• Journal of Life Science
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• v.27 no.9
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• pp.1070-1077
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• 2017

Chondrocyte apoptosis induced by reactive oxygen species (ROS) plays an important role in the pathogenesis of osteoarthritis. Schisandrin A, a bioactive compound found in fruits of the Schisandra genus, has been reported to possess multiple pharmacological and therapeutic properties. Although several studies have described the antioxidant effects of analogues of schisandrin A, the underlying molecular mechanisms of this bioactive compound remain largely unresolved. The present study investigated the cytoprotective effect of schisandrin A against oxidative stress (hydrogen peroxide [$H_2O_2$]) in SW1353 human chondrocyte cells. The results showed that schisandrin A preconditioning significantly inhibited $H_2O_2-induced$ growth inhibition and apoptotic cell death by blocking the degradation of poly (ADP-ribose) polymerase proteins and down-regulating pro-caspase-3. These antiapoptotic effects of schisandrin A were associated with attenuation of mitochondrial dysfunction and normalization of expression changes of proapoptotic Bax and antiapoptotic Bcl-2 in $H_2O_2-stimulated$ SW1353 chondrocytes. Furthermore, schisandrin A effectively abrogated $H_2O_2-induced$ intracellular ROS accumulation and phosphorylation of histone H2AX at serine 139, a widely used marker of DNA damage. Thus, the present study demonstrates that schisandrin A provides protection against $H_2O_2-induced$ apoptosis and DNA damage in SW1353 chondrocytes, possibly by prevention of ROS generation. Collectively, our data indicate that schisandrin A has therapeutic potential in the treatment of oxidative disorders caused by overproduction of ROS.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.1
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• pp.51-59
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• 2012

Contents of phenolics and flavonoids, antioxidant activity and cytotoxicity were investigated in the methanol extracts of three different $Taraxacum$ species, $Taraxacum$ $coreanum$, $Taraxacum$ $mongolicum$, and $Taraxacum$ $officinale$. Total phenolics content at $1000mg\;kg^{-1}$ was more present in shoot parts than in roots, and was highest in $T.$ $mongolicum$ shoot and root extracts (76.8 and $40.0mg\;kg^{-1}$, respectively), followed by $T.$ $coreanum$ and $T.$ $officinale$ ($p$ < 0.05). Total flavonoid level had same tendency to total phenolics among $Taraxacum$ species, showing lower amounts ($6.5{\sim}36.4mg\;kg^{-1}$) than total phenolics. The antioxidant activity of the methanol extracts from all the species dose-dependently increased. DPPH free radical scavenging activity at $1,000mg\;kg^{-1}$ was highest in shoot and root extracts from $T.$ $mongolicum$ by 89.6 and 83.4%, respectively. According to MTT assay, cell viability of Calu-6 (human pulmonary carcinoma) was lowest in the $T.$ $mongolicum$ shoot and root extracts ($IC_{50}$ values=83.4 and $66.4mg\;kg^{-1}$, respectively), and followed by $T.$ $coreanum$ and $T.$ $officinale$ (lowest). Calu-6 was more sensitive to the extracts than SNU-601 (human gastric carcinoma). Antioxidative and anticancer activities in three different $Taraxacum$ species was more correlated with total phenolics content ($r^2$=0.0097 to 0.6213) than with total flavonoids level ($r^2$=0.0027 to 0.4627). The results showed total phenolics content and total flavonoids level were highly correlated with anticancer activity and antioxidant activity, and their content and activities were different depending on species.

• Journal of Life Science
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• v.26 no.2
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• pp.147-154
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• 2016

Osteosarcoma (OS) is the most common and malignant bone tumors. Although many types of resection surgery and experimental agents were developed, median survival and clinical prognosis are poorly investigated. Recently, several researches have reported that Eucheuma cottonii has potent as protective effects of coal dust-induced lung damage via inhibition of malondialdehyde (MDA) and oxidative stress in bronchoalveolar lavage fluids (BALF). However, anti-cancer effects and specific molecular mechanism of extract from Eucheuma cottonii (EE) has not been clearly studied yet. This study evaluated that anti-cancer potential of EE in human osteosarcoma Saos-2 cells. EE indicated cytotoxicity on Saos-2 cells in a dose-dependent manner. Morphological degradation and nucleic condensation were also observed under the EE treatment. However, it did not significantly affect on non-cancerous kidney HEK-293 cells under the same concentration which is shown cytotoxicity on Saos-2 cells. The phosphorylation of Fas-Associated Death Domain (FADD) and expression of cleaved caspase-8, -7 and -3 were upregulated in a dose-dependent manner. In immunofluorescence staining, expression level of Fas and cleaved PARP were upregulated by EE treatment. Furthermore, treatment of EE induces upregulation of sub G1 phase by flow cytometry analysis. The results demonstrated that EE has a therapeutic potential against osteosarcoma via FADD mediated caspase cascade apoptosis signal pathway.

