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Détails du magazine
Format
Magazine
eISSN
1337-9569
Première publication
19 Jun 2009
Période de publication
4 fois par an
Langues
Anglais

Chercher

Volume 7 (2014): Edition 1 (March 2014)

Détails du magazine
Format
Magazine
eISSN
1337-9569
Première publication
19 Jun 2009
Période de publication
4 fois par an
Langues
Anglais

Chercher

7 Articles
Accès libre

Antagonism at combined effects of chemical fertilizers and carbamate insecticides on the rice-field N2-fixing cyanobacterium Cylindrospermum sp. in vitro

Publié en ligne: 16 Jul 2014
Pages: 5 - 11

Résumé

Abstract

Effects of chemical fertilizers (urea, super phosphate and potash) on toxicities of two carbamate insecticides, carbaryl and carbofuran, individually to the N2-fixing cyanobacterium, Cylindrospermum sp. were studied in vitro at partially lethal levels (below highest permissive concentrations) of each insecticide. The average number of vegetative cells between two polar heterocysts was 16.3 in control cultures, while the mean value of filament length increased in the presence of chemical fertilizers, individually. Urea at the 10 ppm level was growth stimulatory and at the 50 ppm level it was growth inhibitory in control cultures, while at 100 ppm it was antagonistic, i.e. toxicity-enhancing along with carbaryl, individually to the cyanobacterium, antagonism was recorded. Urea at 50 ppm had toxicity reducing effect with carbaryl or carbofuran. At 100 and 250 ppm carbofuran levels, 50 ppm urea only had a progressive growth enhancing effect, which was marked well at 250 ppm carbofuran level, a situation of synergism. Super phosphate at the 10 ppm level only was growth promoting in control cultures, but it was antagonistic at its higher levels (50 and 100 ppm) along with both insecticides, individually. Potash (100, 200, 300 and 400 ppm) reduced toxicity due to carbaryl 20 and carbofuran 250 ppm levels, but potash was antagonistic at the other insecticide levels. The data clearly showed that the chemical fertilizers used were antagonistic with both the insecticides during toxicity to Cylindrospermum sp.

Keywords

  • cyanobacterium
  • cylindrospermum
  • insecticides
  • chemical fertilizers
  • toxicity
  • antagonism
Accès libre

Comparative study of the fungicide Benomyl toxicity on some plant growth promoting bacteria and some fungi in pure cultures

Publié en ligne: 16 Jul 2014
Pages: 12 - 16

Résumé

Abstract

Six laboratory experiments were carried out to investigate the effect of the fungicide Benomyl on pure cultures of some plant growth promoting bacteria (PGPB) and some fungi. The highest LD50 was recorded for Bacillus circulans and proved to be the most resistant to the fungicide, followed by Azospirillum braziliense, while Penicillium sp. was the most affected microorganism. LD50 values for the affected microorganisms were in 21-240 orders of magnitude lower in comparison with the LD50 value for Azospirillum braziliense. The results indicate a strong selectivity for Benomyl against Rhizobium meliloti and Penicillium sp. when compared to other microorganisms tested. The highest safety coefficient was recorded for Bacillus circulans followed by Azospirillum braziliense, while Rhizobium meliloti, showed the lowest safety coefficient value compared to other bacteria. The lowest toxicity index was recorded for Bacillus circulans and Azospirillum braziliense. The slope of the curves for Bacillus sp. and Rhizobium meliloti was steeper than that of the other curves, suggesting that even a slight increase of the dose of the fungicide can cause a very strong negative effect. In conclusion, Benomyl could be applied without restriction when using inocula based on growth promoting bacteria such as symbiotic nitrogen fixers (Rhizobium meliloti), non-symbiotic nitrogen fixers (Azospirillum braziliense) or potassium solibilizers (Bacillus circulans), given that the fungicide is applied within the range of the recommended field dose.

