• ALGAE
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• v.30 no.2
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• pp.147-161
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• 2015

Brown algal extracts have long been used as feed supplements to promote health of farm animals. Here, we show new molecular insights in to the mechanism of action of a fucose containing polymer (FCP) rich fraction from the brown seaweed Ascophyllum nodosum using the Caenorhabditis elegans-Pseudomonas aeruginosa PA14 infection model. FCP enhanced survival of C. elegans against pathogen stress, correlated with up-regulation of key immune response genes such as: lipases, lysozyme (lys-1), saponin-like protein (spp-1), thaumatin-like protein (tlp-1), matridin SK domain protein (msk-1), antibacterial protein (abf-1), and lectin family protein (lfp). Further, FCP caused down regulation of P. aeruginosa quorum sensing genes: (lasI, lasR, rhlI, and rhlR), secreted virulence factors (lipase, proteases, and elastases) and toxic metabolites (pyocyanin, hydrogen cyanide, and siderophore). Biofilm formation and motility of pathogenic bacteria were also greatly attenuated when the culture media were treated with FCP. Interestingly, FCP failed to mitigate the pathogen stress in skn-1, daf-2, and pmk-1 mutants of C. elegans. This indicated that, FCP treatment acted on the regulation of fundamental innate immune pathways, which are conserved across the majority of organisms including humans. This study suggests the possible use of FCP, a seaweed component, as a functional food source for healthy living.

• Natural Product Sciences
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• v.22 no.3
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• pp.201-208
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• 2016

Here in this study, we investigated the lifespan-extending effect and underlying mechanism of methanolic extract of Moringa olelifa leaves (MML) using Caenorhabditis elegans (C. elegans) model system. To define the longevity properties of MML we conducted lifespan assay and MML showed significant increase in lifespan under normal culture condition. In addition, MML elevated stress tolerance of C. elegans to endure against thermal, oxidative and osmotic stress conditions. Our data also revealed that increased activities of antioxidant enzymes and expressions of stress resistance proteins were attributed to MML-mediated enhanced stress resistance. We further investigated the involvement of MML on the aging-related factors such as growth, food intake, fertility, and motility. Interestingly, MML significantly reduced growth and egg-laying, suggesting these factors were closely linked with MML-mediated longevity. We also observed the movement of aged worms to estimate the effects of MML on the health span. Herein, MML efficiently elevated motility of aged worms, indicating MML may affect health span as well as lifespan. Our genetic analysis using knockout mutants showed that lifespan-extension activity of MML was interconnected with several genes such as skn-1, sir-2.1, daf-2, age-1 and daf-16. Based on these results, we could conclude that MML prolongs the lifespan of worms via activation of SKN-1 and SIR-2.1 and inhibition of insulin/IGF pathway, followed by DAF-16 activation.

• Journal of Microbiology and Biotechnology
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• v.28 no.6
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• pp.883-892
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• 2018

Probiotics, including Enterococcus faecium, confer a health benefit on the host. An Enterococcus strain was isolated from healthy chicken cecum, identified as E. faecium by 16S rDNA gene sequence analysis, and designated as E. faecium L11. To evaluate the potential of E. faecium L11 as a probiotic, the gastrointestinal tolerance, immunomodulatory activity, and lifespan extension properties of the strain were assayed. E. faecium L11 showed >66% and >62% survival in artificial gastric juice (0.3% pepsin, pH 2.5) and simulated small intestinal juice (0.5% bile salt and 0.1% pancreatin), respectively. Heat-killed E. faecium L11 significantly (p < 0.05) increased immune cell proliferation compared with controls, and stimulated the production of cytokines (IL-6 and $TNF-{\alpha}$) by activated macrophages obtained from ICR mice. In addition, E. faecium L11 showed a protective effect against Salmonella Typhimurium infection in Caenorhabditis elegans. In addition, feeding E. faecium L11 significantly (p < 0.05) extended the lifespan of C. elegans compared with the control. Furthermore, genes related to aging and host defense were upregulated in E. faecium L11-fed worms. In conclusion, E. faecium L11, which prolongs the lifespan of C. elegans, may be a potent probiotic supplement for livestock.

