• Molecules and Cells
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• v.19 no.3
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• pp.452-457
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• 2005

The adaptor protein (AP) complexes are involved in membrane transport of many proteins. There are 3 AP complexes in C. elegans unlike mammals that have four. To study the biological functions of the AP-3 complexes of C. elegans, we sought homologues of the mouse and human genes that encode subunits of the AP-3 complexes by screening C. elegans genomic and EST sequences. We identified single copies of homologues of the ${\mu}3$, ${\sigma}3$, ${\beta}3$ and ${\delta}$ genes. The medium chain of AP-3 is encoded by a single gene in C. elegans but two different genes in mammals. Since there are no known mutations in these genes in C. elegans, we performed RNAi to assess their functions in development. RNAi of each of the genes caused embryonic and larval lethal phenotypes. APM-3 is expressed in most cells, particularly strongly in spermatheca and vulva. We conclude that the products of the C. elegans ${\mu}3$, ${\sigma}3$, ${\beta}3$ and d genes are essential for embryogenesis and larval development.

• Journal of Life Science
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• v.16 no.4
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• pp.704-709
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• 2006

The present study intends to characterize the DNA damage-inducible responses in Caenorhabditis elegans. To study UV-inducible responses in C. elegans, two UV-inducible cDNA clones were isolated from C. elegans by using subtration hybridization method. To investigate the expression of isolated genes, UV100 and UV150, the cellular levels of the transcript were determined by Northern blot analysis after UV-irradiation. The transcripts of isolated gene increased rapidly and reached maximum accumulation after UV-irradiation. Compared to the message levels of control, the levels of maximal increase were approximately 2 folds to UV-irradiation. These results implied that the effects of damaging agents are complex and different regulatory pathways exist for the induction of these genes. To study the function of UV100 and UV150 gene in response to UV irradiation, we carried out a RNAi experiment and investigated the UV sensivity. This result indicated that UV100 gene involved in stage-specific repair pathway or regulated by development.

• Molecules and Cells
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• v.27 no.3
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• pp.345-350
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• 2009

We previously reported that flavone induces embryonic lethality in Caenorhabditis elegans, which appeared to be the result of cell cycle arrest during early embryogenesis. To test this possibility, here we examined whether flavone inhibits the activity of a key cell cycle regulator, CDC-25.1 in C. elegans. A gain-of-function cdc-25.1 mutant, rr31, which exhibits extra cell divisions in intestinal cells, was used to test the inhibitory effects of flavone on CDC-25 activity. Flavone inhibited the extra cell divisions of intestinal cells in rr31, and modifications of flavone reduced the inhibitory effects. The inhibitory effects of flavone on CDC-25.1 were partly, if not completely, due to transcriptional repression.

• Toxicological Research
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• v.24 no.4
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• pp.235-243
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• 2008

While in some instances, loss of diversity results from acute toxicity (e.g. major pollution incidents), in most cases it results from long-term sub-lethal effects that alter the relative competitive ability and fitness of certain organisms. In such cases the sub-lethal effects will cause a physiological response in the organism that ultimately leads to community level changes. Very sensitive tools are now available to study sub-lethal responses at the molecular level. However, relating such laboratory measurements to ecological effects represents a substantial challenge that can only be met by investigation at all scales (molecular, individual organism and community level) with an appropriate group of organisms. Among the various in vertebrates which can be used as model organisms in such a way, the soil nematode, Caenorhabditis elegans appear to be a promising biological model to diagnose environmental quality. This paper reviews the current status of multilevel biomarkers in environmental toxicology, and C. elegans as promising organisms for this approach.

• Archives of Pharmacal Research
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• v.29 no.7
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• pp.582-586
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• 2006

Due to consumer reluctance to take synthetic drugs for nematode infections and the appearance of resistance to anthelminthic drugs, new drugs from natural products must be developed. Caenorhabditis elegans is one of the freely living nematodes and serves as a good model system for screening anthelminthic drugs. In this study, thirteen flavonoid derivatives were tested for anthelminthic activity and the relationships between their activities and structures were investigated. The structural information combined with the data for the larval growth inhibition of C. elegans provided meaningful structural insights in the search for new anthelminthic drugs.

