M Gnassia-Barelli

Université de Nouakchott, Nouakchot, Nouakchott, Mauritania

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Publications (57)110.9 Total impact

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    ABSTRACT: This study aims to evaluate the health status of Bizerta lagoon using a sentinel species, the Neogastropod Murex trunculus. Trace metal concentrations (Cd, Cu and Zn) in the foot and digestive gland, and biomarkers such as acetylcholinesterase (AChE), catalase (CAT) and glutathione transferase (GST) activities in the digestive gland, were determined in samples collected at four sites at different periods of the year. One site, in the North of the lagoon, is influenced by urban and industrial waste waters. Another, to the south, is located at the outfall of Ichkeul Lake. A third site is one that may be impacted by eutrophication processes, and the last, in the center of lagoon, is considered as less polluted. Temperature and salinity were simultaneously measured during the mollusc samplings. They varied greatly, from 13.5 °C and 30 psu in February to much higher values in summer-autumn: 30.7 °C and 37 psu. Metal concentrations were always higher in the digestive gland than in the foot. In the digestive gland, the lowest Cd and Cu concentrations were found in the center of the lagoon (mean $\pm $ standard deviation: 9.35 $\pm $ 0.78 $\mu $g Cd g$^{-1}$ and 84.5 $\pm $ 15.3 $\mu $g Cu g$^{-1})$ and no significant Zn variations were noted (682 $\pm $ 38 $\mu $g g$^{-1})$ between sites. Metal concentrations in both types of tissue were higher in winter than in summer. AChE varied significantly among sites with high activities for individuals in the center of lagoon (15.4 $\pm $ 0.3 nmol min$^{-1}$mg$^{-1}$ protein), whereas GST were low (12.2 $\pm $ 0.8 nmol min$^{-1}$mg$^{-1}$ protein); CAT activities were low in this site 8.7 $\pm $ 0.5 $\mu $mol min$^{-1}$mg$^{-1}$ protein. Season also had an influence on biomarkers, with low AChE in winter and rather low CAT and GST in summer. Principal component analysis showed that the center of lagoon can be considered as a reference site, whereas high chemical and biochemical responses were found in M. trunculus from other sites; particularly at the site which may be subject to eutrophication. Cette étude a pour but d'évaluer l'état de la lagune de Bizerte en utilisant une espèce sentinelle, le néogastéropode, Murex trunculus. Dans ce but, les concentrations en métaux-traces (Cd, Cu et Zn) du pied et de la glande digestive, ainsi que des biomarqueurs, tels que les activités de l'acétylcholinestérase (AChE), catalase (CAT), glutathion transférase (GST) dans la glande digestive, sont déterminés dans des échantillons prélevés en quatre sites, à différentes périodes de l'année. Au nord de la lagune, un site est influencé par des eaux usées urbaines et industrielles, au sud un site est localisé à la sortie du lac Ichkeul, un troisième site peut être soumis à des processus d'eutrophisation, et enfin celui du centre est considéré comme moins pollué. La température et la salinité sont mesurées pendant la collecte des mollusques. Elles varient beaucoup de 13,5 °C et 30 psu en février à des valeurs bien plus élevées en été-automne : 30,7 °C et 37 psu. Les concentrations en métaux sont toujours plus fortes dans la glande digestive que dans le pied. Dans la glande digestive, les plus faibles concentrations de Cd et Cu sont trouvées au centre de la lagune (moyenne $\pm $ écart-type : 9,35 $\pm $ 0,78 $\mu $g Cd g$^{-1}$ et 84,5 $\pm $ 15,3 $\mu $g Cu g$^{-1})$ et il n'y a pas de variations significatives du zinc (682 $\pm $ 38 $\mu $g g$^{-1})$ en fonction du lieu de prélèvement. Les concentrations métalliques dans les deux tissus sont plus élevées en hiver qu'en été. AChE varie significativement en fonction des sites avec de fortes activités au centre de la lagune (15,4 $\pm $ 0,3 nmol min$^{-1}$mg$^{-1}$ protéine) tandis que CAT et GST sont faibles (respectivement 8,7 $\pm $ 0,5 $\mu $mol min$^{-1}$mg$^{-1}$ protéine et 12,2 $\pm $ 0,8 nmol min$^{-1}$mg$^{-1}$ protéine). La saison a aussi une influence sur les biomarqueurs avec AChE faible en hiver et CAT et GST plutôt faibles en été. Une analyse en composantes principales montre que le centre de la lagune peut être considéré comme un site de référence, tandis que des réponses chimiques et biochimiques élevées sont trouvées dans M. trunculus prélevé en d'autres sites et en particulier au site où des phénomènes d'eutrophisation peuvent survenir.
