Book Chapter contribution by Mohammed Musa Lawan, Ph.D.
Elsevier Publications, May 3, 2014
Joerg Feldmann, Abdelkarem Elgazali, Mohamed F. Ezzeldin,
Zuzana Gajdosechova, Eva Krupp, Fata... more Joerg Feldmann, Abdelkarem Elgazali, Mohamed F. Ezzeldin,
Zuzana Gajdosechova, Eva Krupp, Fatai Aborode, Mohamed M. Lawan,
Andrea Raab, Asta H. Petursdottir and Kenneth Amayo
10.1. INTRODUCTION
10.1.1. Chemical Speciation?
Chemical speciation is defined according to IUPAC [1] as follows: (1) Chemical species: specific form of an element defined as to isotopic composition, electronic or oxidation state, and/or complex or molecular structure. (2) Speciation analysis: analytical activities of identifying and/or measuring the quantities of one or more individual chemical species in a sample. (3) Speciation of an element: distribution of an element among defined chemical species in a system.
In contrast to this, “fractionation analysis” is clearly different from what we understand as speciation and speciation analysis. This way of describing a sample/analyte is defined by IUPAC [1] as follows. Fractionation is the process of classification of an analyte or a group of analytes from a certain sample according to physical (e.g., size and solubility) or chemical (e.g., bonding and reactivity) properties.
These definitions allow to clarifying the differences between the terms “spe-ciation” and “fractionation,” and have been used for understanding the tasks and possibilities of element speciation analysis.
Papers by Mohammed Musa Lawan, Ph.D.
African science has substantial potential, yet it grapples with significant challenges. Here we d... more African science has substantial potential, yet it grapples with significant challenges. Here we describe the establishment of the Biomedical Science Research Centre (BioRTC) in Yobe State, Northeast Nigeria, as a case study of a hub fostering on-continent research and describe strategies to surmount some of these barriers. We detail the steps taken to establish BioRTC, emphasising the critical importance of stakeholder engagement, community involvement, resource optimisation, and collaborations. Although we are in the early stages of our journey, our experience can nonetheless serve as a guide to others embarking on similar endeavours in resource-limited settings. We invite the support and collaboration of those who share our vision and believe in our potential.
This research work examined the nutrient and heavy metal accumulation capacity of three different... more This research work examined the nutrient and heavy metal accumulation capacity of three different species of Striga plant from two different locations (western and eastern Yobe) in Yobe State; Kukar Gadu and Damaturu towns respectively. Atomic absorption spectrometry and other analytical techniques were employed to estimate the amount of nutrient and heavy metal bioaccumulation of the three (3) species of Striga grass. Nitrogen, Potassium and Phosphorus were also within the optimum recommended levels in the parasitic plant but lower in the host plant. The concentration of nitrogen analysis in the three (3) species range between 479.75826.91 mg/kg in stem, 145.60-532.09mg/kg in leaves and 701.33 – 859.06mg/kg in root. Concentration of phosphorus in the three (3) species ranged between 18.83+ 202.76 mg/kg in stem, 17.40-176mg/kg in leaves and 49.28 – 275.27mg/kg in root while the hostorium of S. gesneriodes has between 56.75-265.49mg/kg. Potassium concentrations in the three (3) speci...
International Journal of Trend in Scientific Research and Development, Aug 7, 2021
International Journal of Trend in Scientific Research and Development, Aug 7, 2021
The control of Striga infestation in agricultural produce proved to be difficult especially in Af... more The control of Striga infestation in agricultural produce proved to be difficult especially in Africa. This study therefore aimed at finding a way of making the plant useful. The results revealed that all the plants contain flavonoids, glycosides, tannins, phenols, oxalate and carbohydrates. Alkaloid and saponnins were only found to be present in S. gesnerioides. A relative high amount of flavonoids (6.86+0.42 mgRutin/g) and phenols in the stem (9.36+0.55 mgGAE/g) of S. gesnerioides closely followed by leaves of S. hermontheca 4.06+0.25 mgRutin/g, 13.06+0.32 mgGAE/g respectively. The presence of these bioactive components indicates the plant’s potential as a source of major secondary metabolites that may serve as novel medicines. The percentage inhibition concentration at 50% (IC50) of S. hermontheca stem, root and leaves were 73.13 µg/g, 41.39 µg/g and 207.01 µg/g respectively. The stem, roots and haustorium of S. gesneriodes indicated an IC50 of 70.39 µg/g, 55.33 µg/g and 55.07 µg...
