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1.
Chemosphere ; 247: 125925, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32069717

RESUMO

Environmental pollutants could change the intestinal microbiota communities, while data concerning the dynamics of the intestinal microbiota in response to different environmental chemicals in amphibian are lacking. We compared the effects of Cu, Cd, Cr and NO3-N on intestinal microbiota of B. gargarizans tadpoles by using high-throughput 16S rRNA sequencing technology. Our results revealed that responses of intestinal microbiota to three metals and NO3-N showed different characteristics. At the phylum level, the most 100 OTUs were predominantly colonized by Proteobacteria, and meanwhile, expansion of Proteobacteria was observed in Cu 64 µg/L, Cd (100 µg/L and 200 µg/L) and NO3-N100 mg/L treatment groups. In addition, the abundance of Bacteroidetes significantly increased in the gut administrate with Cu, Cd, Cr, NO3-N 20 mg/L exposures, while declined abundance of Fusobacteria was observed in Cu64 µg/L Cd100 µg/L Cd200µg/L-exposed groups. At the genus level, several genera exhibited increased prevalence of abundance such as Shewanella, Azospira and Flavobacterium. The functional prediction revealed that exposures of three metals and NO3-N increase the risks of metabolic disorders and diseases. Our research could be an important step toward an assessment of the ecological risks of different chemicals to aquatic organisms using intestinal microbiota.


Assuntos
Bufonidae/microbiologia , Poluentes Ambientais/toxicidade , Microbioma Gastrointestinal/efeitos dos fármacos , Animais , Bacteroidetes/genética , Bufonidae/genética , Cádmio/farmacologia , Microbioma Gastrointestinal/fisiologia , Larva/efeitos dos fármacos , Metais/toxicidade , Nitratos/toxicidade , RNA Ribossômico 16S/genética
2.
Ecotoxicol Environ Saf ; 192: 110323, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32066008

RESUMO

The black soldier fly larvae (BSFL) have become a promising candidate for waste disposal and are an ideal feed source for animal nutrition. The uptake of heavy metals could influence the growth of BSFL, but the effects of heavy metal pressures on the gut microbiota of BSFL are largely uncharacterized. Here, we examine the influences of Cu and Cd on the growth and gut microbiota of BSFL as well as the distribution of accumulated heavy metals in the larvae and their feces. Exposure to Cu (from 100 to 800 mg/kg) and Cd (from 10 to 80 mg/kg) did not significantly inhibit the weight gain of BSFL. With elevated exposure doses, the contents of both Cu and Cd accumulated in the bodies and feces of BSFL were remarkably increased. In the BSFL feces, Cu mainly existed as residues, while Cd mainly existed as either water-soluble states (in the low-exposure groups) or residues (in the high-exposure groups). Cd was more readily enriched (47.1%-91.3%) than Cu (<30%) in vivo. More importantly, exposure to Cu and Cd remarkably altered the gut microbiota of BSFL, particularly in the phyla Proteobacteria, Firmicutes and Bacteroidetes. High exposure to the metals (i.e., Cu-800 and Cd-80 groups) substantially decreased the abundances of most of the dominant families, but significantly stimulated the enrichment of Brucellaceae, Enterobacteriaceae, Alcaligenaceae, Campylobacteraceae, and Enterococcaceae. Moreover, the bacterial diversity in the BSFL gut was significantly reduced following high exposure to the metals. These results may fill a gap in our knowledge of the effects of heavy metals on the intestinal microbiome of BSFL.


Assuntos
Dípteros/efeitos dos fármacos , Microbioma Gastrointestinal/efeitos dos fármacos , Metais Pesados/farmacologia , Animais , Bactérias/isolamento & purificação , Bioacumulação , Cádmio/farmacocinética , Cádmio/farmacologia , Cobre/farmacocinética , Cobre/farmacologia , Dípteros/crescimento & desenvolvimento , Dípteros/metabolismo , Dípteros/microbiologia , Fezes/química , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Larva/metabolismo , Larva/microbiologia , Metais Pesados/farmacocinética , Eliminação de Resíduos
3.
Chemosphere ; 247: 125958, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32069726

