• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.04a
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• pp.62-62
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• 1995

한국산 천연자원중 한방이나 민간요법에서 항종양제로 빈번히 사용되어온 생약들 중에서 103종을 선정하여 이들 성분들을 추출하고 시험관내에서 항종양성이 우수하고 정상세포에 손상을 적게 주는 생약 6종을 선별하여 암세포주에 대한 독성능 (in vitro)과 항종양성 면역감시기구(in vivo)및 LD$_{50}$등을 측정하여 항종양제로의 신약개발을 목적으로 수행하였다. 방법: 선별된 6종의 생약유효성분을 METHANOL로 추출하여 조추출물을 얻었으며 이물질들을 순차적으로 각각의 유기용매로 추출, column chromatography법으로 분획하였으며 분획분에 대한 암세포독성능은 MTT colorimetric 검정법을 이용하여 IC$_{50}$값을 구하였다. 면역감시기구 측정방범으로는 Balb/c mouae암,수 각 10수씩에 P388암세포주를 접종한군과 접종하지 않은 실험군에 생약추출분획물 8.6mg/0.2ml씩 20일간 매일 경구 투여시키고 대조군에는 생리식염수 0.2ml씩을 매일 경구 투여시켜 NK cell의 활성 MIF Recombinant IL-2로 유도시킨 NK cell활성능, chemotaxis등을 측정하였다. 생체내 항종양능 시험은 tumor panel system에 따라 mouse leukemia cell을 사용하여 측정하였다. 각분획성분의 투여용량은 실험동물에서 독성실험결과로 LD$_{50}$량을 구해 항암효과 평가시에 Maximum dose로 하였고 최고용량을 기준으로 일정한 공비를 적응하여 3단계의 투여량을 설정하였다. (중략)

• Journal of Preventive Medicine and Public Health
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• v.16 no.1
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• pp.79-88
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• 1983

There has been some evidence concerning the fact that trihalomethanes(THMs), toxic chlorinated compounds, may be present in drinking water. One of the important methodologies to evaluate the toxicity of THMs is to determine enzyme alteration in experimental animal tissues after treatment. This study was intended to investigate how lactic dehydrogenase(LDH) of rat tissues is affected by administration of chloroform($CHCl_3$) and dichloromonobromomethane($CHCl_2\;Br$). THMs, high dose(1/10 LD50) or low dose(1/50 LD50) of $CHCl_3$ or $CHCl_{2}Br$ were administered orally to experimental rats for 4 or 8 weeks. The treated groups of rats were sacrificed to determine LDH specific activity and isozyme pattern in various organs which were liver, thigh muscle, kidney and brain. The conclusions were obtained as follows: 1. Alteration of LDH activities and isozyme patterns were revealed before morphologic changes in tissues. 2. The LDH specific activities were increased significantly in liver and brain after administration of high concentrations of $CHCl_3$ and $CHCl_{2}Br$ for 4 weeks respectively. Otherwise, they were decreased significantly in liver, muscle and kidney after administration for 8 weeks. 3. The isozyme activities of LDH-4 and LDH-5 were increased in muscle, brain, and especially the liver. 4. It was more distinct for the decrement of LDH H-type isozyme than the increment of M-type isozyme in muscle.

• Environmental Analysis Health and Toxicology
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• v.6 no.3_4
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• pp.105-121
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• 1991

The object of this study is to investigate the toxicity of fenvalerate [(RS)-$\alpha$-cyano-3 -phonoxybenzyl-(RS)-2-(4-ch1orophenyl)-3-methylbutyrate] and the effect of carbaryl on the toxicity of fenvalerate. Rats were treated with fenvalerate (50 mg/kg, 100 mg/kg), carbaryl (50 mg/kg, 100 mg/kg) or mixtures of the two compounds (fenvalerate+carbaryl: 50 mg/kg+50 mg/kg, 50 mg/kg+100 mg/kg) by oral administration for 1~3 weeks. Control groups were treated with corn oil. The experimental results were summarized as follows. 1. LD$_{50}$ values of fenvalerate and carbaryl in male rats were 385 mg/kg and 625 mg/kg respectively. When 50 mg/kg and 100 mg/kg of carbaryl were administratrd, LD$_{50}$values of fenvalerate were 265 mg/kg and 225 mg/kg respectively. 2. Biochemical parameters such as ALT, LDH and glucose in serum were much more increased in the groups treated with mixture than the groups treated with either one of fenvalerate or carbaryl. 3. The groups treated with carbaryl and mixture for 3 weeks, the contents of cytochrome P-450 in the liver were significantly increased. In renal microsomal fractions, however, no significant changes of drug metabolizing enzyme activities were observed. 4. The activities of aniline hydroxylase in hepatic microsomal fractions were increased in the groups treated with fenvalerate and mixture and activity was much more increased in the groups treated with mixture. 5. The activities of ATPase in the groups treated with fenvalerate were decreased than that of groups treated with mixture. TBA values and the activity of glucose-6 -phosphatase in the liver were not significantly changed. 6. In mixture treated groups, the activities of cholinesterase in serum and in the liver were more decreased than those of carbaryl treated groups. The activities of carboxylesterase in serum in the liver were slightly increased in mixture treated groups, but in fenvalerate treated groups, the activities of carboxylesterase were much more increased than those of control groups. 7. As a result of this study, when carbaryl was as the synergist of fenvalerate, carbaryl inhibited the activities of esterases, so the toxicity of fenvalerate was increased.sed.

