Effects of Antioxidant Enzymes of Ascorbate-Glutathione Cycle in Soybean (Glycine Max) Leaves Exposed to Ozone

2011 ◽  
Vol 204-210 ◽  
pp. 672-677 ◽  
Author(s):  
Tian Hong Zhao ◽  
Jun Li Wang ◽  
Yan Wang ◽  
Ying Cao

Open-top chambers (OTCs) were used to investigate the mechanism of antioxidant enzymes to eliminate reactive oxygen species (ROS) of plants under troposphere O3stress. The results indicated that, compared to control, the O3concentration of 80±10 nL·L-1and 110±10 nL·L-1induced an increase on malondialdehyde (MDA) content and a decrease on superoxide anion (O2)production rate and hydrogen peroxide (H2O2) content during the whole growth stage. Simultaneity, it showed a trend of increasing in earlier stage and decreasing in later stage of the activities of ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR) and glutathione reductase (GR), while the dehydroascorbate reductase (DHAR) activity was increased in earlier period, decreased in middle periods and then increased in later period compared to control, respectively. The results show that elevated O3concentration accelerates ROS metabolism rates, reduces the efficiency of antioxidant enzymes that can not tolerate oxidative damage caused by elevated O3concentration, which represents injured affects to soybean.

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1040 ◽  
Author(s):  
Ya Zhang ◽  
Xiangchun Zhang ◽  
Qing Yuan ◽  
Wenchao Niu ◽  
Chunyu Zhang ◽  
...  

Anticancer metallodrugs that aim to physiological characters unique to tumor microenvironment are expected to combat drug tolerance and side-effects. Recently, owing to the fact that reactive oxygen species’ is closely related to the development of tumors, people are committed to developing metallodrugs with the capacity of improving the level of reactive oxygen species level toinduce oxidative stress in cancer cells. Herein, we demonstrated that peptide templated gold clusters with atomic precision preferably catalyze the transformation of hydrogen peroxide into superoxide anion in oxidative pressure-type tumor cells. Firstly, we successfully constructed gold clusters by rationally designing peptide sequences which targets integrin ανβ3 overexpressed on glioblastoma cells. The superoxide anion, radical derived from hydrogen peroxide and catalyzed by gold clusters, was confirmed in vitro under pseudo-physiological conditions. Then, kinetic parameters were evaluated to verify the catalytic properties of gold clusters. Furthermore, these peptide decorated clusters can serve as special enzyme-like catalyst to convert endogenous hydrogen peroxide into superoxide anion, elevated intracellular reactive oxygen species levels, lower mitochondrial membrane potential, damage biomacromolecules, and trigger tumor cell apoptosis consequently.


2007 ◽  
Vol 34 (7) ◽  
pp. 601 ◽  
Author(s):  
Stanislawa Pukacka ◽  
Ewelina Ratajczak

The ascorbate–glutathione system was studied during development and desiccation of seeds of two Acer species differing in desiccation tolerance: Norway maple (Acer platanoides L., orthodox) and sycamore (Acer pseudoplatanus L., recalcitrant). The results showed remarkable differences in the concentration and redox balance of ascorbate and glutathione between these two kinds of seeds during development, and a significant dependence between glutathione content and acquisition of desiccation tolerance in Norway maple seeds. There were relatively small differences between the species in the activities of enzymes of the ascorbate–glutathione cycle: ascorbate peroxidase (APX, EC 1.11.1.11), monodehydroascorbate reductase (MR, EC 1.6.5.4), dehydroascorbate reductase (DHAR, EC 1.8.5.1), and glutathione reductase (GR, EC 1.6.4.2). At the end of seed maturation, ascorbic acid content and the activities of the above enzymes was about the same in both species The electrophoretic pattern of APX isoenzymes was also similar for both species, and the intensity of the bands decreased at the end of seed maturation in both species. When sycamore seeds were desiccated to a moisture content of less than 26%, there was a marked decrease in seed viability and an increase in the production of reactive oxygen species. During desiccation, Norway maple seeds had a more active defence system, which was reflected in a higher glutathione content, a higher glutathione redox status, a higher ascorbate redox status, and higher activities of APX, MR, DHAR, GR and GPX (glutathione peroxidase). During desiccation, sulfhydryl-to-disulfide transition into proteins was more intense in Norway maple seeds than sycamore seeds. All of these results suggest that, in orthodox seeds, the ascorbate–glutathione cycle plays an important role in the acquisition of tolerance to desiccation, in protein maturation, and in protection from reactive oxygen species.