RESUMO

Widespread contamination of agricultural soil with toxic metals such as cadmium (Cd) is a major threat to crop production and human health. Metallochaperones are a unique class of proteins that play pivotal roles in detoxifying metallic ions inside cells. In this study, we investigated the biological function of an uncharacterized metallochaperone termed OsHIPP29 in rice plants and showed that OsHIPP29 resides in the plasma membrane and nucleus and detoxifies excess Cd and Zn. OsHIPP29 was primarily expressed in shoots during the vegetative stage and in leaf sheath and spikelet at the flowering stage. It can be differentially induced by excess Cd, Zn, Cu, Fe and Mn. To identify the function of OsHIPP29 in mediating rice response to Cd stress, we examined a pair of OsHIPP29 mutants, RNAi lines and transgenic rice overexpressing OsHIPP29 (OX) under Cd stress. Both mutant and RNAi lines are sensitive to Cd in growth as reflected in decreased plant height and dry biomass. In contrast, the OX lines showed better growth under Cd exposure. Consistent with the phenotype, the OX lines accumulated less Cd in both root and shoot tissues, whereas OsHIPP29 knockout led to higher accumulation of Cd. These results point out that expression of OsHIPP29 is able to contribute to Cd detoxification by reducing Cd accumulation in rice plants. Our work highlights the significance of OsHIPP29-mediated reduced Cd in rice plants, with important implications for further developing genotypes that will minimize Cd accumulation in rice and environmental risks to human health.


Assuntos
Agricultura/métodos , Cádmio/farmacologia , Oryza/metabolismo , Poluentes do Solo/metabolismo , Biomassa , Cádmio/análise , Cádmio/metabolismo , Genótipo , Humanos , Chaperonas Moleculares/metabolismo , Oryza/efeitos dos fármacos , Oryza/genética , Folhas de Planta/metabolismo , Poluentes do Solo/análise
4.
Chemosphere ; 240: 124846, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31550594

RESUMO

Cadmium (Cd) precipitation and dissolution in pore water is associated with dissolved organic carbon (DOC)-induced reduction-oxidation of sulfur (S) under waterlogging and is vital for controlling the bioavailability in paddy soil. A 120-day soil incubation experiment, including application of sulfur (S, 30 mg kg-1) and wheat straw (W, 1.0%) alone or in combination (W + S) into Cd-contaminated paddy soil under waterlogging, was conducted to investigate the dynamic of dissolved Cd and its relationship with DOC, S2-, Fe2+, pH, Eh and pe + pH in soil pore water. The results showed that the lowest dissolved Cd concentration was observed in the W + S-treated soil pore water among all treatments when the soil Eh remained at lower values during the period of 15-60 days of incubation, which could be attributed to CdS precipitation and/or co-precipitation of Cd absorbed by FeS2 because of the reduction in sulfur. The application of S resulted in a Cd rebound in the pore water irrespective of W addition when the Eh began to increase from its lowest values during the period of 45-75 days of incubation, and SOB genera were observed in the S added soil. This could be attributed to re-dissolution of the precipitated Cd in soils under the SOB-driven oxidation of sulfide such as CdS and FeS2. In conclusion, DOC-driven reduction-oxidation of sulfur controls Cd dissolution in the pore water of Cd-contaminated paddy soil under waterlogging conditions. Further studies are required to investigate the interaction of sulfur and SOM-induced DOC on Cd bioavailability in rice-planted paddy soils.


Assuntos
Cádmio/uso terapêutico , Poluição Ambiental/efeitos adversos , Poluentes do Solo/química , Enxofre/uso terapêutico , Cádmio/farmacologia , Enxofre/farmacologia , Água
5.
World J Microbiol Biotechnol ; 35(12): 188, 2019 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-31741120

RESUMO

Soil contamination due to cadmium (Cd) is a ubiquitous environmental problem for which inexpensive remediation alternatives are required. Phytoaccumulation, the use of plants to extract and accumulate heavy metals from the contaminated environment, is such an alternative. In this study, we aimed at establishing effective plant-bacteria interplay between Brachiaria mutica and Cd-resistant endophytic bacteria eventually leading to improved phytoremediation. B. mutica was grown in a Cd-contaminated soil and inoculated with three Cd-tolerant endophytic bacteria individually as well as in combination. Plant physiological parameters, biomass production, bacterial colonization, and Cd-accumulation were observed at four different Cd exposures, i.e., 100, 200, 400 and 1000 mg kg-1 of soil. The combined application of endophytic bacteria was more effective as compared to their individual applications at all concentrations. Nevertheless, highest performance of consortium was seen at 100 mg Cd kg-1 of soil, i.e., root length was enhanced by 46%, shoot length by 62%, chlorophyll content by 40%, and dry biomass by 64%; which was reduced with the increase in Cd concentration. The bacterial population was highest in the root interior followed by rhizosphere and shoot interior. Concomitantly, plants inoculated with bacterial consortium displayed more Cd-accumulation in the roots (95%), shoots (55%), and leaves (44%). Higher values of BCFroot (> 1), and lower values for BCFshoot and TF (< 1) indicates capability of B. mutica to accumulate high amounts of Cd in the roots as compared to the aerial parts. The present study concludes that plant-endophyte interplay could be a sustainable and effective strategy for Cd removal from the contaminated soils.


