Jiyun Ahn's research while affiliated with Korea Food Research Institute and other places

Publications (111)

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We investigated the effects of 6-gingerol on adiposity and obesity-induced inflammation by focusing on the regulation of adipogenesis and adipokines in white adipose tissue (WAT) of diet-induced obese mice. C57BL/6 mice were fed a high-fat diet (HFD) containing 0.05% 6-gingerol for 8 weeks. 6-Gingerol supplementation significantly reduced body weig...
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Skeletal muscle atrophy is characterized by reduced muscle function and size. Oxidative stress contributes to muscle atrophy but can be treated with antioxidants. This study investigated the antioxidant activity of a castor oil plant leaf (Ricinus communis L.) extract (RC) and its effects on muscle atrophy. Rutin was identified as the major compoun...
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Schisandra chinensis fruit (Omiza in Korean), used for the production tea or liquor, and is known to enhance skeletal muscle function. However, the effect of Omiza extract (OM) on obesity-induced skeletal muscle atrophy remains unclear. This study investigated the effect of OM on skeletal muscle mass and performance in obese mice. OM increased skel...
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Skeletal muscle atrophy is defined as wasting or loss of muscle. Although glucocorticoids (GCs) are well-known anti-inflammatory drugs, their long-term or high-dose use induces skeletal muscle atrophy. Valeriana fauriei (VF) is used to treat restlessness, anxiety, and sleep disorders; however, its effects on skeletal muscle health have not been inv...
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Fuzhuan brick tea (FBT) is a post-fermented tea that is intentionally fermented by the fungus Eurotium cristatum. Previous studies have reported the anti-obesity effect of FBT, but the underlying mechanism remains unclear. The present study investigated whether FBT exerts anti-obesity effects through energy expenditure and browning of white adipose...
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Background Although mounting evidence indicates that insulin resistance (IR) co-occurs with mitochondrial dysfunction in skeletal muscle, there is no clear causal link between mitochondrial dysfunction and IR pathogenesis. In this study, the exact role of mitochondria in IR development was determined. Methods Six-week-old C57BL/6 mice were fed a h...
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Background : 2,6-Dimethoxy-1,4-benzoquinone (DMBQ), a natural phytochemical present in fermented wheat germ, has been reported to exert anti-cancer, anti-inflammatory, and anti-adipogenic effects. However, the effect of DMBQ on muscle hypertrophy and myoblast differentiation has not been elucidated. Purpose : We investigated the effect of DMBQ on...
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Background & Aims The development of non-alcoholic fatty liver disease (NAFLD) can be modulated by microRNAs (miRNA). Dietary polyphenols modulate the expression of miRNA such as miR-467b-3p in the liver. Additionally, 6-gingerol (6-G), the functional polyphenol of ginger, has been reported to ameliorate hepatic steatosis; however, the exact mechan...
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Scope: γ-Oryzanol, a well-known antioxidant, has been used by body builders and athletes to boost strength and increase muscle gain, without major side effects. However, the effect of γ-oryzanol on sarcopenia and the underlying molecular mechanism is poorly understood. Results: Aged mice fed with the γ-oryzanol diet did not show significant chan...
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Chrysanthemum zawadskii Herbich (CZH) is used in traditional medicine to treat inflammatory diseases and diabetes. However, the effects of CZH on muscle wasting remains to be studied. Here, we investigated the effect of CZH on dexamethasone (DEX), a synthetic glucocorticoid, induced muscle atrophy. To examine the effect of CZH on muscle atrophy, C2...
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Codium fragile (CF) is a type of green algae consumed as kimchi in Asia. UPLC-QTOF-MS/MS analysis showed that CF contain lysophosphatidyl choline, canthaxanthin, retinoic acid, α-tocopherol, and unsaturated fatty acids, which reportedly improve skeletal muscle health. However, the effect of CF on skeletal muscle mass and function remains to be eluc...
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Post-menopausal conditions exacerbate the biological aging process and this is often accompanied by visceral adiposity with sarcopenia. Mitochondrial impairment is a hallmark of frailty and sarcopenia in the elderly. However, the exact mechanism underlying the development of obesogenic sarcopenia and the involvement of mitochondria remains unclear....
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Background : The enhancement of energy expenditure has attracted attention as a therapeutic target for the management of body weight. Withaferin A (WFA), a major constituent of Withania somnifera extract, has been reported to possess anti-obesity properties, however the underlying mechanism remains unknown. Purpose : To investigate whether WFA exe...
