• Journal of Cancer Prevention
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• 제21권2호
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• pp.95-103
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• 2016

Background: Excess energy supply induces chronic low-grade inflammation in association with oxidative stress in various tissues including intestinal epithelium. The objective of this study was to investigate the effect of high-fat diet (HFD) on intestinal cell membrane integrity and intestinal tumorigenesis in $Apc^{Min/+}$ mice. Methods: Mice were fed with either normal diet (ND) or HFD for 12 weeks. The number of intestinal tumors were counted and biomarkers of endotoxemia, oxidative stress, and inflammation were determined. Changes in intestinal integrity was measured by fluorescein isothiocyanate (FITC)-dextran penetration and membrane gap junction protein expression. Results: HFD group had significantly higher number of tumors compared to ND group (P < 0.05). Blood total antioxidant capacity was lower in HFD group, while colonic 8-hydroxy-2'-deoxyguanosine level, a marker of oxidative damage, was higher in HFD group compared to that of ND group (P < 0.05). The penetration of FITC-dextran was substantially increased in HFD group (P < 0.05) while the expressions of membrane gap junction proteins including zonula occludens-1, claudin-1, and occludin were lower in HFD group (P < 0.05) compared to those in ND group. Serum concentration of lipopolysaccharide (LPS) receptor (CD14) and colonic toll-like receptor 4 (a LPS receptor) mRNA expression were significantly higher in HFD group than in ND group (P < 0.05), suggesting that significant endotoxemia may occur in HFD group due to the increased membrane permeability. Serum interleukin-6 concentration and myeloperoxidase activity were also higher in HFD group compared to those of ND group (P < 0.05). Conclusions: HFD increases oxidative stress disrupting intestinal gap junction proteins, thereby accelerating membrane permeability endotoxemia, inflammation, and intestinal tumorigenesis.

• 생약학회지
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• 제42권4호
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• pp.309-316
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• 2011

Fatty liver disease refers to a range of disorders associated with fatty liver, which occur in excessive eating, evident infection or significant consumption of alcohol. This study was to investigate the effects of water and ethanol extracts of Triticum aestivum young leaf on lipid metabolism and accumulation in liver of mice fed with high-fat diet. Male C57BL/6 mice were divided into normal diet group, high fat diet (HFD) group, high fat diet group administrated with 200 mg/kg/day of T. aestivum water extract (HFD-TAWE) and high-fat group administrated with 200 mg/kg/day of T. aestivum ethanol extract (HFD-TAEE). TAWE and TAEE were administrated orally for 5 weeks once at the same time point. Both TAWE and TAEE significantly reduced body weight, food intake and liver tissue weight, which were augmented in high fat-fed mice. The serum levels of triglyceride, total and LDL-cholesterol also were significantly attenuated in both HFD-TAWE and HFD-TAEE groups compared to the HFD group. Moreover, administration of HFD-TAWE or HFD-TAEE reduced the lipid accumulation in liver tissue of mice fed with high fat diet. Levels of total lipids and triglyceride in liver tissues also was significantly reduced in HFDTAWE and HFD-TAEE groups compared to HFD group. The activities of serum ALT and AST revealed in HFD group were remarkedly decreased in HFD-TAEE groups. These results indicate that both water and ethanol extract of T. aestivum may improve the lipid accumulation in liver as well as lipid metabolism in serum, and that in particular, the ethanol extract of T. aestivum may has the potent anti-hyperlipidemic effect, suggesting that it may be a useful candidate for the therapy preventing fatty liver diseases.