Mots clés

  • Aspergillus niger
  • Penicillium sp.
  • Fusarium oxysporum
  • Benomyl
  • toxicity
Accès libre

Exposure-dependent variation in cryolite induced lethality in the nontarget insect, Drosophila melanogaster

Publié en ligne: 16 Jul 2014
Pages: 17 - 22

Résumé

Abstract

The starting point of toxicity testing of any chemical in an organism is the determination of its Lethal Concentration 50 (LC50). In the present study, LC50 of a fluorinated insecticide cryolite is determined in a non-target insect model, Drosophila melanogaster. Interestingly, the result shows that acute LC50 of cryolite was much greater in comparison to the chronic one in case of Drosophila larvae. Larvae which were exposed to 65,000 to 70,000 μg/ml cryolite through food showed 50% mortality after 18 hours of acute exposure, whereas only 150 to 160 μg/ml cryolite was sufficient to cause 50% mortality in case of chronic exposure. Thus cryolite in a small amount when applied once cannot produce noticeable changes in Drosophila, whereas the same amount when used continuously can be fatal. The non-feeding pupal stage was also seen to be affected by chemical treatment. This suggests that the test chemical affects the developmental fate and results in failure of adult emergence. Absence of chemical-induced mortality in adults assumes that the toxicity of cryolite might be restricted to the preimaginal stages of the organism. Reduction in body size of larvae after ingestion of cryolite (with food) in acute treatment schedule is another interesting finding of this study. Some individuals consuming cryolite containing food cannot survive whereas the few survivors manifest a significant growth retardation which might be due to a tendency of refusal in feeding. Hence the present findings provide a scope of assessment of risk of other similar non-target groups

Keywords

  • cryolite
  • Drosophila melanogaster
  • fluoride
  • insecticide
  • LC50
Accès libre

Long-term (30 days) toxicity of NiO nanoparticles for adult zebrafish Danio rerio

Publié en ligne: 16 Jul 2014
Pages: 23 - 26

Résumé

Abstract

Nickel oxide in the form of nanoparticles (NiO NPs) is extensively used in different industrial branches. In a test on adult zebrafish, the acute toxicity of NiO NPs was shown to be low, however longlasting contact with this compound can lead to its accumulation in the tissues and to increased toxicity. In this work we determined the 30-day toxicity of NiO NPs using a static test for zebrafish Danio rerio. We found the 30-day LC50 value to be 45.0 mg/L, LC100 (minimum concentration causing 100% mortality) was 100.0 mg/L, and LC0 (maximum concentration causing no mortality) was 6.25 mg/L for adult individuals of zebrafish. Considering a broad use of Ni in the industry, NiO NPs chronic toxicity may have a negative impact on the population of aquatic organisms and on food web dynamics in aquatic systems.

Keywords

  • zebrafish
  • toxicity
  • nickel oxide
  • nanoparticles
Accès libre

Antioxidant action of SMe1EC2, the low-basicity derivative of the pyridoindole stobadine, in cell free chemical models and at cellular level

Publié en ligne: 16 Jul 2014
Pages: 27 - 32

Résumé

Abstract

The aim of the study was to evaluate the antioxidant action of SMe1EC2, the structural analogue of the hexahydropyridoindole antioxidant stobadine. The antiradical activity of SMe1EC2 was found to be higher when compared to stobadine, as determined both in cell-free model systems of AAPH-induced oxidation of dihydrorhodamine 123 and 2´,7´-dichloro-dihydrofluorescein diacetate, and in the cellular system of stimulated macrophages RAW264.7. Analysis of proliferation of HUVEC and HUVEC-ST cells revealed absence of cytotoxic effect of SMe1EC2 at concentrations below 100 μM. The antioxidant activity of SMe1EC2, superior to the parent drug stobadine, is accounted for by both the higher intrinsic free radical scavenging action and by the better bioavailability of the low-basicity SMe1EC2 relative to the high-basicity stobadine.

Keywords

  • antioxidant
  • hexahydropyridoindole
  • SMe1EC2
  • stobadine
  • oxidative stress
Accès libre

Peripheral blood and bone marrow responses under stress of cypermethrin in albino rats