Scientific Reports, 2016
To understand the biochemistry of methylmercury (MeHg) that leads to the formation of mercurysele... more To understand the biochemistry of methylmercury (MeHg) that leads to the formation of mercuryselenium (Hg-Se) clusters is a long outstanding challenge that promises to deepen our knowledge of MeHg detoxification and the role Se plays in this process. Here, we show that mercury selenide (HgSe) nanoparticles in the liver and brain of long-finned pilot whales are attached to Se-rich structures and possibly act as a nucleation point for the formation of large Se-Hg clusters, which can grow with age to over 5 μm in size. The detoxification mechanism is fully developed from the early age of the animals, with particulate Hg found already in juvenile tissues. As a consequence of MeHg detoxification, Se-methionine, the selenium pool in the system is depleted in the efforts to maintain essential levels of Se-cysteine. This study provides evidence of so far unreported depletion of the bioavailable Se pool, a plausible driving mechanism of demonstrated neurotoxic effects of MeHg in the organism affected by its high dietary intake.
PLOS ONE, 2015
Background Selenium (Se) is an essential oligonutrient, as a component of several Se-containing p... more Background Selenium (Se) is an essential oligonutrient, as a component of several Se-containing proteins (selenoproteins), which exert important biological functions within an organism. In livestock, Se-enriched products have been proposed as dietary supplements to be included into functional feeds for animal preventive health care. To this end, it is important to understand the optimal range of concentrations for supplementation and how long it takes to be assimilated into the organism. Methods In this study, rainbow trout (Oncorhynchus mykiss) were fed a control diet containing 0.9 g Kg-1 Se or the same diet supplemented with a Se-Yeast product (Sel-Plex) to achieve Se concentrations ranging from 1.5-8.9 g Kg-1 for a period of ten weeks. Fish were sampled every two weeks for analysis. The kinetics of Se bioaccumulation and the effects on fish selenoprotein expression was determined in different tissues combining chemical and bimolecular techniques. Results The Sel-Plex enriched diets did not have any effect on survival and growth performance. The highest Se levels were found in liver and kidney followed by muscle and blood cells. Analysis of the Se concentration factor showed that liver is able to initially regulate the PLOS ONE |
Industrial and anthropogenic activities have resulted in high levels of metallic contaminants in ... more Industrial and anthropogenic activities have resulted in high levels of metallic contaminants in the environment, thus creating imbalance in the biotic and abiotic regimes of the ecosystem. This has remained as a stabbing problem in the mind of environmental and agricultural scientists, since metallic contaminants unlike biodegradable contaminants are persistent in affecting the biophysical population of our environment. This problem requires an insightful assessment before the best remediation option can be selected appropriately. In this paper, we present an overview of chemical speciation and its adaptations in environmental cleanup for achieving result oriented remediation technique.
Advanced Journal of Chemistry-Section A, 2021
The control of Striga infestation in agricultural produce proved to be difficult especially in Af... more The control of Striga infestation in agricultural produce proved to be difficult especially in Africa. This study therefore aimed at finding a way of making the plant useful. The results revealed that all the plants contain flavonoids, glycosides, tannins, phenols, oxalate and carbohydrates. Alkaloid and saponnins were only found to be present in S. gesnerioides. A relative high amount of flavonoids (6.86+0.42 mgRutin/g) and phenols in the stem (9.36+0.55 mgGAE/g) of S. gesnerioides closely followed by leaves of S. hermontheca 4.06+0.25 mgRutin/g, 13.06+0.32 mgGAE/g respectively. The presence of these bioactive components indicates the plant's potential as a source of major secondary metabolites that may serve as novel medicines. The percentage inhibition concentration at 50% (IC50) of S. hermontheca stem, root and leaves were 73.13 µg/g, 41.39 µg/g and 207.01 µg/g respectively. The stem, roots and haustorium of S. gesneriodes indicated an IC50 of 70.39 µg/g, 55.33 µg/g and 55.07 µg/g respectively while S. aciatica 52.35 µg/g, and 72.71 µg/g respectively. Compared to standard ascorbic acid with IC50 of 57.78 µg/g, the three species have relative significant antioxidant activity. Further successive extraction, purification and characterization of the bioactive components found present in this research will make further research interesting.