    http://dx.doi.org/10.1051/alr:2008033. 01/2008;
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    ABSTRACT: Relationships between biochemical and physiological biomarkers (acetylcholinesterase [AChE], catalase, and glutathione S-transferase [GST] activities, thiobarbituric acid reactive substances, glycogen, lipids and proteins) and accumulated concentrations of contaminants (polychlorinated biphenyls [PCBs], polycyclic aromatic hydrocarbons and metals) were examined in the keystone species Nereis diversicolor. The chemical analyses of worms and sediments allowed the designation of the Seine estuary and the Authie estuary as a polluted and relatively clean site respectively. Worms from the Seine estuary exhibited higher GST and lower AChE activities. Generally, larger worms had higher concentrations of energy reserves. Principal component analyses clearly highlighted intersite differences: in the first plan, GST activities and chemical concentrations were inversely related to concentrations of energy reserves; in the second one, PCB concentrations and AChE activity were inversely related. Depleted levels of energy reserves could be a consequence of combating toxicants and might predict effects at higher levels of biological organization. The use of GST and AChE activities and energy reserve concentrations as biomarkers is validated in the field in this keystone species.
    Environmental Pollution 08/2007; 148(2):445-58. · 3.73 Impact Factor
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    ABSTRACT: Suborganismal responses to toxicants can be sensitive tools to assess marine pollution, but their ecological significance is a matter of debate. Among these biomarkers, those linked to reproduction are most probably related to populational effects. To test this hypothesis, Nereis diversicolor were collected in the multipolluted Seine estuary and the comparatively clean Authie estuary (France). Energy reserves were higher in Authie worms, suggesting a better physiological status. The number of oocytes per female was higher for the polychaetes from the Authie, but it was related to the size of animals, which was higher at this site. Densities of worms were depleted in the Seine compared to those in Authie. Demographic structure of the Seine population was also altered. The concomitant changes in energy reserves, egg production, and population structure and density suggest that the effects on biomarkers and at the population level are related.
    Ecotoxicology and Environmental Safety 04/2007; 66(3):402-11. · 2.20 Impact Factor
  • G Damiens, M Gnassia-Barelli, F Loquès, M Roméo, V Salbert
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    ABSTRACT: Mytilus galloprovincialis mussels from a clean area were transplanted from 2003 to 2005 to several stations in the Bay of Cannes (North-Western Mediterranean Sea) including a site considered as reference, for 1 month at the end of spring (May). Several biomarkers (AChE, GST and CAT activities, TBARS and MT concentrations) were measured in the transplanted organisms. The concentrations of metals (Cd, Cu and Zn) were determined in the transplanted mussels, PAH and PCB analyses were performed in the mussels caged in 2004. The integrated biomarker response (IBR) was calculated; pollutant concentrations in mussels were displayed as star plots and compared to IBR star plots. Visualization was thus possible between sites for comparison with exposure conditions. Results demonstrated that the mussels from the Old harbour site (VP) are characterized by elevated copper and PCB concentrations, those from Canto harbour (PC) presented high PCB contents and those from the mouth of the Siagne River (ES) high PAH concentrations compared to the animals transplanted in the reference site (IL). In 2003, there was a visual correlation between the copper gradient measured in the transplanted mussels and the IBR variation. In 2004, the agreement between the copper gradient and the PCB gradient measured in the caged mussels and the IBR variation was good whereas the PAH gradient did not seem to contribute to the IBR demonstrating that the chosen biomarkers did not respond to PAHs. In 2005, IBR showed that other contaminants, not measured might be present in VP, PC and ES compared to the reference station (IL).