Publié en ligne: 16 Jul 2014
Pages: 33 - 40

Résumé

Abstract

Pyrethroids, commercially available pesticides, are greatly in use these days, and thus they carry considerable chances of contaminating various ecosystems. Haematotoxicity of cypermethrin, a broadly used type II pyrethroid, has been assessed in the present study. Selected parameters included determination of total RBC count, haemoglobin concentration (Hb conc.), packed cell volume (PCV), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), erythrocyte sedimentation rate (ESR), total leukocyte count (TLC), differential leukocyte count (DLC), along with qualitative analysis of blood and bone marrow. Of these parameters, those showing significant decline following cypermethrin intoxication included total RBC count, Hb conc., PCV, MCV, MCH, whereas non-significant decrease was observed in the case of MCHC. ESR, TLC and DLC, on the other hand, increased significantly following cypermethrin intoxication. Qualitative changes included altered red cell morphology such as microcystosis, appearance of stomatocytes, poikilocytosis, giant platelet formation, etc. in peripheral blood and increased erythroid precursors in bone marrow of treated rats. These parameters were however normalised following twenty-two days of recovery phase

Keywords

  • pyrethroid
  • blood
  • toxicity
  • contamination
  • environment
Accès libre

Melatonin protects uterus and oviduct exposed to nicotine in mice

Publié en ligne: 16 Jul 2014
Pages: 41 - 46

Résumé

Abstract

Smoking is associated with higher infertility risk. The aim of this study was to evaluate protective effects of melatonin on the uterus and oviduct in mice exposed to nicotine. Adult female mice (n=32) were divided into four groups. Group A: control animals received normal saline, Group B: injected with nicotine 40 μg/kg, Group C: injected with melatonin 10 μg, Group D: injected with nicotine 40 μg/kg and melatonin 10 μg. All animals were treated over 15 days intraperitoneally. On the 16th day, animals in the estrus phase were dissected and their uterus and oviducts were removed. Immunohistochemistry was recruited for studying apoptosis and for detection of estrogen receptor (ER) alpha in luminal epithelium of the uterus and oviduct. Enzyme-linked immunosorbent assay was used for serum estradiol level determination. Nicotine in group B decreased estradiol level and ERalpha numbers both in the uterus and oviduct (p<0.05). Co-administration of melatonin-nicotine in Group D ameliorated the histology of the uterus and oviduct, increased ERalpha numbers and reduced apoptosis in the uterus and oviduct compared with the nicotine Group B (p<0.05). This study indicates that nicotine impairs the histology of the uterus and oviduct and co-administration of melatonin-nicotine ameliorates these findings, partly through alteration in ERalpha numbers and reduction of apoptosis

Keywords

  • nicotine
  • melatonin
  • uterus
  • oviduct
  • estrogen receptor
7 Articles
Accès libre

Antagonism at combined effects of chemical fertilizers and carbamate insecticides on the rice-field N2-fixing cyanobacterium Cylindrospermum sp. in vitro

Publié en ligne: 16 Jul 2014
Pages: 5 - 11

Résumé

Abstract

Effects of chemical fertilizers (urea, super phosphate and potash) on toxicities of two carbamate insecticides, carbaryl and carbofuran, individually to the N2-fixing cyanobacterium, Cylindrospermum sp. were studied in vitro at partially lethal levels (below highest permissive concentrations) of each insecticide. The average number of vegetative cells between two polar heterocysts was 16.3 in control cultures, while the mean value of filament length increased in the presence of chemical fertilizers, individually. Urea at the 10 ppm level was growth stimulatory and at the 50 ppm level it was growth inhibitory in control cultures, while at 100 ppm it was antagonistic, i.e. toxicity-enhancing along with carbaryl, individually to the cyanobacterium, antagonism was recorded. Urea at 50 ppm had toxicity reducing effect with carbaryl or carbofuran. At 100 and 250 ppm carbofuran levels, 50 ppm urea only had a progressive growth enhancing effect, which was marked well at 250 ppm carbofuran level, a situation of synergism. Super phosphate at the 10 ppm level only was growth promoting in control cultures, but it was antagonistic at its higher levels (50 and 100 ppm) along with both insecticides, individually. Potash (100, 200, 300 and 400 ppm) reduced toxicity due to carbaryl 20 and carbofuran 250 ppm levels, but potash was antagonistic at the other insecticide levels. The data clearly showed that the chemical fertilizers used were antagonistic with both the insecticides during toxicity to Cylindrospermum sp.

