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Francis Andreux - One of the best experts on this subject based on the ideXlab platform.
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leaching of Oryzalin and diuron through undisturbed vineyard soil columns under outdoor conditions
Chemosphere, 2006Co-Authors: David Landry, Sylvie Dousset, Francis AndreuxAbstract:Field studies monitoring herbicide pollution in the vineyards of Burgundy (France) have revealed that drinking water reservoirs are contaminated with several pre-emergence herbicides. An assessment of the leaching of two such herbicides, diuron and Oryzalin, was therefore performed using lysimeters, under outdoor conditions, from May 2001 to May 2002. Four vineyard soils from Vosne-Romanee (Burgundy) were chosen along a topolithosequence: a rendosol and three calcosols. After 673 mm of rainfall, greater amounts of diuron than Oryzalin were measured in percolates: respectively 0.10-0.84% and 0.02-0.43% of applied herbicide, depending on soils. Measurements for diuron metabolites detected greater amounts of DCPMU than DCPU in the percolates: respectively 0.05-0.13% and 0-0.04% of the applied diuron. At the end of the monitoring period, more residues of diuron than Oryzalin were recovered in the soil profiles: respectively 4.6-9% and 1.4-4.4%. The Oryzalin residues were found mainly in the upper 10 cm of soil columns, whereas diuron residues were present in the whole core. The mobility of both Oryzalin and diuron seems fairly well-related to soil organic carbon content; the mobility of diuron is also related to soil texture (sand and coarse material contents). Under such experimental conditions, this study confirms that diuron leaching, and therefore potential groundwater contamination, is greater than that of Oryzalin.
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laboratory leaching studies of Oryzalin and diuron through three undisturbed vineyard soil columns
Chemosphere, 2004Co-Authors: David Landry, Sylvie Dousset, Francis AndreuxAbstract:The leaching of diuron and Oryzalin through undisturbed soil columns was studied in the laboratory using three vineyard soils from Vosne-Romanee (Burgundy): a rendosol, a calcosol and a vegetated calcosol. After 845 mm of simulated rainfall in 15 days, soil leachates contained higher amounts of diuron (3.2%, 11.8% and 18.8% of applied diuron, respectively) than Oryzalin (0.2%, 4.9%, 3.7%, respectively). A greater proportion of soil extractable residues was obtained for diuron (42.5%, 26.8% and 32.2%, respectively) than for Oryzalin (14.7%, 12% and 15.5%, respectively). The greater mobility of diuron might be related to its higher water solubility (36.4 mgl(-1) compared with 2.6 mgl(-1) for Oryzalin) and smaller adsorption coefficient (400 lkg(-1), compared with 700-1100 lkg(-1) for Oryzalin). The mobility of the two herbicides was greater in the two calcosols than in the rendosol, not only due to different organic carbon contents but also different soil textures and structures.
David Landry - One of the best experts on this subject based on the ideXlab platform.
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leaching of Oryzalin and diuron through undisturbed vineyard soil columns under outdoor conditions
Chemosphere, 2006Co-Authors: David Landry, Sylvie Dousset, Francis AndreuxAbstract:Field studies monitoring herbicide pollution in the vineyards of Burgundy (France) have revealed that drinking water reservoirs are contaminated with several pre-emergence herbicides. An assessment of the leaching of two such herbicides, diuron and Oryzalin, was therefore performed using lysimeters, under outdoor conditions, from May 2001 to May 2002. Four vineyard soils from Vosne-Romanee (Burgundy) were chosen along a topolithosequence: a rendosol and three calcosols. After 673 mm of rainfall, greater amounts of diuron than Oryzalin were measured in percolates: respectively 0.10-0.84% and 0.02-0.43% of applied herbicide, depending on soils. Measurements for diuron metabolites detected greater amounts of DCPMU than DCPU in the percolates: respectively 0.05-0.13% and 0-0.04% of the applied diuron. At the end of the monitoring period, more residues of diuron than Oryzalin were recovered in the soil profiles: respectively 4.6-9% and 1.4-4.4%. The Oryzalin residues were found mainly in the upper 10 cm of soil columns, whereas diuron residues were present in the whole core. The mobility of both Oryzalin and diuron seems fairly well-related to soil organic carbon content; the mobility of diuron is also related to soil texture (sand and coarse material contents). Under such experimental conditions, this study confirms that diuron leaching, and therefore potential groundwater contamination, is greater than that of Oryzalin.
