chlorophyll-a and cypermethrin

In this study, toxic effects of the cypermethrin in Allium cepa L. cells were investigated. For this aim, we investigated the changes in pigment contents, antioxidant enzymes, mitotic index and chromosomal abnormalities as indicators of toxicity. The seeds were treated with different doses (1.5, 3.0, 6.0 ppm) of cypermethrin for 72 h. The result showed that there was a significant alteration in the tested parameters depending on treatment dose in the seeds exposed to cypermethrin when compared to the control group. Cypermethrin exposure significantly reduced the carotenoid, chlorophyll a and b pigments in all treatment groups. The activity of superoxide dismutase showed a concentration-time dependent increase and the maximum increase was observed on day 15 of treatment at 6.0 ppm cypermethrin exposure. The activity of catalase increased gradually with increasing cypermethrin concentration, but a soft decrease in CAT activity was decreased after 15 days of 1.5 ppm and 3.0 ppm cypermethrin treatment. In the roots treated with 1.5, 3.0, and 6.0 ppm cypermethrin, the level of malondialdehyde was about 1.8, 2.4, and 3.4 times higher than the control group, respectively. It was also found that cypermethrin has a mitodepressive action on mitosis, and the MI was decreased depending on the dose of cyprmethrin. All of the concentrations of cypermethrin induced chromosomal abnormalities and the most common abnormality observed in the present study was chromosome bridges.

Topics: Carotenoids; Catalase; Chlorophyll; Chlorophyll A; Chromosome Aberrations; Chromosomes, Plant; Lipid Peroxidation; Malondialdehyde; Micronucleus Tests; Mitosis; Mitotic Index; Onions; Plant Cells; Plant Leaves; Plant Roots; Pyrethrins; Superoxide Dismutase

The growth of three marine phytoplankton species Skeletonema costatum, Scrippsiella trochoidea and Chattonella marina and the response of the antioxidant defense system have been investigated on exposure to commercial cypermethrin for 96 h and 32 days in a co-culture system. Growth of the three species was generally comparable over 96 h with an inoculation of 1:3:6.5 (C. marina:S. trochoidea:S. costatum), with stimulation at 5 μg l(-1) and inhibition under higher concentrations (50, 100 μg l(-1)). However, when inoculating at ratios of 1:1:1 during a 32 day test, S. costatum became the most sensitive species and was significantly inhibited in all test groups under the dual stresses of cypermethrin and interspecies competition. The growth of C. marina was significantly inhibited at the concentrations higher than 5 μg l(-1), while the growth of S. trochoidea was significantly promoted at low concentrations. Superoxide dismutase (SOD) activities significantly increased during 6-12 h exposure periods in test treatments at low concentrations, and enhanced in the control as well due to interspecies competition. The lipid peroxidation product malondialdehyde was enhanced at high concentrations, but did not increase in control and low concentration cultures with high SOD activities, indicating that algal cells activated the antioxidant enzymes promptly to protect the cells from lipid membrane damage. Results from this study suggested that cypermethrin pollution in maricultural sea waters might lead to a shift in phytoplankton community structure from diatom to harmful dinoflagellate species, and thus potentially stimulatory for harmful algal blooms.

Topics: Alveolata; Biodiversity; Chlorophyll; Chlorophyll A; Diatoms; Lipid Peroxidation; Malondialdehyde; Phytoplankton; Pyrethrins; Superoxide Dismutase; Water Pollutants, Chemical