To understand the biochemistry of methylmercury (MeHg) that leads to the formation of mercury-sel... more To understand the biochemistry of methylmercury (MeHg) that leads to the formation of mercury-selenium (Hg-Se) clusters is a long outstanding challenge that promises to deepen our knowledge of MeHg detoxification and the role Se plays in this process. Here, we show that mercury selenide (HgSe) nanoparticles in the liver and brain of long-finned pilot whales are attached to Se-rich structures and possibly act as a nucleation point for the formation of large Se-Hg clusters, which can grow with age to over 5 μm in size. The detoxification mechanism is fully developed from the early age of the animals, with particulate Hg found already in juvenile tissues. As a consequence of MeHg detoxification, Se-methionine, the selenium pool in the system is depleted in the efforts to maintain essential levels of Se-cysteine. This study provides evidence of so far unreported depletion of the bioavailable Se pool, a plausible driving mechanism of demonstrated neurotoxic effects of MeHg in the organism affected by its high dietary intake. Irreversible neurological damage to the central nervous system associated with exposure to methylmercury (MeHg) has led to strict regulations of MeHg concentrations in the food we consume 1,2. The damage caused by MeHg is particularly dangerous during embryotic development as MeHg can be transported through the placenta to the foetus 3,4. Prenatal exposure to MeHg has been linked with cognitive deficit in children 4 and spontaneous abortions and stillbirth in severe cases 5. At the cellular level, methylmercury-related toxic effects are thought to be caused by binding of MeHg to cysteinyl groups of proteins 6 , which may have severe implications on the synthesis of cellular glutathione, thus leading to oxidative damage. However, marine mammals and seabirds, which can accumulate unparalleled quantities of mercury (Hg) in the liver tissue do not present the toxic effects observed in humans and are able to tolerate brain-MeHg concentrations above the human threshold of severe neurological damage without showing apparent symptoms of poisoning 7. The protective effect of selenium (Se) against the toxicity of Hg species has long been observed and extensively studied under controlled conditions in exposure experiments 8–10. Its pivotal role in detoxification is based on the high affinity of Hg to nucleophilic bio-selenols and subsequent formation of organic and inorganic compounds, including bio-mineralized mercury selenide (HgSe) particles. Although predominantly formed in the liver, HgSe particles were found in a wide range of biological tissues of whales and dolphins 11,12 suggesting that the formation of HgSe is not a liver-specific process but takes place locally, in individual organs. Formation of HgSe particles is generally viewed as a detoxification mechanism, and an increasing number of authors argue that this mechanism may also have negative consequences on the biosynthesis of essential amino acids 13. Selenium is covalently bound to Se-proteins as constituent of the 21 st amino acid selenocysteine (Se-cysteine), and Se-cysteine forms an essential part of the active centre in the respective Se-enzymes 14. Amongst the wide variety of Se-protein's
Abstract
Background
Selenium (Se) is an essential oligonutrient, as a component of several Se-con... more Abstract
Background
Selenium (Se) is an essential oligonutrient, as a component of several Se-containing proteins
(selenoproteins), which exert important biological functions within an organism. In livestock,
Se-enriched products have been proposed as dietary supplements to be included
into functional feeds for animal preventive health care. To this end, it is important to understand
the optimal range of concentrations for supplementation and how long it takes to be
assimilated into the organism.
