• Nutrition Research and Practice
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• 제16권2호
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• pp.147-160
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• 2022

BACKGROUND/OBJECTIVES: Patients with chronic kidney disease (CKD) have a high concentration of uremic toxins in their blood and often experience muscle atrophy. Indoxyl sulfate (IS) is a uremic toxin produced by tryptophan metabolism. Although an elevated IS level may induce muscle dysfunction, the effect of IS on physiological concentration has not been elucidated. Additionally, the effects of ursolic acid (UA) on muscle hypertrophy have been reported in healthy models; however, it is unclear whether UA ameliorates muscle dysfunction associated with chronic diseases, such as CKD. Thus, this study aimed to investigate whether UA can improve the IS-induced impairment of mitochondrial biogenesis. MATERIALS/METHODS: C2C12 cells were incubated with or without IS (0.1 mM) and UA (1 or 2 μM) to elucidate the physiological effect of UA on CKD-related mitochondrial dysfunction and its related mechanisms using real-time reverse transcription-polymerase chain reaction, western blotting and enzyme-linked immunosorbent assay. RESULTS: IS suppressed the expression of differentiation marker genes without decreasing cell viability. IS decreased the mitochondrial DNA copy number and ATP levels by downregulating the genes pertaining to mitochondrial biogenesis (Ppargc1a, Nrf1, Tfam, Sirt1, and Mef2c), fusion (Mfn1 and Mfn2), oxidative phosphorylation (Cycs and Atp5b), and fatty acid oxidation (Pdk4, Acadm, Cpt1b, and Cd36). Furthermore, IS increased the intracellular mRNA and secretory protein levels of interleukin (IL)-6. Finally, UA ameliorated the IS-induced impairment in C2C12 cells. CONCLUSIONS: Our results indicated that UA improves the IS-induced impairment of mitochondrial biogenesis by affecting differentiation, ATP levels, and IL-6 secretion in C2C12 cells. Therefore, UA could be a novel therapeutic agent for CKD-induced muscle dysfunction.

• 한국식품과학회지
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• 제54권4호
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• pp.398-402
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• 2022

본 연구에서는 폴리페놀 함유 블랙 초크베리가 콜레스테롤 대사에 미치는 영향을 HepG2 세포에서 콜레스테롤 대사 관련 유전자 발현을 측정함에 따라 조사하였다. 블랙 초크베리는 콜레스테롤 대사와 관련하여 콜레스테롤 흡수, 생합성, 유출과 관련된 유전자 발현을 조절하는 것으로 나타났다. 이는 블랙 초크베리의 혈중 콜레스테롤 저하 효과가 콜레스테롤 및 담즙 대사 관련 유전자 발현을 조절함에 의한 것으로 사료된다. 추후 블랙 초크베리 내 어떠한 생리활성물질이 콜레스테롤 대사 유전자 발현을 조절하여 이러한 효과를 나타내는 지에 대한 연구가 필요하며, 블랙 초크베리의 콜레스테롤 저하 효과를 동물 및 임상에서 기전 연구를 진행하여 천연 유래 기능성 소재로서의 블랙 초크베리의 중요성을 검증할 필요가 있을 것으로 사료된다.

• 한국자기공명학회논문지
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• 제25권4호
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• pp.58-63
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• 2021

Apolipoprotein B-100 (apo B-100), the main protein component that makes up LDL (Low density lipoprotein), consists of 4,536 amino acids and serves to combine with the LDL receptor. The oxidized LDL peptides by malondialdehyde (MDA) or acetylation in vivo act as immunoglobulin (Ig) antigens and peptide groups were classified into 7 peptide groups with subsequent 20 amino acids (P1-P302). The biomimetic peptide P143 (IALDD AKINF NEKLS QLQTY) out of C-group peptides carrying the highest value of IgG antigens were selected for structural studies that may provide antigen specificity. Experimental results show that P143 has β-sheet in Ile[1]-Asn[9] and α-helice in Gln[16]-Tyr[20] structure. Homonuclear 2D-NMR (COSY, TOCSY, NOESY) experiments were carried out for NMR signal assignments and structure determination for P143. On the basis of these completely assigned NMR spectra and proton distance information, distance geometry (DG) and molecular dynamic (MD) were carried out to determine the structures of P143. The proposed structure was selected by comparisons between experimental NOE spectra and back-calculated 2D NOE results from determined structure showing acceptable agreement. The total Root-Mean-Square-Deviation (RMSD) value of P143 obtained upon superposition of all atoms were in the set range. The solution state P143 has a mixed structure of pseudo α-helix and β-turn(Phe[10] to Glu[12]). These results are well consistent with calculated structure from experimental data of NOE spectra. Structural studies based on NMR may contribute to the prevent oxidation studies of atherosclerosis and observed conformational characteristics of apo B-100 in LDL using monoclonal antibodies.