Assuntos
Brachiaria/metabolismo , Brachiaria/microbiologia , Cádmio/metabolismo , Endófitos/fisiologia , Bactérias/metabolismo , Biodegradação Ambiental , Biomassa , Brachiaria/efeitos dos fármacos , Brachiaria/crescimento & desenvolvimento , Cádmio/análise , Cádmio/farmacologia , Produtos Agrícolas , Metais Pesados , Folhas de Planta/metabolismo , Raízes de Plantas/microbiologia , Brotos de Planta/metabolismo , Brotos de Planta/microbiologia , Rizosfera , Solo/química , Microbiologia do Solo , Poluentes do Solo
6.
Environ Sci Pollut Res Int ; 26(27): 27816-27822, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31342354

RESUMO

The bioavailability of metals can be influenced not only by soil properties but also by other species living at polluted sites. However, in laboratory experiments, usually only one test species is used to estimate bioavailability. In this study, a two-species approach was applied to assess the impact of the earthworm Lumbricus rubellus on the bioavailability of cadmium and lead to the springtail Folsomia candida using natural soils from a gradient of metal pollution. Earthworms were kept in half of the soil replicates for 4 weeks. Subsequently, the uptake and elimination kinetics of cadmium and lead in F. candida exposed for 21 days to the soils was determined. Earthworm activity affected soil properties but did not significantly affect metal uptake rate constants in springtails. The slightly higher uptake due to the presence of earthworms, which was consistent in all tested soils and for both metals, suggests that further research is needed on the role of species interactions in affecting metal bioavailability in soil.


Assuntos
Ampicilina/análogos & derivados , Cádmio/farmacologia , Chumbo/farmacologia , Oligoquetos/efeitos dos fármacos , Ampicilina/química , Animais , Artrópodes/química , Artrópodes/efeitos dos fármacos , Disponibilidade Biológica , Cádmio/química , Poluição Ambiental , Cinética , Chumbo/química , Solo
7.
J Appl Microbiol ; 127(3): 713-723, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31211899

RESUMO

AIM: Study is focused on the influence of cadmium addition to growth media on production yield, their size and molecular mass of exopolysaccharides (EPS) synthesized by three rhizosphere bacteria strains. Inhibition of bacterial growth by increasing concentrations of Cd2+ was also analysed. METHODS AND RESULTS: The highest impact of Cd2+ was noticed on the growth of Arthrobacter sp. and Rhizobium metallidurans. Chryseobacterium sp. and Arthrobacter sp. produced significantly lower when compared to R. metallidurans amounts of EPS under the influence of Cd2+ . In all bacterial strains both size and molecular mass decreased after addition of Cd2+ to growth media. It causes a change in EPS conformation to more planar, which minimizes the volume of liquid in the interglobular space next to the bacterial wall. Results confirmed strong effect of Cd2+ on the structure and synthesis of bacterial EPS what can be a key factor in the interactions between rhizosphere bacteria and host plants in heavy metal polluted soils. CONCLUSION: This work proves that due to the presence of cadmium ions, the size and conformation of EPS produced by selected bacterial strains is changed to minimize their impact on cell. We suggest that shifting in EPS conformation from bigger globular particles to the smaller planar ones could be one of the probable mechanisms of Cd resistance in metallotolerant bacteria, and finally explain increased efficiency of heavy metal phytoextraction by EPS-producing plant growth-promoting micro-organisms. SIGNIFICANCE AND IMPACT OF THE STUDY: One of the most promising remediation technique for Cd-contaminated areas is the phytoremediation in which rhizosphere bacteria play an important role by protecting plants' roots from toxic condition thus enhancing efficiency of intake. EPS secretion by bacteria is one of the most common mechanisms to protect the cell from impact of unpleasant environmental conditions, for example, toxicity of heavy metals like Cd.


Assuntos
Bactérias/efeitos dos fármacos , Cádmio/farmacologia , Polissacarídeos Bacterianos/biossíntese , Poluentes do Solo/farmacologia , Arthrobacter/efeitos dos fármacos , Arthrobacter/metabolismo , Biodegradação Ambiental , Flavobacteriaceae/efeitos dos fármacos , Flavobacteriaceae/metabolismo , Polissacarídeos Bacterianos/química , Rhizobium/efeitos dos fármacos , Rizosfera
8.
Int J Mol Sci ; 20(10)2019 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-31091675