Microcosm and mesocosm studies evidence that pyrethroid insecticides may have a severe effect on zooplankton populations. The effect may cascade to phytoplankton communities and thus worsen the impact of eutrophication and algal blooms. In natural freshwater systems, pyrethroids are usually only detectable during the first 24 h after application to adjacent areas, a period too short for mesocosm and microcosm studies to reveal potential effects. In this study we compare the effects of environmentally realistic concentrations of the pyrethroid cypermethrin on: (i) the swimming ability of Daphnia magna; (ii) the feeding efficiency, measured as the content of chlorophyll pigments in the gut; and (iii) the total body carbohydrate content. The latter two were measured using a newly developed high performance planar chromatography (HPPC) system. Sublethal effects on the gut content of chlorophyll pigments, carbohydrate substances and the swimming ability of D. magna were observed at nominal concentrations between 0.05 and 0.6 microg cypermethrinL(-1), which lies within the concentration range occurring in freshwater systems after pesticide application. In addition, the content of chlorophyll pigments in the gut was significantly reduced (>50%) after only 6 h of exposure to 0.1 microg cypermethrinL(-1). Most of the D. magna had recovered 3 days after exposure doses lower than 0.2 microg cypermethrinL(-1). We conclude that HPPC analysis of the gut content of chlorophyll pigments was the most sensitive endpoint of our study due to its capacity to detect significant reductions in feeding within hours of exposure to environmentally realistic concentrations of cypermethrin.

Topics: Analysis of Variance; Animal Nutritional Physiological Phenomena; Animals; Chlorophyll; Chromatography; Daphnia; Dose-Response Relationship, Drug; Insecticides; Locomotion; Pyrethrins

The aim of this study was to investigate the short-term (2 weeks) effects of the herbicide metsulfuron methyl alone and in combination with the insecticide cypermethrin in freshwater enclosures (80 l). We used a factorial design with four levels of herbicide (0, 1, 5, 20 microg/l) and two levels of insecticide (0 and 0.05 microg/l). The root growth of the macrophyte species Elodea canadensis and Myriophyllum spicatum decreased following exposure to the lowest concentration of metsulfuron methyl tested. Metsulfuron methyl exposure resulted in a decreased pH in the aquatic enclosure at the lowest concentration tested, which is most likely a further indication of decreased macrophyte primary production. The biomass of periphytic algae growing on the leaves of M. spicatum increased in the enclosures exposed to metsulfuron methyl. The species composition of the periphytic algae differed significantly from the controls in the enclosures exposed to 20 microg/l of the herbicide. The increased biomass of periphytic algae on the leaves of the macrophytes is probably an indirect effect of the herbicide exposure. The exposure to metsulfuron methyl possibly induced a leakage of nutrients from the macrophyte leaves, which promoted an increased algal growth. The exposure to metsulfuron methyl did not alter the biomass or the species composition of the phytoplankton community. The zooplankton communities in the enclosures were dominated by rotifers, which were not affected by the exposure to cypermethrin. However, a cypermethrin exposure of 0.05 microg/l initially decreased the abundance of copepod nauplii. Ten days after exposure, the abundance of nauplii was significantly higher in the insecticide-exposed enclosures compared with the non-exposed enclosures. This might be an indication of a sub-lethal stress response, which either increased the number of offspring produced or induced an increased hatching of copepod resting stages. No combined effects of the herbicide and insecticide exposure, either direct or indirect, were observed in the enclosure study. Significant effects on the macrophytes were observed following exposure to 1 microg metsulfuron methyl per litre in the enclosure study. Furthermore, a single species laboratory assay indicated that the shoot elongation of E. canadensis decreased following exposure to >or=0.1 microg metsulfuron methyl per litre. These concentrations are well within the range of expected environmental concentrations, thus this study s

Topics: Animals; Arylsulfonates; Biomass; Chlorophyll; Chlorophyll A; Drug Interactions; Ecosystem; Environment, Controlled; Environmental Exposure; Fresh Water; Herbicides; Hydrocharitaceae; Insecticides; Models, Biological; Multivariate Analysis; No-Observed-Adverse-Effect Level; Phytoplankton; Plant Roots; Pyrethrins; Saxifragaceae; Toxicity Tests, Acute; Water Pollutants, Chemical; Zooplankton