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Although drug therapies are available for postmenopausal osteoporosis, these drugs are not free of side effects and long-term adherence to them are low. A safe and effective nutritional approach to counter postmenopausal osteoporosis is an important research goal. We fed ovariectomized (OVX) Sprague–Dawley rats a diet supplemented with 1% or 2% gre...
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Macroautophagy/autophagy, a self-degradative process, regulates metabolic homeostasis in response to various stress conditions and is a therapeutic target for nonalcoholic fatty liver disease. We found that autophagic activity was inhibited as a result of a significant reduction in the expression of autophagy-related genes such as Ulk1 in a mouse m...
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Background/objectives: This study investigates correlations between circulating microRNAs (miRNAs) and obesity-related parameters among young women (aged 20-30 years old) in Korea. Subjects/methods: We analyzed TaqMan low density arrays (TLDAs) of circulating miRNAs in 9 lean (body mass index [BMI] < 25 kg/m2) and 15 obese (BMI > 25 kg/m2) women...
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The effects of a mixture of Hippophae rhamnoides (HR) and Zingiber mioga (ZM) extract (ZH) on intracellular lipid accumulation were investigated in vitro and the anti-obesity effects of ZH evaluated in mice with high-fat diet-induced obesity. The results revealed that ZH inhibited lipid accumulation in 3T3-L1 adipocytes and Huh-7 cells by suppressi...
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Methylglyoxal (MGO), a reactive carbonyl species, causes cellular damage and is closely related to kidney disease, particularly diabetic nephropathy. Although MGO has been reported to induce autophagy and apoptosis, the relationships between the two pathways are unclear. Here, we evaluated whether autophagy may be the underlying mechanism inhibitin...
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Shikonin, a natural plant pigment, is known to have anti-obesity activity and to improve insulin sensitivity. This study aimed to examine the effect of shikonin on hepatic steatosis, focusing on the AMP-activated protein kinase (AMPK) and energy expenditure in Hepa 1-6 cells and in high-fat fed mice. Shikonin increased AMPK phosphorylation in a dos...
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As obesity promotes ectopic fat accumulation in skeletal muscle, resulting in impaired skeletal muscle and mitochondria function, it is associated with skeletal muscle loss and dysfunction. This study investigated whether Chrysanthemi zawadskii var. latilobum (CZH) protected mice against obesity-induced skeletal muscle atrophy and the underlying mo...
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Dietary habits can alter the skeletal muscle performance and mass, and Undaria pinnatifida extracts are considered a potent candidate for improving the muscle mass and function. Therefore, in this study, we aimed to assess the effect of U pinnatifida extracts on exercise endurance and skeletal muscle mass. C57BL/6 mice were fed a 0.25% U pinnatifid...
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Background/objectives: In Oriental medicine, certain foods may be beneficial or detrimental based on an individual's constitution; however, the scientific basis for this theory is insufficient. The purpose of this study was to investigate the effect of body constitution, based on the Sasang type of Korean traditional medical classification system,...
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Patrinia scabiosaefolia (PS) and Hippophae rhamnoides (HR) are traditionally used functional foods. Extracts from the root of PS are known for their anti‐inflammatory effects, whereas those from the leaf of HR are effective at both preventing and treating obesity. This study investigated whether the extract combination of PS and HR (PHE) affected w...
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Nonalcoholic fatty liver disease (NAFLD) is a common risk factor for metabolic syndrome that increases the risk of future cardiovascular disease, stroke, and diabetes. Recently, autophagy has been proposed as a means to prevent NAFLD. We investigated whether substances with autophagy-inducing activity alleviate NAFLD. The Valeriana fauriei (V. faur...
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Endoplasmic reticulum (ER) stress and autophagy are regulated by shared signaling pathways, and their dysfunction is directly related to pathological conditions. This study investigated the function of the unc-51 like autophagy activating kinase 1 (ULK1)-autophagy related 13 (ATG13) complex in ER stress conditions through a knockout (KO) approach....
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Gliadin is a major protein component of gluten and causes gluten toxicity through intestinal stress. We previously showed that gliadin intake induces oxidative stress in the intestine and reduces fertility in a Caenorhabditis elegans model. To elucidate the possible link between intestinal stress and reproduction, changes in the intestine and germ...
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Senile osteoporosis increases the risk of skeletal fractures with age. Cheonggukjang (CGJ), a traditional Korean dry fermented soybean product, has numerous therapeutic effects; however, its effects on bone mineral density (BMD) and bone metabolism in senile osteoporosis are unclear. In this study, we treated the senescence-accelerated mouse prone...