RESUMO

Cadmium (Cd2+) in the environment is a significant health hazard. Chronic low Cd2+ exposure mainly results from food and tobacco smoking and causes kidney damage, predominantly in the proximal tubule. Blood Cd2+ binds to thiol-containing high (e.g., albumin, transferrin) and low molecular weight proteins (e.g., the high-affinity metal-binding protein metallothionein, ß2-microglobulin, α1-microglobulin and lipocalin-2). These plasma proteins reach the glomerular filtrate and are endocytosed at the proximal tubule via the multiligand receptor complex megalin:cubilin. The current dogma of chronic Cd2+ nephrotoxicity claims that Cd2+-metallothionein endocytosed via megalin:cubilin causes renal damage. However, a thorough study of the literature strongly argues for revision of this model for various reasons, mainly: (i) It relied on studies with unusually high Cd2+-metallothionein concentrations; (ii) the KD of megalin for metallothionein is ~105-times higher than (Cd2+)-metallothionein plasma concentrations. Here we investigated the uptake and toxicity of ultrafiltrated Cd2+-binding protein ligands that are endocytosed via megalin:cubilin in the proximal tubule. Metallothionein, ß2-microglobulin, α1-microglobulin, lipocalin-2, albumin and transferrin were investigated, both as apo- and Cd2+-protein complexes, in a rat proximal tubule cell line (WKPT-0293 Cl.2) expressing megalin:cubilin at low passage, but is lost at high passage. Uptake was determined by fluorescence microscopy and toxicity by MTT cell viability assay. Apo-proteins in low and high passage cells as well as Cd2+-protein complexes in megalin:cubilin deficient high passage cells did not affect cell viability. The data prove Cd2+-metallothionein is not toxic, even at >100-fold physiological metallothionein concentrations in the primary filtrate. Rather, Cd2+-ß2-microglobulin, Cd2+-albumin and Cd2+-lipocalin-2 at concentrations present in the primary filtrate are taken up by low passage proximal tubule cells and cause toxicity. They are therefore likely candidates of Cd2+-protein complexes damaging the proximal tubule via megalin:cubilin at concentrations found in the ultrafiltrate.


Assuntos
Albuminas/metabolismo , Cádmio/toxicidade , Túbulos Renais Proximais/efeitos dos fármacos , Lipocalina-2/metabolismo , Microglobulina beta-2/metabolismo , Animais , Cádmio/farmacologia , Intoxicação por Cádmio , Linhagem Celular , Túbulos Renais Proximais/citologia , Proteína-2 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Metalotioneína/metabolismo , Ligação Proteica , Ratos , Receptores de Superfície Celular/metabolismo
9.
Plant Mol Biol ; 100(4-5): 561-569, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31053987

RESUMO

KEY MESSAGE: Plant defensin AtPDF2.6 is not secreted to the apoplast and localized in cytoplasm. AtPDF2.6 is mainly expressed in root vascular bundles of xylem parenchyma cell, and significantly induced by Cd stress. AtPDF2.6 detoxicate cytoplasmic Cd via chelation, thus enhanced Cd tolerance in Arabidopsis. In order to detoxify the heavy metal cadmium (Cd), plants have evolved several mechanisms, among which chelation represents the major Cd-detoxification mechanism. In this study, we aimed to identify a new defensin protein involved in cytoplasmic Cd detoxification by using plant molecular genetics and physiological methods. The results of bioinformatic analysis showed that the Arabidopsis thaliana defensin gene AtPDF2.6 has a signal peptide that may mediate its secretion to the cell wall. Subcellular localization analysis revealed that AtPDF2.6 is localized to the cytoplasm and is not secreted to the apoplast, whereas histochemical analysis indicated that AtPDF2.6 is mainly expressed in the root xylem parenchyma cells and that its expression is significantly induced by Cd. An in vitro Cd-binding assay revealed that AtPDF2.6 has Cd-chelating activity. Heterologous overexpression of AtPDF2.6 increased Cd tolerance in Escherichia coli and yeast, and AtPDF2.6 overexpression significantly enhanced Cd tolerance in Arabidopsis, whereas functional disruption of AtPDF2.6 decreased Cd tolerance. These data suggest that AtPDF2.6 detoxifies cytoplasmic Cd via chelation and thereby enhances Cd tolerance in Arabidopsis. Our findings accordingly challenge the commonly accepted view of defensins as secreted proteins.


Assuntos
Proteínas de Arabidopsis/fisiologia , Arabidopsis/metabolismo , Cádmio/metabolismo , Proteínas de Homeodomínio/fisiologia , Poluentes do Solo/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Cádmio/farmacologia , Citoplasma/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Raízes de Plantas/metabolismo , Estresse Fisiológico , Regulação para Cima , Xilema/metabolismo
10.
Toxicol Ind Health ; 35(4): 277-293, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30983556

