China
Africa
Explore chapters and articles related to this topic
Improved metal phytoremediation through plant biotechnology
Published in A.A. Balkema, Tailings and Mine Waste 2000, 2022
E.A.H. Pilon-Smits, Y.-L. Zhu, N. Terry
The goal of this study is to enhance heavy metal tolerance and accumulation in Indian mustard by means of genetic engineering. To this aim, Indian mustard plants were engineered to overproduce the heavy metal binding peptides glutathione and phytochelatins. Glutathione (γ-Glu-Cys-Gly, GSH) plays several important roles in the defense of plants against environmental stresses, and is the precursor for phytochelatins (PCs): heavy metal-binding peptides involved in heavy metal tolerance and sequestration. Glutathione is synthesized from its constituent amino acids in two enzymatic reactions, catalyzed by γ-glutamyl-cysteine synthetase (γ-ECS) and glutathione synthetase (GS), respectively (Fig. 1). Upon exposure to heavy metals, glutathione is aggregated to phytochelatins (structure: (γ-glu-cys)ngly), by phytochelatin synthase (PS).
Strategies, Design, and Chemistry in Small Interfering RNA Delivery Vehicle Systems for Cancer Therapy
Published in Loutfy H. Madkour, Nanoparticle-Based Drug Delivery in Cancer Treatment, 2022
Glutathione is a thiol-containing tripeptide composed of glutamic acid, cysteine, and glycine and works as the main antioxidant in cells. Glutathione is distinguished from other common peptides by the unique structure of γ-glutamate, rendering glutathione inert to normal intracellular peptidase-mediated degradation [93]. The cell maintains reduced glutathione (GSH) by de novo synthesis from the three amino acids and reduction of oxidized glutathione (GSSG) by glutathione reductase, which induces the concentration of GSH to be 50–1000 times higher than that of GSSG in cells [94,95]. In this way, GSH concentrations can be distinguished between the intracellular and extracellular environment. The GSH concentration within cells is 0.5–10 mM but decreases to 10–30 μM in the blood plasma [93–95]. Thus, the disulfide linkage can be preferably cleaved in the cytoplasm or intracellular compartments while it is slowly degraded during blood circulation. The payload drug release from disulfide crosslinked nanoparticles was observed from 2 to 4 h after internalization by the cells in cultured cells [96].
Cardamine iolifolia O.E. Schulz
Published in Gary Bañuelos, Zhi-Qing Lin, Dongli Liang, Xue-bin Yin, Selenium Research for Environment and Human Health: Perspectives, Technologies and Advancements, 2019
J.J. Ming, Y.K. Yang, H.Q. Yin, Y. Kang, Y.F. Zhu, F.F. Chen, J.Q. Xiang
Selenium is one of the essential trace elements for humans and animals. It participates in the synthesis of glutathione peroxidase (GSH-Px) and has the function of scavenging free radicals and participating in anti-aging activities (Brooks et al. 2001). An increase in Se content in plant tissues can regulate the balance of enzymatic system in plants (Han et al. 2013, Shahid et al. 2018, Zhang et al. 2012), reduce the accumulation of plasma membrane peroxidation from stress, and increase the plant’s resistance to stress (Zhang et al. 2014). However, excessive Se can also cause toxic stress to plants. In the present study, the response changes of enzymatic detoxification mechanisms under selenate stress were investigated in Cardamine violifolia to provide additional information for cultivating this plant species.