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Scope Skeletal muscle mass and quality can be negatively affected by aging, inactivity, and disease, while a loss of muscle mass is associated with chronic disease status, falls, and mortality. We investigated the effects of Hydrangea serrata on skeletal muscle mass and function, along with the underlying mechanisms. Methods and results Hydrangea...
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Background & aims: Altered microRNA (miRNA) expression is associated with the pathophysiology of obesity; however, little is known about the miRNAs commonly dysregulated in the blood and visceral fat tissue of obese patients. This study compared the circulating and visceral fat miRNA expression in subjects with and without obesity. Methods: For...
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Recent studies suggest an alternative pathway of lipid breakdown called lipophagy, which delivers lipid droplets (LDs) to lysosomes for degradation of LDs. However, molecular mechanisms regulating lipophagy are still largely unknown. In this study, we evaluated the effect of oleic acid (OA) on lipophagy in cells. We found that OA treatment results...
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Osteopenia is a preclinical phase of osteoporosis, it occurs naturally with aging and increases the risk of bone fractures in elderly males. Previous studies have revealed the beneficial effects of soybean on preventing bone loss due to its isoflavone contents. Fermentation alters the soybean isoflavone contents, that is, isoflavone glucosides is h...
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In this study, accelerated solvent extraction (ASE) of capsanthin from red paprika was optimized by response surface methodology using a Box–Behnken design. Three independent variables (temperature, static time, and extraction solvent) were studied at 1 500 psi. As the response variable, capsanthin was quantitatively determined by ultra-performance...
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Inula japonica Thunb. (Asteraceae) is a flowering plant that grows mainly in Korea, Japan, and China and its flower extract has diverse biological effects such as anti-inflammatory and antioxidative activities. However, the effects on obesity and enhancement of endurance capacity have not been explored yet. This study aims to reveal the effects of...
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The consumption of soybeans is known to have beneficial effects on osteoporosis in postmenopausal women. However, the effects of soybean fermentation on the bioavailability and the anti-osteoporotic effect have not yet been elucidated. To address this question, we fed ovariectomized C57BL/6J mice with a 5% nonfermented raw soybean (RS)- or fermente...
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2,6-Dimethoxy-1,4-benzoquinone is a natural phytochemical present in fermented wheat germ. It has been reported to exhibit anti-inflammatory, antitumor, and antibacterial activities. However, the anti-adipogenic effects of 2,6-dimethoxy-1,4-benzoquinone and the mechanisms responsible have not previously been elucidated. Such findings may have ramif...
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Doenjang (DJ), a fermented soybean product used in soups, stews, and sauces, contains high quality proteins, fats, vitamins, minerals, and other functional ingredients, including isoflavones and saponins. This study investigated whether DJ improves the bioavailability of isoflavones compared to boiled soybean (BS) in sham‐operated or ovariectomized...
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Although classification of an individual’s Sasang constitution is a key step in the prescription of traditional Korean medicine, the classifying process is complex and not objective. Identification of metabolic-based biomarkers could allow the development of a reliable and sensitive classification technique and even therapeutic management. Our pilo...
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Introduction: Apigenin has been reported to elicit anti-inflammatory effects. In this study, we investigated the effect of apigenin on sciatic nerve denervation-induced muscle atrophy. Methods: Sciatic nerve denervated mice were fed a 0.1% apigenin-containing diet (AP) for 2 weeks. Muscle weight and cross sectional area (CSA), and the expression...
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Mitochondrial dysfunction is associated with insulin resistance. Although chicoric acid (CA) is known to have beneficial effects on insulin sensitivity, the involvement of mitochondrial function has not been elucidated yet. Here, we investigated the effect of CA on insulin resistance and mitochondrial dysfunction. In palmitate-induced insulin-resis...
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Coffee is a widely consumed beverage worldwide and is believed to help prevent the occurrence of various chronic diseases. However, the effect of coffee on skeletal muscle hypertrophy, differentiation and the mechanisms of action responsible have remained unclear. To investigate the effect of coffee on skeletal muscle hypertrophy, mice were fed a n...
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This study was designed to evaluate the effect of ovariectomy on nutrikinetics of genistein metabolites. To characterize the time-dependent changes in genistein metabolite concentrations, we identified 13 genistein metabolites using ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry. The nutrikinetics of the individ...