Methods
In this study, rainbow trout (Oncorhynchus mykiss) were fed a control diet containing 0.9 g
Kg-1 Se or the same diet supplemented with a Se-Yeast product (Sel-Plex) to achieve Se
concentrations ranging from 1.5–8.9 g Kg-1 for a period of ten weeks. Fish were sampled
every two weeks for analysis. The kinetics of Se bioaccumulation and the effects on fish
selenoprotein expression was determined in different tissues combining chemical and
bimolecular techniques.
Results
The Sel-Plex enriched diets did not have any effect on survival and growth performance.
The highest Se levels were found in liver and kidney followed by muscle and blood cells.
Analysis of the Se concentration factor showed that liver is able to initially regulate theamount of Se accumulated. However, with higher dietary Se level (4.8 and 8.9 g Kg-1) and
longer times of exposure (10 weeks), regulation is ineffective and the Se tissue concentration
increases. The expression of the selected trout selenoprotein transcripts showed an inverse
correlation with Sel-Plex augmentation in most cases. In liver, kidney and blood cells
the highest up-regulation of the trout selenoprotein genes was seen mostly in the group fed
the diet enriched with the lowest concentration of Sel-Plex (0.5 g Kg-1) for 10 weeks.
Abstract
Industrial and anthropogenic activities have resulted in high levels of metallic contami... more Abstract
Industrial and anthropogenic activities have resulted in high levels of metallic contaminants in the environment,
thus creating imbalance in the biotic and abiotic regime
s of the ecosystem. This has remained as a stabbing
problem in the mind of environmental and agricultural scientists, since metallic contaminants unlike
biodegradable contaminants are persistent in affecting the biophysical population of our environment. This
problem requires an insightful assessment before the best remediation option can be selected appropriately. In
this paper, we present an overview of chemical speci
ation and its adaptations in environmental cleanup for
achieving result oriented remediation technique.
Conference Presentations by Mohammed Musa Lawan, Ph.D.
M. M. Lawan, P. Davide, J. Feldmann and E. Krupp
Department of Chemistry, Metson building, Univ... more M. M. Lawan, P. Davide, J. Feldmann and E. Krupp
Department of Chemistry, Metson building, University of Aberdeen. UK.
The identification of selenium as essential micronutrient with protection against destructive oxidation products in the body, anti cancer properties encourages the consumption of selenium rich and selenium enriched food products in order to make up for the possible deficiency of selenium in diets. People are exposed to selenium mainly through their diets (plant and sea foods). Fish is an important source of human exposure to selenium. In this study the concentration of total selenium in different organs of Rainbow trout fish was determined by monitoring 77Se and 78Se isotopes using inductively coupled plasma mass spectrometry (ICPMS), after samples decomposition by microwave assisted digestion. The mean level of the total selenium was 4.62 ± 3.12 mg kg-1 in kidney, 2.20 ± 0.12 mg kg-1 in liver, 0.87± 0.13 mg kg-1 in muscle and 0.87 ± 0.10 mg kg-1 in gills. In order to evaluate the accuracy of the method, the total selenium content in a dogfish muscle (DORM-2) reference material was determined. The highest selenium concentration was found in kidney and liver which are the main target organs for selenium accumulation.
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Book Chapter contribution by Mohammed Musa Lawan, Ph.D.
Zuzana Gajdosechova, Eva Krupp, Fatai Aborode, Mohamed M. Lawan,
Andrea Raab, Asta H. Petursdottir and Kenneth Amayo
10.1. INTRODUCTION
10.1.1. Chemical Speciation?
Chemical speciation is defined according to IUPAC [1] as follows: (1) Chemical species: specific form of an element defined as to isotopic composition, electronic or oxidation state, and/or complex or molecular structure. (2) Speciation analysis: analytical activities of identifying and/or measuring the quantities of one or more individual chemical species in a sample. (3) Speciation of an element: distribution of an element among defined chemical species in a system.
