• 한국동물생명공학회지
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• 제35권4호
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• pp.357-365
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• 2020

The aim of present study was to investigate regulatory mechanism of alpha-linolenic acid (ALA) during in vitro maturation (IVM) on nuclear and cytoplasmic maturation of porcine oocytes. Basically, immature cumulus-oocyte complexes (COCs) were incubated for 22 h in IVM-I to which hormone was added, and then further incubated for 22 h in IVM-II without hormone. As a result, relative cumulus expansion was increased at 22 h after IVM and it was enhanced by treatment of ALA compared with control group (p < 0.05). During IVM process within 22 h, cAMP level in oocytes was decreased at 6 h (p < 0.05) and it was recovered at 12 h in ALA-treated group, while oocytes in control group recovered cAMP level at 22 h. In cumulus cells, it was reduced in all time point (p < 0.05) and ALA did not affect. Treatment of ALA enhanced metaphase-I (MI) and MII population of oocytes compared with oocytes in control group at 22 and 44 h, respectively (p < 0.05). Intracellular GSH levels in ALA group was increased at 22 and 44 h after IVM (p < 0.05), whereas it was increased in control group at 44 h after IVM (p < 0.05). In particular, the GSH in ALA-treated oocytes during 22 h of IVM was higher than control group at 22 h (p < 0.05). Lipid amount in oocytes from ALA group was higher than control group (p < 0.05). Treatment of ALA did not influence to absorption of glucose from medium. Cleavage and blastocyst formation of ALA-treated oocytes were enhanced compared with control group (p < 0.05). These findings suggest that supplementation of ALA could improve oocyte maturation and development competence through increasing GSH synthesis, lipid storage, and regulation of cAMP accumulation during early 22 h of IVM, and these might be mediated by cumulus expansion.

• 한국식품저장유통학회지
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• 제13권6호
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• pp.774-782
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• 2006

연근 에탄올 추출물이 알코올 투여로 유발된 간 손상에 미치는 영향을 알아보기 위하여 흰쥐에게 기본식이군 (BD), 알코올 투여군 (ET), 기본식이와 연근 에탄올 추출물 저용량 (200 mg/kg) 투여군 (BD-LREL), 기본식이와 연근 에탄올 추출물 고용량 (400 mg/kg) 투여군 (BD-LREL), 알코올과 연근 에탄올 추출물 저용량 (200 mg/kg) 병합 투여군 (ET-LREL) 및 알코올과 연근 에탄올 추출물 고용량 (400 mg/kg) 병합 투여군 (ET-LREH)의 6군으로 나누어 6주간 사육하였다. 체중증가량은 알코올 단독 투여군 (ET)이 기본식이군 (BD)에 비하여 감소되었으나 유의차가 없었다. 알코올과 연근 에탄올 추출물 저용량 (ET-LREL)과 고용량(ET-LREH) 병합 투여군은 알코올 투여로 감소된 체중을 기본식이군 (BD)에 근접하게 증가시켰다. 식이효율은 알코올 단독 투여군 (ET)이 기본식이군 (BD)에 비하여 유의하게 저하되었으나, 알코올 단독 투여군 (ET)을 제외한 모든 실험군의 식이효율은 유사하였다. 알코올 투여로 증가된 혈청 중 AST, ALT및 ALP 활성은 연근 에탄올 추출물 경구 투여로 저하되었다. 간조직 중 XO 활성은 알코올 단독투여군 (ET)이 기본식이군 (BD)에 비하여 유의하게 증가되었고 연근 에탄올 추출물 투여로 알코올 투여로 증가된 XO 활성을 용량 의존적으로 감소시켰다. 간조직 중 SOD와 GSH-Px 활성은 알코올 단독 투여군 (ET)이 기본식이군 (BD)에 비하여 현저히 증가되었는데 이는 알코올 투여로 생성된 활성 산소를 소거하려는 생리 적응 현상으로 사료되며, 연근 에탄올 추출물 투여로 SOD 활성이 용량 의존적으로 유의하게 감소하였다. 간조직 중 catalase 활성도 알코올 단독 투여군 (ET)이 기본식이군 (BD)에 비하여 유의하게 증가되었으나 연근 에탄올 추출물 투여로 증가된 활성을 용량 의존적으로 감소시켰지만 유의차는 없었다. 간조직 중 GSH 함량은 알코올 단독 투여군 (ET)이 기본식이군 (BD)에 비하여 유의하게 감소되었으며, 알코올과 연근 에탄올 추출물 고용량 투여군 (ET-LREH)은 알코올 투여로 감소된 GSH 함량을 기본식이군 (BD)에 근접토록 증가시켰다. 간조직 중 과산화지질 함량은 알코올 단독 투여군 (ET)이 기본식이군 (BD)에 비하여 증가되었으나, 알코올과 연근 에탄올 추출물 고용량 병합 투여군 (ET-LREH)은 알코올 투여로 증가된 과산화지질 함량을 유의하게 저하시켰다. 이상의 결과 연근 에탄올 추출물은 알코올 투여로 증가된 혈청 AST, ALT 및 ALP 활성과 간조직의 과산화지질 함량, XO, SOD, GSH-Px 및 catalase 활성을 저하시켜 알코올로 유도된 지방간 및 손상된 간조직을 보호하는 항산화효과가 있는 것으로 추정된다.

