• Journal of the Korean Society of Food Culture
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• v.38 no.2
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• pp.112-118
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• 2023

Seaweed-derived foods have long been popular in Korea because of their high content of nutrients that are beneficial to the human body. Recently, Korean seaweeds have been used as raw materials to produce new natural products with health benefits. Herein, we compared the antioxidant activity of 16 Korean seaweed extracts to explore their potential utility as health foods. The total phenolic content (TPC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of seaweed extracts were determined. We also investigated their ability to protect human diploid fibroblast (HDF) cells against hydrogen peroxide. The results showed that seaweed extracts at a concentration of 100 ㎍/mL did not cause any cell toxicity. Sargassum thunbergii (Jichung-i) had the highest TPC and radical scavenging effects, followed by Porphyra tenera (Gim), Silvetia siliquosa (Tteumbugi), and Sargassum fusiforme (Tot). Hydrogen peroxide increased the production of intracellular reactive oxygen species, while P. tenera (Gim), Saccharina japonica (Dasima), and S. thunbergii (Jichung-i) extracts significantly decreased it. The effect was highest in the S. thunbergii (Jichung-i)-treated HDF cells. These findings indicate that S. thunbergii (Jichung-i) shows promise as a potential antioxidant raw material.

• Korean Journal of Pharmacognosy
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• v.53 no.1
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• pp.42-48
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• 2022

In order to maintain bone homeostasis, it is necessary to balance bone resorption and remodeling through the differentiation of osteoclasts that absorb old bone and osteoblasts that form new bone. However, bone resorption due to excessive osteoclast differentiation is a major cause of osteoporosis and controlling excessive osteoclast differentiation has been known as a treatment strategy for osteoporosis. Therefore, in this study, the effect of an ethanol extract of Sphaerotylus antarcticus Kirkpatrick, 1907 (SAE), polar-derived sponge with unknown biological activity, on the osteoclast differentiation process of RANKL-induced RAW264.7 cells and the generated ROS was evaluated. In the study results, SAE down-regulated the formation and function of RANKL-induced osteoclasts and osteoclast differentiation specific proteins, genes in a concentration-dependent manner. In addition, it was possible to confirm the result of restoring the lost antioxidant enzyme along with down-regulation of ROS generated by RANKL. Therefore, in this study, we propose the possibility of SAE as a potential regulator of osteoporosis due to excessive osteoclast differentiation and report the biological value of the diversity of marine-derived natural products by identifying the first biological activity against SAE that is not yet known.

• Korean Journal of Ecology and Environment
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• v.52 no.3
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• pp.192-201
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• 2019

While a fairly large amount of organic matter is produced daily via phytoplankton photosynthesis in Lake Paldang, South Korea, knowledge of the role of algal-derived organic matter (OM) as a refractory OM source is not adequate. To understand the contribution of algal-derived OM to the refractory pool, biodegradation experiment and $KMnO_4$ oxidation experiment were conducted for 60 days using $^{13}C$ and $^{15}N$ labeled natural phytoplankton assemblage. The assemblage was collected from Lake Paldang on May 20, 2010. The photosynthetically produced total organic carbon ($TO^{13}C$), particulate organic carbon ($PO^{13}C$), and particulate nitrogen ($P^{15}N$) remained at 26%, 20%, and 17% of the initial concentrations, respectively, in the form of non-biodegradable organic matter. In addition, 12% and 38% of $PO^{13}C$ remained after $KMnO_4$ treatment on Day 0 and 60, respectively. These results indicate that photosynthetic products could be an important source of refractory organic matter after microbial degradation. Moreover, the microbially transformed algal-derived OM could contribute to the oxidation rate of the chemical oxygen demand.

• Journal of Life Science
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• v.32 no.1
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• pp.51-55
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• 2022

Matrix metalloproteinase (MMP) enzymes are responsible for the degradation and formation of the extracellular matrix (ECM), and overproduction of MMPs is observed in several diseases, such as cancer and asthma, that progress with metastatic characteristics. Natural products, especially phytochemicals, have been an important source of MMP inhibitors with reduced side effects. Although the majority of phytochemicals inhibit the enzymatic activity of MMPs, some suppress MMP production. In this context, the current study evaluated the potential of Corydalis heterocarpa, a halophyte with reported bioactivities, to inhibit MMP expression in PMA-stimulated HT-1080 cells. A crude C. heterocarpa extract was shown to decrease the mRNA and protein expression of MMP-2 and MMP-9 while increasing the endogenous MMP inhibitors TIMP-1 and TIMP-2 which regulate MMP expression in healthy tissues. In addition, our results show that the inhibitory effects of C. heterocarpa might occur through suppression of the phosphorylation of MAPK signaling, the upstream activator of MMP overexpression. In conclusion, C. heterocarpa is a potential source of antimetastatic compounds that might serve as lead molecules to develop novel MMP inhibitors.