In contrast to this, “fractionation analysis” is clearly different from what we understand as speciation and speciation analysis. This way of describing a sample/analyte is defined by IUPAC [1] as follows. Fractionation is the process of classification of an analyte or a group of analytes from a certain sample according to physical (e.g., size and solubility) or chemical (e.g., bonding and reactivity) properties.
These definitions allow to clarifying the differences between the terms “spe-ciation” and “fractionation,” and have been used for understanding the tasks and possibilities of element speciation analysis.
Papers by Mohammed Musa Lawan, Ph.D.
Background
Selenium (Se) is an essential oligonutrient, as a component of several Se-containing proteins
(selenoproteins), which exert important biological functions within an organism. In livestock,
Se-enriched products have been proposed as dietary supplements to be included
into functional feeds for animal preventive health care. To this end, it is important to understand
the optimal range of concentrations for supplementation and how long it takes to be
assimilated into the organism.
Methods
In this study, rainbow trout (Oncorhynchus mykiss) were fed a control diet containing 0.9 g
Kg-1 Se or the same diet supplemented with a Se-Yeast product (Sel-Plex) to achieve Se
concentrations ranging from 1.5–8.9 g Kg-1 for a period of ten weeks. Fish were sampled
every two weeks for analysis. The kinetics of Se bioaccumulation and the effects on fish
selenoprotein expression was determined in different tissues combining chemical and
bimolecular techniques.
Results
The Sel-Plex enriched diets did not have any effect on survival and growth performance.
The highest Se levels were found in liver and kidney followed by muscle and blood cells.
Analysis of the Se concentration factor showed that liver is able to initially regulate theamount of Se accumulated. However, with higher dietary Se level (4.8 and 8.9 g Kg-1) and
longer times of exposure (10 weeks), regulation is ineffective and the Se tissue concentration
increases. The expression of the selected trout selenoprotein transcripts showed an inverse
correlation with Sel-Plex augmentation in most cases. In liver, kidney and blood cells
the highest up-regulation of the trout selenoprotein genes was seen mostly in the group fed
the diet enriched with the lowest concentration of Sel-Plex (0.5 g Kg-1) for 10 weeks.
Industrial and anthropogenic activities have resulted in high levels of metallic contaminants in the environment,
thus creating imbalance in the biotic and abiotic regime
s of the ecosystem. This has remained as a stabbing
problem in the mind of environmental and agricultural scientists, since metallic contaminants unlike
biodegradable contaminants are persistent in affecting the biophysical population of our environment. This
problem requires an insightful assessment before the best remediation option can be selected appropriately. In
this paper, we present an overview of chemical speci
ation and its adaptations in environmental cleanup for
achieving result oriented remediation technique.
Conference Presentations by Mohammed Musa Lawan, Ph.D.
Department of Chemistry, Metson building, University of Aberdeen. UK.
The identification of selenium as essential micronutrient with protection against destructive oxidation products in the body, anti cancer properties encourages the consumption of selenium rich and selenium enriched food products in order to make up for the possible deficiency of selenium in diets. People are exposed to selenium mainly through their diets (plant and sea foods). Fish is an important source of human exposure to selenium. In this study the concentration of total selenium in different organs of Rainbow trout fish was determined by monitoring 77Se and 78Se isotopes using inductively coupled plasma mass spectrometry (ICPMS), after samples decomposition by microwave assisted digestion. The mean level of the total selenium was 4.62 ± 3.12 mg kg-1 in kidney, 2.20 ± 0.12 mg kg-1 in liver, 0.87± 0.13 mg kg-1 in muscle and 0.87 ± 0.10 mg kg-1 in gills. In order to evaluate the accuracy of the method, the total selenium content in a dogfish muscle (DORM-2) reference material was determined. The highest selenium concentration was found in kidney and liver which are the main target organs for selenium accumulation.