RESUMO

The aim of the study was to investigate the effect of physical training on bone parameters of rats exposed to alcohol (Al) and/or cadmium (Cd). Young female rats were divided into one control group and six groups exposed to Cd and/or Al. Al (36% calories of diet) and Cd (20 mg Cd/kg feed) were administered with liquid diet. Half of the rats from the treated groups were subjected to treadmill training (20 m/min for 0.5 h, 4 days a week). The experiment was carried out for 5 months. Al decreased the concentration of calcium (Ca) and iron (Fe) in the femur, whereas Cd and Cd + Al intake reduced the contents of Ca, Fe and zinc. Al and/or Cd caused an increase in both C-terminal telopeptide of type I collagen (CTX1; bone resorption marker) and osteocalcin (OC; formation indicator) and enhanced the degree of porosity and flexural strength of the femur. Al partially prevented the loss of Fe from the bone caused by Cd, but intensified the inhibition of growth of body weight in comparison with separate exposure to Cd. In rats co-exposed to Cd + Al, the levels of CTX1 were greater compared with those treated with Al or Cd separately, and the density was less than that in rats exposed to Al separately. The training caused increases of magnesium and Ca contents, decreases in CTX1, as well as increases in OC and bone density, decreasing their porosity. The effect of training on the bone status, however, was limited (especially in rats co-exposed to Cd and Al) because of the increase in their mineralization, stimulated by exercises, was insufficient in relation to collagen production intensity. In conclusion, training had favourable effects on some bone parameters, but did not compensate for the negative effects of Al and/or Cd exposure on the poor mineralization and histopathological and morphological changes in the femur.


Assuntos
Densidade Óssea/efeitos dos fármacos , Remodelação Óssea/efeitos dos fármacos , Cádmio/farmacologia , Etanol/farmacologia , Condicionamento Físico Animal/fisiologia , Animais , Peso Corporal/efeitos dos fármacos , Reabsorção Óssea , Cálcio/metabolismo , Colágeno Tipo I/metabolismo , Feminino , Fêmur/efeitos dos fármacos , Ferro/metabolismo , Magnésio/metabolismo , Distribuição Aleatória , Ratos , Ratos Wistar , Zinco/metabolismo
11.
Chemosphere ; 224: 884-891, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30986894

RESUMO

Comparative accumulation of cadmium (Cd) and nickel (Ni) and the consequences for the metabolism of common weed dandelion (triploid ones of Taraxacum sect. Taraxacum) were studied here for the first time. Cd accumulated more in both shoots and roots (489 and 2486 µg/g DW) than Ni (165 and 858 µg/g DW) after 14 days of exposure and only root Ni content did not increase between 7 and 14 days of exposure. Surprisingly, though Ni was less accumulated than Cd, it had more negative impact on basic physiology (root dry biomass, shoot water content and chlorophyll amount). Ni also evoked more extensive depression of mineral nutrients (K, Ca, Mg, and Mn) in the shoots than Cd while root potassium content was elevated by both metals. Ni suppressed accumulation of total thiols but anatomical changes and ROS formation (detected by fluorescence microscopy of total ROS and lipid peroxidation) were induced more by Cd. Total soluble phenols, major (caftaric and cichoric) and minor (chlorogenic and caffeic) phenolic acids were elevated by both metals and rather increased with prolonged exposure in the shoots (14 versus 7 days). On the contrary, typically depletion of these metabolites was found in the roots after prolonged exposure to Ni, but not to Cd. Data showed distinct toxicity of Cd and Ni in dandelion. More expressive tolerance of dandelion to Cd than to Ni indicates its potential use for the remediation of Cd-contaminated environment.


Assuntos
Cádmio/metabolismo , Níquel/metabolismo , Taraxacum/metabolismo , Biodegradação Ambiental , Cádmio/farmacologia , Cádmio/toxicidade , Hidroxibenzoatos , Peroxidação de Lipídeos , Níquel/farmacologia , Níquel/toxicidade , Nutrientes , Estresse Oxidativo/efeitos dos fármacos , Fenóis/metabolismo , Raízes de Plantas/metabolismo , Brotos de Planta/metabolismo , Espécies Reativas de Oxigênio
12.
Int J Biol Macromol ; 133: 945-956, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31005690

RESUMO

Abiotic stress induced by heavy metals retards the growth and development of plants. Therefore, it is essential to have an insight into the potential toxic effects of heavy metals. The present article investigates the effect of zinc and cadmium on the structure and function of garlic phytocystatin (GPhyCys). The cysteine proteinase inhibitory assay showed a reduction in the inhibitory activity upon binding with zinc and cadmium. UV-vis absorption spectroscopy revealed the complex formation of zinc and cadmium with garlic phytocystatin. Fluorescence quenching experiment confirmed the quenching of fluorophores upon binding of zinc and cadmium. Synchronous and 3-dimensional fluorescence spectroscopy suggest the alteration in the microenvironment around aromatic residues of garlic phytocystatin upon binding with the above metals. Circular dichroism showed a reduction in the alpha-helical content of native garlic phytocystatin. Scanning electron micrographs showed the morphological changes in the native garlic phytocystatin upon addition of zinc and cadmium. The observations confirmed the alteration in structure and conformation of garlic phytocystatin upon interaction with zinc and cadmium. It can be safely concluded that the high concentration of zinc and cadmium can alter the functioning of cysteine proteinase present in garlic and affects the growth and development of plants.


