reduction of organic peroxides using glutathione. US treatment ameliorated the ratios of ascorbic acid/glutathione and reduced/oxidized glutathione, ensuring the development of plantlets with significantly improved shoot parameters, such as higher shoot length and fresh weight, by the end of the subculture period.

Antioxidant defence system and physiological responses of Iranian crested wheatgrass (Agropyron cristatum L.) to drought and salinity stress

Crested wheatgrass (Agropyron cristatum L.) is a cool-season perennial grass, which has demonstrated its potential for use as turfgrass. However, limited information is available on its drought and salinity tolerance. The main purpose of this study was to investigate the changes in the antioxidant defence system and physiological traits of six Iranian crested wheatgrass genotypes under drought and salinity stresses. The experimental design comprised a split plot with water treatments (control well-watered, salinity stress and water stress) as main plots and genotypes as subplots. This study demonstrated the variations in drought and salinity tolerance among crested wheatgrass genotypes. ‘ACSKI’, ‘ACAMI’ and ‘ACDTI’ generally performed better than other genotypes under drought and salinity conditions, mainly by maintaining higher activities of antioxidant enzymes like superoxide dismutase, peroxidase, catalase, ascorbate peroxidase and non-enzyme antioxidants like glutathione, higher proline and total non-structural carbohydrates content. The increased, decreased, and unchanged activities of antioxidant enzymes in the crested wheatgrass genotypes indicates a different forms of metabolism of antioxidant enzymes in response to drought and salinity stress. In general, drought and salinity stress increases the malondialdehyde (MDA) content and hydrogen peroxide (H2O2) content; however, ‘ACSKI’, ‘ACAMI’ and ‘ACDTI’ genotypes could tolerate an increase in MDA content and H2O2 content; therefore, lower levels of MDA content and H2O2 content were observed. The results showed that increasing levels of diamine oxidase and polyamine oxidase have been associated with increasing drought and salinity tolerance. Based on the biochemical and physiological parameters that were evaluated, we concluded that the genotype ‘ACSKI’ was superior in terms of drought and salinity tolerance. This superiority was mainly a result of better enzymatic and non-enzymatic antioxidant defence system and better osmotic adjustment under stress conditions.

Oxidative stress parameters in two Pelophylax esculentus complex frogs during pre- and post-hibernation: Arousal vs heavy metals

In spring, frogs from temperate regions are faced with arousal-induced oxidative stress and exposure to various xenobiotics from the environment. The question is whether pollutants can significantly modify the antioxidative defense system (AOS) response of hibernators during recovery from hibernation. If this assumption is true, we would then expect different patterns of seasonal variations in the AOS between individuals exposed to different levels of pollution. To examine this assumption, we determined the relationship between seasonal variations of accumulated metals and AOS parameters in the skin and muscle of two frog species from the Pelophylax esculentus complex (P. ridibundus and P. esculentus) inhabiting two localities (the Danube-Tisza-Danube canal and the Ponjavica River) with different levels of pollution during pre- and post-hibernation periods, respectively autumn and spring. Our results showed that even though there were differences in the concentrations of accumulated metals and AOS parameters between localities and species, the frogs displayed almost the same patterns of AOS variations during seasons, with a higher AOS response observed in spring. The parameters SH groups, GSH, GR and SOD had been contributed most rather than others. Our findings indicate that oxidative stress during the post-hibernation period was mainly caused by the organisms' recovery from hibernation, as the result of natural selection acting on the AOS, and that the accumulated metals did not significantly modify the AOS response. The present study provides new insight into the biological and physiological cellular responses of frogs to arousal stress.

Effect of the phosphogypsum amendment of saline and agricultural soils on growth, productivity and antioxidant enzyme activities of tomato (Solanum lycopersicum L.).

