Dae Young Kwon

Korea Food Research Institute, Sŏul, Seoul, South Korea

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Publications (141)329.74 Total impact

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    ABSTRACT: Since Korean mistletoe (Viscum album) has been used for alleviating metabolic diseases, it may also prevent the impairment of energy, glucose, lipid, and bone metabolisms in an estrogen-deficient animal model. We determined that long-term consumption of Korean mistletoe water extract (KME) can alleviate menopausal symptoms such as hot flush, increased abdominal fat mass, dyslipidemia, hyperglycemia, and decreased bone mineral density in ovariectomized (OVX) rats fed a high-fat diet, and explored the mechanisms of the effects. OVX rats were divided into four groups and fed high-fat diets supplemented with either 0.6% dextrin (control), 0.2% lyophilized KME + 0.4% dextrin (KME-L), or 0.6% lyophilized KME (KME-H). Sham rats were fed with the high-fat diets with 0.6% dextrin as a normal-control without estrogen deficiency. After eight weeks, OVX rats exhibited impaired energy, glucose and lipid metabolism, and decreased uterine and bone masses. KME-L did not alleviate energy dysfunction. However, KME-H lowered serum levels of total-, LDL-cholesterol, and triglycerides and elevated serum HDL-cholesterol levels in OVX rats with dyslipidemia, to similar levels as normal-control rats. Furthermore, KME-H improved HOMA-IR, an indicator of insulin resistance, in OVX rats. Surprisingly, KME-H fed rats had greater lean mass in the abdomen and leg without differences in fat mass but neither dosage of KME altered bone mineral density in the lumbar spine and femur. The increased lean mass was related to greater phosphorylation of mTOR and eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1) in the quadriceps muscles. Hepatic triglyceride contents were lowered with KME-H in OVX rats by increasing carnitine palmitoyltransferase-1 (CPT-1) expression and decreasing fatty acid synthase (FAS) and sterol regulatory element-binding protein-1c (SREBP-1c) expression. In conclusion, KME may be useful for preventing some menopausal symptoms such as hot flushes, dyslipidemia, hepatic steatosis, and loss of muscle mass in post-menopausal women.
    Experimental biology and medicine (Maywood, N.J.). 09/2014;
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    ABSTRACT: The inhibitory effects of yuja peel extract (Citrus junos Tanaka) on experimental colitis and colorectal cancer cells were evaluated. Yuja peel extracted with 70% ethanol (YPEE) reduced LPS-induced secretion of nitric oxide (NO), tumour necrosis factor-alpha (TNF-α), monocyte chemotactic protein-1 (MCP-1), and interleukin-6 (IL-6) by reduction of cyclooxygenase-2 (COX-2), nitric oxide synthase (NOS), and p38 phosphorylation in RAW264.7 cells. YPEE at 100 mg/(kg·day) also reduced both disease activity index (DAI) and colon shortening induced by Dextran sulphate sodium (DSS) in mice. COX-2 expression was decreased in colon tissue by YPEE. In addition, YPEE induced apoptotic body appearance in HT-29 colorectal cancer cells via decreasing COX-2. Furthermore, YPEE at 100 mg/(kg·day) inhibited tumour growth in tumour xenografts, which was accompanied by reduced COX-2 expression in colon tissue. Taken together, Yuja may be useful in preventing colitis and colorectal cancer via reduction of COX-2 expression.
    Journal of Functional Foods 05/2014; 8:301–308. · 2.63 Impact Factor
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    ABSTRACT: Brain insulin resistance is related to both diabetes and Alzheimer's disease. We investigated whether both chungkookjangs, soybeans fermented in a traditional method (TFC) and with Bacillus lichenifomis (SFC), can protect against cognitive dysfunction and glucose dysregulation in rats with Alzheimer's disease and type 2 diabetes. Partial pancreatectomy (Px) and ICV β-amyloid (25-35) infusion into the CA1 region were fed either control diet (AD-CON), 10 % cooked soybeans (CSB), 10 % TFC, or 10 % SFC in a high fat diet for 8 weeks. Px rats infused β-amyloid (35-25) as a normal-control group (Non-AD-CON). SFC increased isoflavonoid aglycones, DDMP soyasaponin βg, E soyasaponin Be and lysoposphatidylcholines in comparison to CSB. SFC markedly decreased its accumulation in β-amyloid deposition in AD rats and improved hippocampal insulin signaling (pAkt → pGSK → pTau) that exacerbated in AD-CON rats. AD rats markedly impaired cognitive function than Non-AD-CON rats as measured by a water maze and passive avoidance tests while the disturbance was prevented in an ascending order of CON < CSB and TFC < SFC. In comparison to Non-AD rats, AD-CON rats lowered whole body glucose infusion rates and increased hepatic glucose output at hyperinsulinemic state during euglycemic hyperinsulinemic clamp which SFC normalized in AD rats. Interestingly, insulin secretion, especially at the second phase during hyperglycemic clamp, was higher in AD-CON rats, compared to Non-AD rats while CSB, TFC, SFC lowered it in AD-rats. However, SFC restored β-cell mass in AD rats that reduced β-cell mass by increased β-cell apoptosis. β-Amyloid accumulation in the hippocampus exacerbated insulin resistance and decreased β-cell mass and SFC prevented their exacerbation in AD diabetic rats.