• Molecules and Cells
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• 제46권8호
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• pp.496-512
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• 2023

A fructose-enriched diet is thought to contribute to hepatic injury in developing non-alcoholic steatohepatitis (NASH). However, the cellular mechanism of fructose-induced hepatic damage remains poorly understood. This study aimed to determine whether fructose induces cell death in primary hepatocytes, and if so, to establish the underlying cellular mechanisms. Our results revealed that treatment with high fructose concentrations for 48 h induced mitochondria-mediated apoptotic death in mouse primary hepatocytes (MPHs). Endoplasmic reticulum stress responses were involved in fructose-induced death as the levels of phosho-eIF2α, phospho-C-Jun-N-terminal kinase (JNK), and C/EBP homologous protein (CHOP) increased, and a chemical chaperone tauroursodeoxycholic acid (TUDCA) prevented cell death. The impaired oxidation metabolism of fatty acids was also possibly involved in the fructose-induced toxicity as treatment with an AMP-activated kinase (AMPK) activator and a PPAR-α agonist significantly protected against fructose-induced death, while carnitine palmitoyl transferase I inhibitor exacerbated the toxicity. However, uric acid-mediated toxicity was not involved in fructose-induced death as uric acid was not toxic to MPHs, and the inhibition of xanthine oxidase (a key enzyme in uric acid synthesis) did not affect cell death. On the other hand, treatment with inhibitors of the nicotinamide adenine dinucleotide (NAD)⁺-consuming enzyme CD38 or CD38 gene knockdown significantly protected against fructose-induced toxicity in MPHs, and fructose treatment increased CD38 levels. These data suggest that CD38 upregulation plays a role in hepatic injury in the fructose-enriched diet-mediated NASH. Thus, CD38 inhibition may be a promising therapeutic strategy to prevent fructose-enriched diet-mediated NASH.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2023년도 임시총회 및 춘계학술대회
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• pp.56-56
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• 2023

The cone of Pinus rigida × Pinus taeda (PRT), a plant in the Pinaceae family, has long been used in traditional medicine to treat hemostasis, bruises, and burns. Previous research has shown that regulating oxidation-reduction reactions in reactive oxygen species can help inhibit melanogenesis, the process of melanin synthesis, which is a common target for addressing hyperpigmentation. Inhibiting tyrosinase is also known to be effective in this regard. Based on these findings, we conducted an investigation into the inhibitory effect of the ethyl acetate fraction of PRT (ERT) on melanogenesis in B16 F10 cells. We know that the expression levels of melanin biosynthesis-related proteins, including tyrosinase, TRP-1, and TRP-2, are regulated by MITF (microphthalmia-associated transcription factor) and cAMP, with cAMP affecting the activity of protein kinase A (PKA). PKA can reduce melanogenesis, and CREB reduces the phosphorylation of melanin-producing enzymes. In addition, the MAPK signaling pathway, composed of ERK, JNK, p38, and other factors, is also known to play a role in the inhibition of melanogenesis in melanocytes. Our immunoblotting results showed that ERT inhibited the expression of melanin production-related proteins (tyrosinase, TRP-1, TRP-2, and MITF) that were significantly increased by a-MSH treatment to promote melanin production. Furthermore, the phosphorylation levels of factors related to cAMP/PKA/CREB and MAPK signaling pathways were significantly reduced without affecting the total form. In conclusion, we believe that treatment with ERT can inhibit melanin synthesis by modulating the phosphorylation of cAMP/PKA/CREB and MAPK signaling pathways at the cellular level. These findings suggest the potential of ERT as a raw material for functional cosmetics and pharmaceuticals, thanks to its antioxidant activity and ability to inhibit melanogenesis. We thought that these findings of ERT as a natural plant resource will inspire further research and development in this area.