The objective of this study was to investigate the effects of phosphogypsum (PG) amendment on the physiochemical proprieties of saline and agricultural soils along with the growth, productivity and antioxidant enzyme activities of tomato plants ( Solanum lycopersicum L.) grown on the amended soils under controlled conditions. Obtained results showed that the amendment of saline soil (H) by PG induced a decrease in pH as well as in electrical conductivity. However, for the non saline soil (MC), there was a decrease in pH associated with an increase in electrical conductivity. For both soils, PG amendment led to an increase in Calcium (Ca) and sodium (Na), and a decrease in potassium (K) in plant tissues. Cadmium (Cd), Zinc (Zn) and Chromium (Cr) contents in different parts of plants increased in proportion with PG concentration in the soils. Apart from Cd, all the analyzed metals in tomato fruit were found to be below the recommended maximum allowable concentration (MAC). Our results showed that PG application, at doses not exceeding 20%, seems to be beneficial for growth, photosynthetic activity and productivity of tomato plants as well as in decreasing salinity of saline soils. In these conditions, the use of PG could be a promising project for the rehabilitation of marginalized and saline ecosystems with either ornamental or non-fruit species. For both soils, a significant accumulation of MDA in shoots was detected, reflecting cell membrane damage especially when the PG amendment reached 20%. Beyond 20 and 40% PG, tomato plants developed an enzymatic antioxidant defense system in response to salinity and heavy metal stress. However, at 80% PG, enzymes activities were significantly inhibited.

Identification and functional characterization of Oncomelania hupensis macrophage migration inhibitory factor involved in the snail host innate immune response to the parasite Schistosoma japonicum

Schistosomiasis, caused by parasitic trematodes of the genus Schistosoma, remains a devastating public health problem, with over 200 million people infected and 779 million people at risk worldwide, especially in developing countries. The freshwater amphibious snail Oncomelania hupensis is the obligate intermediate host of Schistosoma japonicum. This unique and long-standing host-parasite interaction highlights the biomedical importance of the molecular and cellular mechanisms involved in the snail immune defense response against schistosome infection. In recent years, a number of immune-related effectors and conserved signalling pathways have been identified in molluscs, especially in Biomphalaria glabrata, which is an intermediate host for Schistosoma mansoni, but few have been reported in O. hupensis. Here we have successfully identified and functionally characterized a homologue of mammalian macrophage migration inhibitory factor (MIF) from O. hupensis (OhMIF). MIF, a pleiotropic regulator of innate immunity, is a constitutively expressed mediator in the host’s antimicrobial defense system and stress response that promotes the pro-inflammatory functions of immune cells. In the present study, we detected the distribution of OhMIF in various snail tissues, especially in immune cell types (hemocytes) and found that OhMIF displays significantly increased expression in snails following challenge with S. japonicum. Knockdown of OhMIF was conducted successfully in O. hupensis and significantly reduced the percentage of phagocytic cell populations in circulating hemocytes. Furthermore, OhMIF is not only implicated in the activation and differentiation of hemocytes, but also essential to promote the migration and recruitment of hemocytes towards the infected sites. These results provide the first known functional evidence in exploring the molecular mechanisms involved in the O. hupensis innate immune defense response to the parasite S. japonicum and help to better understand the complex host-parasite interaction.

ENZYMATIC ACTIVITY OF GLUTATHIONE S-TRANSFERASE AND THE LEVEL OF REDUCED GLUTATHIONE IN PIKE ESOX LUCIUS L. AND ITS OBLIGATE PARASITE CESTODE TRIAENOPHORUS NODULOSUS