    European Journal of Nutrition 04/2014; · 3.13 Impact Factor
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    ABSTRACT: We hypothesized that differences in red peppers pungencies and bioactive compounds are associated with different effects on obesity and glucose tolerance, and tested the hypothesis in ovariectomized (OVX) rats fed high fat diets. Increasing red pepper pungency was associated higher concentrations of capsaicin, dihydrocapsaicin and total capsaicinoids; and lower concentrations of β-carotene, total carotenoids and chlorogenic acid. After 8 weeks of consuming 1% different types of red peppers, moderately and severely pungent red peppers (MSP and SSP) improved energy homeostasis better than less pungent red pepper (LSP): MSP and SSP increased energy expenditure and decreased visceral fat mass. This was related to elevated uncoupling proteins (UCP)-1, UCP-2 and UCP-3 expressions and decreased expressions of genes involved in fatty acid synthesis. LSP enhanced insulin sensitivity and improved hepatic insulin signaling. In conclusion, red peppers with different color and pungency differently modulate energy and glucose homeostasis in OVX rats fed high fat diets.
    Journal of Functional Foods 03/2014; · 2.63 Impact Factor
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    ABSTRACT: In this study, we performed in vitro and in vivo studies to examine whether a 70% ethanol extract of Prunus mume fruits (EMS) exhibits anti-diabetic effects. Treatment with EMS increased glucose uptake in C2C12 myotubes, and also increased PPAR-γ activity or PPAR-γ mRNA expression. To confirm these in vitro results, we next conducted an animal experiment. A high-fat diet significantly increased the body weight, fat accumulation, and glucose levels in mice. Under the same conditions, 5% EMS attenuated the high-fat diet-induced increase in body weight and fat accumulation and improved the impaired fasting glucose level and glucose tolerance. High performance liquid chromatography analysis demonstrated that EMS contained chlorogenic acid, caffeic acid, rutin, luteolin-7-glucoside, naringin, apigenin-7-glucoside, and hesperidin. Taken together, these findings suggest that EMS exerts an anti-diabetic effect both in vitro and in vivo, which is mediated, at least in part, by the activation of PPAR-γ.
    Food Chemistry 12/2013; 141(4):4115-21. · 3.33 Impact Factor
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    ABSTRACT: We investigated the contribution of genetic variations of KLF5 to basal metabolic rate (BMR) and resting metabolic rate (RMR) and the inhibition of obesity in Korean children. A variation of KLF5 (rs3782933) was genotyped in 62 Korean children. Using multiple linear regression analysis, we developed a model to predict BMR in children. We divided them into several groups; normal versus overweight by body mass index (BMI) and low BMR versus high BMR by BMR. There were no differences in the distributions of alleles and genotypes between each group. The genetic variation of KLF5 gene showed a significant correlation with several clinical factors, such as BMR, muscle, low-density lipoprotein cholesterol, and insulin. Children with the TT had significantly higher BMR than those with CC (p = 0.030). The highest muscle was observed in the children with TT compared with CC (p = 0.032). The insulin and C-peptide values were higher in children with TT than those with CC (p= 0.029 vs. p = 0.004, respectively). In linear regression analysis, BMI and muscle mass were correlated with BMR, whereas insulin and C-peptide were not associated with BMR. In the high-BMR group, we observed that higher muscle, fat mass, and C-peptide affect the increase of BMR in children with TT (p < 0.001, p < 0.001, and p = 0.018, respectively), while Rohrer's index could explain the usual decrease in BMR (adjust r(2) = 1.000, p < 0.001, respectively). We identified a novel association between TT of KLF5 rs3782933 and BMR in Korean children. We could make better use of the variation within KLF5 in a future clinical intervention study of obesity.