• 한국축산식품학회지
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• 제43권6호
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• pp.1128-1149
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• 2023

In order to extend the shelf life of refrigerating raw lamb by inhibiting the growth of microorganisms, preventing the oxidation of fat and protein, and absorbing the juice outflow of lamb during storage, an active packaging system based on plastic/gelatin bilayer film with essential oil was developed in this study. Three kinds of petroleum-derived plastic films, oriented polypropylene (OPP), polyethylene terephthalate, and polyethylene, were coated with gelatin to make bilayer films for lamb preservation. The results showed significant improvement in the mechanical properties, oxygen, moisture, and light barriers of the bilayer films compared to the gelatin film. The OPP/gelatin bilayer film was selected for further experiments because of its highest acceptance by panelists. If the amount of juice outflow was less than 350% of the mass of the gelatin layer, it was difficult for the gelatin film to separate from lamb. With the increase in essential oil concentration, the water absorption capacity decreased. The OPP/gelatin bilayer films with 20% mustard or 10% oregano essential oils inhibited the growth of bacteria in lamb and displayed better mechanical properties. Essential oil decreased the brightness and light transmittance of the bilayer films and made the film yellow. In conclusion, our results suggested that the active packaging system based on OPP/gelatin bilayer film was more suitable for raw lamb preservation than single-layer gelatin film or petroleum-derived plastic film, but need further study, including minimizing the amount of essential oil, enhancing the mechanical strength of the gelatin film after water absorption.

• Animal Bioscience
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• 제36권11호
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• pp.1738-1746
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• 2023

Objective: The aim of this study was to investigate quality characteristics of reduced-salt, low-fat pork sausage (PS) using pre-rigor muscle and sea tangle extract (STE) to reduce salt level of sausages during refrigerated storage. Methods: Pork ham was prepared with pre-rigor and post-rigor muscle from the local market. Sausages using post-rigor muscle were manufactured with the 1.5% of salt content, and samples with pre-rigor muscle were processed by different salt concentrations (0.8%). Accordingly, PSs were prepared in 4 treatments (REF, PS with 1.5% of salt using post-rigor muscle; CTL, PS with 0.8% of salt using pre-rigor muscle; TRT1, PS with 0.8% of salt and 5% of STE using pre-rigor muscle; TRT2, PS with 0.8% of salt and 10% of STE using pre-rigor muscle). For the evaluation of quality characteristics and shelf-life of reduced-salt PS, pH and color values, cooking loss (%), expressible moisture (%), textural properties, lipid oxidation (thiobarbituric reactive substances), protein denaturation (volatile basic nitrogen), and microbiological analysis (total plate counts and Enterobacteriaceae counts) were determined. Results: The pH and temperature of pre-rigor raw pork ham were higher than those of post-rigor pork ham. Hardness of TRT2 was higher than that of REF or CTL. TRT2 had higher gumminess and chewiness than CTL. TRT1 and TRT2 had lower volatile basic nitrogen than CTL. Total plate counts of TRT2 were lower than those of CTL. Expressible moisture values of TRT1 and TRT2 were similar to those of REF. The addition of STE into PS improved functional properties and shelf-life of PS. Conclusion: Reduced-salt PS containing pre-rigor muscle and STE had similar functional properties to those of regular-salt ones, while containing approximately 47% less salt compared to regular-salt level.

• IMMUNE NETWORK
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• 제23권3호
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• pp.25.1-25.17
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• 2023

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection induces excessive pro-inflammatory cytokine release and cell death, leading to organ damage and mortality. High-mobility group box 1 (HMGB1) is one of the damage-associated molecular patterns that can be secreted by pro-inflammatory stimuli, including viral infections, and its excessive secretion levels are related to a variety of inflammatory diseases. Here, the aim of the study was to show that SARS-CoV-2 infection induced HMGB1 secretion via active and passive release. Active HMGB1 secretion was mediated by post-translational modifications, such as acetylation, phosphorylation, and oxidation in HEK293E/ACE2-C-GFP and Calu-3 cells during SARS-CoV-2 infection. Passive release of HMGB1 has been linked to various types of cell death; however, we demonstrated for the first time that PANoptosis, which integrates other cell death pathways, including pyroptosis, apoptosis, and necroptosis, is related to passive HMGB1 release during SARS-CoV-2 infection. In addition, cytoplasmic translocation and extracellular secretion or release of HMGB1 were confirmed via immunohistochemistry and immunofluorescence in the lung tissues of humans and angiotensin-converting enzyme 2-overexpressing mice infected with SARS-CoV-2.