Helminthes are a group of invertebrates living in the internal organs of a wide range of hosts. Helminthes are evolutionarily adapted to a relatively stable environment, formed by the host’s ability to maintain homeostasis under variable environmental conditions and pollution. Therefore, it is interesting to evaluate the ability of the parasite to independently adapt to adverse environmental factors. In this paper, we hypothesized that the host’s defense system response to a challenging environment is more pronounced than that of the parasite living inside the host. To study the activation of the protective mechanisms involving biotransformation of xenobiotics and antioxidant defense, the activity of the enzyme glutathione S-transferase (GST) and the concentration of reduced glutathione (GSH) were measured in an obligate parasite Triaenophorus nodulosus and its host – pike Esox lucius L. living in a pond contaminated by wastes from the Kostomuksha iron mine and ore dressing mill (Northern Karelia). Biological samples obtained from intact Lake Kamennoe were used for reference. The fish collected from the disturbed environment had an elevated level of reduced glutathione in all organs, whereas the activity of glutathione S-transferase increased only in kidneys and muscles. In T. nodulosus from the contaminated lake a decline of GST activity and the absence of response from GSH were observed. The results show that the external environment affects the intestinal parasite indirectly, via the variations of the physiological and biochemical status of the host, as a result of the host-parasite co-evolution.

Is Vitamin C Beneficial to Patients with CAP?

Community-acquired pneumonia (CAP) is one of the most common causes of morbidity and mortality in elderly and children. Vitamin C is known as a physiological antioxidant, regulating innate immune system in the lung. Vitamin C has been used to prevent and treat CAP. However, the use of vitamin C for preventing and treating CAP has been a subject of controversy. We aim to review the most significant findings about vitamin C supplementation in patients with pneumonia based on literature from the PubMed. First, we reviewed recent advances about the role of oxidative stress in CAP. Oxidative stress is a crucial component of the host defense system and inflammatory response. However, excessive oxidative stress can cause a systemic inflammatory response leading to tissue damage. The degree of oxidative stress has been associated with the severity of CAP. Vitamin C is beneficial to the host defense system by regulating the innate immunity in the lungs. We also discuss the prophylactic use of vitamin C for pneumonia. Vitamin C supplementation decreased the pneumonia risk in patients with vitamin C deficiency. However, it is not beneficial for prophylactic use of vitamin C to prevent pneumonia in the well-nourished population. Finally, we summarize the effect of vitamin C on mechanical ventilation used during respiratory failure. Administration of vitamin C decreases the duration of mechanical ventilation by decreasing oxidative stress.

LINE-1 methylation is positively associated with healthier lifestyle but inversely related to body fat mass in healthy young individuals

With the goal of investigating if epigenetic biomarkers from white blood cells (WBC) are associated with dietary, anthropometric, metabolic, inflammatory and oxidative stress parameters in young and apparently healthy individuals. We evaluated 156 individuals (91 women, 65 men; age: 23.1±3.5 years; body mass index: 22.0±2.9 kg/m2) for anthropometric, biochemical and clinical markers, including some components of the antioxidant defense system and inflammatory response. DNA methylation of LINE-1, TNF-α and IL-6 and the expression of some genes related to the inflammatory process were analyzed in WBC. Adiposity was lower among individuals with higher LINE-1 methylation. On the contrary, body fat-free mass was higher among those with higher LINE-1 methylation. Individuals with higher LINE-1 methylation had higher daily intakes of calories, iron and riboflavin. However, those individuals who presented lower percentages of LINE-1 methylation reported higher intakes of copper, niacin and thiamin. Interestingly, the group with higher LINE-1 methylation had a lower percentage of current smokers and more individuals practicing sports. On the other hand, TNF-α methylation percentage was negatively associated with waist girth, waist-to-hip ratio and waist-to-stature ratio. Plasma TNF-α levels were lower in those individuals with higher TNF-α methylation. This study suggests that higher levels of LINE-1 and TNF-α methylation are associated with better indicators of adiposity status in healthy young individuals. In addition, energy and micronutrient intake, as well as a healthy lifestyle, may have a role in the regulation of DNA methylation in WBC and the subsequent metabolic changes may affect epigenetic biomarkers.