    Chemosphere 02/2007; 66(3):574-83. · 3.14 Impact Factor
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    ABSTRACT: Active bio-monitoring in terms of biomarkers was attempted using Crassostrea gigas larvae produced in the laboratory and transplanted using special containers to two sites at the entrance (A) and inner part (P) of the harbour of Arcachon (French Atlantic Coast). The larvae were kept in the medium for 48 h. Their physiological status and their biomarker levels : acetylcholinesterase AChE, catalase CAT and glutathione S-transferase GST activities were determined together with metallothionein MT and Thiobarbituric Acid Reactive Substances TBARS concentrations. Copper and PAH (polycyclic aromatic hydrocarbon) concentrations were determined in the exposed larvae and in the sediments collected under the containers. Cadmium, lead and zinc could be also analyzed in the sediments. Toxicity tests demonstrate that the larvae are in better physiological conditions in A compared to P. Larvae transplanted in the inner harbour (P) present relatively high GST activity (869.1+/-39.3 nmol min(-1)mg protein(-1)), TBARS (2.74+/-0.19 nmol mg protein(-1)), compared to those exposed at the harbour entrance (A). Copper measured in the sediments (65+/-1 mg kg(-1) d.w.) collected under the cages at P is higher than at A. Larvae placed in A present higher total PAH concentrations compared to the inner part. The data tend to reveal a lower copper and higher PAH contamination in A than in P. Therefore larvae, developing in the natural medium, show different responses according to their immersion sites. These responses, obtained within 48 h, may be related to the chemical contamination of the environment and may be used for seawater quality assessment in future studies.
    Environment International 02/2007; 33(1):27-33. · 6.25 Impact Factor
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    ABSTRACT: Glutathione S-transferase is involved in the detoxication of many chemical compounds. Northern blot analysis of mRNA GST gene from the mussel Mytilus galloprovincialis shows the presence of a transcript of 850 bp (GenBank accession no. Gi:22094808 and AF527010). The cDNA cloned sequence is constituted by an ORF of 621 bp encoding for a protein of 23,700 Da present in the gills and digestive gland of M galloprovincialis. The sequence, called Mg (M. galloprovincialis) GST-p, is clearly related to the pi class GST. M. galloprovincialis treated with Cd (200 microg/L) and BaP (100 microg/L) or co-treated with Cd and BaP take up cadmium in the gills (16.2 +/- 4.2 and 12.6 +/- 1.2 microg Cd/g dry wt. after exposure to Cd and Cd + BaP, respectively) and in the digestive gland. The transcription of GST-pi gene, by semi-quantitative RT-PCR, shows the lowest value in the digestive glands of mussels exposed to BaP, whereas the treatment with cadmium and the co-treatment with cadmium and BaP evoke GST-pi gene expression higher than controls. Mussels collected from six sites along the south coast of Portugal show different GST-pi transcription levels, some of which are related to their pollutant content.