• 한국식품영양과학회지
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• 제43권4호
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• pp.498-506
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• 2014

본 연구에서는 다양한 생리활성물질을 다량 함유하고 있는 국내산(전라북도 부안군) 오디의 혈액순환장애의 개선 효과를 확인하기 위하여 in vitro 및 고지혈증 동물모델을 이용한 실험을 진행하였다. MBE가 DPPH 라디칼을 50% 소거하는 $SC_{50}$값은 $89.36{\pm}5.46{\mu}g/mL$로 정제되지 않은 복합물질임을 감안하면 다른 식물추출물에 비해 항산화능이 우수함을 알 수 있었다. RAW 264.7 세포 및 HepG2 세포에 대한 MBE의 세포독성은 2,500 ${\mu}g/mL$ 이하의 농도를 처리한 경우 세포독성을 나타내지 않았다. In vitro 실험에서 COX-2의 활성저해 효과를 측정한 결과 MBE의 $IC_{50}$값은 $215.94{\pm}18.15$이었고, human LDL의 산화억제 효과는 최종반응 농도가 200 및 400 ${\mu}g/mL$일 경우 유의적인 감소(P<0.05) 효과가 있었다. 또한 TNF-${\alpha}$에 의하여 활성화된 HUVECs에서 MBE가 증가된 ICAM-1 및 VCAM-1의 발현을 감소(P<0.05)시켰으며 LPS에 의하여 활성화된 RAW 264.7 세포에서 MBE가 증가된 COX-2 및 5-LO의 발현을 감소(P<0.05)시킴을 알 수 있었다. 고지혈증 동물모델을 이용한 실험에서 MBE의 일부 실험군(200 mg 및 400 mg/kg 체중/day, 14 days)에서 혈청 total cholesterol의 수치는 음성대조군에 비해 유의적으로 감소(P<0.05)시켰으나 혈청 C-reactive protein의 수치는 모든 실험군에서 음성대조군 대비 유의적으로 감소하지 않았다. 이러한 MBE의 항산화능, COX-2 활성억제 및 COX-2와 5-LO의 발현억제를 통한 염증억제, 혈중 total cholesterol 감소를 통한 이상지질혈증의 개선 효과 및 ICAM-1과 VCAM-1의 발현억제를 통한 혈관협착 방지의 효과들을 종합해 보면 오디추출물인 MBE가 혈액순환장애를 유발하거나 확대시키는 다양한 핵심요소들을 다각도로 개선시킴으로써 혈액순환장애의 예방과 치료에 긍정적인 효과가 있을 것으로 사료된다.

• 한국양식학회지
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• 제17권2호
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• pp.144-150
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• 2004

본 연구는 현재 국내 넙치 양식장에서 이용되고 있는 MP, DEP-1, DEP-2, DEP-3, FEP-1, FEP-2에 대해서 농림부에서 규정하고 성분규격 등록항목 외에 사료의 P/E ratio, POV, AnV, Totox, VBN, 총균수, 사료내 지방산 및 아미노산 조성과 그동안 이루어진 넙치 사료영양관련 연구결과를 바탕으로 비교 분석하여 국내 시판중인 넙치 사료의 품질을 평가하기 위해서 이루어졌다. 6가지 사료 모두 요구량 이상으로 단백질이 과잉첨가 된 것으로 생각되며 MP, DEP-1, DEP-2, FEP-1은 사료 내 지질 함량도 과잉첨가 된 것으로 나타났다. 그리고 PH ratio를 기준으로 볼때, MP와 FEP-2는 특히 단백질 함량이 과잉 첨가된 것으로 나타났으며, FEP-1는 특히 지방이 너무 많이 첨가된 것으로 판단된다. 그리고 MP가 배합사료에 비해 사료내 인 함량이 요구량 이상으로 과잉 첨가되어 있어 수질오염을 일으킬 가능성이 높은 것으로 판단된다. 지방산패 및 단백질 부패는 MP가 배합사료에 비해 높게 나타났으며, 이로 인한 문제가 발생할 가능이 높으며, 더욱더 취급 시에 보관 및 관리에 신경을 써야 될 것으로 생각된다. 그리고 지방산의 조성에 있어서는 DHA와 EPA 모두 MP가 배합사료보다 높게 나타났으며, 배합사료는 이에 대한 고찰이 필요할 것으로 생각된다. 사료 내 라이신 함량은 MP와 FEP-2가 요구량 수준으로 첨가되어 있는 것으로 생각되며, 그 외 사료들은 요구량 기준으로 라이신 함량이 부족할 가능성이 높기 때문에 추가첨가가 필요할 것으로 생각된다. 따라서, 농림부에서 양축용 사료 및 반추동물용 섬유질 배합사료의 성분등록을 축종과 사육시기별 품질관리 기준과 같이 양어용 배합사료의 특성을 고려하여 어종별, 크기별 품질관리 기준이 마련되어야 사료회사 및 양식업자가 배합사료에 대한 신뢰성을 회복하고, 이를 통하여 생사료에서 배합사료로 전환을 앞당길 수 있는 계기가 될 것으로 사료된다.