• 대한예방한의학회지
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• 제17권2호
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• pp.169-178
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• 2013

Objectives : Many cancers acquired resistance to chemotherapy, thus limiting its anticancer efficacy. It is known that Glutathione (GSH) is related to the development of drug resistance. The expression of GSH synthesizing glutamylcysteine ligase (GCL) was controlled by nuclear factor-E2-related factor(Nrf2). Previous studies showed that pharmacological depletion of GSH results in ROS increase, apoptotic response, and sensitization to oxidizing stimuli. In the current study, we examined Saussurea Lappa (SL) have the inhibitory effect on Nrf2 activity using human lung cancer A549 cells overexpressing Nrf2. Methods : Cell viability of A549 cells on SL treatment was determined by MTT assay. To detect the apeptosis in SL-treated A549 cells, sub-G1 population was measured by flow cytometry analysis (FACS). The level ROS was determined by FACS and fluorescence microscopy. To investigate whether SL have effect the suppression on Nrf2, we performed western blotting analysis. The GSH content was measured since GSH plays an important role in response to oxidative stress and was regulated by Nrf2. Results : A549 cells treated with an SL extract showed a substantial decrease in cell viability, along with a concomitant increase in apoptosis compared to untreated cells. Treatment of the SL extract led to increased Reactive oxygen species (ROS) production and a suppression of Nrf2. In addition, the antioxidant NAC attenuated SL-induced ROS generation, Nrf2 inhibition, and apoptosis. Taken together, these data show that the SL extract induced the production of ROS, and the inhibition of Nrf2, consequently resulting in A549 cell death. Conclusions : These results suggest that SL might be an effective agent to enhance anticancer drug sensitivity via Nrf2 inhibition.

• Biomolecules & Therapeutics
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• 제26권2호
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• pp.167-174
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• 2018

Alterations in sulfur amino acid metabolism are associated with an increased risk of a number of common late-life diseases, which raises the possibility that metabolism of sulfur amino acids may change with age. The present study was conducted to understand the age-related changes in hepatic metabolism of sulfur amino acids in 2-, 6-, 18- and 30-month-old male C57BL/6 mice. For this purpose, metabolite profiling of sulfur amino acids from methionine to taurine or glutathione (GSH) was performed. The levels of sulfur amino acids and their metabolites were not significantly different among 2-, 6- and 18-month-old mice, except for plasma GSH and hepatic homocysteine. Plasma total GSH and hepatic total homocysteine levels were significantly higher in 2-month-old mice than those in the other age groups. In contrast, 30-month-old mice exhibited increased hepatic methionine and cysteine, compared with all other groups, but decreased hepatic S-adenosylmethionine (SAM), S-adenosylhomocysteine and homocysteine, relative to 2-month-old mice. No differences in hepatic reduced GSH, GSH disulfide, or taurine were observed. The hepatic changes in homocysteine and cysteine may be attributed to upregulation of cystathionine ${\beta}-synthase$ and down-regulation of ${\gamma}-glutamylcysteine$ ligase in the aged mice. The elevation of hepatic cysteine levels may be involved in the maintenance of hepatic GSH levels. The opposite changes of methionine and SAM suggest that the regulatory role of SAM in hepatic sulfur amino acid metabolism may be impaired in 30-month-old mice.