    Comparative Biochemistry and Physiology Part C Toxicology & Pharmacology 07/2006; 143(2):196-203. · 2.71 Impact Factor
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    ABSTRACT: Larval stages of bivalve molluscs are highly sensitive to pollutants. Oysters from a hatchery from Normandy (English Channel) were induced to spawn, and fertilized eggs were exposed to copper or cadmium for 24 h. Metal accumulation (from 0.125 to 5 microg Cu L(-1) and from 25 to 200 microg Cd L(-1)) and MT concentrations were measured in larvae. Compared to controls, larvae accumulated copper and cadmium with an increase in MT concentrations particularly with cadmium (i.e. 130.96 ng Cu (mg protein)(-1) and 12.69 microg MT (mg protein)(-1) at 1 microg Cu L(-1) versus 23.19 ng Cu (mg protein)(-1) and 8.92 microg MT (mg protein)(-1) in control larvae; 334.3 ng Cd (mg protein)(-1) and 11.70 microg MT (mg protein)(-1) at 200 microg Cd L(-1) versus 0.87 ng Cd (mg protein)(-1) and 4.60 microg MT (mg protein)(-1) in control larvae). Larvae were also obtained from oysters of a clean area (Arcachon Bay) and a polluted zone (Bidassoa estuary) and exposed to copper in the laboratory, their MT concentration was measured as well as biomarkers of oxidative stress. Biomarker responses and sensitivity to copper for the larvae from Arcachon oysters were higher than for those from Bidassoa.
    Environmental Pollution 05/2006; 140(3):492-9. · 3.73 Impact Factor
  • Z Sidoumou, M Gnassia-Barelli, Y Siau, V Morton, M Roméo
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    ABSTRACT: Bivalve molluscs from the Western coast of Senegal were sampled and measured for their cadmium, copper and zinc concentrations. This part of Africa has not been studied as regards heavy metal concentrations in the molluscs. The collected species are two small African bivalve molluscs, living in the sand: Cardita ajar and Dosinia isocardia; the African mussel Perna perna which is the only mussel of this genus in the Western coast of Africa and the oyster Crassostrea gasar, which lives in mangroves attached to the rhizophores, in the intertidal zone. C. gasar and C. ajar present higher cadmium concentrations, respectively 6.82+/-0.54 and 13.77+/-0.80 microg Cd/g (d.w.) than the two other species (D. isocardia: 3.88+/-0.31 microg/g and P. perna 2.37+/-0.22 microg/g. Copper and zinc concentrations are in the range of the published values for C. gasar and P. perna collected elsewhere in Africa. The results suggest that cadmium may be present in high concentrations in Senegalese waters where upwellings occur.
    Environment International 05/2006; 32(3):384-7. · 6.25 Impact Factor
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    ABSTRACT: Cadmium, copper and zinc concentrations (in whole soft body and in tissues) were measured in Hexaplex trunculus collected from the Bizerta lagoon in Tunisia. An evaluation of the biological effects of the most toxic metals (cadmium and copper) and of two organics (carbofuran and lindane), present in the sediments of the Bizerta lagoon, was attempted by measuring biomarkers (acetylcholinesterase: AChE, catalase: CAT and glutathione S-transferase: GST activities) in animals experimentally exposed for 48 or 72 h. The concentration ranges as follows: Zn>Cu>Cd. Copper concentrations are highly variable (8.0 to 235 microg g(-1) d.w.) whereas cadmium (range 1.35-4.86 microg g(-1)) and zinc (range 360-1320 microg g(-1)) concentrations are less variable. The digestive gland and the gill take up more metal than the muscle. AChE activity in H. trunculus is decreased by exposure to carbofuran or the mixture carbofuran and cadmium, in the digestive gland and muscle and by copper and by lindane in the digestive gland. AChE is generally inhibited by carbamates but some other compounds may also decrease this activity as observed in this paper. An increase in CAT activity associated with a decrease in GST activity is noted in the muscle of H. trunculus exposed to cadmium, to carbofuran and to the mixture of cadmium and carbofuran, and in the digestive gland of animals exposed to lindane. These pollutants may act upon glutathione and decrease the GST activity that cannot detoxify them and CAT activity has a protective effect. On the contrary, copper increases CAT and GST activities in the digestive gland of exposed gastropods; these enzymes seem to cooperate and play together their rôle of anti-oxidant enzymes. If H. trunculus is not a bioindicator species for metal concentrations, due to a high variability in metal concentrations, nevertheless the biochemical responses to pollutants (cadmium, copper, carbofuran and lindane) represented by AChE, CAT and GST activities may act as biomarkers of exposure in this species.
