Selenium and mercury in organisms: Interactions and mechanisms

2008 ◽  
Vol 16 (NA) ◽  
pp. 71-92 ◽  
Author(s):  
Dan-Yi Yang ◽  
Yu-Wei Chen ◽  
John M. Gunn ◽  
Nelson Belzile

This paper reviews the growing literature dealing with the antagonistic effect of selenium (Se) compounds on the toxicity of mercury (Hg) compounds in higher animals and organisms present in the aquatic environment. It covers both laboratory and field studies and summarizes the possible mechanisms that explain the protective action of Se compounds on mercuric mercury (Hg2+) and methylmercury (CH3Hg+) toxicity. The review is subdivided according to the molecular form of Hg and the organisms in which the antagonism has been studied. Many authors suggest that the protective effect of selenite on the toxicity of Hg2+in mammals is due mainly to the in vivo formation of mercuric selenide (HgSe), a stable and biologically inert complex. The detection of HgSe has been confirmed in several studies in support of this mechanism. Possible mechanisms that may be involved in the antagonism between Se compounds and CH3Hg+in mammals and aquatic organisms are also presented. The possibility of adding Se compounds to contaminated lakes and reservoirs as a remediation technique to limit the bioaccumulation of Hg2+and CH3Hg+is critically discussed.

2018 ◽  
Vol 68 (12) ◽  
pp. 2747-2751
Author(s):  
Marioara Nicula ◽  
Nicolae Pacala ◽  
Lavinia Stef ◽  
Ioan Pet ◽  
Dorel Dronca ◽  
...  

Living organisms take nutrients from the environment, and together with them, substances with toxic potential � such as heavy metals. Lead is one common metal pollutant especially in aquatic environment, from where the fish can be intoxicated very easily. Bioavailability, distribution, toxic action, synergistic and antagonistic effects are characteristics which can alter the fish health. Our experimental study followed the effects of lead overload in water on iron distribution, in different tissues sample Carassius gibelio Bloch fish. We performed the experiment in four different fish groups: control C; lead � Pb (administration of lead in water 0.075mg/mL of water, as Pb(NO3)2 x � H2O); lead (the same dose) and 2% of freeze-dry garlic incorporated into fishes� food � Pb+garlic; lead (the same dose) and 2% chlorella incorporated into fishes� food � Pb+chlorella, for 21 consecutive days. The iron concentration was analysed with AAS (Atomic Absorption Spectroscopy) from gills, muscle, skin (and scales), intestine, liver, heart, brain, ovary, testicles, and kidney. The obtained data presented a significantly decrease of iron content in all tested tissue samples that demonstrated, alteration of iron homeostasis, explained by a strong antagonistic effect of lead on iron. Our experiment showed that biologic active principles from garlic and chlorella act like natural protectors, and potentiate the iron deficiency even in the case of lead overload in aquatic environment, for fish.


2017 ◽  
Vol 68 (9) ◽  
pp. 2006-2009
Author(s):  
Marioara Nicula ◽  
Nicolae Pacala ◽  
Isidora Radulov ◽  
Mirela Ahmadi ◽  
Dorel Dronca ◽  
...  

In living organisms lead is classified as potential toxic metal, and in high concentration can produce intoxication with the alteration of some vital organs, especially liver and kidney. In aquatic environment lead can be absorbed by fishes and other organisms, with different distribution in various tissues. Our aim of experiment was to verify and demonstrate the protective effect of lyophilized garlic and chlorella against bioaccumulation of lead in fishes living in aquatic environment deliberated polluted with lead. Thus, lyophilized garlic and chlorella administrated as supplements in fodder for fishes (Carassius gibelio) diminished the antagonistic effect of lead against zinc in all tested tissues: liver, kidney, heart, brain, ovary, testis, muscles myotome � epaxial, skin � with scales, gills, and intestine.