    Genomics & informatics. 12/2013; 11(4):263-71.
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    ABSTRACT: Traditionally fermented soybeans (chungkookjang; TFC) may have potent anti-diabetic activity, depending on the ambient microorganisms and conditions. We hypothesized that one of the major Bacillus species in TFC contributes to the anti-diabetic activity and could be used to standardize a highly functional TFC. We tested the hypothesis by using cell-based studies to evaluate insulin sensitizing and insulinotropic action of chungkookjangs fermented with various Bacillus spp. and fermentation periods. The 70% methanol and water extracts of chungkookjang fermented with Bacillus licheniformis (BL) for 48 h contained similar profiles of isoflavonoids and peptides to methanol and water extracts of TFC with potent anti-diabetic activity. Water extracts (mainly containing peptides) of TFC and BL fermented for 48 h and 72 h had a better insulin sensitizing action via activating peroxisome proliferator-activated receptor-γ (PPAR-γ) and increased the expression of PPAR-γ in 3T3-L1 adipocytes better than unfermented cooked soybeans (CSB). The 70% methanol extracts (predominantly isoflavone aglycones) of BL fermented for 48 h and 72 h improved glucose-stimulated insulin secretion and protected β-cell viability better than CSB in insulinoma cells, and the improvement by BL was similar to TFC. In conclusion, the BL water extract fermented for 48 h exhibited equal insulin sensitization as TFC and BL methanol extract exerted similar insulinotropic actions to those of TFC. B. licheniformis may be one of the major microorganisms responsible for anti-diabetic actions of chungkookjang. It is important to make chungkookjang that retains the anti-diabetic properties of the most efficacious traditional chungkookjang using a standardized method.
    Food & function. 10/2013;
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    ABSTRACT: Capsaicin has been reported to regulate blood glucose levels and to ameliorate insulin resistance in obese mice. This study demonstrates that capsaicin increases glucose uptake directly by activating AMP-activated protein kinase (AMPK) in C2C12 muscle cells, which manifested as an attenuation of glucose uptake when compound C, an AMPK inhibitor, was co-administered with capsaicin. However, the insulin signaling molecules insulin receptor substrate-1 (IRS-1) and Akt were not affected by capsaicin. Additional results showed that p38 mitogen-activated protein kinase (MAPK) is also involved in capsaicin-induced glucose transport downstream of AMPK because capsaicin increased p38 MAPK phosphorylation significantly and its specific inhibitor SB203580 inhibited capsaicin-mediated glucose uptake. Treatment with an AMPK inhibitor reduced p38 MAPK phosphorylation, but the p38 MAPK inhibitor had no effect on AMPK. Capsaicin stimulated ROS generation in C2C12 muscle cells, and when ROS were captured using the nonspecific antioxidant NAC, the increase in both capsaicin-induced AMPK phosphorylation and capsaicin-induced glucose uptake was attenuated, suggesting that ROS function as an upstream activator of AMPK. Taken together, these results suggest that capsaicin, independent of insulin, increases glucose uptake via ROS generation and consequent AMPK and p38 MAPK activations.
    Biochemical and Biophysical Research Communications 08/2013; · 2.28 Impact Factor
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    ABSTRACT: Our preliminary study revealed that dementia induced by β-amyloid accumulation impairs peripheral glucose homeostasis (S. Park, D.S. Kim, S. Kang, and N.R. Moon, unpublished results). We therefore evaluated whether long-term oral consumption of yuzu (Citrus junos Tanaka) extract improves cognitive dysfunction and glucose homeostasis in β-amyloid-induced rats. Male rats received hippocampal CA1 infusions of β-amyloid (25-35) [plaque forming β-amyloid; Alzheimer disease (AD)] or β-amyloid (35-25) [non-plaque forming β-amyloid; C (non-Alzheimer disease control)] at a rate of 3.6 nmol/d for 14 d. AD rats were divided into 2 dietary groups that received either 3% lyophilized 70% ethanol extracts of yuzu (AD-Y) or 3% dextrin (AD-C) in high-fat diets (43% energy as fat). The AD-C group exhibited greater hippocampal β-amyloid deposition, which was not detected in the C group, and attenuated hippocampal insulin signaling. Yuzu treatment prevented β-amyloid accumulation, increased tau phosphorylation, and attenuated hippocampal insulin signaling observed in AD-C rats. Consistent with β-amyloid accumulation, the AD-C rats experienced cognitive dysfunction, which was prevented by yuzu. AD-C rats gained less weight than did C rats due to decreased feed consumption, and yuzu treatment prevented the decrease in feed consumption. Serum glucose concentrations were higher in AD-C than in C rats at 40-120 min after glucose loading during an oral-glucose-tolerance test, but not at 0-40 min. Serum insulin concentrations were highly elevated in AD-C rats but not enough to lower serum glucose to normal concentrations, indicating that rats in the AD-C group had insulin resistance and a borderline diabetic state. Although AD-C rats were profoundly insulin resistant, AD-Y rats exhibited normal first and second phases of glucose tolerance and insulin sensitivity and secretion. In conclusion, yuzu treatment prevented the cognitive dysfunction and impaired energy and glucose homeostasis induced by β-amyloid infusion.