    Science of The Total Environment 05/2006; 359(1-3):135-44. · 3.16 Impact Factor
  • Z Sidoumou, M Gnassia-Barelli, Y Siau, V Morton, M Roméo
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    ABSTRACT: No abstract available.
    Bulletin of Environmental Contamination and Toxicology 06/2005; 74(5):988-95. · 1.11 Impact Factor
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    M Roméo, C Frasila, M Gnassia-Barelli, G Damiens, D Micu, G Mustata
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    ABSTRACT: In a preliminary biomonitoring study, accumulated trace metal concentrations (Cd, Cu, Zn, Hg, Fe, Mn) have been measured in the mussel Mytilus galloprovincialis collected in the Black Sea, at 100 km from the Danube Delta in February 2001 and February 2002. Mussels were collected from four sites. In 2001 metal concentrations were determined in the whole soft body whereas, in 2002, the distribution of metals was evaluated in three different organs (gills, visceral mass and remaining tissues). The results obtained in 2002 confirmed those of 2001. For a given site, concentrations were always higher in the gills and visceral mass of mussels than in the remaining tissues. Principal component analysis allowed separating stations as a function of the metal concentrations in the organs. It is concluded that the mussels M. galloprovincialis are suitable biomonitors to assess changes in metal pollution in this coastal area of the Black Sea.
    Water Research 03/2005; 39(4):596-604. · 4.66 Impact Factor
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    G Damiens, E His, M Gnassia-Barelli, F Quiniou, M Roméo
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    ABSTRACT: Crassostrea gigas D-shaped larvae were subjected to different conditions of temperature and salinity for 24 h and four biomarkers (acetylcholinesterase (AChE) activity, thiobarbituric acid reactive substances (TBARS) levels, glutathione S-transferase (GST) and catalase (CAT) activities) were measured. AChE activity decreased when salinity increased from 25 to 30 and 35 psu at 20 and 25 degrees C. Temperature did not seem to have an influence on AChE activity. TBARS levels increased as a function of salinity when the temperature was maintained at 20 degrees C, whereas at 25 degrees C no effect of salinity could be observed. Variations in GST and CAT activities were not significant with salinity and temperature except that catalase activity was higher at 25 degrees C than at 20 degrees C. Exposure experiments were conducted at 23 degrees C and 30 psu with carbofuran (100 and 1000 microg/l) and malathion (100 and 300 microg/l). There was an inhibition of AChE activity with carbofuran, and a toxic effect shown by an increase in TBARS levels counteracted by increases in GST and CAT activities which protected the larvae. When two pairs of adults producing larvae were taken into consideration, significant differences in biomarker levels were noted between the larval offspring of each pair. Malathion induced a decrease in AChE activity and an increase in CAT activity.
    Comparative Biochemistry and Physiology Part C Toxicology & Pharmacology 07/2004; 138(2):121-8. · 2.71 Impact Factor
  • Mohamed Dellali, Michèle Romeo, Mauricette Gnassia-Barelli, Patricia Aïssa
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    ABSTRACT: From May 1998 to May 1999, the clams Ruditapes decussatus were collected each month at three stations of the Bizerta lagoon. This paper represents a synthesis between the results already published of catalase (CAT) activity, of glutathione S-transferase (GST) activity and acetylcholinesterase (AChE) activity measured in the clams. Hydrological parameters (temperature, salinity, dissolved oxygen, pH) were determined. Microbial loads (total aerobic bacteria, faecal bacteria and Vibrionaceae) were analyzed in the clams and the sediments. A global Principal Component Analysis was performed including all parameters. On the first principal axis, the temperature, salinity and bacterial loads as well as CAT activities were important factors always opposed to dissolved oxygen, whereas, on the second axis, AChE activity was opposed to pH. Principal Component Analyses were also carried out for results at each station with all parameters. CAT activities were generally high in summer from July to October. AChE activities were low during the months of January, February and March at one station whereas these low activities were shifted to the months of May, June and July at the two other stations. Among the biochemical biomarkers studied, the variations in CAT activities appeared to be the most significant factor of the multivariate analysis. The variations in AChE activity were also significant whereas those in GST activity appeared to be less significant.
