• BMB Reports
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• 제45권8호
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• pp.464-469
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• 2012

Endothelial cells (ECs) apoptosis induced by oxidized low-density lipoprotein (ox-LDL) is thought to play a critical role in atherosclerosis. MicroRNAs (miRNAs) are a class of noncoding RNAs that posttranscriptionally regulate the expression of genes involved in diverse cell functions, including differentiation, growth, proliferation, and apoptosis. MiRNA let-7 family is known to be involved in the regulation of cell apoptosis. However, the function of let-7 in ox-LDL induced ECs apoptosis and atherosclerosis is still unknown. Here, we show that let-7c expression was markedly up-regulated in ox-LDL induced apoptotic human umbilical cord vein endothelial cells (HUVECs). Let-7c over-expression enhanced apoptosis in ECs whereas inhibition of let-7c could partly alleviate apoptotic cell death mediated by ox-LDL. Searching for how let-7c affected apoptosis, we discovered that antiapoptotic protein Bcl-xl was a direct target of let-7c in ECs. Our data suggest that let-7c contributes to endothelial apoptosis through suppression of Bcl-xl.

• BMB Reports
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• 제50권6호
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• pp.323-328
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• 2017

Lysophosphatidylcholine (LPC) is a major phospholipid component of oxidized low-density lipoprotein (ox-LDL) and is implicated in its atherogenic activity. This study investigated the effects of LPC on cell viability, intracellular calcium homeostasis, and the protective mechanisms of chlorogenic acid (CGA) in human umbilical vein endothelial cells (HUVECs). LPC increased intracellular calcium ($[Ca^{2+}]_i$) by releasing $Ca^{2+}$ from intracellular stores and via $Ca^{2+}$ influx through store-operated channels (SOCs). LPC also increased the generation of reactive oxygen species (ROS) and decreased cell viability. The mRNA expression of Transient receptor potential canonical (TRPC) channel 1 was increased significantly by LPC treatment and suppressed by CGA. CGA inhibited LPC-induced $Ca^{2+}$ influx and ROS generation, and restored cell viability. These results suggested that CGA inhibits SOC-mediated $Ca^{2+}$ influx and ROS generation by attenuating TRPC1 expression in LPC-treated HUVECs. Therefore, CGA might protect endothelial cells against LPC injury, thereby inhibiting atherosclerosis.

• Archives of Pharmacal Research
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• 제26권4호
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• pp.286-293
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• 2003

Several polyphenolic compounds and complex mixtures were isolated from brown algae species. The 1,1-diphenyl-2-picryhydarzyl (DPPH) radical scavenging activity and ferric reducing antioxidant power (FRAP) of these compounds were evaluated to determine their physiological usefulness as antioxidants for vascular protection. The antioxidative protection of low-density lipoprotein (LDL) was also evaluated and compared with that of catechin, because the generation of oxidized LDL is one of the most active and specific risk factors contributing to atherogenesis. Oral administration to rats of a commercially available sample ($VNP^{TM}$) containing 30% of these polyphenolic compounds and 70% dietary fiber revealed that the serum reducing capacity measured in terms of FRAP value was significantly elevated 30 min after the treatment, but declined rather quickly thereafter, indicating the good oral absorption of the compounds and their fast binding to the lumenal surface of the blood vessels. An eight-week, human, clinical trial (n=31) of $VNP^{TM}$ showed significant improvement in erectile function measured by IIEF (international index of erectile function) score. These results collectively demonstrated the usefulness of these polyphenolic compounds as fundamental chemopreventive agents against vascular risk factors originating from oxidative stress.