• 한국식품영양과학회지
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• 제45권12호
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• pp.1701-1707
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• 2016

본 연구에서는 C57BL/6J 마우스에 고지방 식이를 통한 비만을 유도시키며 동시에 잣송이 초임계 추출물을 식이에 첨가하여 8주간 식이 투여하여 항비만 식품 소재로서의 기능성을 알아보고자 하였다. 잣송이 초임계 추출물 20 mg/kg b.w.(HFD+PC low), 잣송이 초임계 추출물 100 mg/kg b.w. (HFD+PC high) 섭취군의 체중증가량은 고지방식이 유도 비만 대조군(HFD)에 비해 각각 유의적으로 감소하였고, 간, 백색 지방, 총 지방 무게의 변화량 역시 잣송이 초임계 추출물 섭취군이 HFD군에 비해 유의적으로 감소하였다. 실험동물의 혈청 지질 함량은 총콜레스테롤, 중성지방, LDL/VLDL 콜레스테롤, HDL 콜레스테롤이 HFD군에 비해 잣송이 초임계 추출물 섭취군에서 유의적으로 감소하였으나, HDL/LDL 비율을 계산한 결과에서는 잣송이 초임계 추출물 섭취군이 HFD군에 비해 유의적으로 증가하였음을 확인하였다. 실험동물군의 지방 조직에서 adipogenic transcription factor ($PPAR-{\gamma}$, SREBP, C/EBP)의 발현을 측정한 결과, 잣송이 초임계 추출물 섭취군이 HFD군에 비해 유의적으로 감소하였다. 또한, adipogenic enzyme(FAS, LPL)의 발현을 측정한 결과, 잣송이 초임계 추출물 섭취군이 HFD군에 비해 유의적으로 감소하였다. 이러한 결과로부터 잣송이 초임계 추출물이 항비만 효과를 가진 천연 기능성 식품의 개발에 있어 기초 자료로 활용할 수 있을 것으로 기대할 수 있다.

• 생명과학회지
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• 제27권11호
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• pp.1357-1368
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• 2017

본 연구에서는 청국장의 항비만 및 항염증 효과를 알아보고자 C57BL/6 마우스에 고지방식이를 13주감 섭취시켜 비만을 유도한 후에 고지방 식이에 청국장을 10% 첨가하여 항비만과 항염증 활성을 확인하였다. 고지방식이를 통해 비만이 유도된 mice (HFD)에 고지방식이와 함께 청국장을 첨가하여 섭취한 그룹(CGJ)의 체중 증가율은 고지방식이군과 비교하였을 때 현저하게 감소하였을 뿐만 아니라 정상식이군보다도 유의적으로 감소하였으며 혈중 TG, TC, glucose, insulin, AST와 ALT 분비는 감소하였고 adiponectin의 수치는 유의적으로 증가하였다(p<0.05). 또한 H&E와 Oil red O staining을 통해 13주 동안 고지방식이를 통해 유도된 지방 간의 심각정도가 청국장의 섭취로 인하여 감소한 것을 확인하였다(p<0.05). 간세포는 대식세포, T세포와 같은 면역시스템의 세포들을 포함하고 있는데 비만으로 유도된 간 조직의 염증반응에 청국장이 미치는 영향을 조사하기 위해 FACS 분석을 수행하였다. CGJ군은 HFD군에 비하여 T cell의 침윤과 대식세포의 축적, 호중구의 유입이 유의적으로 감소하였다(p<0.05). 간 조직으로 침윤된 면역세포의 증가가 간 조직 내 염증반응을 유도하는지 확인하기 위해 염증성 cytokine의 수준을 조사한 결과 간과 지방 조직에서 염증성 cytokine인 MCP-1과 $TNF-{\alpha}$의 mRNA 발현이 감소하였으며 지방합성에 관여하는 $PPAR-{\gamma}$, SREBP-1와 $CEBP/{\alpha}$의 mRNA 발현 역시 감소하였다. 이러한 결과들을 통해 청국장이 면역 시스템과 지방생성 전사 인자들의 발현에 관여함으로써 adipogenesis를 조절함과 동시에 염증 억제 효과를 가진다는 사실을 증명하였다.