• Natural Product Sciences
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• v.25 no.3
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• pp.255-260
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• 2019

Piper nigrum L. (Piperaceae), which is a well-known food seasoning, has been used as a traditional medicine for the treatment of vomiting, abdominal pain, diarrhea and anorexia in Korea, China and Japan. Methanol extract from the fruit of P. nigrum was successively partitioned as n-hexane, methylene chloride, ethyl acetate, n-butanol and $H_2O$ soluble fractions. Among those fractions the ethyl acetate soluble fraction showed the most potent DPPH radical scavenging activity, and piperine was isolated from the ethyl acetate fraction. To know the antioxidant activity of piperine, we tested the activities of superoxide dismutase (SOD) and catalase together with oxidative stress tolerance and intracellular ROS level in Caenorhabditis elegans. To investigate whether piperine-mediated increased stress tolerance was due to regulation of stress-response gene, we quantified SOD-3 expression using transgenic strain including CF1553. Consequently, piperine enhanced SOD and catalase activities of C. elegans, and reduced intracellular ROS accumulation in a dose-dependent manner. Moreover, piperine-treated CF1553 worms exhibited significantly higher SOD-3::GFP intensity.

• Korean Journal of Pharmacognosy
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• v.51 no.2
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• pp.115-121
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• 2020

Caenorhabditis elegans model system was used to investigate the antioxidant activity of methanol extract of Mallotus japonicus twigs. The ethyl acetate soluble fraction of the M. japonicus methanol extract showed the best DPPH radical scavenging activity. The ethyl acetate fraction was measured for the activity of superoxide dismutase (SOD), catalase, and oxidative stress tolerance by using C. elegans along with reactive oxygen species (ROS) level. In addition, to confirm that the regulation of the stress response gene is responsible for the increased stress tolerance of C. elegans treated by the ethyl acetate fraction, SOD-3 expression was measured using a transgenic strain. As a result, the ethyl acetate fraction increased SOD and catalase activity, and decreased ROS accumulation in a dose-dependent manner. In addition, the ethyl acetate fraction-treated CF1553 worm showed higher SOD-3::GFP intensity than the control worm.

• Korean Journal of Pharmacognosy
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• v.51 no.3
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• pp.192-198
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• 2020

Caenorhabditis elegans model system was used to investigate the antioxidant activity of Beta vulgaris L. (Chenopodiaceae) methanol extract. The methanol extract showed DPPH radical scavenging and superoxide quenching activity in a dose-dependent manner. The B. vulgaris methanol extract was measured for the activity of superoxide dismutase (SOD), catalase, and oxidative stress tolerance by using C. elegans, along with reactive oxygen species (ROS) level. In addition, to see that the regulation of the stress response gene is responsible for the increased stress tolerance of C. elegans treated by the methanol extract, SOD-3 expression was measured using a transgenic strain. As a result, the B. vulgaris methanol extract increased SOD and catalase activities, and decreased ROS accumulation, dose-dependently. Furthermore, the methanol extract-treated CF1553 worm showed higher SOD-3::GFP intensity than the control.

• Korean Journal of Pharmacognosy
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• v.52 no.4
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• pp.251-256
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• 2021

Oat, the seeds of Avena sativa L. (Gramineae), is an important dietary staple for people in many countries. Previous studies reported that A. sativa had various pharmacological effects such as anti-inflammatory, antitumor, neurotonic, and antispasmodic activities. In this study, Caenorhabditis elegans model system was used to investigate the antioxidant activity of methanol extract of oat. The ethyl acetate soluble fraction of the oat methanol extract showed the best DPPH radical scavenging activity. The ethyl acetate fraction was measured for the activity of superoxide dismutase (SOD), catalase, and oxidative stress tolerance by using C. elegans along with reactive oxygen species (ROS) level. In addition, to confirm that the regulation of the stress response gene is responsible for the increased stress tolerance of C. elegans treated by the ethyl acetate fraction, SOD-3 expression was measured using GFP-expressing transgenic worm. As a result, the ethyl acetate fraction increased SOD and catalase activities, and decreased ROS accumulation in a dose-dependent manner. In addition, the ethyl acetate fraction-treated CF1553 worm showed higher SOD-3::GFP intensity compared to the control.

• Korean Journal of Pharmacognosy
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• v.52 no.2
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• pp.105-111
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• 2021

To investigate the antioxidant activities of Pinus densiflora needle (Pinaceae), which is widely used as a traditional medicine in Korea, Caenorhabditis elegans model system was used. The n-butanol fraction of P. densiflora needle methanol extract showed the most potent DPPH radical scavenging and superoxide quenching activities in a dose-dependent manner. The n-butanol fraction was measured for the activities of superoxide dismutase (SOD), catalase, and oxidative stress tolerance by using C. elegans with reactive oxygen species (ROS) level. In addition, to see that the regulation of the stress response gene is responsible for the increased stress tolerance of C. elegans treated by the butanol extract, SOD-3 expression was measured using a transgenic strain. As a result, the P. densiflora needle n-butanol fraction increased SOD and catalase activities, and decreased ROS accumulation, dose-dependently. Furthermore, the n-butanol fraction-treated CF1553 worm showed higher SOD-3::GFP intensity than the control.