• Korean Journal of Environment and Ecology
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• v.20 no.3
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• pp.345-351
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• 2006

This study investigates the toxic effects of $Cd^{2+}$on frog (Rana dybowskii) by the determination of oocyte maturation and development of embryo exposure to different concentrations of the toxicant. The results show that $Cd^{2+}$ concentration of 0.1ppm suppressed the maturation of the oocytes. To examine the reversibility of the inhibitory effects, the oocytes were exposed to the $Cd^{2+}$ only for 3 hours, and then transferred to plain medium and cultured further for 17 hours. The oocytes were recovered from the toxic effect of the $Cd^{2+}$ when they were exposed to 1ppm, but not to 2.5ppm of the $Cd^{2+}$. The development of 2 cell embryos to 32 cell was completely suppressed at 0.1ppm and the longer the embryos were exposed to the $Cd^{2+}$, the more damage appeared to the embryos and the cytolysis of the 32 cell was induced by $Cd^{2+}$ at 0.1ppm. On the other hand, the embryos of blastula stage were cultured 96 hours in presence of the $Cd^{2+}$ at various concentrations and were examined. The rates of mortality and malformed larvae were investigated by probit analysis. From the results of LC$_{50}$ of 0.1ppm and EC$_{50}$ of 0.08ppm, Tl of 5.0 was derived, which indicates $Cd^{2+}$ is to be considered a teratogenic compound. Such specific malformations occurred in 14.3% as spine deformations at the 0.05ppm, in 75.0% as tail deformations at the 0.1ppm, in 66.7% as abdominal deformations at the 0.01ppm and in 26.0% as profound deformations at the 0.1ppm of $Cd^{2+}$ concentration which living embryos were exposed to. $Cd^{2+}$ suppressed growth to head-tail length at 0.1ppm. In conclusion, The study results reveal that $Cd^{2+}$ must be considered highly toxic effect to oocyte maturation and embryonic development.

• Journal of Life Science
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• v.28 no.7
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• pp.819-826
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• 2018

Orostachys japonicus (OJ) is a medicinal herb with immunoregulatory, anti-aging, anti-oxidative, and many other therapeutic properties. The purpose of this study was to elucidate the anti-cancer property of cultivated OJ. SW480 cell viability was significantly reduced by cumulative exposure to OJ extract. We also observed inhibitory effects of OJ after 72 hr through the growth and migration of SW480 cells using scratch assay. SW480 cells in OJ-free medium began to move into the scratch site at 24 hr; however, cells in medium containing OJ did not migrate into the scratch site until 48 hr. Male C57BL/6 mice (4 weeks old) were orally administered OJ extract for 31 days before injection of SW480 cells. At 7, 14, and 28 days after subcutaneous injection of SW480 cells, tumor weight and volume were analyzed. The body weight of the OJ-treated group was continuously increased during administration of the OJ extract relative to the control group. Injection of SW480 cells caused a reduction in body weight in all groups; however, the OJ-treated group exhibited a significant increase in body weight after 14 days. Tumor weight and volume were lower in the OJ-treated group than in the control group after 28 days. Although these results suggest that OJ suppresses the proliferation and migration of human colon cancer cells, additional studies are required to provide preclinical evidence before launching clinical trials evaluating OJ as an anti-cancer biohealth product.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.5
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• pp.924-930
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• 2002

Ixeris dentata extracts exllibited antimicrobial activity against some bacteria and fungi. Also EtOH extracts showed strong antioxidant activity and RC$_{50}$ value was 28 $\mu\textrm{g}$/mL. The inhibitory effect of Ixeris dentata on the mutagenicity in Salmonella and cytotoxicity on cancer cell were studied. Ixeris dentata extracts showed anti-mutagenic effects of 78.83 and 75.96% on B(a)P in S. typhimurium TA98 and Th100, respectively. These extracts showed 78.72% antimutagenicity on TA100 against MNNG. The Ixeris dentata extract with strong antimutagenic activities was further fractionated by hexane, ethyl acetate, butanol and water. Butanol fraction was found to be highest in antimutagenic activity against MNNG than the other fractions. Butanol fraction of Ixreis dentate revealed the highest cytotoxicity against AS49 human lung carcinoma cells in which cell growth was inhibited by 93.75% at 375 $\mu\textrm{g}$/mL. Hexane fraction of ixeris dentate exhibited 68.56% inhibition against MCF-7 human breast adenocarcinoma cells at 500 $\mu\textrm{g}$/mL. Hexane fraction of Ixeris dentata exhibited 84.91% inhibition against Hep 3B human hepatocellular carcinoma cells at 500 $\mu\textrm{g}$/mL. From these results, it is considered that Ixeris dentata has strong antimutagenic and anticancer effects in vitro. However, these extracts and fractions did not show any cytotoxic effect against 293 cells.