2014 ◽  
Vol 7 (2) ◽  
pp. 207-215 ◽  
Author(s):  
C. Paciolla ◽  
A. Florio ◽  
G. Mulè ◽  
A.F. Logrieco

During their life cycle, plants can undergo simultaneous attack by different pathogens that produce various toxins. It is well known that in some plant-fungal interactions, mycotoxins play an important role in pathogenesis and induce a reactive oxygen species increase. Plants counteract the overaccumulation of reactive oxygen species by reinforcing their defence systems. The mycotoxins T-2 toxin (T-2) and beauvericin (BEA) are produced by some Fusarium species and have different chemical structures, mechanisms of action and biological activities. In this study, the individual and combined effects of these two toxins on defence systems, such as the ascorbate-glutathione cycle and peroxidases, were evaluated in cherry tomato shoots. Hydrogen peroxide content as an index of oxidative stress was also measured. Inhibitory effects on ascorbate peroxidase, dehydroascorbate reductase and ascorbate, and stimulatory effects on glutathione reductase, monodehydroascorbate reductase and reduced glutathione were observed when tomato plants were simultaneously treated with BEA and T-2. The trend of these biochemical parameters highlight the presence of a range of defence mechanisms activated by plants in response to mycotoxins. The interaction between BEA and T-2 resulting in synergistic and/or antagonistic effects on the studied defence systems is also discussed. It is concluded that the effects of these mycotoxins alone are not predictive of their combined effects.


Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4337
Author(s):  
Maphuti T. Lebelo ◽  
Anna M. Joubert ◽  
Michelle H. Visagie

2-Methoxyestradiol (2ME), a 17β-estradiol metabolite, exerts anticancer properties in vitro and in vivo. To address 2ME’s low bioavailability, research led to the in silico design of sulphamoylated 2ME analogues. However, the role of oxidative stress induced in the activity exerted by sulphamoylated compounds remains elusive. In the current study, the influence of 2-Ethyl-17-oxoestra-1,3,5(10)-trien-3-yl sulphamate (ESE-one) on reactive oxygen species (ROS) induction and its effect on cell proliferation, as well as morphology, were assessed in breast tumorigenic cells (MCF-7 and MDA-MB-231). Fluorescent microscopy showed that sulphamoylated estradiol analogues induced hydrogen peroxide and superoxide anion, correlating with decreased cell growth demonstrated by spectrophotometry data. ESE-one exposure resulted in antiproliferation which was repressed by tiron (superoxide inhibitor), trolox (peroxyl inhibitor) and N,N′-dimethylthiourea (DMTU) (hydrogen peroxide inhibitor). Morphological studies demonstrated that tiron, trolox and DMTU significantly decreased the number of rounded cells and shrunken cells in MCF-7 and MDA-MB-231 cells induced by ESE-one. This in vitro study suggests that ESE-one induces growth inhibition and cell rounding by production of superoxide anion, peroxyl radical and hydrogen peroxide. Identification of these biological changes in cancer cells caused by sulphamoylated compounds hugely contributes towards improvement of anticancer strategies and the ROS-dependent cell death pathways in tumorigenic breast cells.


Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 622
Author(s):  
Maphuti T. Lebelo ◽  
Anna M. Joubert ◽  
Michelle H. Visagie

