• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.4
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• pp.357-362
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• 1997

This study was carried out to investigate the effects of herbicide treatment and seeding method on the forage yield, weed control, and persistency in the Artemisia princeps dominated pasture. It was arranged as a randomized block design with seven treatments(\circled1 oversowing(control),\circled2 glyphosate 4 ${\ell}$/ha + oveysowing a \circled3glyphosate 4 ${\ell}$/ha + chiselreseeding, \circled4 paraquat dichloride 3 ${\ell}$/ha + oversowing,\circled5 paraquat dichloride 3 ${\ell}$/ha + chiselreseeding, \circled6 dicamba 4 ${\ell}$/ha + oversowing and \circled7 dicamba 4 ${\ell}$/ha + chiselreseeding), and conducted at National Livestock Research Institute in Suwon from June, 1985 to October, 1987. In the Artemisia princeps dominated pasture, the treatments of glyphosate 4 ${\ell}$/ha before oversowipg or chisel reseeding controlled 80.7-83.3% of the Artemisia princeps, and for two years the average dry weight of Artemisiaprinceps greatly decreased, but dry matter(DM) yield of forage increased 57-96% than that pf control. In the herbicide treatments, the average DM yield of forage in the plots with chisel r e d i n g was significantly higher when compared to oversowing. The results in this study indicated that herbicide treatment was effective for the control of Artemisiaprinceps, and good renovation of grassland and higher DM yield of forage could be obtained by application of glyphosate.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.1
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• pp.67-74
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• 1997

This experiment was conducted in 1992 and 1993 at the forage experimental field, College of Agriculture and Life Sciences, Seoul National University, Suweon to determine timing of rye(Secde cemde L.) harvest and residue chemical treatment prior to tillage in minimizing the adverse effects of the rye residue on growth and yield of succeeding corn(Zea muys L.). Eight treatments were established in 1993 which included four treatments such as no paraquat (1, l'diiethyl- 4, 4'-bipyridinium dichloride), paraquat treatment at 10, 23, and both 23 and 10 days prior to tillage when rye was harvested on April 14, and another four treatments such as no paraquat, paraquat treatment at 1, 5 and 10 days prior to tillage when rye was harvested on April 26. No paraquat treatment significantly resulted in reductions in corn plant height on June 3 and 10 when rye was harvested on April 14, but differences in the plant height and leaf number of corn among treatments were generally nonsignificant. Corn LA1 and silk emergence were not affected by paraquat treatment times regardless of rye harvested dates, but silk emergence was delayed by 1 to 2 days with no paraquat when rye harvested on April 14. Corn dry matter and TDN yields were significantly increased by paraquat treatment at 10 and 5 days prior to tillage treatment when rye was harvested on April 14 and 26, respectively, but other agronomic characteristics such as dry matter percentage, ear percent to total dry matter, and stover and ear yields of corn at harvest showed little or no response to paraquat treatment times.

• The Korean Journal of Pesticide Science
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• v.2 no.3
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• pp.85-89
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• 1998

Effect of soil residue paraquat (1,1-dimethyl-4,4-dipyridinium dichloride) on growth of barley (Hordeum vulgare L. cv. Sacheon No.6 and cv. Tapgolbori) and soybean [Glycine max (L.) Merr. cv. Alcheon and Danyeop] was investigated. Changes in soil residue paraquat during the cultivation period and residue amount in the p1ants at harvest were also determined. Experiments were conducted at two paraquat residue conditions; the first was done in an apple orchard soil where paraquat residue recorded 30.2 ppm in 1996, but decreased to about 9 to 9.8 ppm at the time of crop seeding and the second was conducted in the soil fortified to about 27 to 32 ppm paraquat residue. In both conditions, no crop injury due to the residue paraquat was observed and number of emerged seedlings and plant height of the two crops were not affected by soil residue paraquat. Residue amount of paraquat in the plants occurred less than 0.5 ppm detection limit. At the first condition, soil residue paraquat was further slightly decreased for 90 days after seeding, while no great change in the residue level was found at the second condition for 30 days after seeding. The results suggest that no carry-over effect occurs at about 30 ppm of soil residue paraquat and at present crop cultivation in Korean orchard soils are safe with respect to crop growth and paraquat residue in the plants.