• Korean Journal of Agricultural Science
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• v.24 no.2
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• pp.132-137
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• 1997

Effective storage facilities are required to stabilize the price of agricultural and marine products to preserve their qualities due to the big fluctuation of shrimp price in Korea. It is easy to make the cave because of good conditions of the land configuration, soil and convenient transportation. The cave storage can save the cost about 40% in building site and equipment, and about 50% in maintenance comparing to existing low temperature storage facilities. The cave storage provide to improve the quality of their stored products with the low heat conductivity, the constant temperature and humidity year round. Therefore, more low temperature storage facilities are required because the items are expanded from potatoes, sweet potatoes, onions, garlics, apples and chestnuts to tangerines, grapes, cabbages, radishes, and wet ginsengs. The demands of the low temperature storage facilities can be substituted into the cave storage facilities. Thus, studies are conducted to observe the changes of the components of the pure and the seasoned salted shrimps with fermentation period during stored at room temperature in cave and to establish the storing at underground facilities to produce high quality salted fish to make profit.

• Ocean and Polar Research
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• v.39 no.2
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• pp.85-106
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• 2017

The Lago Sofia conglomerate in southern Chile is a deep-marine gravelly deposit, which is hundreds of meters thick and kilometers wide and extends laterally for more than 100 km, filling the foredeep trough of the Cretaceous Magallanes Basin. For understanding the depositional processes and environments of this gigantic deep-sea conglomerate, detailed analyses on sedimentary facies, architecture and paleoflow patterns were carried out, highlighting the differences between the northern (Lago Pehoe and Lago Goic areas) and southern (Lago Sofia area) parts of the study area. The conglomerate bodies in the northern part occur as relatively thin (< 100 m thick), multiple units intervened by thick mudstone-dominated sequences. They show paleoflows toward ENE and S to SW, displaying a converging drainage pattern. In the southern part, the conglomerate bodies are vertically interconnected and form a thick (> 400 m thick) conglomerate sequence with rare intervening fine-grained deposits. Paleoflows are toward SW. The north-to-south variations are also distinct in sedimentary facies. The conglomerate bodies in the southern part are mainly composed of clast-supported conglomerate with sandy matrix, which is interpreted to be deposited from highly concentrated bedload layers under turbidity currents. Those in the northern part are dominated by matrix- to clast-supported conglomerate with muddy matrix, which is interpreted as the products of composite mass flows comprising a turbidity current, a gravelly hyperconcentrated flow and a mud-rich debris flow. All these characteristics suggest that the Lago Sofia conglomerate was formed in centripetally converging submarine channels, not in centrifugally diverging channels of submarine fans. The tributaries in the north were dominated by mass flows, probably affected by channel-bank failures or basin-marginal slope instability processes. In contrast, the trunk channel in the south was mostly filled by tractive processes, which resulted in the vertical and lateral accretion of gravel bars, deposition of gravel dunes and filling of scours and channels, similar to deposits of terrestrial gravel-bed rivers. The trunk channel developed along the axis of foredeep trough and its confinement within the trough is probably responsible for the thick, interconnected channel fills. The large-scale architecture of the trunk-channel fills shows an eastward offset stacking pattern, suggesting that the channel migrated eastwards most likely due to the uplift of the Andean Cordillera.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.6
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• pp.791-798
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• 1998

To develop natural flavoring substances. optimal hydrolysis conditions for two stage enzyme hydrolysates (TSEH) using low-utilized shellfishes such as purplish clam and frozen oyster stored at $-20^{\circ}C$ for 60 days. The optimal conditions for TSEH method were revealed in temperature at $50^{\circ}C$ 3 hours digestion with alcalase (Aroase AP-10, $0.3%$ w/v, pH 8.0) at the 1st stage and $45^{\circ}C$ 2 hours digestion with neutrase (Pandidase NP-2, $0.3\%$ w/v, pH 6.0) at the 2nd stage. Among water extracts, autolytic extracts and 4 kinds of enzyme hydrolysates tests, TSEH method was superior to other methods on the aspect of yields, nitrogen contents, taste such as umami and control of off-flayer formation, and transparency of extracts. From the results of chemical experiments and sensory evaluation, we may conclude that TSEH from low-utilized marine products is more flavorable compared the conventional enzyme hydrolysates, it could be commercialized as the seasoning substances.