    Water Air and Soil Pollution 06/2004; 156(1):131-144. · 1.75 Impact Factor
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    ABSTRACT: The effects of 4,4'DDE, methoxychlor and imidazole were studied on glutathione S-transferase activities in the gills and hepatopancreas of the clam Ruditapes decussatus. The contamination doses were 0.14 microM for 4,4'DDE, 0.14 microM for methoxychlor and 25 microM for imidazole. GST activities were spectrophotometrically measured. SDS-PAGE and isoelectric focusing (IEF) were used to separate the different GST isoforms in control and treated animals, followed by Western blotting performed with anti-alpha, anti-mu and anti-pi GST anti-sera. In the hepatopancreas, GST-CDNB activities were always two to five-fold lower than in the gills where the activities were significantly increased after exposure to 4,4'DDE (ca. 1.6-fold) and to methoxychlor (ca. 1.3-fold) compared to the controls (ca. 3 micromolmin(-1)mg(-1)protein) whereas they remained unchanged after treatment with imidazole. When using glutathione S-transferase anti-alpha, anti-mu and anti-pi anti-sera, a single 26 kDa polypeptide was observed in the hepatopancreas and in the gills in all the tested conditions. Five GST subunits were observed after IEF showing greater immuno-reactivity with the anti-pi mammalian class antiserum than with the anti-alpha or anti-mu mammalian anti-sera. One isoform of pI 5.77 was particularly induced by 4,4'DDE and methoxychlor; it was recognized by the three anti-sera tested and seemed to be more efficient in the gills than in the hepatopancreas. This isoform may play a role in organochlorine detoxication.
    Aquatic Toxicology 06/2004; 68(1):87-94. · 3.51 Impact Factor
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    ABSTRACT: The clam Ruditapes decussatus is distributed worldwide and due to its ecological and economical interest has been proposed as a bioindicator in areas where mussels are not available. The accumulation of several anthropogenic compounds in their tissues suggests that they possess mechanisms that allow them to cope with the toxic effects of these contaminants. Besides pollutant uptake, the use of biomarkers is pointed out in this paper since it is a promising approach to monitor the effect of these contaminants in the marine environment. Biomarkers complement the information of the direct chemical characterization of different types of contaminants. Therefore, the aim of this paper is to review the role of several biomarkers: (metallothioneins (MT), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidases (GPx) (total and selenium-dependent), lipid peroxidation (measured as MDA, one of the final products of lipid peroxidation), glutathione S-transferase (GST) and acetylcholinesterase (AChE), measured in different tissues of the clam R. decussatus, in laboratory conditions and under various environmental stresses, in two ecosystems (Ria Formosa lagoon- Portugal) and Bizerta lagoon (Tunisia) in a perspective of a multibiomarker approach to assess environmental changes. Experiment and field studies are in good agreement since MT levels, especially in the gills, the first target tissue of these contaminants, can be used as biomarker of exposure to Cd. GPx and MDA may also be determined in this respect. AChE activity is inhibited by pesticide and, to a less extent, by metal exposure in the gills and whole soft body of clams. However, the induction of GST isoforms experimentally demonstrated is not observed in the field because only global GST activity was determined. The whole set of results opens new research perspectives for the use of this species to assess the effect of mixtures of pollutants in the aquatic environment.