• Korean Journal of Pharmacognosy
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• v.48 no.2
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• pp.141-147
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• 2017

As an ongoing study about Allium hookeri (Liliaceae), this study was performed to evaluate the anti-oxidative effect of the leaves of this plant. Ethanol extract of A. hookeri leaves was successively partitioned as methylene chloride, ethyl acetate, n-butanol and $H_2O$ soluble fractions. The ethyl acetate soluble fraction showed the most potent DPPH radical scavenging and superoxide quenching activities among those fractions. To prove antioxidant activity of ethyl acetate fraction of A. hookeri leaves, we checked the activities of superoxide dismutase (SOD) and catalase, and intracellular ROS level and oxidative stress tolerance in Caenorhabditis elegans. In addition, to verify if increased stress tolerance of C. elegans by treating of ethyl acetate fraction was due to regulation of stress-response gene, we checked SOD-3 expression using transgenic strain. As a consequence, the ethyl acetate fraction increased SOD and catalase activity of C. elegans, and reduced intracellular ROS accumulation in a dose-dependent manner. Besides, the ethyl acetate fraction-treated CF1553 worms showed higher SOD-3::GFP intensity.

• Korean Journal of Pharmacognosy
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• v.52 no.3
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• pp.163-169
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• 2021

Using the Caenorhabditis elegans model system, the antioxidant activity of methanol extract of the guzeunggupoprocessed Liriope platyphylla F. T. Wang (Liliaceae) tuber was calculated. Between the methanol extracts of guzeunggupo-processed and non-processed L. platyphylla tuber, the processed L. platyphylla tuber showed higher DPPH radical scavenging effect than the non-processed one. The ethyl acetate soluble fraction of the methanol extract of the guzeunggupo-processed L. platyphylla tuber showed the best DPPH radical scavenging activity. The ethyl acetate fraction of the processed sample was measured for the activities of superoxide dismutase (SOD), catalase, and oxidative stress tolerance by using C. elegans along with reactive oxygen species level. In addition, to verify the regulation of the stress response gene is responsible for the increased stress tolerance of C. elegans treated by the ethyl acetate fraction of the processed sample, SOD-3 expression was measured using a transgenic strain (CF1553). Consequently, the ethyl acetate fraction of the processed sample, increased SOD and catalase activities, and decreased ROS accumulation in a dose-dependent manner. Furthermore, the ethyl acetate fraction of the processed sample-treated CF1553 worm showed higher SOD-3::GFP intensity than the control worm.

• Korean Journal of Pharmacognosy
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• v.51 no.4
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• pp.325-331
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• 2020

Through Caenorhabditis elegans model system, the antioxidant activity of methanol extract of the guzeunggupo-processed Platycodon grandiflorum A. De Candolle (Campanulaceae) roots was calculated. Between the methanol extracts of guzeunggupo-processed and non-processed P. grandiflorum roots, the processed P. grandiflorum root showed higher DPPH radical scavenging effect than the non-processed one. The ethyl acetate soluble fraction of the methanol extract of the guzeunggupo-processed P. grandiflorum showed the best DPPH radical scavenging activity. The ethyl acetate fraction of the processed sample was measured for the activities of superoxide dismutase (SOD), catalase, and oxidative stress tolerance by using C. elegans along with reactive oxygen species level. In addition, to confirm the regulation of the stress response gene is responsible for the increased stress tolerance of C. elegans treated by the ethyl acetate fraction of the processed sample, SOD-3 expression was measured using a transgenic strain (CF1553). Consequently, the ethyl acetate fraction of the processed sample, increased SOD and catalase activities, and decreased ROS accumulation in a dose-dependent manner. Furthermore, the ethyl acetate fraction of the processed sample-treated CF1553 worm showed higher SOD-3::GFP intensity than the control worm.