Data
Nutrikinetic parameters of genistein-derived metabolites. AUC, area under the metabolite peak versus time curve; Tmax, time to achieve maximum concentration; Pmax, maximum peak area; t1/2, elimination half-life. (DOCX)
Data
Study design. Detailed flow chart of animal experiments. After 2 weeks of recovery from ovariectomy, the experiment was started and the time was 0 week. Stool was received at 4 weeks and 8weeks that was before genistein administration, respectively. Blood samples were collected at different time points (0.5, 1, 2, 4, 8, and 16 h) after genistein in...
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Scope: We investigated whether apigenin protected against skeletal muscle atrophy induced by obesity. Methods and results: Mice were fed a high fat diet (HFD) for 9 wks to induce obesity, and then were assigned to two groups; the HFD group received a high fat diet, and the HFD+AP group received a 0.1% apigenin-containing HFD. After additional fe...
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Scope: Cheonggukjang (CGJ) is a soybean-based quick-fermented food popular in Korea that contains a variety of biologically active compounds including isoflavones and saponins. Isoflavone bioavailability may be important for the bone health of postmenopausal women; therefore, the aim of this study was to evaluate the influence of fermentation on t...
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Apigenin, a natural flavone abundant in various plant-derived foods including parsley and celery, has been shown to prevent inflammation and inflammatory diseases. However, the effect of apigenin on skeletal muscle hypertrophy and myogenic differentiation has not previously been elucidated. Here, we investigated the effects of apigenin on quadricep...
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Osteoporosis increases fragility fractures and is a major health issue in the elderly. Curcumin, an active constituent of Curcuma longa, was reported to exert a beneficial effect on osteoporotic bone loss. However, poor aqueous solubility has limited its pharmacological efficacy. Although application of poly(lactic-co-glycolic acid) (PLGA) nanopart...
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Obesity is characterized by increased fat mass, as adipose tissue serves as a storage site for excess energy from food consumption. In obesity, altered lipid metabolism of adipose tissue, characterized by fatty acid uptake, de novo lipogenesis, and lipolysis, are induced. In this study, we examined the effect of zerumbone, a major sesquiterpene fro...
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Red paprika (Capsicum annuum L.) is a widely used natural food colorant and source of vital micronutrients. The main carotenoid in red paprika is capsanthin. In this study, the effects of red paprika and capsanthin on impaired lipid metabolism were investigated in diet-induced obese mice. Forty male mice were divided into 4 groups; normal diet (ND)...
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Background: Korean diet has received considerable attention because of the low prevalence of obesity and metabolic disorders in Korea. Although the Korean diet has been shown to have health benefits, these effects have been investigated by analyzing individual nutrients or food components. In this study, we used a dietary pattern approach to invest...
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Coumestrol is a natural phytochemical present in plants such as red clover and soy, and has been reported to stimulate the estrogen receptor as a major phytoestrogen. While the molecular mechanisms responsible for the anti-adipogenic effects of phytoestrogens such as genistein and daidzein have been previously investigated, the effects of coumestro...
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Osteoporosis induced bone fracture is not limited to simple damage according to its fractured region and the age of the damaged person. Therefore, there has been more necessity to understand and study the biomechanical aspects of osteoporosis, and relevant research has actively been conducted. With the development of medical imaging technology, the...
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Scope: Yuja (Citrus junos Tanaka) possesses various health benefits, but its effects on bone health are unknown. In this study, the preventative effects of yuja peel ethanol extract (YPEE) on osteopenia were determined in ovariectomized (OVX) rats, and the mechanisms by which YPEE and its flavanones regulate osteoblastogenesis were examined in vit...
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There has been great interest in the browning of fat for the treatment of obesity. Although β-lapachone (BLC) has potential therapeutic effects on obesity, the fat browning effect and thermogenic capacity of BLC on obesity have never been demonstrated. Here, we showed that BLC stimulated the browning of white adipose tissue (WAT), increased the exp...
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Limonin, the most prevalent limonoid in citrus fruits, is widely used as a dietary supplement because of its biological activities. Although studies have shown that limonin inhibits bone resorption in osteoclasts and improves bone quality in orchidectomised rats, the anti-osteoporosis activity of limonin in ovariectomised (OVX) animal models is sti...
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Zingiber mioga is a perennial herb belonging to the ginger family (Zingiberaceae) that is used medicinally to treat cough and rheumatism in China and consumed throughout Japan. The aim of the present study was to investigate the anti-obesity effects of Z. mioga following extraction with distilled water or 70% ethanol. In 3T3-L1 preadipocyte cells,...