    Biomarkers 01/2004; 9(4-5):305-30. · 1.88 Impact Factor
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    ABSTRACT: An active biomonitoring experiment was performed using mussels collected at a clean site, Fier d'Ars, and transplanted to two locations, outside the harbor of La Rochelle and in the Baie de L'Aiguillon along the coast of Charentes (French Atlantic coast) beginning in April for several months. Mussels were collected in June and October. The cadmium, copper, and zinc concentrations of all resident and transplanted mussel samples and the polycyclic aromatic hydrocarbon and polychlorinated biphenyl concentrations in some mussel samples and in the sediment samples were determined. Mussel response was evaluated for several biochemical biomarkers: concentrations of metallothionein, activities of glutathione S-transferase and acetylcholinesterase (AChE) and levels of thiobarbituric reactive substance (TBARS). The physiological status of the animals was assessed using the condition index. A principal component analysis performed with the chemical and biochemical results of the evaluations of the resident and transplanted mussels collected in June allowed them to be separated into three groups: resident mussels from la Rochelle with high metal and TBARS levels, resident mussels from Baie de L'Aiguillon with a very high condition index, and resident mussels from Fier d'Ars and transplanted mussels at La Rochelle and Baie de L'Aiguillon with low TBARS and AChE activities. Strong seasonal variation from June to October of all parameters was noted. Mussels transplanted to La Rochelle appeared to be the most "polluted" in their pollutant concentrations and biochemical responses; moreover, the La Rochelle site had the highest concentration of organics in sediments of all the sites. The choice of Fier d'Ars as a reference site may be questionable because some of the biomarker responses of the mussels were higher than expected there, although these pollutants in mussels and sediment were present at the lowest concentrations measured.
    Environmental Toxicology 11/2003; 18(5):295-305. · 2.71 Impact Factor
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    ABSTRACT: Mussels, coming from an aquaculture farm located in a clean open bay, were transplanted to several stations of the bays of Nice and Cannes (NW Mediterranean) including a reference site for one month at three periods. Several biomarkers: activities of glutathione S-transferase (GST; exposure to organics), of catalase (exposure to oxidative stress) and of acetylcholinesterase (inhibited by some pesticides) and the lipid peroxidation (thiobarbituric acid reactive substances: TBARS) were measured in transplanted mussels. Cd, Cu and Zn concentrations were also measured as well as their condition index. The results demonstrated some seasonal variations in GST and catalase activities with higher levels in June compared to October. The condition index was also higher in June than in October. Principal component analyses performed with the whole set of data allowed to separate stations or groups of stations according to their responses. The mussels from the harbour of Nice were characterized by high TBARS levels and catalase activity in October 1999 whereas in the harbour of Cannes, animals presented very high copper concentrations and GST activities in June 2000. At the reference site, mussels generally presented low enzymatic activities (except AChE activity) and peroxidation levels and low heavy metal concentrations.
    Environmental Pollution 02/2003; 122(3):369-78. · 3.73 Impact Factor
  • Lila Ferrat, Mauricette Gnassia-Barelli, Christine Pergent-Martini, Michèle Roméo
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    ABSTRACT: Mercury concentrations, non-protein thiol levels and the enzyme activities of glutathione-S-transferase (GST) were measured in the blades and sheaths of the marine phanerogam Posidonia oceanica. The seagrass was collected in January and June and at three sites: the Bay of Rosignano (Italy) known for its mercury contamination, the north of the Lérins islands (Bay of Cannes, France), the Bay of Tonnara (Corsica, France). The two latter sites are considered as free of any known industrial inputs. Mercury concentrations and GST activities in both tissues were always higher in samples from Rosignano, particularly in June. Non-protein thiol levels were significantly higher in the blades than in the sheaths of P. oceanica from Tonnara and Lérins. In contrast, at Rosignano, the sheaths presented a significantly higher non-protein thiol concentration than the blades, particularly in June. Levels in the sheaths appeared to increase with the degree of pollution. Western Blot performed on sheaths of P. oceanica collected in June at Rosignano and Lérins revealed a characteristic band of GSTs at 31 kDa, proving the presence of the GST enzyme in this tissue. Mercury seemed to exert an influence upon non-protein thiol metabolism, including GST induction, in P. oceanica collected from the NW Mediterranean.