• Journal of Life Science
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• v.26 no.4
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• pp.431-438
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• 2016

The tumour necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is considered a promising anticancer agent due to its unique ability to induce cancer cell death having only negligible effects on normal cells. However, many cancer cells tend to be resistant to TRAIL. In this study, we investigated the effects and molecular mechanisms of sodium butyrate (SB), a histone deacetylase inhibitor, in sensitizing TRAIL-induced apoptosis in 5637 human bladder cancer cells. Our results indicated that co-treatment with SB and TRAIL significantly increased the apoptosis induction, compared with treatment with either agent alone. Co-treatment with SB and TRAIL effectively increased the cell-surface expression of death receptor (DR) 5, but not DR4, which was associated with the inhibition of cellular Fas-associated death domain (FADD)-like interleukin-1β-converting enzyme (FLICE) inhibitory protein (c-FLIP). Furthermore, the activation of caspases (caspase-3, -8 and -9) and degradation of poly(ADP-ribose) were markedly increased in 5637 cells co-treated with SB and TRAIL; however, the synergistic effect was perfectly attenuated by caspase inhibitors. We also found that combined treatment with SB and TRAIL effectively induced the expression of pro-apoptotic Bax, cytosolic cytochrome c and cleave Bid to truncated Bid (tBid), along with down-regulation of anti-apoptotic Bcl-xL expression. These results collectively suggest that a combined regimen of SB plus TRAIL may offer an effective therapeutic strategy for safely and selectively treating TRAIL-resistant bladder cancer cells.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.203-203
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• 2017

The Earth's climate is rapidly changing because of increasing carbon dioxide content in atmosphere so, climate prediction models anticipate that earth surface temperature will rise by 3 to $5^{\circ}C$ in next 50 to 100 years. Therefore, frequency of un-expected weather events such as drought, salinity, low or high temperature and flooding etc. will be increasing worldwide. Furthermore, increased atmosphere temperature can influence pests and pathogens spread as well. Therefore, to protect enormous grain loss from unexpected weather conditions, studies related with combine stress conditions like abiotic plus biotic stress condition are really required. Thus, our research focused on physiological responses under combined abiotic and biotic stress condition in rice plant. To induce uniform stress condition, we used NaCl (100 mM) and salicylic acid (0.5 and 1.0 mM SA) as each stress a stimulator. Each artificial abiotic and biotic stress inducer was applied to hydroponically grown rice seedlings alone or together for four day. The data were collected in a time-dependent manner [1, 2, 3 and 4 day(s) after treatment (DAT)] and were matched with our anticipation that shoot length and shoot fresh weight was decreased in solo and combined abiotic and biotic stress condition. The lipid peroxidation content was significantly increased ($1.5{\pm}0.2$ to $2.7{\pm}0.1mg$ mg of $MDA\;g^{-1}FW$) in the first two days in both stress exposed plants, and showed the opposite trend ($0.5{\pm}0.01$ to $0.1{\pm}0.001mg$ of $MDA\;g^{-1}FW$) in last two days under multi stress condition. Superoxide dismutase (SOD) activity did not showed difference in only biotic stress condition (alone 0.5 and 1.0 mM SA) as compared to control however, it was significantly increased in multi stress condition or solo abiotic stress condition whereas, catalase (CAT), and ascorbate peroxidase (APX) activities were significantly decreased in solo biotic and combined abiotic and biotic condition. In particular, both enzymes activities were more decreased in multi stress condition as compared to solo biotic stress condition. The results for relative mRNA expression level of CAT and APX enzymes were in agreement with results of spectrophotometric values. Correlation value between each stress condition and phenotypic data showed that biotic stress condition showed high correlation with activity of CAT and APX whilst, abiotic stress condition revealed significant correlation with SOD activity.

• Journal of Food Hygiene and Safety
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• v.13 no.4
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• pp.355-359
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• 1998

Platelet activation is originated by the intracellular or/and extracellular $Ca^{2+}$. Agonist-induced $Ca^{2+}$ entry through a plasma-membrane pathway has been reported repeatedly, but the mechanisms has proven harder to elucidate. Recently, a number of natural products have been isolated from medicinal plants and marine organisms and have proved to be useful chemical tools for resolving the mechanism of cellular functions. In an attempt to understand the mechanism of platelet activation in Bupleuri Radix, we have studied some aspects of the isolation of active components and their dependence of external $Ca^{2+}$> on platelet activation. Acetone extract of Bupleuri Radix has the most activity on platelet activation and it's active components were identified as saikosaponin a and d. Their optimal concentration was respectively $20\;\mu\textrm{g}/ml$ and $5\;\mu\textrm{g}/ml$ and their platelet activation was not dependent on external $Ca^{2+}$>, whereas optimal concentration of each agonist was arachidonic acid ($10\;\mu\textrm{M}$), collagen ($10\;\mu\textrm{M}/ml$), thrombin (0.1 unit/mi), PAF (5 nM), PMA ($5\;\mu\textrm{M}$), ionophore A23187 ($2\;\mu\textrm{g}$) and their dependence of external $Ca^{2+}$> on platelet activation appeared to thrombin > collagen $\geq$ PAF > PMA > arachdonic acid> ionophore A23187. These results suggest that saikosaponin is different from each agonists in the dependence of external $Ca^{2+}$ on platelet activation.