    Journal of Nutrition 05/2013; · 4.20 Impact Factor
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    ABSTRACT: The purpose of this study is to determine the protective effect of Taraxacum official (dandelion) leaf extract (DLE) on high-fat-diet (HFD)-induced hepatic steatosis, and elucidate the molecular mechanisms behind its effects. To determine the hepatoprotective effect of DLE, we fed C57BL/6 mice with normal chow diet (NCD), high-fat diet (HFD), HFD supplemented with 2g /kg DLE DLE (DL), and HFD supplemented with 5g/kg DLE (DH). We found that the HFD supplemented by DLE dramatically reduced hepatic lipid accumulation compared to HFD alone. Body and liver weights of the DL and DH groups were significantly lesser than those of the HFD group, and DLE supplementation dramatically suppressed triglyceride (TG), total cholesterol (TC), insulin, fasting glucose level in serum, and Homeostatic Model Assessment Insulin Resistance (HOMA-IR) induced by HFD. In addition, DLE treatment significantly increased activation of adenosine monophosphate (AMP)-activated protein kinase (AMPK) in liver and muscle protein. DLE significantly suppressed lipid accumulation in the liver, reduced insulin resistance, and lipid in HFD-fed C57BL/6 mice via the AMPK pathway. These results indicate that the DLE may represent a promising approach for the prevention and treatment of obesity-related non-alchoholic fatty liver disease.
    Food and chemical toxicology: an international journal published for the British Industrial Biological Research Association 04/2013; · 2.99 Impact Factor
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    ABSTRACT: The present study aimed to identify key metabolites related to weight reduction in humans by studying the metabolic profiles of sera obtained from 34 participants who underwent dietary intervention with black soybean peptides (BSP) for 12 weeks. This research is a sequel to our previous work in which the effects of BSP on BMI and blood composition of lipid were investigated. Sera of the study were subjected to ultra performance liquid chromatography and quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS), and the data were analyzed using partial least-squares discriminate analysis (PLS-DA) score plots. Body mass index and percent body fat of the test group were reduced. Levels of betaine, benzoic acid, pyroglutamic acid, pipecolic acid, N-phenylacetamide, uric acid, l-aspartyl-l-phenylalanine, and lysophosphatidyl cholines (lysoPCs) (C18:1, C18:2, C20:1, and C20:4) showed significant increases. Levels of l-proline, valine, l-leucine/isoleucine, hypoxanthine, glutamine, l-methionine, phenylpyruvic acid, several carnitine derivatives, and lysoPCs (C14:0, PC16:0, C15:0, C16:0, C17:1, C18:0, and C22:0) were significantly decreased. In particular, lysoPC 16:0 with a VIP value of 12.02 is esteemed to be the most important metabolite for evaluating the differences between the 2 serum samples. Our result confirmed weight-lowering effects of BSP, accompanied by favorable changes in metabolites in the subjects' blood. Therefore, this research enables us to better understand obesity and increases the predictability of the obesity-related risk by studying metabolites present in the blood.
    Journal of obesity 01/2013; 2013:874981.