• Journal of Nutrition and Health
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• 제42권2호
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• pp.107-118
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• 2009

In patients with type 2 diabetes, oxidative stress could be increased by their metabolic changes. Elevated plasma homocysteine is considered as one of markers of enhanced oxidative stress. Due to oxidative stress, some complications like cardiovascular or renal diseases may develop in type 2 diabetes patients. Plasma homocysteine concentration may be increased if folate status were inadequate. Protective effects against oxidative stress may be diminished if the status of anti-oxidative nutrient as vitamin C was poor. It is, therefore, important to maintain adequate status of folate and vitamin C in type 2 diabetes patients. Thus, this study was performed to determine the effects of supplementation of folate and/or ascorbate on blood glycated hemoglobin ($HbA_{1c}$) level, serum concentrations of homocysteine and cholesterol, plasma oxidized low density-lipoprotein (LDL), concentration and plasma glutathione peroxidase (GSH-Px) activity in the patients with type 2 diabetes. A total of 92 type 2 diabetes patients participated voluntarily with written consents. They were divided into one of the four experimental groups; Control (C), Folate-supplemented (F), Ascorbate-supplemented (A), and Folate plus ascorbate-supplemented (FA). The subjects in C were taken placebo, those in F were supplemented 1 mg of folate, those in A received 1,000 mg of ascorbate, and those in FA were given 1 mg of folate plus 1,000 mg of ascorbate daily for 4 weeks. Supplementation of folate or ascorbate resulted to increase serum folate level or plasma ascorbate concentration apparently, respectively. Folate supplementation not ascorbate seemed to decrease plasma concentrations of homocysteine and oxidized LDL and reduce plasma GSH-Px activity. There might not be synergic effect of the supplementation of folate plus ascorbate. The results indicate that oxidative stress in the patients with type 2 diabetes may lower mainly by folate supplementation.

• Journal of Nutrition and Health
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• 제55권4호
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• pp.450-461
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• 2022

Purpose: DNA damage and repair responses are induced by metabolic diseases and environmental stress. The balance of DNA repair response and the antioxidant system play a role in modulating the entire body's health. This study uses a high-fat and high-calorie (HFC) drink to examine the new roles of a plant-based multivitamin/mineral supplement with phytonutrients (PMP) for regulating the antioxidant system and cellular DNA repair signaling in the body resulting from metabolic stress. Methods: In a double-blind, randomized, parallel-arm, and placebo-controlled trial, healthy adults received a capsule containing either a PMP supplement (n = 12) or a placebo control (n = 12) for 8 weeks. Fasting blood samples were collected at 0, 1, and 3 hours after consuming a HFC drink (900 kcal). The blood samples were analyzed for the following oxidative stress makers: areas under the curve reactive oxygen species (ROS) levels, plasma malondialdehyde (MDA), erythrocytes MDA, urinary MDA, oxidized low-density lipoprotein, and the glutathione:oxidized glutathione ratio at the time points. We further examined the related protein levels of DNA repair signaling (pCHK1 (Serine 345), p-P53 (Serine 15), and 𝛄H2AX expression) in the plasma of subjects to evaluate the time-dependent effects of a HFC drink. Results: In a previous study, we showed that PMP supplementation for eight weeks reduces the ROS and endogenous DNA damage in human blood plasma. Results of the current study further show that PMP supplementation is significantly correlated with antioxidant defense. Compared to the placebo samples, the blood plasma obtained after PMP supplementation showed enhanced DNA damage response genes such as pCHK1(Serine 345) (a transducer of DNA response) and 𝛄H2AX (a hallmark of DNA damage) during the 8 weeks trial on metabolic challenges. Conclusion: Our results indicate that PMP supplementation for 8 weeks enhances the antioxidant system against oxidative stress and prevents DNA damage signaling in humans.

• 한국약용작물학회지
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• 제19권5호
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• pp.334-340
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• 2011