The effects of two pyrethroid insecticides, cypermethrin and fenvalerate, on a green alga (Scenedesmus bijugatus) and three species of cyanobacteria (Synechococcus elongatus, Nostoc linckia, and Phormidium tenue), all isolated from a black cotton soil, were studied using either cell number or chlorophyll a as toxicity criterion. All the four species were either unaffected or stimulated at 5 micrograms ml-1. Of the two insecticides, cypermethrin, at 10 to 50 micrograms ml-1, inhibited S. bijugatus while these concentrations stimulated or only slightly inhibited the growth of S. elongatus. There was a significant inhibition in the growth of S. bijugatus and stimulation in S. elongatus with 10 to 50 micrograms ml-1 fenvalerate. The growth of N. linckia was enhanced by both insecticides while P. tenue was significantly affected.

Topics: Chlorophyll; Chlorophyll A; Chlorophyta; Cyanobacteria; Insecticides; Nitriles; Pyrethrins; Soil Microbiology

Interactions of several pyrethroids with membrane lipids in the form of dipalmitoylphosphatidylcholine (DPPC) liposomes have been studied using fluorescent membrane probes. Fluorescence anisotropy values and lifetimes (determined by phase-shift and demodulation techniques) of the fluorescent probe, 1,6-diphenyl-1,3,5-hexatriene, were decreased in gel phase liposomes by pyrethroids at concentrations on the order of 10 microM. The pyrethroids containing a cyano substituent were also observed to cause collisional quenching of diphenylhexatriene fluorescence. Pyrethroids differed in their effectiveness at lowering the phase transition temperature of DPPC, and in their ability to broaden the temperature range of this transition. The fluorescence intensity of DPPC-incorporated chlorophyll a was used to monitor the pretransition of DPPC and the lateral diffusion of a membrane component located in the polar headgroup region. Permethrin did not affect chlorophyll a fluorescence intensity at any temperature. It may be concluded from these results that pyrethroids are preferentially located in the interior hydrophobic regions of the lipid bilayer, and that these compounds can disorder hydrocarbon packing in the bilayer core. However, polar headgroups were not disordered, and diffusion of membrane components in the polar headgroup region was not altered.

Topics: Allethrins; Chlorophyll; Diphenylhexatriene; Fluorescence Polarization; Fluorescent Dyes; Liposomes; Nitriles; Permethrin; Phosphatidylcholines; Pyrethrins; Temperature

Topics: Animals; Chlorophyll; Electric Conductivity; Hydrogen-Ion Concentration; Insecticides; Oxygen Consumption; Pyrethrins; Salmonidae; Stereoisomerism; Temperature; Time Factors; Trout

Cypermethrin (Ripcord) was applied at 25 g ai ha-1 by fixed-wing aircraft to a large field (11.6 ha) of winter wheat bordered on three sides by drainage ditches. About 60% of the nominal application rate was deposited on the crop and about 6% (maximum) was deposited over the water surface. The amount of spray drift deposited upwind declined sharply with increasing distance from the treated field. Downwind, the spray drift was small but occurred over a much greater distance. Very low (0.03 micrograms liter-1 maximum) concentrations of cypermethrin were found in subsurface water samples and these declined rapidly after spraying. Bioassay tests, using a sensitive indicator species, confirmed that only a small amount of cypermethrin contamination had occurred in the ditch adjacent to the downwind perimeter of the field. Frequent sampling of the zooplankton and macroinvertebrate fauna of the ditches indicated that there were no marked biological effects resulting from the cypermethrin application. Only a few air-breathing corixids and the highly susceptible water mites showed minor short-term reductions in abundance after spraying. No effects were observed on either caged or indigenous fish stocks and no significant residues of cypermethrin were found in fish tissues.

Topics: Animals; Chlorophyll; Electric Conductivity; Fishes; Fresh Water; Hydrogen-Ion Concentration; Insecticides; Oxygen; Pesticide Residues; Pyrethrins; Time Factors; Water; Water Pollution, Chemical; Zooplankton