• The Korean Journal of Pesticide Science
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• v.5 no.1
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• pp.12-18
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• 2001

The effects of organophosphorus were examined with inhibition of the cholinesterase activity on tile chicken plasma in vivo and in vitro. The cholinesterase activity in chicken plasma determined by tile Ellman mettled was $23{\mu}mol$/min/g protein. After oral administration with 0.2 and 0.5 times of organophosphorus terbufos $LD_{50}$(1.81 mg/kg), cholinesterase activity were inhibited to 36% and 96% of control after 15min in vivo, respectively. After oral administration with 0.2 and 0.5 times of terbufos $LD_{50}$(1.81 mg/kg), then the recovery of cholinesterase activity followed to 99% and 56% of control after 11hr, respectively. Ki of phosphorodithioate and phosphorothioate with P=S was $74{\sim}322\;mole^{-1}min^{-1}$ in vitro. Ki of phosphate and phosphorothiolate with P=O was $13898{\sim}79610\;mole^{-1}min^{-1}$. Toxicology of organophosphorus with P=S was higher than that of organophosphorus with P=S by oxidation. $pI_{50}$ of phosphorodithioate and phosphorothioate with P=S was $21{\sim}102$ mg/L. $pI_{50}$ of phosphate and phosphorothiolate with P=O was $0.519{\sim}0.071$ mg/L. Enzyme-Inhibition method with cholinesterase was the rapid bioassay method to detect the organohpophorus pesticides in vitro.

• Korean journal of applied entomology
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• v.35 no.1
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• pp.52-57
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• 1996

This experiment was carried out to evaluate the effect of sublethal doses of BPMC, etofenprox,and buprofezin on N. lugens. and its predator C. lividipennis. Buprofezin was found to be the most toxic to N. lugens and the most safe to C. lividipennis among the three insecticides, based on LD50 values. Selective toxicity index calculated by dividing LDSo value of C. lividipennis by that of N. lugens indicated that buprofezin was very safe to C. lividipennis, showing selective toxicity of 2703.3. Longevity and fecundity of N. lugens treated with LDIU and LDm of buprofezin and BPMC were not significantly different with those of untreated brown planthoppers. However, egg hatchability' of N. lugens was greatly reduced when treated with LDm of buprofezin, having the highest inhibition rate of 17.7%. Hatchability of eggs from insects treated with BPMC was similar to that of control. The oviposited peak of treated hoppers appeared late as compared to the untreated which showed the peak at early part of the ovipositional period. The longevity and fecundity of C. lividipennis treated with BPMC were significantly reduced as compared with the untreated. Etofenprox also induced fecundity reduction when treated with LDlo, and LDm. However, C. lividipennis treated with sublethal doses of buprofezin showed no redution in logevity and fecundity. From these results, it may be said that buprofezin can be used to control brown planthopper without disrupting of C. lividipennis population in the rice field.

• Korean journal of applied entomology
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• v.23 no.4 s.61
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• pp.221-232
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• 1984

A series of experiments were carried out in the laboratory and fields to reevaluate the effects of Padan (cartap) to the brown planthopper (BPH). Nilapanata lugens. The $LD_{50}\;land\;LC_{50}$ values for the female and male BPH were determined by the topical application and seedling- dipping/root -soaking methods. The values were differed with the sex and test methods, and the BPH mortality was greatly increased with a rise in temperatures $(25-35^{\circ}C)$. In a viewpoint of honeydew excretion and offsprings produced, there was no any possibility in BPH resurgence at the sublethal exposures of Padan. The BPH mortality to Padan 4 G was greatly low in the pot tests compared with those to diazinon and carbofuran, but in the paddy fields the efficacy of Padan 4G was nearly reversed. A single application of Padan 4G at the rate of 4kg/10a dramatically suppressed the BPH populations in the paddy fields, and the control effect was much more accelerated in the drained paddy field than in the submerged paddy field.