The study was done to investigate the effects of the extracts from the different parts of Lythrum salicaria (LS) on liver protective activities in chronically alcohol-treated rats. SD male rats except normal animals were administrated with alcohol ($30m{\ell}$ of 30%~40% ethanol/kg/day) and the extracts (300 mg/kg/day) for 10 weeks. Chronic alcohol administration decreased body weight, high density lipoprotein (HDL)-cholesterol and the reduced form-glutathione (GSH), whereas increased the ethanol content, glutamic-oxaloacetic transaminase (GOT), total cholesterol, low density lipoprotein (LDL)- cholesterol, triglyceride in blood/serum and the ratio of the oxidized form of glutathione (GSSG) and total GSH (GSSG/total GSH) in liver tissue. Groups treated with the extracts of leaf, root and stem, showed decrease in GOT, total cholesterol and GSSG/total GSH and increase in hepatic aldehyde dehydrogenase (ALDH), total GSH and serum albumin. Administration with the root extract of LS decreased blood ethanol content compared with the other part extracts. But, serum triglyceride values in rats treated with root and stem extract were higher than that of the negative control animals. Flower extract-fed group showed decrease in body weight and serum triglyceride, but increase in the ratio of GOT and glutamic-pyruvic transaminase (GPT), and GSSG/total GSH. From the results, we conclude that the extracts of root and leaf among the plant parts of LS might be useful for the amelioration of the chronic alcohol-induced liver demage of rat.

• 한국식품영양과학회지
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• 제33권7호
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• pp.1147-1153
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• 2004

3주 동안 매일 200 mL의 녹용추출물 보충이 제2형 당뇨환자의 혈당수치, 혈장 지질 수준 및 항산화 영양상태 등에 미치는 영향을 알아보기 위하여, 당뇨환자군(10명)에게 중재연구를 수행하였다 3주 동안의 녹용추출물 섭취 후의 지질 수준을 섭취 전과 비교해 보면 당뇨환자군에게서 총 콜레스테롤, LDL-콜레스테롤 및 HDL-콜레스테롤 수준은 녹용추출물 섭취 전후에 변화가 나타나지 않았으나 혈장 중성지방의 평균수준은 녹용섭 취 후에 다소 낮아지는 경 향을 보였다. 혈장 내 LDL의 산화정도에 영향을 미치는 혈장 평균 CD수준은 녹용 추출물 섭취 전 53.78kl.75 UmoyL에서 섭취 후 51.03$\pm$1.30 $\mu$mol/L로 약 5% 정도의 유의적인 감소를 보였다. 녹용추출물 섭취 후 대상자에게서 혈장 항산화 비타민농도, 총항산화능인 TRAP 수준 및 항산화 효소 활성도의 변화가 나타나지 않았다. 녹용추출물 섭취 전과 후에 환자군의 혈장 GOT와 GPT 수준은 변화가 없었다. 본 연구결과 녹용 섭취 후 당뇨환자의 혈장 CD값이 감소하였으므로 이런 결과가 당뇨환자의 항산화 상태의 개선과 관련이 있을 것으로 기대하였으나 항산화 상태의 향상이 나타나지 않은 것으로 보아 당뇨환자에게서 녹용추출물 섭취 후에 나타났던 CD 감소효과는 항산화와는 다른 기전이 관련되어 있는 것으로 보여진다. 최근 우리나라에도 당뇨병 환자가 증가하는 것과 더불어 건강기능식품에 대한 관심이 증대하고 있으므로 앞으로 당뇨환자의 LDL 산화 정도를 개선하는 영양중재 연구 및 건강기능식품에 관한 연구가 보다 폭 넓고 다양하게 이루어져야 하리라고 생각된다.

• Asian-Australasian Journal of Animal Sciences
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• 제22권10호
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• pp.1420-1428
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• 2009