• Journal of Life Science
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• v.23 no.2
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• pp.167-174
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• 2013

Peroxiredoxin 6 (Prx 6) is a member of the thiol-specific antioxidant protein family, which may play a role in protection against oxidative stress and in regulating phospholipid turnover. The aim of this study was to determine whether a human Prx 6/Luc vector was stably expressed and responded to antioxidants in a lung cell line (NCI-H460). To achieve this, the luciferase signal, hPrx 6 mRNA expression, and superoxide dismutase (SOD) activity were measured in transfectants with a hPrx 6/Luc plasmid after treatment with four antioxidant extracts, including Korea white ginseng (KWG), Korea red ginseng (KRG), Liriope platyphylla (LP), and red Liriope platyphylla (RLP). First, the hPrx 6/Luc plasmid was successfully constructed with DNA fragments of human Prx 6 promoter, amplified by PCR using genomic DNA isolated from NCI-H460 cells, and cloned into the pTransLucent reporter vector. The orientation and sequencing of the hPrx 6/Luc plasmid were identified with restriction enzyme and automatic sequencing. A luciferase assay revealed significant enhancement of luciferase activity in the four treatment groups compared with a vehicle-treated group, although the ratio of the increase was different within each group. The KRG- and LP-treated groups showed higher activity than the KWG- and RLP-treated groups. Furthermore, the luciferase activity against RLP occurred roughly in a dose-dependent manner. However, the level of endogenous hPrx 6 mRNA did not change in any group treated with the four extracts. The SOD activity was in agreement with the luciferase activity. Therefore, these results indicate that the hPrx 6/Luc vector system may successfully express and respond to antioxidant compounds in NCI-H460 cells. The data also suggest that the Prx 6/Luc vector system may be effectively applied in screening the response of hPrx 6 to antioxidant compounds in transgenic mice.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.26 no.1
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• pp.163-186
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• 2000

We have previously screened 150 medicinal plants on the inhibition of elastase and found a significant inhibitory effects of the extracts of Areca catechu L. on the aging and inflammation against the skin tissues. To isolate and identify the compounds having biological activity, we was further purified by each of the solvent fractions, silica gel column chromatography, preparative TLC and reversed-Phase HPLC. Peak in HPLC, which coincided with the inhibitory activity against elastase, was identified as Phenolic substance using various colorimetric methods, UV, and IR. $IC_{50}$/ values of phenolic substance purified from Areca catechu were 26.9 $\mu\textrm{g}$/$m\ell$ for porcine pancreatic elastase (PPE) and 60.8 $\mu\textrm{g}$/$m\ell$ for human neutrophil elastase (HNE). This Phenolic substance showed more potent activity than those of reference compounds, oleanolic acid (76.5 $\mu\textrm{g}$/$m\ell$ for PPE, 219.2 $\mu\textrm{g}$/$m\ell$ for HNE) and ursolic acid (31.0 $\mu\textrm{g}$/$m\ell$ for PPE, 118.6 $\mu\textrm{g}$/$m\ell$ for HNE). According to the Lineweaver-Burk Plots, the inhibition against both PPE and HNE by this phenolic substance was competitive with substrate. Phenolic substance from Areca catechu exhibited high free radical scavenging effect ($SC_{50}$/ : 6 $\mu\textrm{g}$/$m\ell$) and inhibited effectively hyaluronidase activity ($IC_{50}$/: 210 $\mu\textrm{g}$/$m\ell$). These results suggest that the Phenolic substance Purified from Areca catechu showed anti-aging effect by protecting connective tissue proteins.