• BMB Reports
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• 제55권10호
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• pp.500-505
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• 2022

Uncoupling protein 2 (Ucp2) was first introduced as a member of Uncoupling protein family and a regulator of ROS formation; however, its role in adipose tissue is not fully understood. In the present study, we have investigated the role of Ucp2 against high-fat diet (HFD)-induced obesity in epididymal white adipose tissue (eWAT) and browning of inguinal white adipose tissue (iWAT). Diet-induced obesity is closely related to macrophage infiltration and the secretion of pro-inflammatory cytokines. Macrophages surround adipocytes and form a crown-like-structure (CLS). Some reports have suggested that CLS formation requires adipocyte apoptosis. After 12 weeks of HFD challenge, Ucp2 knockout (KO) mice maintained relatively lean phenotypes compared to wild-type (WT) mice. In eWAT, macrophage infiltration, CLS formation, and inflammatory cytokines were reduced in HFD KO mice compared to HFD WT mice. Surprisingly, we found that apoptotic signals were also reduced in the Ucp2 KO mice. Our study suggests that Ucp2 deficiency may prevent diet-induced obesity by regulating adipocyte apoptosis. However, Ucp2 deficiency did not affect the browning capacity of iWAT.

• The Korean Journal of Physiology and Pharmacology
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• 제23권5호
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• pp.335-344
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• 2019

Obesity causes inflammation and impairs thermogenic functions in brown adipose tissue (BAT). The adipokine lipocalin 2 (LCN2) has been implicated in inflammation and obesity. Herein, we investigated the protective effects of caloric restriction (CR) on LCN2-mediated inflammation and oxidative stress in the BAT of high-fat diet (HFD)-fed mice. Mice were fed a HFD for 20 weeks and then either continued on the HFD or subjected to CR for the next 12 weeks. CR led to the browning of the white fat-like phenotype in HFD-fed mice. Increased expressions of LCN2 and its receptor in the BAT of HFD-fed mice were significantly attenuated by CR. Additionally, HFD+CR-fed mice had fewer neutrophils and macrophages expressing LCN2 and iron-positive cells than HFD-fed mice. Further, oxidative stress and mitochondrial fission induced by a HFD were also significantly attenuated by CR. Our findings indicate that the protective effects of CR on inflammation and oxidative stress in the BAT of obese mice may be associated with regulation of LCN2.

• Toxicological Research
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• 제35권4호
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• pp.403-410
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• 2019

Curcumin, a hydrophobic polyphenol isolated from the Curcuma longa L. plant, has many pharmacological properties, including antioxidant, anti-inflammatory, and chemo-preventive activities. Curcumin has been shown to have potential in preventing nonalcoholic fatty liver disease (NAFLD). However, the low bioavailability of curcumin has proven to be a major limiting factor in its clinical adoption. Theracurmin, a highly bioavailable curcumin that utilizes micronized technology showed improved biological absorbability in vivo. The aim of this study was to investigate the role of theracurmin in modulating hepatic lipid metabolism in vivo. A fatty liver mouse model was produced by feeding mice a high fat diet (HFD; 60% fat) for 12 weeks. We found that treatment for 12 weeks with theracurmin significantly lowered plasma triacylglycerol (TG) levels and reduced HFD-induced liver fat accumulation. Theracurmin treatment lowered hepatic TG and total cholesterol (T-CHO) levels in HFD-fed mice compared to controls. In addition, theracurmin administration significantly reduced lipid peroxidation and cellular damage caused by reactive oxygen species in HFD-fed mice. Overall, these results suggest that theracurmin has the ability to control lipid metabolism and can potentially serve as an effective therapeutic remedy for the prevention of fatty liver.

• Nutrition Research and Practice
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• 제17권5호
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• pp.870-882
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• 2023

BACKGROUND/OBJECTIVES: Obesity is a major risk factor for metabolic syndrome, a global public health problem. Mentha canadensis (MA), a traditional phytomedicine and dietary herb used for centuries, was the focus of this study to investigate its effects on obesity. MATERIALS/METHODS: Thirty-five male C57BL/6J mice were randomly divided into 2 groups and fed either a normal diet (ND, n = 10) or a high-fat diet (HFD, n = 25) for 4 weeks to induce obesity. After the obesity induction period, the HFD-fed mice were randomly separated into 2 groups: one group continued to be fed HFD (n = 15, HFD group), while the other group was fed HFD with 1.5% (w/w) MA ethanol extract (n = 10, MA group) for 13 weeks. RESULTS: The results showed that body and white adipose tissue (WAT) weights were significantly decreased in the MA-supplemented group compared to the HFD group. Additionally, MA supplementation enhanced energy expenditure, leading to improvements in plasma lipids, cytokines, hepatic steatosis, and fecal lipids. Furthermore, MA supplementation regulated lipid-metabolism-related enzyme activity and gene expression, thereby suppressing lipid accumulation in the WAT and liver. CONCLUSIONS: These findings indicate that MA has the potential to improve diet-induced obesity and its associated complications, including adiposity, dyslipidemia, hepatic steatosis, and inflammation.