• The Korean Journal of Mycology
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• v.27 no.2 s.89
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• pp.164-169
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• 1999

This study was carried out in an attempt to select chemicals such as zeolite granules, chitosan, wood-vinegar, $Ca(OCl)_2$, NaOCl, against bacterial brown blotch caused by Pseudomonas tolaasii on Flammulina velutipes in laboratory and mushroom unit. Results obtained using these chemicals were summarized. Inhibitory effect on $Ca(OCl)_2$ and wood-vinegar with 0.5% concentration was shown to caual pathogen, P. tolaasii, by slight damage on the mycelial growth of F. velutipes. Those materials were recognized as promising one for control of bacterial brown bloth on F. velutipes. Disease incidence in control was the highest value as 43.8%; whereas chemical treatment was estimated as 14.6% with 0.5% of $Ca(OCl)_2$. Disease incidence was inhibited about 20% in chemical treatment with 0.5% of wood-vinegar, 1.0% of $Ca(OCl)_2$, and 26.1% with 1.0% of wood-vinegar. For the inhibition effects of chemical concentrations, it was effective at the low concentration which was 0.5% rather than that of 1.0%. Quality of mushrooms was significantly improved, and yields was also increased by 30% in the chemical treatment. In case of $Ca(OCl)_2$ treatment at 1.0% concentration, the yields was increased by 35.6% showed the highest value among tested chemicals. However, the overall effects including disease incidence, quality and yields suggests that $Ca(OCl)_2$ is relatively more effective than wood-vinegar, and the optimal concentration controlling the disease was $0.5{\sim}1.0%$ with $Ca(OCl)_2$ and 0.5% with wood-vinegar.

• Journal of Korean Society of Forest Science
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• v.87 no.2
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• pp.230-238
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• 1998

This study was conducted to compare the regeneration of the seedlings under different vegetation types and to identify the presence of allelopathy in Abies koreana(Ak) natural forest in Banyabong Peak(elevation, 1715m), of Mt. Chiri. Twenty quadrats($10m{\times}10m$) were placed in May, 1996 to classify vegetation structure using TWINSPAN. Water-soluble extracts from leaves and soil humus of different vegetation types were collected to test their effects on both seed germination of Ak and mycelial growth of ectomycorrhizal fungi. Phenolic compounds from soil humus were quantified using HPLC. Among the four vegetation types, Sasa borealis(Sb) was found in both Ak-Quercus mongolica(Qm) and Ak-Rhododendron schlippenbachii(Rs) communities. Natural seeding of Ak was $230,000{\pm}90,000seeds/ha$ in 1995 and their germination rate was 25% in an ideal laboratory condition. Density of Ak seedlings less than 5cm in height was 52,000/ha in 1996, while that of seedlings taller than 5cm in height was only 4,000/ha. In the case of Ak-Qm community, density of Ak seedlings with Sb understory was only 7% of the density of seedlings with Rs understary, suggesting the inhibitory effect of Sb. The germination rate of Ak seeds was significantly reduced by leaf extracts of Sb, and Rhododendron mucronulatum var. ciliatum(Rm) and Ak. Soil humus extract of Ak-Qm-Sb subcommunity reduced germination of Ak seeds by 81% and also reduced by 19% the respiration of mycelia of ectomycorrhizal fumgus, Lactarius sp. Among the seven phenolic compounds identified from the soil humus, extract, Ak-Qm-Sb subcommunity contained significantly high content of p-hydroxybenzoic acid, vanillic acid, and syringic acid. Particularly, p-hydroxybenzoic acid was present at 4.2ppm in the Sb roots and at 16.5ppm in the Sb humus, suggesting that it could be the primary allelopathic compound in Abies koreana forests with Sasa borealis understory.