• The Korean Journal of Pesticide Science
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• v.2 no.3
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• pp.90-95
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• 1998

Soil residues of paraquat (1,1-dimethyl-4,4-dipyridinium dichloride) were determined in apple, pear, grape, and peach orchards for which 15 sites each were selected randomly from the corresponding large-scale production area throughout the country. Strong adsorption capacity measured using wheat bioassay (paraquat concentration required to reduce 50% root growth of wheat, SAC-WB) was also investigated on the orchard soils and the paraquat residue level was calculated against total SAC-WB values (SAC-WB value + paraquat residue). Average bound residue of paraquat on the 60 sites was 6.9 ppm, while paraquat residue in apple orchard reached 20.2 ppm which was the highest among the orchards and was almost double as compared with those in the other three orchards. Loosely bound residue of paraquat determined on the bound residue high top five soils occurred less than 0.5 ppm detection limit. Average SAC-WB value was 276.1 ppm and there were no any correlations between the SAC-WB value and clay content, organic matter content, and cation exchange capacity of the orchard soils. Paraquat residue level of the orchard soils against total SAC-WB recorded 2.43%.

• Toxicological Research
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• v.16 no.2
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• pp.173-178
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• 2000

This study was carried out to investigate cytotoxicity of several herbicides (Bentazone, Butachlor. Paraquat and Ethalfluralin) in cultured mouse NIH 3T3 fibroblasts. Tetrazolium (MTT), neutral red (NR) and sulforhodamine protein B (SRB) of the colorimetric assays were performed to evaluate the cytotoxicity on cell organelles. 2 x 10$^4$cell/$m\ell$ of NIH 3T3 fibroblast in each well of 24 multidish were cultured. After 24 hours, the cells were treated with solution (1, 25, 50 or 100 $\mu$M) of each herbicide. After the NIH 3T3 fibroblasts of all groups were cultured in the same condition for 48 hours, MTT, NR and SRB assays were performed to evaluate the cytotoxicity. The light microscopic study was carried out to examine morphological changes of cultured NIH 3T3 fibroblasts. The MTT$_{50}$ of Bentazone, Butachlor, Paraquat and Ethalfluralin were 1560.97 $\mu$M, 56.15 $\mu$M, 3138.81 $\mu$M and 1301.82 $\mu$M, respectively. The NR$_{50}$ of Bentazone, Butachlor. Paraquat and Ethalfluralin were 1763.93 $\mu$M, 45.98 $\mu$M, 1030.85 $\mu$M and 1808.29 $\mu$M, respectively. The SRB$_{50}$ of Bentazone, Butachlor. Paraquat and Ethalfluralin were 1913.38 $\mu$M, 65.30 $\mu$M, 1860.73 $\mu$M and 1086.93 $\mu$M, respectively. The morphological changes of NIH 3T3 fibroblasts showed severe degeneration in Butachlor 50 $\mu$M and 100 $\mu$M concentrations. These results indicate that Butachlor has high cytotoxicity, Bentazone, Paraquat and Ethalfluralin very weak cytotoxicity against NIH 3T3 fibroblasts.lasts.

• Biomedical Science Letters
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• v.6 no.1
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• pp.45-53
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• 2000

The anti-oxidative effects of Korean red ginseng extracts (total saponine, water extracts, alcohol extracts, lipophilic extracts), which were administered with the concentration of 200 mg/kg BW, were investigated after the injection of paraquat (1,1-dimethyl-4,4-bipyrimidinium dichloride: PQ) with dosage of 100 mg/kg BW on the peritoneal cavity to 6 weeks of 23~26 gm ICR male mice. The accumulation of hydrogen peroxide ($H_2O$$_2$) on the liver of mouse was lowered only in alcohol extract-treated group (p<0.05). The activity of glutathione peroxidase increased in the mouse treated with lipophilic ginseng extracts. And GSSG level was lowered in all groups, and this might be due to the paraquat ions that might prevent the reaction of GSSG into GSH. But we cannot find any relation between glutathione oxide-reductase activity on Korean ginseng extracts. Finally, the lipid peroxidation (MDA) level was lowest (p<0.01) in the group of mouse treated with water extracts of ginseng.

• Journal of Ginseng Research
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• v.23 no.3 s.55
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• pp.182-189
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• 1999