• The Korean Journal of Physiology and Pharmacology
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• 제21권3호
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• pp.317-325
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• 2017

Non-alcoholic fatty liver disease (NAFLD) has become the most prevalent liver disease in parallel with worldwide epidemic of obesity. Reactive oxygen species (ROS) contributes to the development and progression of NAFLD. Peroxisomes play an important role in fatty acid oxidation and ROS homeostasis, and catalase is an antioxidant exclusively expressed in peroxisome. The present study examined the role of endogenous catalase in early stage of NAFLD. 8-week-old male catalase knock-out (CKO) and age-matched C57BL/6J wild type (WT) mice were fed either a normal diet (ND: 18% of total calories from fat) or a high fat diet (HFD: 60% of total calories from fat) for 2 weeks. CKO mice gained body weight faster than WT mice at early period of HFD feeding. Plasma triglyceride and ALT, fasting plasma insulin, as well as liver lipid accumulation, inflammation (F4/80 staining), and oxidative stress (8-oxo-dG staining and nitrotyrosine level) were significantly increased in CKO but not in WT mice at 2 weeks of HFD feeding. While phosphorylation of Akt (Ser473) and $PGC1{\alpha}$ mRNA expression were decreased in both CKO and WT mice at HFD feeding, $GSK3{\beta}$ phosphorylation and Cox4-il mRNA expression in the liver were decreased only in CKO-HF mice. Taken together, the present data demonstrated that endogenous catalase exerted beneficial effects in protecting liver injury including lipid accumulation and inflammation through maintaining liver redox balance from the early stage of HFD-induced metabolic stress.

• Nutrition Research and Practice
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• 제16권1호
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• pp.46-59
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• 2022

BACKGROUND/OBJECTIVES: Aster yomena (Kitam.) Honda (AY) has remarkable bioactivities, such as antioxidant, anti-inflammation, and anti-cancer activities. On the other hand, the effects of AY against obesity-induced insulin resistance have not been reported. Therefore, this study examined the potential of AY against obesity-associated insulin resistance in high-fat diet (HFD)-fed mice. MATERIALS/METHODS: An obesity model was established by feeding C57BL/6J mice a 60% HFD for 16 weeks. The C57BL6/When ethyl acetate fraction from AY (EFAY) at doses of 100 and 200 mg/kg/day was administered orally to mice fed a HFD for the last 4 weeks. Normal and control groups were administered water orally. The body weight and fasting blood glucose were measured every week. Dietary intake was measured every other day. After dissection, blood and tissues were collected from the mice. RESULTS: The administration of EFAY reduced body and organ weights significantly compared to HFD-fed control mice. The EFAY-administered groups also improved the serum lipid profile by decreasing the triglyceride, total cholesterol, and low-density lipoprotein compared to the control group. In addition, EFAY ameliorated the insulin resistance-related metabolic dysfunctions, including the fasting blood glucose and serum insulin level, compared to the HFD-fed control mice. The EFAY inhibited lipid synthesis and insulin resistance by down-regulation of hepatic fatty acid synthase and up-regulation of the AMP-activated protein kinase pathway. EFAY also reduced lipid peroxidation in the liver, indicating that EFAY protected hepatic injury induced by obesity. CONCLUSIONS: These results suggest that EFAY improved obesity-associated insulin resistance by regulating the lipid and glucose metabolism, suggesting that AY could be used as a functional food to prevent obesity and insulin resistance.