• Toxicological Research
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• 제3권2호
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• pp.129-141
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• 1987

Hepatocytes isolated from rats which have been pretreated with phenobarbital (80 mg/kg for 3 days), were able to take up N-acetylcysteine from surrounding medium and were able to synthesize the reduced glutathione ($GSH^{\ast}-3$) intracellularly. The N-acetylcysteine is quickly deacetylated after the uptake and increases the pool size of cysteine, which was very low initially (5 nmol/$10^6$ cells). From this increased intracellular cysteine pool, GSH was synthesized. Freshly isolated rat hepatocytes contained a high level of GSH (30 nmol/$10^6$ cells), but upon incubation with the diethylmaleate, it was markedly decreased (10 nmol/$10^6$ cells). The hepatocytes with depleted GSH have lost viability upon incubations with acetaminophen (5mM) and paraquat (2 mM). However, when the N-acetylcysteine (1 mM) was added to this incubation condition, these chemical induced hepatocellular necrosis were prevented for longer durations. This N-acetylcysteine dependent protective effect against the hepatotoxic chemicals was lost by adding methionine sulfoximine (10 mM), an inhibitor of GSH biosynthesis. Both the carbontetrachloride (5 mM) and chioroform (5 mM) added to the incubation medium caused rapid losses of GSH and cell viability, even without the prior depletion of cellular GSH. However, again, if the 1mM N-acetylcysteine was supplemented, the rates of losses of GSH and cell viability were retarded in both cases. Even though large amounts of the added N-acetylcysteine was present in the cell, N-acetylcysteine conjugate of acetaminophen was not formed. Instead, only large amounts of GSH conjugate of the drug was produced. Thus, it is concluded that the added N-acetylcysteine is taken up and utilized for resynthesis of GSH. In turn, this resynthesized GSH contributes to the protection against cytotoxicity inducible with hepatotoxic drugs.

• Biomolecules & Therapeutics
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• 제17권4호
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• pp.455-460
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• 2009

Foods of plant origin, especially fruits and vegetables, have attracted attention because of their potential benefits to human health. In this report, Rubi Fructus (RF), the dried unripe fruit of Rubus coreanus Miq (Rosaceae) and ellagic acid (EA) purified from RF were used to test their potential hepatoprotective effect against acetaminophen (AAP)-induced hepatotoxicity in rats. RF extract (RFext) and EA reduced the elevated levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) in serum and the content of lipid peroxide in liver by AAP administration, while the increment of the cellular glutathione (GSH) content and the induction of glutathione S-transferase (GST) and glutathione peroxidase (GSH-PX) which were decreased by AAP administration. RFext and EA from RFext did not affect the two major form of cytochrome P450s, cytochrome P450 2E1 (CYP2E1) and cytochrome P450 1A2 (CYP1A2), but downregulated the cytochrome P450 3A4 (CYP3A4) related to the conversion of AAP to N-acetyl-P-benzoquinone imine (NAPQI). These results suggest that RFext and EA from RF exhibit a hepatoprotective effect not only by increasing antioxidant activities but also by down-regulating CYP3A4 in the AAP-intoxicated rat.

• Preventive Nutrition and Food Science
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• 제8권3호
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• pp.239-244
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• 2003

Recently, we reported (J Korean Soc Food Sci Nutr, 31(3): 516-520, 2002) that Semisulcospira libertina (Marsh Snail) pretreatment has a hepatoprotective effect on $CCl_4$-induced liver damage in rats. The purpose of this study was to investigate the possible mechanisms of hepatoprotection by S. libertina (SL) on liver injury induced by acetaminophen (AA). Male ICR mice were pretreated with dehydrated powder of SL once daily for three consecutive days, given a single toxic dose of AA (450 mg/kg) and liver function determined 24 h later. Liver damage was assessed by quantifying serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and sorbitol dehydrogenase (SDH) activities, and by measuring hepatic lipid peroxidation. To confirm possible mechanism(s), the content of hepatic glutathione (GSH) and gene expression of tumor necrosis factor a (TNF $\alpha$) mRNA by reverse transcription-polymerase chain reaction (RTPCR) were also measured. Pretreatment with SL dramatically lowered AA-elevated ALT, AST and SDH activities. SL pretreatment decreased AA-produced lipid peroxidation by 11% and restored the AA-depleted hepatic GSH by 27%. Furthermore, SL markedly suppressed the expression of TNF $\alpha$ mRNA induced by AA. Our findings revealed that the possible hepatoprotective mechanisms of SL could be attributed, at least in part, to the glutathione-mediated detoxification as well as the regulation of TNF $\alpha$ mRNA expression.