• Journal of Life Science
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• v.23 no.5
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• pp.689-697
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• 2013

In the United States, about 40,000 new cases of oral cancer are diagnosed each year and nearly 7,800 patients died from it in 2012. Omega-3 polyunsaturated fatty acids have been found to have anticancer effects in a variety of cancer cell lines and animal models, but their effect in oral cancer remains unclear. This study was designed to examine the effect of docosahexaenoic acid (DHA, a kind of omega-3 fatty acid) on oral cancer cells and the molecular mechanism of its action. We found that exposure of squamous cell carcinoma-4 (SCC-4) and squamous cell carcinoma-9 (SCC-9) human oral cancer cells to DHA induced growth inhibition in a dose- and time-dependent manner. Meanwhile, in addition to the elevated levels of apoptotic markers, such as cleaved PARP, subG1 portion and TUNEL-positive nuclei, DHA led to autophagic vesicle formation and an increase in autophagic flux, indicating the involvement of both apoptosis and autophagy in the inhibitory effects of DHA on oral cancer cells. Further experiments revealed that the apoptosis and autophagy induced by DHA were linked to inhibition of mammalian target of rapamycin (mTOR) signaling by AKT inhibition and AMP-activated protein kinase (AMPK) activation in SCC-9 cells. Together, our results suggest that DHA induces apoptosis- and autophagy-associated cell death through the AMPK/AKT/mTOR signaling pathway in oral cancer cells. Thus, utilization of omega-3 fatty acids may represent a promising therapeutic approach for chemoprevention and treatment of human oral cancer.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.7
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• pp.975-982
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• 2015

Piceatannol (trans-3,4,3',5'-trihydroxystilbene), a natural stilbene, is an analogue of resveratrol. In the present study, possible mechanisms by which piceatannol exerts its pro-apoptotic action in cultured human oral cancer YD-15 cells were investigated. To investigate whether or not piceatannol has effects on cancer cell viability, human oral YD-15 cells were treated with piceatannol (0, 50, and $100{\mu}M$). Piceatannol treatment ($100{\mu}M$) showed the strongest inhibition of cell proliferation and reduced cell viability in a dose-dependent manner. Chromatin condensation detected by DAPI staining significantly increased in a concentration-dependent manner, indicating apoptosis. Piceatannol treatment activated initiator Bax (pro-apoptotic) and cPARP in a concentration-dependent manner. Further, piceatannol induced down-regulation of Bcl-2 (anti-apoptotic). We also evaluated the activity of piceatannol against oral cavity cancer tumors in mice. Piceatannol-treated nude mice bearing YD-15 xenograft tumors exhibited significantly reduced tumor volume and weight due to the potent effect of piceatannol on tumor cell apoptosis, as determined by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay. Immunohistochemistry staining showed elevated expression of cleaved-caspase-3 as well as reduced expression of Ki-67 in the piceatannol-treated group. Therefore, piceatannol can be developed as a cancer preventive medicine due to its growth inhibitory effects and induction of apoptosis in human oral cancer cells.

• Korean Journal of Environmental Biology
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• v.36 no.3
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• pp.359-369
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• 2018

Harmful algal blooms (HABs) are a serious problem for public health and fisheries industries, thus there exists a need to investigate the possible ways for effective control of HABs. In the present study, we investigated the algicidal effects of a newly developed GreenTD against the HABs (Chattonella marina, Heterosigma akashiwo, Cochlodinium polykriokides, and Heterocapsa circularisquama) and non-HABs (Chaetoceros simplex, Skeletonema sp. and Tetraselmis sp.), which is focused on the different population density and concentration gradients of algicidal substances. The time series viability of target alga was assessed based on the activity of Chl. a photosynthetic efficiency in terms of $F_v/F_m$, and in vivo fluorescence (FSU). Effective control of Raphidophyta, C. marina and H. akashiwo was achieved at a GreenTD concentration of $0.5{\mu}gL^{-1}$ and $0.2{\mu}gL^{-1}$, respectively, and regrowth of both the species was not observed even after 14 days. The inhibitory ratio of the dinoflagellate, C. polykriokides was more than 80% at $0.2{\mu}gL^{-1}$ of GreenTD. H. circularisquama was constantly affected in the presence of $0.2{\mu}gL^{-1}$ of GreenTD in the high- and low-population density experimental groups. On the other hand, diatoms, C. simplex, and Skeletonema sp. were not significantly affected even in the presence of $0.2{\mu}gL^{-1}$ of GreenTD and exhibited re-growth activity with the passage of incubation time. In particular, green alga Tetraselmis sp. remained unaffected even in the presence of the highest concentration of GreenTD ($1.0{\mu}gL^{-1}$), implying that non-HABs were not greatly influenced by the algicidal substances. As a result, the algicidal activity of GreenTD on the harmful and nonharmful algae was as follows: raphidophyte>dinoflagellates>diatoms>green alga. Consequently, our results indicate that inoculation of GreenTD substances into natural blooms at a threshold concentration ($0.2{\mu}gL^{-1}$) can maximize the algicidal activity against HABs species. If we consider the dilution and diffusion rate in the field application, it is hypothesized that GreenTD will demonstrate economic efficiency, thus leading to effective control against the target HABs in the closed bay.