For the determination of anti oxidative effects of Korean red ginseng extracts, 100 mg/kg body weight of paraquat(1,1-dimethyl-4,4-bipyrimidinium dichloride) was injected to peritoneal cavity of 6 weeks 23-27 g of ICR mail mice which were pretreated with 200 mg/kg body weight of korean red ginseng extracts(total saponin, water extracts, alcohol extracts, lipophilic extracts) and ascorbic acid for 5 days. Most of mice died of paraquat toxicity within 4 days except only $30\%$ of ascorbic acid group. The hepatic total-SOD activity in liver was highest in ascorbic acid group and lipophilic ginseng extracts group next (p<0.0l). The level of hepatic hydroperoxide was lowest in the order of in alcohol extracts group, lipophilic extracts group and ascorbic acid group (p<0.0l). The highest catalase activity was induced by ascorbic acid followed by water extracts and lipophillic extracts (p<0.01). Finally, the lipid peroxidation level (malondialdehyde:MDA) was the lowest in water extracts group and ascorbic acid next (p<0.01). The highest MDA level was appeared in praquat group and next total saponin group next. In conclusion, the order of effectiveness of antioxidants was found to be ginseng water extracts> ascorbic acid> lipophillic extracts> other ginseng extracts. It was also found that any predominant antioxidant was not effective evenly to all of antioxidant test.

• Biomolecules & Therapeutics
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• v.23 no.5
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• pp.407-413
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• 2015

Paraquat dichloride (N,N-dimethyl-4-4'-bipiridinium, PQ) is an extremely toxic chemical that is widely used in herbicides. PQ generates reactive oxygen species (ROS) and causes multiple organ failure. In particular, PQ has been reported to be an immunotoxic agrochemical compound. PQ was shown to decrease the number of macrophages in rats and suppress monocyte phagocytic activity in mice. However, the effect of PQ on macrophage cell viability remains unclear. In this study, we evaluated the cytotoxic effect of PQ on the mouse macrophage cell line, RAW264.7 and its possible mechanism of action. RAW264.7 cells were treated with PQ (0, 75, and $150{\mu}M$), and cellular apoptosis, mitochondrial membrane potential (MMP), and intracellular ROS levels were determined. Morphological changes to the cell nucleus and cellular apoptosis were also evaluated by DAPI and Annexin V staining, respectively. In this study, PQ induced apoptotic cell death by dose-dependently decreasing MMP. Additionally, PQ increased the cleaved form of caspase-3, an apoptotic marker. In conclusion, PQ induces apoptosis in RAW264.7 cells through a ROS-mediated mitochondrial pathway. Thus, our study improves our knowledge of PQ-induced toxicity, and may give us a greater understanding of how PQ affects the immune system.

• Journal of Life Science
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• v.18 no.1
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• pp.129-135
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• 2008

Paraquat (1,1-dimethyl 4,4' -dipyridium dichloride; PQ) is a kind of herbicide. Terminalia chebulae (TC) has been used as a medicine in China and in Korea for treating illnesses such as diarrhea, collapsed anus, spasmodic, diphtheria, asthma etc.. This study was to examin new physiological activities of methanol extract of TC (TCM) on the toxicity of PQ. It was observed biochemical effects on the toxicity of PQ in kidney and lung tissues after treatment orally administered 100, 200, 300 mg/kg of TCM daily for two weeks. In the experiment related to the toxicity of PQ, we got following results: renal and pulmonary lipid peroxide contents, activities of aminopyrine N-demethylase, aldehyde oxidase and xanthine oxidase were significantly increased in control group as compared with normal group, in the treatment of TCM the values were decreased as compared with control group. Activities of superoxide dismutase, catalase and glutathione peroxidase which are free radical scavenging enzymes were also increased in control group as compared with normal goup, but were decreased in TCM group as compared with control group. Collagen content and glucose-6-phosphatase activity in lung tissue were increased in control group as compared with normal, but was decreased in TCM group as compared with control group. From these results, we concluded that TCM can playa role as an effective agent to decrease toxicity of PQ.

• Environmental Mutagens and Carcinogens
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• v.25 no.1
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• pp.32-39
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• 2005

In order to identify potential biomarkers of environmental monitoring, we evaluated heat shock genes expressions as effects of various environmental pollutants (nonylphenol, bisphenol-A, 17a­ethynyl estradiol, bis(2-ethylhexyl)phthalate, endosulfan, paraquat dichloride, chloropyriphos, fenitrothion, cadmium chloride, lead nitrate, potassium dichromate, benzo[a]pyrene and carbon tetrachloride) on larvae of aquatic midge Chironomus tentans (Diptera, Chironomidae). Heat shock protein 70 gene expression increased in most of chemicals treated larvae compared to control. The response was rapid and sensitive to low chemical concentrations but not stressor specific. In conjunction with stressor specific biomarkers, heat shock protein 70 gene expression in Chironomus might be developed for assessing exposure to environmental stressors in the fresh water ecosystem. Considering the potential of Chironomus larvae as biomonitoring species, heat shock gene expression has a considerable potential as a sensitive biomarker for environmental monitoring in Chironomus.