2005 ◽  
Vol 24 (2) ◽  
pp. 79-86 ◽  
Author(s):  
G. A. Petroianu ◽  
A. Schmitt ◽  
K. Arafat ◽  
M. Y. Hasan

Metoclopramide is a benzamide dopamine receptor antagonist and serotonine receptor agonist widely used as an antiemetic and gastric prokinetic drug. In addition, metoclopramide is a weak and reversible inhibitor of cholinesterases. The authors have previously shown that metoclopramide has a cholinesterase protective effect against inhibition by organophosphates (OPs). The putative mode of protective action of metoclopramide is, when administered in excess, competion for the active site of the enzyme with the more potent OP. In the present paper the authors present their results using another benzamide with weak cholinesterase inhibitory properties, tiapride (TIA). The purpose of the study was to quantify in vitro the extent of TIA-conferred protection, using dichlorvos (dichlorovinyl dimethyl phosphate; DDVP) as an inhibitor. DDVP is a moderately toxic (LD50 in rats in the milligram range), non-neuropathic OP. The substance is responsible for a large number of accidental or suicidal exposures. Red blood cell (RBC) acetylcholinesterase (AChE) activities in whole blood and butyrylcholinesterase (BChE) activities in human plasma were measured photometrically in the presence of different DDVP and TIA concentrations and IC50 was calculated. Determinations were repeated in the presence of increasing TIA concentrations. The IC50 of DDVP increases with the TIA concentration in a linear manner. The protective effect of TIA on cholinesterase could be of practical relevance in the treatment of OP poisoning. The authors conclude that in vivo testing of TIA as an OP protective agent is warranted.


2019 ◽  
Vol 70 (2) ◽  
pp. 455-458
Author(s):  
Marioara Nicula ◽  
Nicolae Pacala ◽  
Lavinia Stef ◽  
Ioan Pet ◽  
Isidora Radulov ◽  
...  

Heavy metal pollution of the aquatic environment has become a major concern for the world. As natural water pollutants, heavy metals are among the most toxic due to their cumulative effect and the difficulty of being converted into insoluble compounds in the surface waters. Lead and its compounds are toxic to aquatic organisms, especially fish, even at low concentrations, being able to replace essential elements from the organism. Thus, we tested the concentration of chromium in tissues of Prussian carp�s fingerlings, exposed to chronic lead intoxication, following the synergic and antagonistic effects of some active principles from garlic and chlorella in various tissues. Our experiment was performed on 120 Prussian carps for 21-days as following: C group (without treatment), E1 group (75 ppm Pb into water as Pb(NO3)2 x �H2O), E2 group (75 ppm Pb into water+2% freeze dried garlic in feed), E3 group (75 ppm Pb into water + 2% freeze-dried chlorella in feed). At the end of the experimental period, tissue samples (gills, muscle, heart, skin and scales, intestine, liver, brain, gonads, and kidney) were sampled after anaesthesia. Atomic Absorption Spectrometry was used to determination of chromium concentrations in tissues. Our results revealed that freeze-dried garlic presented antagonistic effect between administrated lead and tested chromium concentration, while the chlorella showed antagonistic and synergic action, depending on the organ tissue that we had analysed.


1963 ◽  
Vol 09 (03) ◽  
pp. 512-524 ◽  
Author(s):  
Chava Kirschmann ◽  
Sara Aloof ◽  
Andre de Vries

SummaryLysolecithin is adsorbed to washed blood platelets and, at sufficient concentration, lyses them, inhibits their clot-retracting activity and promotes their thromboplastin-generating activity. Lysolecithin adsorption to the platelet was studied by using P32-labelled lysolecithin obtained from the liver of rats injected with labelled orthophosphate. The amount of lysolecithin adsorbed to the surface of the washed platelet in saline medium is dependent on the concentration of lysolecithin in solution and reaches saturation — 5 × 10-8 jig per platelet — at a concentration of 9—10 µg per ml. Platelet lysis in saline medium begins at a lysolecithin concentration higher than 18 jig per ml. Plasma and albumin prevent adsorption of lysolecithin to the platelet and protect the platelet from damage by lysolecithin. Albumin is able to remove previously adsorbed lysolecithin from the platelet surface. The protective action of plasma explains the lack of platelet damage in blood, the plasma lecithin of which has been converted to lysolecithin by the action of Vipera palestinae venom phosphatidase, in vitro and in vivo.


2020 ◽  
Author(s):  
K. Zerrouki ◽  
N. Djebli ◽  
L. Gadouche ◽  
I. Erdogan Orhan ◽  
F. SezerSenol Deniz ◽  
...  