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Tyrosol is considered a potential antioxidant; however, little is known regarding the pharmacokinetics of its metabolites. To study the pharmacokinetics of tyrosol-derived metabolites after oral administration of a single dose of tyrosol, we attempted to identify tyrosol metabolites in rat plasma by using ultra-performance liquid chromatography and...
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Dysfunction of pancreatic β-cell is a major determinant for the development of type 2 diabetes. Because of the stimulated insulin secretion in metabolic syndrome, endoplasmic reticulum (ER) stress plays a central mediator for β-cell failure. In this study, we investigated whether an antioxidant phenolic compound, tyrosol protects against β-cell dys...
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Allyl-isothiocyanate (AITC) is an organosulfur phytochemical found in abundance in common cruciferous vegetables such as mustard, wasabi, and cabbage. Although AITC is metabolized primarily through the mercapturic acid pathway, its exact pharmacokinetics remains undefined and the biological function of AITC metabolites is still largely unknown. In...
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Recent studies show that brown rice improves glucose intolerance and potentially the risk of diabetes, although the underlying molecular mechanisms remain unclear. One of the phytochemicals found in high concentration in brown rice is γ-oryzanol (Orz), a group of ferulic acid esters of phytosterols and triterpene alcohols. Here, we found that Orz s...
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β‐laphachone (BLC) is a naphthoquinonea, originally isolated from a Bignoniaceae tree Tabebuia avellanedae Lorentz ex Griseb and has been extensively studied because it possesses a wide range of biological activities. However, the potential of BLC in the anti‐obesity has not been explored.This study was conducted to evaluate the anti‐obesity effect...
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SIRT1 plays a key role in regulating metabolism, and SIRT1 activation may be a promising strategy to treat metabolic syndrome. This study investigated whether zerumbone ameliorated diet‐induced obesity through SIRT1 activation. We used differentiated 3T3‐L1 fibroblasts to examine the effect of zerumbone on adipogenesis through the miR‐146b‐SIRT1 ca...
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Shikonin is a naturally occurring naphthoquinone pigment and a major component of Lithospermum erythrorhizon. Our previous study showed that shikonin inhibited adipocyte differentiation in 3T3‐L1 cells by suppression of ERK pathway. MicroRNAs (miRNAs) are key post transcriptional regulator of adipocyte differentiation. In present study, we investig...
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In this study, we developed a method to quantify esculetin (6,7-dihydroxycoumarin) in plasma and tissues using HPLC coupled with ultraviolet detection and measured the level of esculetin in rat plasma after oral administration. The calibration curve for esculetin was linear in the range of 4.8 ng/mL to 476.2 ng/mL, with a correlation coefficient (r...
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Abstract Agaricus bisporus (white button mushroom, WBM) is widely consumed in most countries and is reported to have anti-inflammatory and antioxidant activities. However, little is known regarding its effects in dextran sulfate sodium (DSS)-induced colitis, which are related to dysfunction of intestinal immunity. The aim of the present study was t...
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We evaluated whether intake of an ethanolic extract of Taheebo (TBE) from Tabebuia avellanedae protects against body weight increase and fat accumulation in mice with high-fat diet (HFD)-induced obesity. Four-week old male C57BL/6 mice were fed a HFD (25% fat, w/w) for 11 weeks. The diet of control (HFD) mice was supplemented with vehicle (0.5% sod...
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Mitochondrial dysfunction is associated with the pathophysiology of insulin resistance. Allylisothiocyanate (AITC) is found in many cruciferous vegetables and has been reported to possess anticancer activity. However, the effect of AITC on insulin resistance and mitochondrial function has not yet been investigated. Here, we show that AITC increased...
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Curcumin, the yellow substance found in turmeric, possesses antioxidant, anti-inflammation, anti-cancer, and lipid-lowering properties. Since we hypothesized that curcumin could ameliorate the development of atherosclerosis, the present study focused on the effects and potential mechanisms of curcumin consumption on high cholesterol diet-induced at...
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Objective This study was designed to evaluate the effects of rice as a carbohydrate source and its molecular mechanisms on insulin resistance induced by a high-fat diet (HFD). Methods C57BL/6J mice were divided into 3 groups and were fed for 12 weeks with a low fat diet (LFD); a HFD (with 18% fat, 0.5% cholesterol, 51.5% w/w corn starch and sucros...