A review of the toxicology of oil in vertebrates: what we have learned following the Deepwater Horizon oil spill
Published in Journal of Toxicology and Environmental Health, Part B, 2021
Ryan Takeshita, Steven J. Bursian, Kathleen M. Colegrove, Tracy K. Collier, Kristina Deak, Karen M. Dean, Sylvain De Guise, Lisa M. DiPinto, Cornelis J. Elferink, Andrew J. Esbaugh, Robert J. Griffitt, Martin Grosell, Kendal E. Harr, John P. Incardona, Richard K. Kwok, Joshua Lipton, Carys L. Mitchelmore, Jeffrey M. Morris, Edward S. Peters, Aaron P. Roberts, Teresa K. Rowles, Jennifer A. Rusiecki, Lori H. Schwacke, Cynthia R. Smith, Dana L. Wetzel, Michael H. Ziccardi, Ailsa J. Hall
Horak et al. (2017) observed hepatotoxic effects of ingested oil on laughing gulls that were orally dosed with artificially weathered DWH oil (5or 10 ml/kg bw/day) for 27 days. Hepatic total glutathione, oxidized glutathione, and reduced glutathione rose significantly, as did relative (% body weight) liver weights. Double-crested cormorants orally dosed with artificially weathered DWH oil (5 or 10 ml/kg bw/day) over a 21-day period showed dose-related elevation in total glutathione, oxidized glutathione, and reduced glutathione, while superoxide dismutase and glutathione peroxidase were significantly reduced. Further, these birds exhibited significant decreases in other liver enzyme activities and clinical chemistry endpoints indicative of diminished hepatic function (Dean et al. 2017). Livers collected at necropsy from these birds showed induction of both CYP1A4/1A5 enzymes as measured by assays for benzyloxyresorufin O-debenzylase (BROD), EROD, methoxyresorufin O-demethylase (MROD), and pentoxyresorufin O-depentylase (PROD) (Alexander et al. 2017).
Investigation of metallothionein level, reduced GSH level, MDA level, and metal content in two different tissues of freshwater mussels from Atatürk Dam Lake coast, Turkey
Published in Chemistry and Ecology, 2019
Organisms in aquatic ecosystems have developed various protective mechanisms against environmental conditions and pollution [17]. Long-term exposure to environmental pollutants may cause a variety of damage to aquatic organisms [18]. The intracellular level of reactive oxygen species (ROS) in aquatic organisms can be increased in the presence of excess metal. To protect against ROS damage, organisms have developed complex antioxidants and detoxifying mechanisms that can inhibit ROS production [15,19,20]. Several biochemical markers are used to evaluate the oxidative stress in mussels that are exposed to metals [21]. Glutathione (GSH) is a tripeptide composed of glutamic acid, cysteine, and glycine amino acids. It is an intracellular antioxidant that plays an important role in xenobiotic damage, cellular defense, detoxification of drugs, and controling the release of ROS [22,23]. Malondialdehyde (MDA) is a product of lipid hydroperoxidation and is considered an important biochemical marker for chemical damage in mussels exposed to aquatic pollutants such as metals [24–26]. Metal-binding proteins such as metallothioneins (MT) are widely used as an important biochemical marker for both oxidative stress and metal toxicity. Because of their high cysteine content, they play an active role in the scavenging of free radicals [21,27]. It is also well known that they have important roles in metal homeostasis and metal detoxification because of their high affinity to metal ions [21].
Environmental impact on the onset of hypertension-induced end-stage renal disease
Published in International Journal of Environmental Health Research, 2018
Kavitha Anbarasu, Vinod Kumar Verma, Syed Sultan Beevi, Velagala Satti Reddy
Glutathione together with its related enzymes encompasses a system that provides protection against ROS-induced damage through repair and neutralization. Further to this, glutathione has multiple physiological functions including detoxification of xenobiotics, modulation of oxidative-regulated signal transduction, regulation of cell proliferation and immune response (Pastore et al. 2003). The majority of glutathione (90–95%) exists in reduced form (GSH) and provides reducing equivalents to antioxidant enzymes, hydroxyl radicals, ROS and so on. Quantification of GSH may yield clues as to mechanisms of disease states or regulation of redox-sensitive pathways in an organism. Since GSH is susceptible to oxidation and/or degradation during sampling and analysis, sample handling and manipulation is extremely important in assessing biologically relevant levels of GSH (Tipple and Rogers 2012). Acidification of plasma as quickly as possible and storing at −70°C could minimize auto-oxidation and degradation of GSH. In this study, appropriate measure was employed during sample collection and processing to avert such events from happening through swift sample acidification, storage at −70°C and analysis within 4 days. Hence, the change observed in the level of reduced GSH in our study is the true depiction of in vivo redox events. In our study, GSH level was not significantly different in ESRD patients when compared with controls. Furthermore, no significant association was found with any of the demographic, nutritional and lifestyle variables.