Assuntos
Cádmio/metabolismo , Cádmio/farmacologia , Cistatinas/metabolismo , Alho/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Zinco/metabolismo , Zinco/farmacologia , Cistatinas/química , Alho/efeitos dos fármacos , Alho/fisiologia , Ligação Proteica , Conformação Proteica/efeitos dos fármacos
13.
Plant Physiol Biochem ; 139: 620-629, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31035173

RESUMO

Being static, plants are frequently exposed to various essential and non-essential heavy metals from the surroundings. This exposure results in considerable ROS generation leading to oxidative stress, the primary response of the plants under heavy metal stress. Withania somnifera is a reputed Indian medicinal plant in Ayurveda, having various pharmacological activities due to the presence of withanolides. The present study deals with the understanding endurance of oxidative stress caused by heavy metal exposure and its management through antioxidant partners in synchronization with secondary metabolites in W. somnifera. The quantitative assessment of enzymatic/non-enzymatic antioxidants revealed significant participation of ascorbate-glutathione-α-tocopherol triad in ROS management. Higher activities of glutathione reductase (GR), monodehydroascorbate reductase (MDHAR) and dehydroascorbate reductase (DHAR) resulted in glutathione and ascorbate accumulation. In addition, superoxide dismutase (SOD), glutathione peroxidase (GPX) and peroxidase (POD) were contributed considerably in ROS homeostasis maintenance. In-situ localization and assays related to ROS generation/scavenging revealed key management of ROS status under Cd stress. Higher antioxidative and reducing power activity attributed to the tolerance capability to the plant. Increased expression of withanolide biosynthetic pathway genes such as WsHMGR, WsDXS, WsDXR and WsCAS correlated with enhanced withanolides. The present study indicated the crucial role of the ascorbate-glutathione-α-tocopherol triad in co-ordination with withanolide biosynthesis in affording the oxidative stress, possibly through a cross-talk between the antioxidant machinery and secondary metabolite biosynthesis. The knowledge may be useful in providing the guidelines for developing abiotic stress resistance in plants using conventional and molecular approaches.


Assuntos
Ácido Ascórbico/metabolismo , Cádmio/farmacologia , Glutationa/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Withania/efeitos dos fármacos , Withania/metabolismo , alfa-Tocoferol/metabolismo , Antioxidantes/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Redutase/metabolismo , NADH NADPH Oxirredutases/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Metabolismo Secundário/efeitos dos fármacos , Superóxido Dismutase/metabolismo
14.
Ann Clin Lab Sci ; 49(2): 193-203, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31028064

RESUMO

Our aims were to evaluate N-acetyl-beta-D-glucosaminidase (NAG) activity in an experimental rat model of chronic exposure to cadmium and its response to ozone therapy. Forty male Wistar rats were divided into five groups: control, cadmium only, cadmium and oxygen, cadmium and ozone, and ozone only. Cadmium concentration (ASA method) and NAG activity (by the Maruhn method) were determined in the supernatants of the kidneys, liver, and pancreas. The histopathological alterations were evaluated in tissue sections.The highest concentration of cadmium and NAG activity was observed in rats intoxicated with cadmium. Ozone therapy led to a decrease in cadmium accumulation in the kidneys and liver. An examination of renal, hepatic and pancreatic tissues revealed severe histopathological lesions in Cadmium group (Cd) treated animals. The histopathological changes in animals treated with ozone were similar, but with slightly decreased intensity. Positive correlations between histochemical lesions, NAG activity and cadmium concentration in the study groups were observed. It has been shown that chronic cadmium intoxication has cytotoxic activity in the kidneys, liver, and pancreas, causing an increase in NAG activity. Ozone therapy significantly reduces NAG activity and the severity of histopathological lesions in the kidneys and liver, confirming its beneficial effects.


Assuntos
Acetilglucosaminidase/metabolismo , Cádmio/farmacologia , Ozônio/toxicidade , Animais , Rim/efeitos dos fármacos , Rim/patologia , Fígado/efeitos dos fármacos , Fígado/patologia , Masculino , Pâncreas/efeitos dos fármacos , Pâncreas/patologia , Ratos Wistar , Distribuição Tecidual/efeitos dos fármacos
15.
Artigo em Inglês | MEDLINE | ID: mdl-31028933

RESUMO

Given the absorbability of nZnO and its inevitable coexistence with trace metals such as Cd and Pb in coastal environment, nZnO can adsorb these pollutants thereby affecting their distribution in different media of marine ecosystem. The marine copepod Tigriopus japonicus was applied in the present study to investigate the combined effect of nZnO and Cd or Pb on mortality and reproduction in marine organisms. For acute exposure, presence of 1.0 mg/L nZnO increased the toxicity of both Cd and Pb, as their LC50 decreased from 5.9 and 75.4 mg/L to 3.95 and 48.0 mg/L, respectively. For 21 d chronic exposure, the reproduction of the copepod was influenced by Cd and Pb at environmental relevant concentrations, and the interaction between nZnO and Cd or Pb appeared to be antagonistic. The waterborne Cd and Pb concentration was affected by nZnO for neither acute nor chronic exposure, indicating no adsorption of these two metals to nZnO at relative low concentration. The overall findings of this study suggested the binary exposure to nZnO/Cd or nZnO/Pb might have potential different toxic mechanisms between acute and chronic exposure.