• BMB Reports
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• v.46 no.12
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• pp.575-581
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• 2013

Lipid droplet (LD) is a cellular organelle that stores neutral lipids as a source of energy and carbon. However, recent research has emerged that the organelle is involved in lipid synthesis, transportation, and metabolism, as well as mediating cellular protein storage and degradation. With the exception of multi-cellular organisms, some unicellular microorganisms have been observed to contain LDs. The organelle has been isolated and characterized from numerous organisms. Triacylglycerol (TAG) accumulation in LDs can be in excess of 50% of the dry weight in some microorganisms, and a maximum of 87% in some instances. These microorganisms include eukaryotes such as yeast and green algae as well as prokaryotes such as bacteria. Some organisms obtain carbon from $CO_2$ via photosynthesis, while the majority utilizes carbon from various types of biomass. Therefore, high TAG content generated by utilizing waste or cheap biomass, coupled with an efficient conversion rate, present these organisms as bio-tech 'factories' to produce biodiesel. This review summarizes LD research in these organisms and provides useful information for further LD biological research and microorganism biodiesel development.

• The Korean Journal of Pharmacology
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• v.8 no.2
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• pp.21-26
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• 1972

Zea mays Linne, which belongs to Graminae family, has been ordinarily used as edibles and fodder. Its stigma, Maydis Stigma, has been discarded without any special application with the exception of being used as diuretic in the sphere of Chinese medicine. Moreover, the pharmacological research toward Maydis Stigma as a medicinal herb has not been regretfully undertaken at all. The authors hereby paid attention to this point of view and made experiment to find out whether the water extract of Maydis Stigma might possess some pharmacological effect on the blood pressure of the rats or not. $LD_{50}$ to the mice was determined and the experiment was performed making the use of several agents related to the blood pressure such as atropine, Avil, dichloroisoproterenol and hexamethonium. The blood pressure of the rats and rabbits was recorded with the equipment of polygraph (Grass model 7 DAB) and its accessory, Statham pressure transducer. The results of the experiment are as follows. 1. $LD_{50}$ to the mice weighing 20g is determined 1,125 mg/kg. 2. The blood pressure manifests the gradual decrease by the rate of $-15.50{\pm}3.32,\;-22.14{\pm}8.73$ and $-46.25{\pm}5.17\;mmHg$ in proportion to ZW 25, 50 and 150mg/kg administered to the rats. 3. The blood pressure also manifests the same gradual decrease in proportion to ZW administered to the rabbits. 4. It is of significant difference to manifest the increase of $+5.14{\pm}4.65\;mmHg$ in the rats pretreated with atropine as compared with $-22.14{\pm}8.73\;mmHg$ of control group when administered each ZW 50mg/kg. 5. The administration of ZW 50 mg/kg to the rats pretreated with Avil, dichloroisoproterenol and hexamethonium does not manifest the significant difference in comparison with the control group.

• Asian Journal of Turfgrass Science
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• v.22 no.1
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• pp.25-34
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• 2008

This study was conducted to determine the optimum dose ranges for a mutation breeding based on the observations of a seed germination and an early growth in turfgrasses. Three warm season (Zoysiagrass, Bermudagrass, and Seashore paspalum) and four cool season turfgrasses (Kentucky bluegrass, Tall fescue, Perennial ryegrass, and Creeping bentgrass) were used in this study. We investigated the percentage of a seed germination and a seedling growth after irradiating the turfgrass seeds with various doses of gamma-ray (50, 100, 150, 200, 250, 300, 400, and 500 Gy). After 24 h with a gamma irradiation, the seeds were sown on the wet filter paper in a petri dish and maintained for 3 weeks at 30$^{\circ}C$ for the warm season turfgrasses and at 25$^{\circ}C$ for the cool season turfgrasses. Data on a seed germination and a seedling growth with three replications were collected. The percentage of seed germination was decreased with an increase of the gamma-ray dose. Shoot and root growth, and the fresh weight were decreased significantly as the radiation dose was increased. A radiation dose indicating a 50% growth inhibition ($LD_{50}$) with a gamma irradiation was varied among those turfgrass species used, with the highest at about 500 Gy for bermudagrass and the lowest at 100Gy for tall fescue. The optimum dose for a gamma irradiation for a selection of turfgrass mutants was considered to be about 300, 150, 500, 150, 200, 100 and 200 Gy for zoysiagrass, seashore paspalum, bermudagrass, Kentucky bluegrass, perennial ryegrass, tall fescue, and creeping bentgrass, respectively.

• Korean Journal of Plant Resources
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• v.29 no.1
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• pp.128-135
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• 2016

This study examined radiation damage and the optimal gamma-ray dose for mutation breeding in oat (Avena sativa L. cv. Samhan). The seed germination rate decreased as the dose increased over 500 Gy. The median lethal dose (LD₅₀) was approximately 392 Gy. The median reduction dose (RD₅₀) for plant height, tiller number, root length, and flash weight was 411, 403, 394, and 411 Gy, respectively. The optimal dose of gamma irradiation for inducing oat mutation appears to be in the range 300-400 Gy. We performed the comet assay to observe nuclear DNA damage induced by gamma-ray irradiation. This assay showed a clear difference with gamma-ray treatments. DNA damage increased temporarily 7 days after treatment depending on the dose, while no significant difference was identified in response to 300 Gy 30 days after the gamma-ray treatments. The growth characteristics of the M₂ generation decreased as the dose increased over 400 Gy.