    Comparative Biochemistry and Physiology Part C Toxicology & Pharmacology 02/2003; 134(1):147-55. · 2.71 Impact Factor
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    ABSTRACT: The aim of this study was to examine the experimental uptake of mercury and the enzymatic response, i.e., glutathione S-transferase (GST) activity, to this metal introduced into the medium under organic (methylmercury chloride) and nonorganic (mercury chloride) forms. Shoots of Posidonia oceanica were collected in a nonpolluted area in the northwestern Mediterranean Sea and were treated in aquaria with increasing mercury concentrations/exposure times (48, 96, and 144 h). Compared with the controls, a significant uptake was noted in the blades contaminated by HgCl2, whereas in the sheaths, a significant decrease of total mercury was noted. The blades exposed to CH3HgCl exhibited higher mercury concentrations than the controls; after 144 h exposure to organic mercury, the levels found in the blades were approximately sevenfold the values of the controls. The uptake noted in the sheaths treated with organic mercury followed the same pattern as with HgCl2 (decreased value compared with the controls) except after 144 h, where a slight increase in mercury was found in this tissue. The percentage of organic mercury in controls and treated blades and sheaths (treatment with both forms of mercury) represented always more than 50% of the total mercury in the plant. Glutathione S-transferase activities were significantly increased in the blades and sheaths of P. oceanica exposed to mercury chloride, whereas exposure to methylmercury was not significant. The presence of a GST isoform of 31 kDa was demonstrated by immunochemical methods (Western blotting) in the sheaths but not in the blades of the phanerogam.
    Environmental Toxicology and Chemistry 12/2002; 21(11):2365-71. · 2.62 Impact Factor
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    ABSTRACT: This paper deals with the purification and the partial characterization of glutathione S-transferase (GST) isoforms from the clam Ruditapes decussatus. For the first step of purification, two affinity columns, reduced glutathione (GSH)-agarose and S-hexyl GSH-agarose, were mounted in series. Four affinity fractions were thus recovered. Further purification was performed using anion exchange chromatography. Seven fractions, which present a GST activity with 1-chloro-2,4-dinitrobenzene (CDNB) as substrate, were collected and analyzed by RP-HPLC. Seven distinct GST isoforms were purified, six of them were homodimers, the last one was a heterodimer consisting of the subunits 3 and 6. Kinetic parameters were studied. Results showed that isoforms have distinct affinity and Vmax for GSH and CDNB as substrates. The catalytic activity of the heterodimer isoform appeared to be a combination of the ability of each subunit. The immunological properties of each purified isoform were investigated using three antisera anti-pi, anti-mu and anti-alpha mammalian GST classes. Three isoforms (3-3, 6-6 and 3-6) seem to be closely related to the pi-class GST. Both isoforms 1-1 and 2-2 cross-reacted with antisera to pi and alpha classes and the isoform 5-5 cross-reacted with the antisera to mu and pi classes. Subunit 4 was recognized by the three antisera used, and its N-terminal amino acid analysis showed high identity (53%) with a conserved sequence of an alpha/m micro /pi GST from Fasciola hepatica.
    European Journal of Biochemistry 10/2002; 269(17):4359-66. · 3.58 Impact Factor

Publication Stats

1k Citations
110.90 Total Impact Points

Institutions

  • 2006
    • Université de Nouakchott
      Nouakchot, Nouakchott, Mauritania
  • 2004
    • Universidade do Algarve
      Фару, Faro, Portugal
  • 1995–2004
    • University of Nice-Sophia Antipolis
      • Faculté des Sciences
      Valbonne, Provence-Alpes-Cote d'Azur, France
  • 1980–1991
    • French Institute of Health and Medical Research
      Lutetia Parisorum, Île-de-France, France
  • 1990
    • Unité Inserm U1077
      Caen, Lower Normandy, France
  • 1989
    • Observatoire Océanologique de Villefranche sur Mer
      Villefranche, Provence-Alpes-Côte d'Azur, France