• Journal of Animal Science and Technology
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• v.65 no.3
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• pp.652-663
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• 2023

The rumen fluids contain a wide range of bacteria, protozoa, fungi, and viruses. The various ruminal microorganisms in the rumen provide nutrients by fermenting the forage they eat. During metabolic processes, microorganisms present in the rumen release diverse vesicles during the fermentation process. Therefore, in this study, we confirmed the function of rumen extracellular vesicles (EVs) and their interaction with the host. We confirmed the structure of the rumen EVs by transmission electron microscope (TEM) and the size of the particles using nanoparticle tracking analysis (NTA). Rumen EVs range in size from 100 nm to 400 nm and are composed of microvesicles, microparticles, and ectosomes. Using the Caenorhabditis elegans smart animal model, we verified the interaction between the host and rumen EVs. Exposure of C. elegans to rumen EVs did not significantly enhance longevity, whereas exposure to the pathogenic bacteria Escherichia coli O157:H7 and Staphylococcus aureus significantly increased lifespan. Furthermore, transcriptome analysis showed gene expression alterations in C. elegans exposed to rumen EVs, with significant changes in the metabolic pathway, fatty acid degradation, and biosynthesis of cofactors. Our study describes the effect of rumen EV interactions with the host and provides novel insights for discovering biotherapeutic agents in the animal industry.

• Molecules and Cells
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• v.28 no.3
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• pp.209-213
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• 2009

Caenorhabditis elegans is a free living soil nematode and thus in its natural habitat, C. elegans encounters many different species of soil bacteria. Although some soil bacteria may be excellent sources of nutrition for the worm, others may be pathogenic. Thus, we undertook a study to understand how C. elegans can identify their preferred food using a simple behavioral assay. We found that there are various species of soil bacteria that C. elegans prefers in comparison to the standard laboratory E. coli strain OP50. In particular, two bacterial strains, Bacillus mycoides and Bacillus soli, were preferred strains. Interestingly, the sole feeding of these bacteria to wild type animals results in extended lifespan through the activation of the autophagic process. Further studies will be required to understand the precise mechanism controlling the behavior of identification and selection of food in C. elegans.

• BMB Reports
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• v.47 no.2
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• pp.80-85
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• 2014

Altered acetylcholine (Ach) homeostasis is associated with loss of viability in flies, developmental defects in mice, and cognitive deficits in human. Here, we assessed the importance of Ach in Caenorhabditis elegans development, focusing on the role of Ach during dauer formation. We found that dauer formation was disturbed in choline acetyltransferase (cha-1) and acetylcholinesterase (ace) mutants defective in Ach biosynthesis and degradation, respectively. When examined the potential role of G-proteins in dauer formation, goa-1 and egl-30 mutant worms, expressing mutated versions of mammalian $G_o$ and $G_q$ homolog, respectively, showed some abnormalities in dauer formation. Using quantitative mass spectrometry, we also found that dauer larvae had lower Ach content than did reproductively grown larvae. In addition, a proteomic analysis of acetylcholinesterase mutant worms, which have excessive levels of Ach, showed differential expression of metabolic genes. Collectively, these results indicate that alterations in Ach release may influence dauer formation in C. elegans.

• BMB Reports
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• v.50 no.1
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• pp.31-36
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• 2017

High-dose caffeine uptake is a developmental stressor and causes food-avoidance behavior (aversion phenotype) in C. elegans, but its mode of action is largely unknown. In this study, we investigated the molecular basis of the caffeine-induced aversion behavior in C. elegans. We found that aversion phenotype induced by 30 mM caffeine was mediated by JNK/MAPK pathway, serotonergic and dopaminergic neuroendocrine signals. In this process, the dopaminergic signaling appears to be the major pathway because the reduced aversion behavior in cat-2 mutants and mutants of JNK/MAPK pathway genes was significantly recovered by pretreatment with dopamine. RNAi depletion of hsp-16.2, a cytosolic chaperone, and cyp-35A family reduced the aversion phenotype, which was further reduced in cat-2 mutants, suggesting that dopaminergic signal is indeed dominantly required for the caffeine-induced food aversion. Our findings suggest that aversion behavior is a defense mechanism for worms to survive under the high-dose caffeine conditions.