Assuntos
Copépodes/efeitos dos fármacos , Testes de Toxicidade Aguda , Poluentes Químicos da Água/toxicidade , Animais , Organismos Aquáticos , Cádmio/farmacologia , Dose Letal Mediana , Reprodução/efeitos dos fármacos , Óxido de Zinco/toxicidade
16.
Plant Physiol Biochem ; 139: 558-568, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31029029

RESUMO

The interplaying defensive roles of silicon (Si) and proline (Pro) in improving growth and yield attributes, physio-biochemical attributes, and antioxidant defense systems in common bean plant grown under saline (NaCl) and/or cadmium (Cd2+) stress were assessed. Seed were sown in plastic pots filled with sand-free ions as a growing medium that watered with a ½-strength Hoagland's nutrient solution. Twenty five days after planting, pots were split into 4 plots; control (no stress), 150 mM NaCl (salt stress), 1.5 mM Cd2+ in CdCl2 (Cd2+ stress), and 100 mM NaCl + 1.0 mM Cd2+ (salt + Cd2+ stress). Four treatments; foliar spray with distilled water, 6 mM Si (in K2SiO3.nH2O) solution, 6 mM Pro solution, and a combination of Si and Pro were allotted under each of the 4 plots. The experimental layout was a completely randomized design with 15 replicates. Compared to control, NaCl or Cd2+ stress significantly (P ≤ 0.05) reduced plant growth and yield attributes, leaf contents of chlorophylls, carotenoids, N, P, and K+, K+/Na+ ratio, RWC, MSI, Pn and Tr, while elevated significantly leaf EL, leaf contents of proline, soluble sugar, glutathione, MDA, Na+, and root, leaf and pod contents of Cd2+. The activities of antioxidant enzymes were also raised. The combined stress (NaCl + Cd2+) was more influential. Addition of Si and/or Pro for common bean plants under NaCl and/or Cd2+ stress significantly enhanced all investigated attributes of physiology, morphology, and biochemistry, and further increased the activities of antioxidant enzymes. Supplementation of Si + Pro was the best treatment having more positive influential, especially reducing the Cd2+ content in Phaseolus vulgaris pods to the limits (0.27 mg kg-1) for legumes. Therefore, this combined treatment is recommended to use for alleviating environmental stress effects, especially salinity and Cd2+ for common bean production.


Assuntos
Cádmio/farmacologia , Phaseolus/efeitos dos fármacos , Phaseolus/metabolismo , Prolina/farmacologia , Silício/farmacologia , Antioxidantes/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Cloreto de Sódio/farmacologia
17.
Chemosphere ; 224: 111-119, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30818189

RESUMO

In this investigation, we assessed the effects of Cu and/or Cd excess on physiological and metabolic processes of the widespread seagrass Zostera marina. Adult were exposed to low Cd and Cu (0.89 and 0.8 µM, respectively) and high Cd and Cu (8.9 and 2.4 µM, respectively) for 6 d at: Control conditions; low Cu; high Cu; low Cd; high Cd; low Cd and low Cu; and high Cd and high Cu. Photosynthetic performance decreased under single and combined treatments, although effects were more negative under Cu than Cd. Total Cu accumulation was higher than Cd, under single and combined treatments; however, their accumulation was generally lower when applied together, suggesting competition among them. Levels of glutathione (GSH) and phytochelatins (PCs) followed patterns similar to metal accumulation, with up to PC5, displaying adaptations in tolerance. A metallothionein (MET) gene showed upregulation only at high Cd, low Cu, and high Cu. The expression of the enzymes glutathione reductase (GR), ascorbate peroxidase (APX), and catalase (CAT) was greatest at high Cu, and at high Cd and Cu together; the highest expression was under Cu, alone and combined. Both metals induced upregulation of the DNA methyltransferases CMT3 and DRM2, with the highest expression at single Cu. The DNA demethylation ROS1 was overexpressed in treatments containing high Cu, suggesting epigenetic modifications. The results show that under copper and/or cadmium, Z. marina was still biologically viable; certainly based, at least in part, on the induction of metal chelators, antioxidant defences and methylation/demethylation pathways of gene regulation.