Keywords

  • cyanobacterium
  • cylindrospermum
  • insecticides
  • chemical fertilizers
  • toxicity
  • antagonism
Accès libre

Comparative study of the fungicide Benomyl toxicity on some plant growth promoting bacteria and some fungi in pure cultures

Publié en ligne: 16 Jul 2014
Pages: 12 - 16

Résumé

Abstract

Six laboratory experiments were carried out to investigate the effect of the fungicide Benomyl on pure cultures of some plant growth promoting bacteria (PGPB) and some fungi. The highest LD50 was recorded for Bacillus circulans and proved to be the most resistant to the fungicide, followed by Azospirillum braziliense, while Penicillium sp. was the most affected microorganism. LD50 values for the affected microorganisms were in 21-240 orders of magnitude lower in comparison with the LD50 value for Azospirillum braziliense. The results indicate a strong selectivity for Benomyl against Rhizobium meliloti and Penicillium sp. when compared to other microorganisms tested. The highest safety coefficient was recorded for Bacillus circulans followed by Azospirillum braziliense, while Rhizobium meliloti, showed the lowest safety coefficient value compared to other bacteria. The lowest toxicity index was recorded for Bacillus circulans and Azospirillum braziliense. The slope of the curves for Bacillus sp. and Rhizobium meliloti was steeper than that of the other curves, suggesting that even a slight increase of the dose of the fungicide can cause a very strong negative effect. In conclusion, Benomyl could be applied without restriction when using inocula based on growth promoting bacteria such as symbiotic nitrogen fixers (Rhizobium meliloti), non-symbiotic nitrogen fixers (Azospirillum braziliense) or potassium solibilizers (Bacillus circulans), given that the fungicide is applied within the range of the recommended field dose.

Mots clés

  • Aspergillus niger
  • Penicillium sp.
  • Fusarium oxysporum
  • Benomyl
  • toxicity
Accès libre

Exposure-dependent variation in cryolite induced lethality in the nontarget insect, Drosophila melanogaster

Publié en ligne: 16 Jul 2014
Pages: 17 - 22

Résumé

Abstract

The starting point of toxicity testing of any chemical in an organism is the determination of its Lethal Concentration 50 (LC50). In the present study, LC50 of a fluorinated insecticide cryolite is determined in a non-target insect model, Drosophila melanogaster. Interestingly, the result shows that acute LC50 of cryolite was much greater in comparison to the chronic one in case of Drosophila larvae. Larvae which were exposed to 65,000 to 70,000 μg/ml cryolite through food showed 50% mortality after 18 hours of acute exposure, whereas only 150 to 160 μg/ml cryolite was sufficient to cause 50% mortality in case of chronic exposure. Thus cryolite in a small amount when applied once cannot produce noticeable changes in Drosophila, whereas the same amount when used continuously can be fatal. The non-feeding pupal stage was also seen to be affected by chemical treatment. This suggests that the test chemical affects the developmental fate and results in failure of adult emergence. Absence of chemical-induced mortality in adults assumes that the toxicity of cryolite might be restricted to the preimaginal stages of the organism. Reduction in body size of larvae after ingestion of cryolite (with food) in acute treatment schedule is another interesting finding of this study. Some individuals consuming cryolite containing food cannot survive whereas the few survivors manifest a significant growth retardation which might be due to a tendency of refusal in feeding. Hence the present findings provide a scope of assessment of risk of other similar non-target groups

Keywords

  • cryolite
  • Drosophila melanogaster
  • fluoride
  • insecticide
  • LC50
Accès libre

Long-term (30 days) toxicity of NiO nanoparticles for adult zebrafish Danio rerio

Publié en ligne: 16 Jul 2014
Pages: 23 - 26

Résumé

Abstract

Nickel oxide in the form of nanoparticles (NiO NPs) is extensively used in different industrial branches. In a test on adult zebrafish, the acute toxicity of NiO NPs was shown to be low, however longlasting contact with this compound can lead to its accumulation in the tissues and to increased toxicity. In this work we determined the 30-day toxicity of NiO NPs using a static test for zebrafish Danio rerio. We found the 30-day LC50 value to be 45.0 mg/L, LC100 (minimum concentration causing 100% mortality) was 100.0 mg/L, and LC0 (maximum concentration causing no mortality) was 6.25 mg/L for adult individuals of zebrafish. Considering a broad use of Ni in the industry, NiO NPs chronic toxicity may have a negative impact on the population of aquatic organisms and on food web dynamics in aquatic systems.