• Journal of Life Science
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• v.31 no.2
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• pp.126-136
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• 2021

Oxidative stress causes injury to and degeneration of retinal pigment epithelial (RPE) cells. It is involved in several retinal disorders and leads to vision loss. In the present study, we investigated the effect of 14 kinds of natural compounds and two kinds of synthetic compounds on oxidative stress-induced cellular damage in human PRE cell lines (ARPE-19). From among them, we selected five kinds of compounds, including auranofin, FK-509, hemistepsin A, honokiol, and spermidine, which have inhibitory effects against hydrogen peroxide (H2O2)-mediated cytotoxicity. In addition, we found that four kinds of compounds (excluding auranofin) have protective effects on H2O2-induced mitochondrial dysfunction. Furthermore, the expression of phosphorylation of histone H2AX, a sensitive marker of DNA damage, was markedly up-regulated by H2O2, whereas it was notably down-regulated by FK-506, honokiol, and spermidine treatment. Meanwhile, five kinds of candidate compounds had no effect on H2O2-induced intracellular reactive oxygen species (ROS) levels, suggesting that the five candidate compounds have protective effects on oxidative stress-induced cellular damage through the ROS-independent pathway. Taken together, according to the results of H2O2-mediated cellular damage―such as cytotoxicity, apoptosis, mitochondrial dysfunction, and DNA damage―spermidine and FK-506 are the natural and synthetic compounds with the most protective effects against oxidative stress in RPE. Although further studies on the identification of the mechanism responsible are required, the results of the present study suggest the possibility of using spermidine and FK-506 to suppress the risk of retinal disorders.

• Journal of Life Science
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• v.31 no.2
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• pp.199-208
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• 2021

Euonymus porphyreus, a species of plant in the Celastraceae family, is widely distributed in East Asia, especially in Southern China. The botanical characteristics of E. porphyreus have been reported, but its antioxidative and anticancer activities remain unclear. In this study, we evaluated the antioxidative and anticancer effects of ethanol extracts of E. porphyreus (EEEP) and the molecular mechanism of its anticancer activity in human lung adenocarcinoma A549 cells. The total polyphenol and flavonoid compound contents from EEEP were 115.42 mg/g and 23.07 mg/g, respectively. EEEP showed significant antioxidative effects with a concentration at 50% of the inhibition (IC50) value of 11.09 ㎍/ml, as measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. EEEP showed cytotoxic activity by increasing the SubG1 cell population of A549 cells in a dose-dependent manner. Apoptosis in A549 cells treated with EEEP was evident due to increased apoptotic cells and apoptotic bodies, as detected by Annexin V and 4,6-diamidino-2-phenylindole (DAPI) staining, respectively. EEEP-induced apoptosis resulted in increased expression of the First apoptosis signal (Fas), p53, and Bax, with decreased expression of Bcl-2 and subsequent activation of caspase-8, -9, and caspase-3, leading to cleavage of poly (ADP-ribose) polymerase (PARP). Collectively, these results suggest that EEEP may exert an anticancer effect by inducing apoptosis in A549 cells through both intrinsic and extrinsic pathways.

• Food Science and Preservation
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• v.31 no.4
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• pp.673-681
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• 2024

This study was conducted to develop kombucha with better functionality. The developed kombucha (CK) was prepared using the sugar extracts from fruits of Cudrania tricuspidata (Carrière) Bureau ex Lavallée instead of the sugar, which is used as a substrate for SCOBY in conventional kombucha (K). During fermentation, the soluble solids content significantly decreased in CK compared to K, and the pH change decreased rapidly in CK compared to K. On the 14^th day of fermentation, the weight of the SCOBY in CK was higher than that in K. Immediately after preparation, K contained only sucrose, but CK contained sucrose, glucose, and fructose. SCOBY appears to use glucose and fructose preferentially during fermentation. K contained acetic acid and citric acid right after preparation. However, as fermentation progressed, the composition changed to acetic acid, citric acid, and lactic acid. At the same time, CK initially consisted of citric acid, lactic acid, and acetic acid. However, acetic acid and citric acid increased but lactic acid decreased significantly on the 14^th day of fermentation. In the cytotoxicity studies, the CK showed a proliferation-promoting effect on normal lung cells (MRC-5) and strong cytotoxicity against human lung cancer cells (A549). These results suggest that the kombucha made from sugar extracts of C. tricuspidata fruits can be used as a more functional beverage than regular kombucha.