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laboratory leaching studies of Oryzalin and diuron through three undisturbed vineyard soil columns
Chemosphere, 2004Co-Authors: David Landry, Sylvie Dousset, Francis AndreuxAbstract:The leaching of diuron and Oryzalin through undisturbed soil columns was studied in the laboratory using three vineyard soils from Vosne-Romanee (Burgundy): a rendosol, a calcosol and a vegetated calcosol. After 845 mm of simulated rainfall in 15 days, soil leachates contained higher amounts of diuron (3.2%, 11.8% and 18.8% of applied diuron, respectively) than Oryzalin (0.2%, 4.9%, 3.7%, respectively). A greater proportion of soil extractable residues was obtained for diuron (42.5%, 26.8% and 32.2%, respectively) than for Oryzalin (14.7%, 12% and 15.5%, respectively). The greater mobility of diuron might be related to its higher water solubility (36.4 mgl(-1) compared with 2.6 mgl(-1) for Oryzalin) and smaller adsorption coefficient (400 lkg(-1), compared with 700-1100 lkg(-1) for Oryzalin). The mobility of the two herbicides was greater in the two calcosols than in the rendosol, not only due to different organic carbon contents but also different soil textures and structures.
Sylvie Dousset - One of the best experts on this subject based on the ideXlab platform.
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leaching of Oryzalin and diuron through undisturbed vineyard soil columns under outdoor conditions
Chemosphere, 2006Co-Authors: David Landry, Sylvie Dousset, Francis AndreuxAbstract:Field studies monitoring herbicide pollution in the vineyards of Burgundy (France) have revealed that drinking water reservoirs are contaminated with several pre-emergence herbicides. An assessment of the leaching of two such herbicides, diuron and Oryzalin, was therefore performed using lysimeters, under outdoor conditions, from May 2001 to May 2002. Four vineyard soils from Vosne-Romanee (Burgundy) were chosen along a topolithosequence: a rendosol and three calcosols. After 673 mm of rainfall, greater amounts of diuron than Oryzalin were measured in percolates: respectively 0.10-0.84% and 0.02-0.43% of applied herbicide, depending on soils. Measurements for diuron metabolites detected greater amounts of DCPMU than DCPU in the percolates: respectively 0.05-0.13% and 0-0.04% of the applied diuron. At the end of the monitoring period, more residues of diuron than Oryzalin were recovered in the soil profiles: respectively 4.6-9% and 1.4-4.4%. The Oryzalin residues were found mainly in the upper 10 cm of soil columns, whereas diuron residues were present in the whole core. The mobility of both Oryzalin and diuron seems fairly well-related to soil organic carbon content; the mobility of diuron is also related to soil texture (sand and coarse material contents). Under such experimental conditions, this study confirms that diuron leaching, and therefore potential groundwater contamination, is greater than that of Oryzalin.
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laboratory leaching studies of Oryzalin and diuron through three undisturbed vineyard soil columns
Chemosphere, 2004Co-Authors: David Landry, Sylvie Dousset, Francis AndreuxAbstract:The leaching of diuron and Oryzalin through undisturbed soil columns was studied in the laboratory using three vineyard soils from Vosne-Romanee (Burgundy): a rendosol, a calcosol and a vegetated calcosol. After 845 mm of simulated rainfall in 15 days, soil leachates contained higher amounts of diuron (3.2%, 11.8% and 18.8% of applied diuron, respectively) than Oryzalin (0.2%, 4.9%, 3.7%, respectively). A greater proportion of soil extractable residues was obtained for diuron (42.5%, 26.8% and 32.2%, respectively) than for Oryzalin (14.7%, 12% and 15.5%, respectively). The greater mobility of diuron might be related to its higher water solubility (36.4 mgl(-1) compared with 2.6 mgl(-1) for Oryzalin) and smaller adsorption coefficient (400 lkg(-1), compared with 700-1100 lkg(-1) for Oryzalin). The mobility of the two herbicides was greater in the two calcosols than in the rendosol, not only due to different organic carbon contents but also different soil textures and structures.