• Journal of Life Science
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• v.33 no.12
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• pp.1015-1024
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• 2023

Antibiotics have greatly contributed to the treatment and prevention of bacterial diseases in humans, animals, and fish. However, antibiotic misuse has led to the emergence and spread of multidrug-resistant bacteria. In addition to antibiotic discovery research, efforts are being made to combat such multidrug-resistant bacteria using antimicrobial agents, antioxidants, host immune enhancement, probiotics, and bacteriophages, as well as various symptomatic therapies. To discover novel bioactive compounds, it is crucial to adopt approaches that incorporate fresh ideas, new targets, innovative techniques, and untapped resources. Halophytes are plants that grow in high-salt soils and are known to adapt to salt-induced stress through unique metabolic processes that produce secondary metabolites. This study aimed to investigate the effects of extracts of halophytes native to Korea on oxidative stress and to determine whether they exert inhibitory activity against biofilms, which are major pathogenic factors of infectious bacteria. The Acinetobacter baumannii strain ATCC 17978, a representative drug-resistant bacterium, was used to measure anti-biofilm activity. The results showed that Aster spathulifolius, Carex kobomugi, Rosa rugosa, and Asparagus cochinchiensis exerted strong antioxidant and anti-biofilm effects without affecting bacterial growth itself. The halophytes used in this study are promising candidates for the development of pharmaceutical agents with antioxidant and antimicrobial properties.

• Food Science of Animal Resources
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• v.30 no.6
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• pp.975-988
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• 2010

Two experiments were conducted to determine whether water extracts from Artemisia capillaries (A. capillaries) and Camellia sinensis (C. sinensis) could be used as alternatives to antibiotic growth promoters in broiler feed. The experiment 1 was verified their chemical composition, extracts yields, total phenolic compounds concentration, antioxidant activity, antimicrobial activity, and chicken splenocytes proliferation through in vitro test. The extract yields of A. capillaries and C. sinensis were 26.5 and 16.8%, respectively. Total phenolic compounds concentrations of them expressed as gallic acid equivalent were 15.28 and 26.74 mg/mL, respectively. Electron donating abilities of them expressed as $SC_{50}$ showing 50% DPPH radical scavenging were 0.30 and 0.06 mg, respectively. Bacterial inhibitory rates of them against Escherichia coli, Staphylococcus aureus, and Salmonella Typhimurium were ranged from 42.1 to 52.3% and from 21.6 to 33.7%, respectively. And, these extracts increased proliferation of chicken splenocytes. Especially, A. capillaris was more excellent than Echinacea and Concanavalin A known as T-cell stimulator. The experiment 2 was investigated their effects on growth performance, relative organ weight, cecal microflora, blood biochemical parameters, and splenic cytokines mRNA expression in broiler chicks. Four hundred eighty 1-day-old male broiler chicks (Ross 308) were divided in to 4 treatment groups with 4 replicates of 30 birds in each group: NC (control, no antibiotics), PC (avilamycin, 10 ppm; salinomycin, 60 ppm), AC (A. capillaries, 100 ppm), and CS (C. sinensis, 100 ppm); treatments were administered through water supplementation. Final body weight was significantly higher in all treated groups than in NC (p<0.05). Cecal Salmonella numbers were significantly or somewhat decreased in all treated groups than in NC (p<0.05). The relative weights and lengths of the small intestine were more significantly decreased in the PC and AC groups than in the other groups. Cecal Salmonella numbers were significantly or somewhat decreased in all treated groups than in the NC group (p<0.05). The contents of total cholesterol, aspatate aminotransferase, and alanine aminotransferase in blood serum were more significantly decreased in all treated groups than in NC (p<0.05). In conclusion, these results suggested the possibility that these extracts could serve as alternatives for antibiotic growth promoters.