Assuntos
Antioxidantes/metabolismo , Cádmio/farmacologia , Cobre/farmacologia , Metilação de DNA/efeitos dos fármacos , Metais/metabolismo , Fitoquelatinas/metabolismo , Zosteraceae/efeitos dos fármacos , Redes Reguladoras de Genes , Zosteraceae/enzimologia , Zosteraceae/metabolismo
18.
J Environ Manage ; 239: 287-298, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30913479

RESUMO

Comparative impact of CO2 application and endophyte inoculation was investigated on the growth, rhizosphere characteristics, and cadmium (Cd) absorption of two ecotypes of Sedum alfredii Hance in response to Cd stress under hydroponic or rhizo-box culture conditions. The results showed that both CO2 application and endophyte inoculation significantly (P < 0.05) promoted plant growth (fresh weight and dry weight), improved root morphological properties (SRL, SRA, SRV, ARD and RTN) and exudation (pH, TOC, TN, soluble sugar and organic acids), changed Cd uptake and distribution of both ecotypes of S. alfredii. Meanwhile soil total and DTPA extractable Cd in rhizo-box decreased by biofortification treatments. Superposition biofortification exhibits utmost improvement for the above mentioned parameters, and has potential for enhancing phytoremediation efficiency of hyperaccumulator and sustaining regular growth of non-hyperaccumulator in Cd contaminated soils.


Assuntos
Cádmio/farmacologia , Dióxido de Carbono/metabolismo , Endófitos/metabolismo , Rizosfera , Sedum/metabolismo , Endófitos/efeitos dos fármacos , Hidroponia , Raízes de Plantas/química , Sedum/química , Sedum/efeitos dos fármacos , Solo/química
19.
Environ Sci Pollut Res Int ; 26(13): 13235-13245, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30900120

RESUMO

Glutathione (GSH) is involved in not only plant developmental processes but also plant responses to abiotic stresses. A hydroponic experiment was performed to explore the protective roles of exogenous GSH in mitigating cadmium (Cd) stress in Brassica campestris L. seedlings by analyzing the morphological and physiological parameters. Results showed that Cd caused severe growth inhibition and Cd accumulation. However, application of GSH significantly mitigated toxic symptoms induced by Cd, including the improvement of the photosynthesis-, plant growth-, and root morphology-related parameters in seedlings under Cd stress. These responses were associated with a striking increase in activities of representative antioxidative enzymes and contents of corresponding non-enzymatic antioxidants. In vivo imaging of O2.- and H2O2, and the detection of lipid peroxidation further demonstrated that increased ability by GSH for Brassica campestris L. seedlings to endure Cd stress was consistent with a striking elevation of ratios of reduced to oxidized glutathione (GSH/GSSG) and ascorbic acid to dehydroascorbic acid (AsA/DHA). Additionally, GSH application increased Cd retained in roots, thus significantly decreased its translocation from root to shoot, ultimately decreased Cd accumulation in shoots. Taken together, our results proved evidence for GSH in ameliorating Cd toxicity via reducing Cd accumulation in shoots and increasing oxidation resistance. Accordingly, application of GSH could be a high-efficiency and promising strategy to decrease Cd concentration in edible parts of Brassica campestris L. in agricultural production.


Assuntos
Antioxidantes/farmacologia , Ácido Ascórbico/química , Brassica/crescimento & desenvolvimento , Cádmio/farmacologia , Glutationa/metabolismo , Peróxido de Hidrogênio/química , Plântula/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Cádmio/química , Peroxidação de Lipídeos , Oxirredução
20.
Ecotoxicol Environ Saf ; 175: 110-117, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-30897409

RESUMO

Cadmium (Cd) is a known human carcinogen. Previous studies have demonstrated that Cd exposure promoted migration and invasion of breast cancer cells. However, the molecular mechanisms underlying this process have not yet been clearly addressed. The purpose of this study was to investigate whether TG-interacting factor (TGIF) was involved in long-term Cd exposure-induced migration and invasion of breast cancer cells. Human breast cancer cells were continuously exposed to Cd for eight weeks. Western blot and qRT-PCR assays were performed to measure the expression of protein and mRNA. Migration and invasion assays were performed to assess the migratory and invasive ability of human breast cancer cells. Our data indicated that long-term Cd exposure obviously increased the expression of TGIF protein and mRNA in human breast cancer cells. Long-term Cd exposure increased the ability of migration and invasion of human breast cancer cells, which could be inhibited by transfection of small interfering RNA (siRNA) targeting TGIF. We also observed that the long-term Cd exposure-induced up-regulation of MMP2 mRNA expression was modulated by TGIF. In conclusion, our findings suggested that TGIF/MMP2 signaling axis might be involved in malignant progression stimulated by long-term Cd exposure in human breast cancer.


Assuntos
Neoplasias da Mama/patologia , Cádmio/efeitos adversos , Exposição Ambiental/efeitos adversos , Proteínas de Homeodomínio/metabolismo , Proteínas Repressoras/metabolismo , Neoplasias da Mama/metabolismo , Cádmio/farmacologia , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Metaloproteinase 2 da Matriz/metabolismo , RNA Mensageiro/metabolismo , Transdução de Sinais , Regulação para Cima
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