• Korean Journal of Clinical Laboratory Science
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• v.56 no.3
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• pp.236-247
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• 2024

The human leukocyte antigen (HLA) system, which is part of the major histocompatibility complex (MHC) plays a vital role in immune responses by differentiating between itself and foreign cells and antigens. The significant diversity of alleles affects disease susceptibility and immune responses within different populations. Specifically, the HLA-A and HLA-DRB1 alleles are associated with various immune-related diseases, and understanding the frequency and haplotype associations of these alleles is vital for genetic and immunological research. To investigate the distribution of these characteristics in Koreans, we isolated peripheral blood mononuclear cells (PBMCs) from blood samples donated by volunteers at the Seoul Central Blood Bank and performed HLA typing on 790 samples. Our study found that the HLA-A and HLA-DRB1 alleles are widely distributed within the Korean population, with HLA-A^*24:02 (21.7%) and HLA-DRB1*09:01 (9.9%) being the most frequent. Significant haplotype associations between specific HLA-A and HLA-DRB1 alleles were identified using the Chi-square test, suggesting that certain genetic combinations may influence disease onset. This insight could contribute to the development of predictive and preventative strategies for various diseases. The unique genetic characteristics of the Korean population highlight the importance of studying the HLA allele and the haplotype distributions in this group as key indicators for understanding disease susceptibility.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.5
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• pp.536-544
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• 2001

Three harmful algal bloom species with similar morphology, Cochlodinium polykrikoides, Gyodinium impudicum and Gymodinium catenatum have damaged to aquatic animals or human health by either making massive blooms or intoxication of shellfishes in a food chain. Eco-physiological and hydrodynamic studies on the harmful algae offer useful informations in the understanding their bloom mechanism by giving promising data for the prediction and modelling of harmful algal blooms event. Thus, we studied the abundance of these species in the coastal area of South Sea of Korea and their effects of temperature, salinity, irradiance and nutrient on the growth for the isolates. The timing for initial appearance of the three species around the coastal area of Namhaedo, Narodo and Wando was between Bate July and late August in 1999 when water temperature ranged from $22.8^{\circ}C\;to\;26.5^{\circ}C$ Vegetative cells of C. polykrikoides and G. impudicum were abundant until late September when water temperature had been dropped to less than $23^{\circ}C$. By contrast, vegetative cell of G. catenatum disappeared before early September, showing shorter period of abundance than the other two species in the South Sea. Both G. impudicum and G. catenatum revealed comparatively low density with a maximal cell density of 3,460 cells/L and 440 cells/L, respectively without making any bloom, while C. polykrikoides made massive blooms with a maximal cell density more than $40\times10^6$cells/L, The three species showed a better growth at the relatively higher water temperature ranging from 22 to $28^{\circ}C$ with their maximal growth rate at $25^{\circ}C$ in culture, which almost corresponded with the water temperature during the outbreak of C. polykrikoides in the coastal area of South Sea. Also, they all showed a relatively higher growth at the salinity from 30 to $35\%$. Specially, G. impudicum showed the euryhalic characteristics among the species, On the other hand, growth rate of G. catenatum decreased sharply with the increase of water temperature at the experimental ranges more than $35\%$. The higher of light intensities showed the better growth rates for the three species, Moreover, C. polykrikoides and G. impudirum continued their exponential growth even at 7,500 lux, the highest level of light intensity in the experiment, Therefore, It is assumed that C. polykrikoides has a physiological capability to adapt and utilize higher irradiance resulting in the higher growth rate without any photo inhibition response at the sea surface where there is usually strong irradiance during its blooming season. Although C. poiykikoides and G. impudicum continued their linear growth with the increase of nitrate ($NO_3^-$) and ammonium ($NH_4^-$) concentrations at less than the $40{\mu}M$, they didn't show any significant differences in growth rates with the increase of nitrate and ammonium concentrations at more than $40{\mu}M$, signifying that the nitrogen critical point for the growth of the two species stands between 13.5 and $40{\mu}M$. Also, even though both of the two species continued their linear growth with the increase of phosphate ($PO_4^{2-}$) concentrations at less than the $4.05{\mu}M$, there were no any significant differences in growth rates with the increase of phosphate concentrations at more than $4.05{\mu}M$, signifying that the phosphate critical point for the growth of the two species stands between 1.35 and $4.05{\mu}M$. On the other hand, C. polykrikoides has made blooms at the oligotrophic environment near Narodo and Namhaedo where the concentration of DIN and DIP are less than 1.2 and $0.3{\mu}M$, respectively. We attributed this phenomenon to its own ecological characteristics of diel vertical migration through which C. polykrikoides could uptake enough nutrients from the deep sea water near bottom during the night time irrespective of the lower nutrient pools in the surface water.