• BMB Reports
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• 제40권3호
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• pp.412-418
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• 2007

Phospholipid hydroperoxide glutathione peroxidase (PHGPx) is an unique antioxidant enzyme that directly reduces lipid hydroperoxides in biomembranes. In the present work, the entire encoding region for Oryza sativa PHGPx was expressed in Escherichia coli M15, and the purified fusion protein showed a single band with 21.0 kD and pI = 8.5 on SDS- and IFE-PAGE, respectively. Judging from CD and fluorescence spectroscopy, this protein is considered to have a well-ordered structure with 12.2% $\alpha$-helix, 30.7%$\beta$-sheet, 18.5% $\delta$-turn, and 38.5% random coil. The optimum pH and temperature of the enzyme activity were pH 9.3 and 27$^{\circ}C$. The enzyme exhibited the highest affinity and catalytical efficiency to phospholipid hydroperoxide employing GSH or Trx as electron donor. Moreover, the protein displayed higher GSH-dependent activity towards t-Butyl-OOH and $H_2O_2$. These results show that OsPHGPx is an enzyme with broad specificity for hydroperoxide substrates and yielded significant insight into the physicochemical properties and the dynamics of OsPHGPx.

• 한국균학회지
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• 제28권1호
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• pp.55-59
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• 2000

까치버섯(Polyozellus multiplex) 메탄올 추출물과 물 추출물은 산화 유발물질인 $H_2O_2$에 대하여 메탄올 추출물과 물 추출물에서 각각 53.5%, 29.4%의 생존율을 보여 까치버섯 추출물의 항산화 효과를 확인하였다. 까치버섯 메탄올 추출물과 물 추출물을 이용하여 동물에 강력한 발암물질인 MHNG를 투여한 후 항산화 효소계를 측정한 결과, 물 추출물은 항산화효소인 glutathione S-transferase(GST)와 superoxide dismutase(SOD) 활성과 조직내의 해독물질인 glutathione(GSH)의 함량을 높여 주었다. 또한 0.5%의 까치버섯 물 추출물은 암억제 유전자인 p53회 발현을 매우 증가시켰다. 이상의 결과로 까치버섯(Polyozellus multiplex)은 항산화 능이 있으며 특히, 물 추출물은 체내의 항산화 효소를 활성화시키고 항산화 물질의 함량을 높여주었고 암 억제유전자인 p53의 발현을 증가시켜 항암효과가 있음을 보여주었다.

• 한국식품영양학회지
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• 제9권4호
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• pp.472-477
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• 1996

간장해에 미치는 녹각의 효과를 밝힐 목적으로 녹각을 성분별로 추출 분리하여 급여하고 galactosamine으로 간장해를 유도한 후 녹각추출물이 간기능 유지에 관여하는 효소활성 및 지질 대사에 미치는 영향을 생화학적 측면에서 고찰하였다. Cytochrome P-450은 녹각추출물 급여로 증가하였으며 갈락토사민 투여로 감소하였으나 neutral-ext.군에서 높은 증가를 보였다. Glutathione peroxidase 활성은 갈락토사민 투여로 감소하였으나, 녹각 추출물 급여로 활성이 증가하였다. 간조직의 글루타티올 함량은 녹각추출물 급여로 유의적 변동이 없었으며 갈락토사민 투여로 감소하였다. 과산화지질 함량은 대조군에 비해 각각의 녹각추출물 급여군에서 감소하여 특히 water-ext. 군에서 감소정도가 가장 현저하였다. 간조직중의 총 지방질, 총 콜레스테롤 및 트리글리세리드의 함량은 대조군에 비해 각각의 녹각추출물 급여군에서 감소하였으며, water-ext.군에서 가장 많이 하게 감소하였다. 이상의 결과로 미루어 볼 때 녹각의 water-ext.과 neutral-ext.에 함유되어 있는 성분이 간기능 유지에 관여하는 효소합성 증가를 통해 활성증가를 유도하고, 이로써 독성의 대사를 촉진시키므로 간독성을 예방할 수 있을 것으로 생각되며, 이와 같은 녹각추출물의 작용이 생체에 흡수되어진 xenobiotics의 해독작용과 연관될 것으로 생각된다.