Zuzana Gajdosechova, Eva Krupp, Fatai Aborode, Mohamed M. Lawan,
Andrea Raab, Asta H. Petursdottir and Kenneth Amayo
10.1. INTRODUCTION
10.1.1. Chemical Speciation?
Chemical speciation is defined according to IUPAC [1] as follows: (1) Chemical species: specific form of an element defined as to isotopic composition, electronic or oxidation state, and/or complex or molecular structure. (2) Speciation analysis: analytical activities of identifying and/or measuring the quantities of one or more individual chemical species in a sample. (3) Speciation of an element: distribution of an element among defined chemical species in a system.
In contrast to this, “fractionation analysis” is clearly different from what we understand as speciation and speciation analysis. This way of describing a sample/analyte is defined by IUPAC [1] as follows. Fractionation is the process of classification of an analyte or a group of analytes from a certain sample according to physical (e.g., size and solubility) or chemical (e.g., bonding and reactivity) properties.
These definitions allow to clarifying the differences between the terms “spe-ciation” and “fractionation,” and have been used for understanding the tasks and possibilities of element speciation analysis.
Background
Selenium (Se) is an essential oligonutrient, as a component of several Se-containing proteins
(selenoproteins), which exert important biological functions within an organism. In livestock,
Se-enriched products have been proposed as dietary supplements to be included
into functional feeds for animal preventive health care. To this end, it is important to understand
the optimal range of concentrations for supplementation and how long it takes to be
assimilated into the organism.
Methods
In this study, rainbow trout (Oncorhynchus mykiss) were fed a control diet containing 0.9 g
Kg-1 Se or the same diet supplemented with a Se-Yeast product (Sel-Plex) to achieve Se
concentrations ranging from 1.5–8.9 g Kg-1 for a period of ten weeks. Fish were sampled
every two weeks for analysis. The kinetics of Se bioaccumulation and the effects on fish
selenoprotein expression was determined in different tissues combining chemical and
bimolecular techniques.
Results
The Sel-Plex enriched diets did not have any effect on survival and growth performance.
The highest Se levels were found in liver and kidney followed by muscle and blood cells.
Analysis of the Se concentration factor showed that liver is able to initially regulate theamount of Se accumulated. However, with higher dietary Se level (4.8 and 8.9 g Kg-1) and
longer times of exposure (10 weeks), regulation is ineffective and the Se tissue concentration
increases. The expression of the selected trout selenoprotein transcripts showed an inverse
correlation with Sel-Plex augmentation in most cases. In liver, kidney and blood cells
the highest up-regulation of the trout selenoprotein genes was seen mostly in the group fed
the diet enriched with the lowest concentration of Sel-Plex (0.5 g Kg-1) for 10 weeks.
Industrial and anthropogenic activities have resulted in high levels of metallic contaminants in the environment,
thus creating imbalance in the biotic and abiotic regime
s of the ecosystem. This has remained as a stabbing
problem in the mind of environmental and agricultural scientists, since metallic contaminants unlike
biodegradable contaminants are persistent in affecting the biophysical population of our environment. This
problem requires an insightful assessment before the best remediation option can be selected appropriately. In
this paper, we present an overview of chemical speci
ation and its adaptations in environmental cleanup for
achieving result oriented remediation technique.
Department of Chemistry, Metson building, University of Aberdeen. UK.
The identification of selenium as essential micronutrient with protection against destructive oxidation products in the body, anti cancer properties encourages the consumption of selenium rich and selenium enriched food products in order to make up for the possible deficiency of selenium in diets. People are exposed to selenium mainly through their diets (plant and sea foods). Fish is an important source of human exposure to selenium. In this study the concentration of total selenium in different organs of Rainbow trout fish was determined by monitoring 77Se and 78Se isotopes using inductively coupled plasma mass spectrometry (ICPMS), after samples decomposition by microwave assisted digestion. The mean level of the total selenium was 4.62 ± 3.12 mg kg-1 in kidney, 2.20 ± 0.12 mg kg-1 in liver, 0.87± 0.13 mg kg-1 in muscle and 0.87 ± 0.10 mg kg-1 in gills. In order to evaluate the accuracy of the method, the total selenium content in a dogfish muscle (DORM-2) reference material was determined. The highest selenium concentration was found in kidney and liver which are the main target organs for selenium accumulation.