In this study we cloned and characterized a novel lipid-accumulating gene, the oxidized low-density lipoprotein receptor 1 (OLR1), which is associated with lipogenesis. We analyzed the gene structure and detected the mRNA transcriptional expression levels in pig adipose tissues at different months of age (MA) and in different economic types (lean type and obese type) using real-time fluorescence quantitative PCR. OLR1 expression profile in different tissues of pig was analyzed. Finally, we studied the correlation between OLR1 and lipid metabolism related genes including peroxisome proliferator-activated $receptor{\gamma}2$ ($PPAR{\gamma}2$), fatty acid synthetase (FAS), triacylglycerol hydrolase (TGH), CAAT/enhancer binding protein $\alpha$ ($C/EBP{\alpha}$) and sterol regulatory element binding protein-1c (SREBP-1c). Results indicated that the OLR1 gene of the pig exhibited the highest homology with the cattle (84%), and the lowest with the mouse (27%). The signal peptide located from amino acid 38 to 60 and the domain from amino acid 144 to 256 were shared by the C-type lectin family. The expression level of OLR1 in pig lung was exceedingly higher than other tested tissues (p<0.01). In pig adipose tissue, the expression level of OLR1 mRNA increased significantly with growth (p<0.01). The expression level of OLR1 mRNA in obese-type pigs was significantly higher than that of lean-type pigs of the same monthly age (p<0.05). In adipose tissue, the expression of OLR1 correlated with $PPAR{\gamma}2$, FAS and SREBP-1c, but not TGH or C/EBP${\alpha}$. In conclusion, OLR1 was highly associated with fat deposition and its transcription, as suggested by high correlations, was possibly regulated by $PPAR{\gamma}2$ and SREBP-1c.

• 대한한의학회지
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• 제38권2호
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• pp.53-60
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• 2017

Objectives: Beakdugu-tang (BDGT) consists of three medicinal herbs, and this prescription has long been used in treatment of various digestant problem in Korea. In this study, we designed to clarify mechanisms by which Korean traditional digestive medicine, BDGT, may exert anti-hepatic steatosis effects via improved insulin resistance cell model in human hepatocellular carcinoma (HepG2) and monocyte (THP-1). Materials and methods: The preparation of BDGT and constituents were extracted with 70% ethanol. HepG2 and THP-1 were treated with different concentrations of BDGT and constituents in the presence and absence of stimulants such as free fatty acids (FFAs) and oxidized low-density lipoprotein (ox-LDL), respectively. Results: The BDGT and its constituents inhibited the FFAs-stimulated lipid accumulation in HepG2 cells. Ethanol extracts of Amomum cardamomum (ACE) improved the ox-LDL induced insulin resistance in THP-1 cells. Also, treatment of monocytic cells with ACE increased anti-hepatic steatosis related gene levels including ABCA, ABCG and SR-B1. Conclusion: The results suggest that the ethanol extract of BDGT and its constituents potently inhibit the FFAs- and ox-LDL induced liver steatosis via improved insulin resistance.

• The Korean Journal of Physiology and Pharmacology
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• 제20권4호
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• pp.347-355
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• 2016

Cryptotanshinone (CPT) is a natural compound isolated from traditional Chinese medicine Salvia miltiorrhiza Bunge. In the present study, the regulatory effect and potential mechanisms of CPT on tumor necrosis factor alpha ($TNF-{\alpha}$) induced lectin-like receptor for oxidized low density lipoprotein (LOX-1) were investigated. Human umbilical vein endothelial cells (HUVECs) were cultured and the effect of $TNF-{\alpha}$ on LOX-1 expression at mRNA and protein levels was determined by Real-time PCR and Western blotting respectively. The formation of intracellular ROS was determined with fluorescence probe $CM-DCFH_2-DA$. The endothelial ox-LDL uptake was evaluated with DiI-ox-LDL. The effect of CPT on LOX-1 expression was also evaluated with SD rats. $TNF-{\alpha}$ induced LOX-1 expression in a dose- and time- dependent manner in endothelial cells. $TNF-{\alpha}$ induced ROS formation, phosphorylation of $NF-{\kappa}B$ p65 and ERK, and LOX-1 expression, which were suppressed by rotenone, DPI, NAC, and CPT. $NF-{\kappa}B$ inhibitor BAY11-7082 and ERK inhibitor PD98059 inhibited $TNF-{\alpha}-induced$ LOX-1 expression. CPT and NAC suppressed $TNF-{\alpha}-induced$ LOX-1 expression and phosphorylation of $NF-{\kappa}B$ p65 and ERK in rat aorta. These data suggested that $TNF-{\alpha}$ induced LOX-1 expression via ROS activated $NF-{\kappa}B/ERK$ pathway, which could be inhibited by CPT. This study provides new insights for the anti-atherosclerotic effect of CPT.