Nowadays, because of the industrialization, a lot of contaminant were available ; the consequences of this availability are apparition of diseases including neurodegeneration. Neurodegenerative diseases of the human brain comprise a variety of disorders that affect an increasing percentage of the population. This study is based on the effect of the Boswellic resin, which is from a medicinal plant and known for its antioxidant effects on nerve cell damage. The objective of this work was to evaluate the in vitro and in vivo effects of the Boswellic resin on anticholinesterase activity and Alzheimer’s disease (AD) induced by D-galactose and aluminum tetrachloride in Swiss mice. Chemical composition of the resin essential oil was identified by the CG-MS analysis. The antioxidant activity was also assessed by the DMPD and metal chelation methods. In order to understand the mechanism of memory improvement, the acetylcholinesterase, AChE, and butyrylcholinesterase, BChE, inhibitory assays were performed. In vivo part of the study was achieved on Swiss mice divided into four groups: control, AD model, treated AD, and treated control group. The identification of chemical composition by CG-MS reach the 89.67% of the total extract compounds presented some very important molecules (p-Cymene, n-Octyl acetate, α-Pinene…). The present study proves that Boswellic resin improves memory and learning in treated Alzheimer’s group, modulates the oxidative stress and be involved in the protective effect against amyloid deposition and neurodegeneration, and stimulates the immune system in mice’s brain.


2017 ◽  
Vol 68 (8) ◽  
pp. 1711-1715
Author(s):  
Stefania Gheorghe ◽  
Gabriela Geanina Vasile ◽  
Cristina Gligor ◽  
Irina Eugenia Lucaciu ◽  
Mihai Nita Lazar

Metallic elements copper (Cu), zinc (Zn), nickel (Ni) and manganese (Mn) are some of the most commonly found in water and sediment samples collected from the Danube - Danube Delta. These elements are important as essential micronutrients, being normally present at low concentrations in biological organisms, but in high concentrations they become toxic with immediate and delayed effects. The role of this metals is still controversial, that�s why bioconcentration potential is so important. In this non-clinical study, we tested in vitro effect of heavy metals on carp, Cyprinus carpio, reproducing in vivo presence of Cu, Zn, Ni and Mn in the Romanian�s surface water. The toxicity tests were performed according to OECD 203 by detecting the average (50%) lethal concentration - LC50 on aquatic organisms (freshwater fish) at 96h. The results pointed out that, copper value for LC 50 at 96h was estimated as 3.4 mg/L (concentrations tested in the range of 0.1 - 4.75 mg/L). Zinc value for LC 50 at 96h was estimated as 20.8 mg/L (concentrations tested in the range of 0.028 � 29.6 mg/L). Nickel value for LC 50 at 96h was estimated as 40.1 mg/L (concentrations tested in the range of 0.008 - 84.5 mg/L). For manganese the mortality effects has recorded at LC 50 at 96h at estimated value higher than 53 mg/L (concentrations tested in the range of 0.04 - 53.9 mg/L). The accuracy of the testing metals concentration was insured by the screening of the dilution water, as well as food and control fish, acclimated in laboratory conditions.


2020 ◽  
Vol 27 ◽  
Author(s):  
Reyaz Hassan Mir ◽  
Abdul Jalil Shah ◽  
Roohi Mohi-ud-din ◽  
Faheem Hyder Potoo ◽  
Mohd. Akbar Dar ◽  
...  

: Alzheimer's disease (AD) is a chronic neurodegenerative brain disorder characterized by memory impairment, dementia, oxidative stress in elderly people. Currently, only a few drugs are available in the market with various adverse effects. So to develop new drugs with protective action against the disease, research is turning to the identification of plant products as a remedy. Natural compounds with anti-inflammatory activity could be good candidates for developing effective therapeutic strategies. Phytochemicals including Curcumin, Resveratrol, Quercetin, Huperzine-A, Rosmarinic acid, genistein, obovatol, and Oxyresvertarol were reported molecules for the treatment of AD. Several alkaloids such as galantamine, oridonin, glaucocalyxin B, tetrandrine, berberine, anatabine have been shown anti-inflammatory effects in AD models in vitro as well as in-vivo. In conclusion, natural products from plants represent interesting candidates for the treatment of AD. This review highlights the potential of specific compounds from natural products along with their synthetic derivatives to counteract AD in the CNS.


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