Recent findings revealed that 2-ethyl-17-oxoestra-1,3,5(10)-trien-3-yl sulfamate (ESE-one) induces antiproliferative activity and cell rounding dependent on the generation of superoxide anion, hydrogen peroxide and peroxyl radical. In the current study, the role of these reactive oxygen species was assessed in the activity exerted by ESE-one on cell cycle progression, mitochondrial membrane potential and cell death induction in breast tumorigenic cells. The influence of ESE-one was also investigated on superoxide dismutase and catalase activity. ESE-one induced a time-dependent accumulation of cells in the G1 phase and G2/M phase that is partially impaired by tiron and trolox and N,N′-dimethylthiourea suggesting that superoxide anion, hydrogen peroxide and peroxyl radical are required for these effects exerted by ESE-one. Flow cytometry data in MCF-7 cells demonstrated that tiron decreased depolarization of the membrane potential in ESE-one exposed cells, indicating that superoxide anion plays a role in the depolarization effects induced by ESE-one. Spectrophotometry data showed that ESE-one decreased catalase activity in both cell lines. This study contributes towards pertinent information regarding the effects of an in silico-designed sulfamoylated compound on antioxidant enzymes leading to aberrant quantities of specific reactive oxygen species resulting in antimitotic activity culminating in the induction of cell death in breast cancer cell lines.


2021 ◽  
Author(s):  
Qingda Wang ◽  
Zhigang Chen ◽  
Xi Zhang ◽  
Yuping Xin ◽  
Yongzhen Xia ◽  
...  

During aerobic respiration, mitochondria generate superoxide anion (O2&middot−), hydrogen peroxide (H2O2), and hydroxyl radical (HO·), and these reactive oxygen species (ROS) are detrimental to mitochondria. Mitochondrial damage is linked to a broad spectrum of pathologies such as Alzheimer's disease, hemochromatosis, and diabetes. Mitochondria contain several enzymes for rapidly removing superoxide anion and hydrogen peroxide, but how they antagonize HO· is elusive, representing a loophole in the anti-ROS system. Herein, we discovered that Rhodanese 2 (Rdl2) is critical for maintaining the functionality and integrity of mitochondria under sub-lethal ROS stress in Saccharomyces cerevisiae. Rdl2 converts stable sulfur species (thiosulfate and dialkyl polysulfide) to reactive sulfane sulfur including persulfide that protects mitochondrial DNA via scavenging HO·. Surprisingly, hydrogen sulfide (H2S) promotes HO· production through stimulating the Fenton reaction, leading to increased DNA damage. Our study may reveal an ex-ante mean for antagonizing HO·, patching the loophole of the anti-ROS system in mitochondria.


2018 ◽  
Vol 38 (5) ◽  
Author(s):  
Véronique Larosa ◽  
Claire Remacle

Reactive oxygen species (ROS) are highly reactive reduced oxygen molecules that result from aerobic metabolism. The common forms are the superoxide anion (O2∙−) and hydrogen peroxide (H2O2) and their derived forms, hydroxyl radical (HO∙) and hydroperoxyl radical (HOO∙). Their production sites in mitochondria are reviewed. Even though being highly toxic products, ROS seem important in transducing information from dysfunctional mitochondria. Evidences of signal transduction mediated by ROS in mitochondrial deficiency contexts are then presented in different organisms such as yeast, mammals or photosynthetic organisms.


2015 ◽  
Vol 1 (1) ◽  
pp. 23-27
Author(s):  
Luis Vitetta ◽  
Samantha Coulson ◽  
Anthony W Linnane

The production of intracellular reactive oxygen species and reactive nitrogen species has long been proposed as leading to the random deleterious modification of macromolecules (i.e., nucleic acids, proteins) with an associated progressive development of the age associated systemic diseases (e.g., diabetes, Parkinson’s disease) as well as contributing to the ageing process.   Superoxide anion (hydrogen peroxide) and nitric oxide (peroxynitrite) comprise regulated intracellular second messenger pro-oxidant systems, with specific sub-cellular locales of production and are essential for the normal function of the metabolome and cellular electro-physiology.  We have posited that the formation of superoxide anion and its metabolic product hydrogen peroxide, and nitric oxide, do not conditionally lead to random damage of macromolecular species such as nucleic acids or proteins.  Under normal physiological conditions their production is intrinsically regulated that is very much consistent with their second messenger purpose of function.   We further propose that the concept of an orally administered small molecule antioxidant as a therapy to abrogate free radical activity (to control oxidative stress) is a chimera.  As such we consider that free radicals are not a major overwhelming player in the development of the chronic diseases or the ageing process.        


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