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Oxidative Stress Mechanisms Caused by Ag Nanoparticles (NM300K) are Different from Those of AgNO3: Effects in the Soil Invertebrate Enchytraeus Crypticus.

Ribeiro MJ, Maria VL, Scott-Fordsmand JJ, Amorim MJ - Int J Environ Res Public Health (2015)

Bottom Line: MT increased only for AgNP.LPO, GST and GPx were for both 3 and 7 d associated with AgNO3, whereas MT and TG were associated with AgNP.These results may reflect a delay in the effects of AgNP compared to AgNO3 due to the slower release of Ag(+) ions from the AgNP, although this does not fully explain the observed differences, i.e., we can conclude that there is a nanoparticle effect.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology & CESAM, University of Aveiro, Aveiro 3810-193, Portugal. mariajribeiro@ua.pt.

ABSTRACT
The mechanisms of toxicity of Ag nanoparticles (NPs) are unclear, in particular in the terrestrial environment. In this study the effects of AgNP (AgNM300K) were assessed in terms of oxidative stress in the soil worm Enchytraeus crypticus, using a range of biochemical markers [catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST), glutathione reductase (GR), total glutathione (TG), metallothionein (MT), lipid peroxidation (LPO)]. E. crypticus were exposed during 3 and 7 days (d) to the reproduction EC20, EC50 and EC80 levels of both AgNP and AgNO3. AgNO3 induced oxidative stress earlier (3 d) than AgNP (7 d), both leading to LPO despite the activation of the anti-redox system. MT increased only for AgNP. The Correspondence Analysis showed a clear separation between AgNO3 and AgNP, with e.g. CAT being the main descriptor for AgNP for  7 d. LPO, GST and GPx were for both 3 and 7 d associated with AgNO3, whereas MT and TG were associated with AgNP. These results may reflect a delay in the effects of AgNP compared to AgNO3 due to the slower release of Ag(+) ions from the AgNP, although this does not fully explain the observed differences, i.e., we can conclude that there is a nanoparticle effect.

No MeSH data available.


Related in: MedlinePlus

Schematic representation of the redox events in the cell when exposed to AgNP and AgNO3 (variation in concentration is signalled in the arrows from low to high (EC20–50–80), top to bottom respectively) and along various time periods (0–3–7 days). Cell at time 0 (left) indicates the general set of existing reactions that occur involving the measured markers in the present study. CAT: catalase, GPx: glutathione peroxidase, GST: glutathione S-transferase, GR: glutathione reductase, TG: total glutathione, MT: metallothionein, LPO: lipid peroxidation.
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ijerph-12-09589-f003: Schematic representation of the redox events in the cell when exposed to AgNP and AgNO3 (variation in concentration is signalled in the arrows from low to high (EC20–50–80), top to bottom respectively) and along various time periods (0–3–7 days). Cell at time 0 (left) indicates the general set of existing reactions that occur involving the measured markers in the present study. CAT: catalase, GPx: glutathione peroxidase, GST: glutathione S-transferase, GR: glutathione reductase, TG: total glutathione, MT: metallothionein, LPO: lipid peroxidation.

Mentions: Figure 3 shows a schematic representation of the events. As can be seen, there are some common features between AgNP and AgNO3 in terms of activated enzymes. Variation is observed in terms of time of activation, which by itself can create a different cascade of events. Moreover, the variation can be observed in terms of the induced levels per concentration and per material. Particular differences include e.g., for AgNP the increased CAT and MT.


Oxidative Stress Mechanisms Caused by Ag Nanoparticles (NM300K) are Different from Those of AgNO3: Effects in the Soil Invertebrate Enchytraeus Crypticus.

Ribeiro MJ, Maria VL, Scott-Fordsmand JJ, Amorim MJ - Int J Environ Res Public Health (2015)

Schematic representation of the redox events in the cell when exposed to AgNP and AgNO3 (variation in concentration is signalled in the arrows from low to high (EC20–50–80), top to bottom respectively) and along various time periods (0–3–7 days). Cell at time 0 (left) indicates the general set of existing reactions that occur involving the measured markers in the present study. CAT: catalase, GPx: glutathione peroxidase, GST: glutathione S-transferase, GR: glutathione reductase, TG: total glutathione, MT: metallothionein, LPO: lipid peroxidation.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4555300&req=5

ijerph-12-09589-f003: Schematic representation of the redox events in the cell when exposed to AgNP and AgNO3 (variation in concentration is signalled in the arrows from low to high (EC20–50–80), top to bottom respectively) and along various time periods (0–3–7 days). Cell at time 0 (left) indicates the general set of existing reactions that occur involving the measured markers in the present study. CAT: catalase, GPx: glutathione peroxidase, GST: glutathione S-transferase, GR: glutathione reductase, TG: total glutathione, MT: metallothionein, LPO: lipid peroxidation.
Mentions: Figure 3 shows a schematic representation of the events. As can be seen, there are some common features between AgNP and AgNO3 in terms of activated enzymes. Variation is observed in terms of time of activation, which by itself can create a different cascade of events. Moreover, the variation can be observed in terms of the induced levels per concentration and per material. Particular differences include e.g., for AgNP the increased CAT and MT.

Bottom Line: MT increased only for AgNP.LPO, GST and GPx were for both 3 and 7 d associated with AgNO3, whereas MT and TG were associated with AgNP.These results may reflect a delay in the effects of AgNP compared to AgNO3 due to the slower release of Ag(+) ions from the AgNP, although this does not fully explain the observed differences, i.e., we can conclude that there is a nanoparticle effect.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology & CESAM, University of Aveiro, Aveiro 3810-193, Portugal. mariajribeiro@ua.pt.

ABSTRACT
The mechanisms of toxicity of Ag nanoparticles (NPs) are unclear, in particular in the terrestrial environment. In this study the effects of AgNP (AgNM300K) were assessed in terms of oxidative stress in the soil worm Enchytraeus crypticus, using a range of biochemical markers [catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST), glutathione reductase (GR), total glutathione (TG), metallothionein (MT), lipid peroxidation (LPO)]. E. crypticus were exposed during 3 and 7 days (d) to the reproduction EC20, EC50 and EC80 levels of both AgNP and AgNO3. AgNO3 induced oxidative stress earlier (3 d) than AgNP (7 d), both leading to LPO despite the activation of the anti-redox system. MT increased only for AgNP. The Correspondence Analysis showed a clear separation between AgNO3 and AgNP, with e.g. CAT being the main descriptor for AgNP for  7 d. LPO, GST and GPx were for both 3 and 7 d associated with AgNO3, whereas MT and TG were associated with AgNP. These results may reflect a delay in the effects of AgNP compared to AgNO3 due to the slower release of Ag(+) ions from the AgNP, although this does not fully explain the observed differences, i.e., we can conclude that there is a nanoparticle effect.

No MeSH data available.


Related in: MedlinePlus