Antonio J Almeida - One of the best experts on this subject based on the ideXlab platform.
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liposomes versus lipid nanoparticles comparative study of lipid based systems as Oryzalin carriers for the treatment of leishmaniasis
Journal of Biomedical Nanotechnology, 2014Co-Authors: Rui Lopes, Maria Manuela Gaspar, Joao D Pereira, Carla Eleuterio, M Carvalheiro, Antonio J Almeida, Mem CruzAbstract:Main-stay in treatment of leishmaniasis relies on chemotherapy but none of the current drugs combines high activity and low toxicity at affordable costs. Dinitroanilines are a new class of drugs with proved in vitro antileishmanial activity. However the development of their pharmaceutical formulations has been compromised by low water solubility and low accumulation in diseased organs. These limitations can be overcome by incorporation in lipid-based nanoformulations such as liposomes and solid lipid nanoparticles. In previous work this strategy was already followed with the incorporation of a dinitroaniline, Oryzalin, resulting in the improvement of the biodistribution profile. The present work aims at demonstrating the in vitro and in vivo therapeutic activity of these Oryzalin nanoformulations, and establishing a systematic comparison of both systems. After Oryzalin incorporation suitable physicochemical properties for parenteral administration were obtained. Nanoformulations revealed reduced cytotoxicity and haemolytic activity when compared with free-Oryzalin, while retaining the in vitro intracellular activity. Therapeutic activity, assessed in a murine model of visceral leishmaniasis, was evaluated in terms of number of administrations, dose-response and influence of the lipid excipient. Results demonstrate the superiority of both Oryzalin nanoformulations on the reduction of parasitic burden in liver and spleen as compared to the control group (84 to 91%) and similar to Glucantime. A strong reduction in ED50 values (3 to 65 fold) as compared to free-Oryzalin was also obtained, depending on the organ and nanoformulation used. Both Oryzalin nanoformulations are potential candidates as therapeutic agents against visceral leishmaniasis.
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lipid nanoparticles containing Oryzalin for the treatment of leishmaniasis
European Journal of Pharmaceutical Sciences, 2012Co-Authors: Rui Lopes, Carla Eleuterio, Mem Cruz, Lidia M Goncalves, Antonio J AlmeidaAbstract:Oryzalin is a dinitroaniline drug that has attracted recent interest for the treatment of leishmaniasis. Its use as an antiparasitic therapeutic agent is limited by the low water solubility associated with an in vivo rapid clearance, leading to the administration of larger and possibly toxic doses in in vivo studies, and the use of solvents that may lead to undesirable side effects. In the present work Oryzalin-containing lipid nanoparticles were produced by a emulsion-solvent evaporation technique using a composition suitable for parenteral administration, i.e., tripalmitin (solid lipid) and a complex mixture of three emulsifying agents (soya lecithin, Tween® 20 and sodium deoxycholate). Physicochemical characterization included the determination of mean particle size, polydispersity index, zeta potential, encapsulation efficiency and DSC studies. Final formulations revealed values of 75%. The effects of various processing parameters, such as lipid and surfactant and composition and concentration, as well as the stability during the harsh procedures of autoclaving (121°C/15 min) and freeze-drying were also evaluated. Formulations revealed to be stable throughout freeze-drying and moist-heath sterilization without significant variations on physicochemical properties and no significant Oryzalin losses. The use of a complex surfactant mixture proved crucial for preserving formulation stability. Particularly, lecithin appears as a key component in the stabilization of tripalmitin-based Oryzalin-containing lipid nanoparticles. Finally, cell viability studies demonstrated that the incorporation of Oryzalin in nanoparticles decreases cytotoxicity, thus suggesting this strategy may improve tolerability and therapeutic index of dinitroanilines.