Pterostilbene Reduced Post-Antibiotic Effect Time of Linezolid against Methicillin-Resistant Staphylococcus aureus

Pterostilbene is biologically classified as a phytoalexin, which is part of the plant's defense system in response to pathogen infection. The present study is to identify the type of interaction and post-antibiotic effect time of pterostilbene in combination with linezolid against methicillin-resistant Staphylococcus aureus American type culture collection 43300 and methicillin-resistant S. aureus American type culture collection 33591. The minimum inhibitory concentration values of individual antimicrobial agents were determined using microbroth dilution technique whereas the microdilution checker board assay was employed to verify the type of interaction of the combined agents from the fractional inhibitory concentration index values. The post-antibiotic effect time of pterostilbene and linezolid and in combination treatment was evaluated using viable plate count method. The minimum inhibitory concentration value of pterostilbene against both strains were the same (31.25 μg/ml) compared to linezolid at 0.78 μg/ml and 1.56 μg/ml, against 43300 and 33591 strain, respectively. microdilution checker analysis of pterostilbene in combination with linezolid against both methicillin-resistant S. aureus strains displayed fractional inhibitory concentration value of 1.25. Despite the indifference interaction between pterostilbene and linezolid as shown by microdilution checker study, post-antibiotic effect analysis demonstrated antagonism as depicted by a decrease of post-antibiotic effect time of linezolid by pterostilbene against both methicillin-resistant S. aureus strains. The duration of post-antibiotic effect time obtained for pterostilbene were twice (3.6±0.15 h) that of linezolid (1.8±0.31 h) against methicillin-resistant S. aureus American type culture collection 43300. However, pterostilbene exhibited shorter post-antibiotic effect time of 0.3±0.10 h compared to linezolid (0.9±0.06 h) against 33591 strain. In conclusion, pterostilbene was not able to prolong the post-antibiotic effect duration of linezolid in both strains and each of the antimicrobials demonstrated a more favorable timing of doses when these agents were used singly.

The Roles of 4β-Hydroxywithanolide E from Physalis peruviana on the Nrf2-Anti-Oxidant System and the Cell Cycle in Breast Cancer Cells.

4[Formula: see text]-Hydroxywithanolide E is an active component of the extract of Physalis peruviana that has been reported to exhibit antitumor effects. Although the involvement of reactive oxygen species (ROS) production and the ataxia-telangiectasia mutated protein (ATM)-dependent DNA damage signaling pathway in 4[Formula: see text]-hydroxywithanolide E-induced apoptosis of breast cancer MCF-7 cells was demonstrated in our previous study, the relationship between ROS production and the cellular defense system response in 4[Formula: see text]-hydroxywithanolide E-induced cell death requires further verification. The present study suggests that ROS play an important role in 4[Formula: see text]-hydroxywithanolide E-induced MCF-7 cell death in which anti-oxidants, such as glutathione or N-acetylcysteine, can resist the 4[Formula: see text]-hydroxywithanolide E-induced accumulation of ROS and cell death. Furthermore, N-acetylcysteine or glutathione can reverse the 4[Formula: see text]-hydroxywithanolide E-induced changes in the cell cycle distribution and the expression of cell cycle regulators. We found that the 4[Formula: see text]-hydroxywithanolide E-induced ROS accumulation was correlated with the upregulation of Nrf2 and Nrf2-downstream genes, such as antioxidative defense enzymes. In general, the activity of Nrf2 is regulated by the Ras signalling pathway. However, we demonstrated that Nrf2 was activated during 4[Formula: see text]-hydroxywithanolide E-induced MCF-7 cell death in spite of the 4[Formula: see text]-hydroxywithanolide E-induced inhibition of the Ras/Raf/ERK pathway. The activity and protein expression of superoxide dismutase and catalase were involved in the 4[Formula: see text]-hydroxywithanolide E-induced ROS production in MCF-7 cells. Furthermore, 4[Formula: see text]-hydroxywithanolide E was demonstrated to significantly reduce the sizes of the tumor nodules in the human breast cancer MDA-MB231 xenograft tumor model.