Keywords

  • zebrafish
  • toxicity
  • nickel oxide
  • nanoparticles
Accès libre

Antioxidant action of SMe1EC2, the low-basicity derivative of the pyridoindole stobadine, in cell free chemical models and at cellular level

Publié en ligne: 16 Jul 2014
Pages: 27 - 32

Résumé

Abstract

The aim of the study was to evaluate the antioxidant action of SMe1EC2, the structural analogue of the hexahydropyridoindole antioxidant stobadine. The antiradical activity of SMe1EC2 was found to be higher when compared to stobadine, as determined both in cell-free model systems of AAPH-induced oxidation of dihydrorhodamine 123 and 2´,7´-dichloro-dihydrofluorescein diacetate, and in the cellular system of stimulated macrophages RAW264.7. Analysis of proliferation of HUVEC and HUVEC-ST cells revealed absence of cytotoxic effect of SMe1EC2 at concentrations below 100 μM. The antioxidant activity of SMe1EC2, superior to the parent drug stobadine, is accounted for by both the higher intrinsic free radical scavenging action and by the better bioavailability of the low-basicity SMe1EC2 relative to the high-basicity stobadine.

Keywords

  • antioxidant
  • hexahydropyridoindole
  • SMe1EC2
  • stobadine
  • oxidative stress
Accès libre

Peripheral blood and bone marrow responses under stress of cypermethrin in albino rats

Publié en ligne: 16 Jul 2014
Pages: 33 - 40

Résumé

Abstract

Pyrethroids, commercially available pesticides, are greatly in use these days, and thus they carry considerable chances of contaminating various ecosystems. Haematotoxicity of cypermethrin, a broadly used type II pyrethroid, has been assessed in the present study. Selected parameters included determination of total RBC count, haemoglobin concentration (Hb conc.), packed cell volume (PCV), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), erythrocyte sedimentation rate (ESR), total leukocyte count (TLC), differential leukocyte count (DLC), along with qualitative analysis of blood and bone marrow. Of these parameters, those showing significant decline following cypermethrin intoxication included total RBC count, Hb conc., PCV, MCV, MCH, whereas non-significant decrease was observed in the case of MCHC. ESR, TLC and DLC, on the other hand, increased significantly following cypermethrin intoxication. Qualitative changes included altered red cell morphology such as microcystosis, appearance of stomatocytes, poikilocytosis, giant platelet formation, etc. in peripheral blood and increased erythroid precursors in bone marrow of treated rats. These parameters were however normalised following twenty-two days of recovery phase

Keywords

  • pyrethroid
  • blood
  • toxicity
  • contamination
  • environment
Accès libre

Melatonin protects uterus and oviduct exposed to nicotine in mice

Publié en ligne: 16 Jul 2014
Pages: 41 - 46

Résumé

Abstract

Smoking is associated with higher infertility risk. The aim of this study was to evaluate protective effects of melatonin on the uterus and oviduct in mice exposed to nicotine. Adult female mice (n=32) were divided into four groups. Group A: control animals received normal saline, Group B: injected with nicotine 40 μg/kg, Group C: injected with melatonin 10 μg, Group D: injected with nicotine 40 μg/kg and melatonin 10 μg. All animals were treated over 15 days intraperitoneally. On the 16th day, animals in the estrus phase were dissected and their uterus and oviducts were removed. Immunohistochemistry was recruited for studying apoptosis and for detection of estrogen receptor (ER) alpha in luminal epithelium of the uterus and oviduct. Enzyme-linked immunosorbent assay was used for serum estradiol level determination. Nicotine in group B decreased estradiol level and ERalpha numbers both in the uterus and oviduct (p<0.05). Co-administration of melatonin-nicotine in Group D ameliorated the histology of the uterus and oviduct, increased ERalpha numbers and reduced apoptosis in the uterus and oviduct compared with the nicotine Group B (p<0.05). This study indicates that nicotine impairs the histology of the uterus and oviduct and co-administration of melatonin-nicotine ameliorates these findings, partly through alteration in ERalpha numbers and reduction of apoptosis

Keywords

  • nicotine
  • melatonin
  • uterus
  • oviduct
  • estrogen receptor

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