Michael L. Johnson - One of the best experts on this subject based on the ideXlab platform.
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surflan and Oryzalin impair reproduction in the teleost medaka oryzias latipes
Marine Environmental Research, 2007Co-Authors: Linda C. Hall, Michael L. Johnson, Mark S Okihiro, Swee J TehAbstract:Abstract We conducted studies to determine if the xenoestrogens Surflan™ and its active ingredient Oryzalin, affect indices of reproductive fitness in medaka ( Oryzias latipes ). Oryzalin (0.5, 0.25 mg/l) or Surflan™ (2.0 μl/l) and Oryzalin (0.5 mg/l) significantly increased the mean number of non-fertilized eggs produced by treated females paired with untreated males, or by untreated females paired with treated males. Oryzalin (1.0, 0.5, 0.25 mg/l) and Surflan™ (3.8, 2.0, 1.0 μl/l) significantly affected the time to hatch of eggs from treated females paired with untreated males, and from untreated females paired with treated males. Surflan™ (3.8, 2.0, 1.0 μl/l) induced intersex lesions in 80–100% of males. Oryzalin-exposed males exhibited a significant increase in the incidence of necrotic spermatids and necrotic spermatogonia, while Oryzalin-exposed females had significantly fewer immature oocytes and an increase in the occurrence of hyperplastic ovaries. Our results indicate that Surflan™ and Oryzalin affect both reproduction and gonadal histology in male and female medaka.
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Identification of the herbicide surflan and its active ingredient Oryzalin, a dinitrosulfonamide, as xenoestrogens
Archives of Environmental Contamination and Toxicology, 2005Co-Authors: Linda C. Hall, J. M. Rogers, Michael S. Denison, Michael L. JohnsonAbstract:Numerous environmental contaminants have been identified as endocrine disruptors (EDs) — substances that alter endocrine homeostasis by interfering with the biological action, production, or pharmacokinetics of endogenous hormones. Xenoestrogens are those EDs whose biological activity is similar to endogenous estrogen. This report presents data that identified Surflan, a proprietary herbicide emulsion, and its active ingredient Oryzalin as xenoestrogens. In vitro, Surflan and Oryzalin activated an estrogen-inducible reporter gene, and Oryzalin competitively displaced 17β-estradiol from the estrogen receptor. In vivo, Surflan and Oryzalin induced expression of estrogen-regulated high-molecular-weight choriogenin genes in medaka (Oryzias latipes). These results are consistent with the characteristics of previously identified xenoestrogens and indicate that Surflan and Oryzalin have the potential to adversely affect numerous estrogen-regulated biological processes.
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identification of the herbicide surflan and its active ingredient Oryzalin a dinitrosulfonamide as xenoestrogens
Archives of Environmental Contamination and Toxicology, 2005Co-Authors: Linda C. Hall, J. M. Rogers, Michael S. Denison, Michael L. JohnsonAbstract:Numerous environmental contaminants have been identified as endocrine disruptors (EDs)--substances that alter endocrine homeostasis by interfering with the biological action, production, or pharmacokinetics of endogenous hormones. Xenoestrogens are those EDs whose biological activity is similar to endogenous estrogen. This report presents data that identified Surflan, a proprietary herbicide emulsion, and its active ingredient Oryzalin as xenoestrogens. In vitro, Surflan and Oryzalin activated an estrogen-inducible reporter gene, and Oryzalin competitively displaced 17beta-estradiol from the estrogen receptor. In vivo, Surflan and Oryzalin induced expression of estrogen-regulated high-molecular-weight choriogenin genes in medaka (Oryzias latipes). These results are consistent with the characteristics of previously identified xenoestrogens and indicate that Surflan and Oryzalin have the potential to adversely affect numerous estrogen-regulated biological processes.