2University of Aberdeen, Trace Element Speciation Laboratory, Aberdeen, United Kingdom, 3Alltech,
Aqua, Lixouri, Greece
Selenium (Se) is an essential trace element, required for efficient function of numerous proteins, including some involved in immunity. Its augmentation may effectively improve animal immune function, and represents an alternative strategy for disease control in aquaculture. The aim of this study is to determine the possible impact of a Se-yeast based additive (Sel-Plex®) on the fish immune response, trying to delineate the bio-molecular mechanisms behind the interactions of this trace element with the fish immune system.We have characterized ten genes encoding for selenoproteins belonging to the glutathione peroxidase (GPxs), thioredoxin reductase (TrxRs) and selenoprotein P (SelPs) families in salmonids. The responsiveness of GPxs, TrxRs and SelPs to Se exposure has been studied in vitro using a trout liver cell line (RTL), to validate their possible use as biomarkers for Se intake in vivo. Afterwards, a ten weeks feeding trial was carried out with rainbow trout given diets containing different concentrations of Sel-Plex®. Every two weeks tissues were collected to measure the expression of selenoproteins and immune-related genes by qPCR. In parallel, ICP-MS was used to quantify the ratio of Se intake/absorption, and HPLC to determine the main Se-metabolites produced in trout from Sel-Plex® intake. All the biomarkers selected were responsive to Se in vitro. TrxRs and SelPs were also induced in vivo, and their transcript expression was inversely correlated with the concentration of Sel-Plex®. These two selenoproteins were selected for antibody production, to further investigate the response at the protein level. TrxRs transcript level was also correlated with the expression of pro-inflammatory genes. Liver and kidney were confirmed to be the most relevant organs in Se metabolism, and several different Se-metabolites accumulated mainly in the hepatic tissue. However, muscle had the highest Se retention, even at low Se level in the diet.
1University of Aberdeen, Chemistry Department, TESLA, AB24 3UE, Aberdeen, United Kingdom,
2University of Aberdeen, Zoology Department, Zoology building, AB24 2TZ., Aberdeen, United
Kingdom
Bioavailability and toxicity of selenium are dependent on its content and chemical species in which it is present in the dietary source [1]. Selenium is integrated in to several Se-containing proteins (selenoproteins) in form of selenocysteine, many of which are fundamental in cell homeostasis [2]. Selenium is also incorporated non-specifically in to proteins (proteins containing selenium) by substituting sulfur of methionine [1]. Fish is potentially an important source of dietary selenium for humans. Thus this study focuses on selenium distribution in the organs of rainbow trout fed on a selenium-spiked diet.
200 rainbow trout fish of about 70 g weights were divided in to four groups; control, diet A, diet B and diet C.The fish were fed with diets containing selenium concentration ranging from 0.1 -8.5 mg Kg-1 for fourteen weeks; four weeks of acclimatization and ten weeks of treatment. Fish were sampled every two weeks of treatment for analysis. The total selenium concentration in different tissues and blood of Rainbow trout were determined using ICP-MS (reaction cell mode) mode by monitoring 77 Se and 78 Se isotopes by external calibration. Germanium was used as an internal standard. In order to evaluate the accuracy of the method total selenium content in dog fish muscle (DORM - 2) was measured and percentage recovery determined. The highest selenium concentrations were found in kidney and liver. Water soluble protein fraction and selenoamino acids in different tissues were investigated using an integrated technique HPLC-ICP-MS-ESI-MS.
References:
1. Yoshida, S., Haratake, M., Fuchigami, T., Nakayama, M. Selenium in Seafood Materials. J Health. Sci. 2011;57(3): 215-224.
2. Pacitti, D., Wang, T., Page, M. M., Martin, S.A.M., Sweetman, J., Feldmann, J., Secombes, C.J. Characterization of cytosolic glutathione peroxidise genes in rainbow trout (Oncorhyncus mykiss) and their modulation by invitro selenium exposure. J. Aquat. Toxicol.2013; 130-131:97-111