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    ABSTRACT: As the traditional homemade chungkookjang is replaced by standardized chungkookjang fermented by inoculating Bacillus spp., it is desirable to maintain the anti-diabetic efficacy of the most potent traditional varieties. Preliminary in vitro research suggested that anti-diabetic efficacy can be achieved by using B. lichemiformis as a starter and fermenting for 48 h. Experimental type 2 diabetic male rats induced by partial pancreatectomy and high fat diets were administered either control diet, 10% cooked soybeans, 10% traditional chungkookjang with potent anti-diabetic efficacy, or standardized chungkookjang fermented with B. lichemiformis for 48 h. Rats were fed their respective diets for 8 weeks after surgery. Cooked soybeans as well as both chungkookjangs partially restored fasting serum glucose concentrations, but only the chungkoojangs increased fasting insulin levels. That trend was also seen in the glucose-stimulated insulin secretion during hyperglycemic clamp and was explained by the greater β-cell mass and BrdU incorporation indicating increased proliferation of β-cells. The euglycemic hyperinsulinemic clamp indicated that all soy products improved insulin sensitivity. Phosphorylation of Akt and AMPK in the liver increased in an ascending order of the control, cooked soybeans, traditional chungkookjang and standardized chungkookjang while PEPCK expression was lowered in a descending order of the control, cooked soybeans, traditional chungkookjang and standardized chungkookjang. These results indicate that standardized chungkookjang is most effective for improving hepatic insulin signaling. In conclusion, chungkookjang fermented with B. lichemiformis retains the anti-diabetic properties of the most efficacious traditional chungkookjang and it may be even more effective for improving insulin function than traditionally prepared chungkookjang.
    Journal of Clinical Biochemistry and Nutrition 01/2013; 52(1):49-57. · 2.25 Impact Factor
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    ABSTRACT: Antlers have been traditionally used for thousands of years as a natural product with medicinal and pharmaceutical properties. In developing healthy foods, Bacillus-mediated fermentation is widely used to enhance the biological activity of nutrients in foods. Recently, fermentation was shown to enhance the osteogenic activity of antlers. This study aimed to elucidate the antiresorptive activity of Bacillus-fermented antler and its mode of action. We found that Bacillus-fermented antler extract strongly inhibited osteoclast differentiation by downregulating the expression and activity of nuclear factor of activated T cells, cytoplasmic 1 (NFATc1). This extract also inhibited the activation of phospholipase C γ 2 (PLC γ 2), a signaling molecule that could regulate NFATc1 transcriptional activity. This suggested that Bacillus-fermented antler extract could inhibit PLC γ 2-NFATc1 signaling required for bone resorption and cell fusion. Consequently, Bacillus-fermented antler extract might benefit osteoclast-related disorders, including osteoporosis; furthermore, it may improve gastrointestinal activity.
    Evidence-based Complementary and Alternative Medicine 01/2013; 2013:748687. · 1.72 Impact Factor
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    ABSTRACT: The antidiabetic effect of the Citrus junos Tanaka (also known as yuja or yuzu) was examined. Ethanol extract of yuja peel (YPEE) significantly stimulated 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-D-glucose (2-NBDG) uptake in C2C12 myotubes. However, ethanol extract of yuja pulp (YpEE) and water extract of yuja peel (YPWE) or pulp (YpWE) did not stimulate glucose uptake. In addition, peroxisome proliferator-activated receptor gamma (PPAR-γ) and AMP-activated protein kinase (AMPK) activities were increased by YPEE in a dose-dependent manner. Pretreatment of AMPK inhibitor decreased the glucose uptake stimulated by YPEE in C2C12 myotubes. We confirmed the anti-diabetic effect of YPEE in mice fed a high fat-diet (HFD). Compared with control mice on a normal diet (ND), these mice showed increased body weight, liver fat, insulin resistance, triacylglycerol (TG), and total cholesterol content. Addition of 5% YPEE significantly reduced the weight gain and rise in liver fat content, serum triacylglycerol (TG), total cholesterol, and insulin resistance found in mice fed a high-fat diet (HFD). Moreover, YPEE reduced the secretion of HFD-induced adipocytokines such as leptin and resistin. YPEE also resulted in increased phosphorylation of AMPK in muscle tissues. These results suggest that ethanol extract of yuja peel exerts anti-diabetic effects via AMPK and PPAR-γ in both cell culture and mouse models.
    Evidence-based Complementary and Alternative Medicine 01/2013; 2013:921012. · 1.72 Impact Factor
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    Cho-Rong Bae, Dae Young Kwon, Youn-Soo Cha
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    ABSTRACT: The aim of the present study is to elucidate the anti-obesity effects of Doenjang with and without salt in C57BL/6J mice. For the analysis, a total of forty mice were randomly divided into four groups: normal diet group (ND), high-fat diet group (HD), high-fat diet supplemented with 20% Doenjang group (DJ), high-fat diet supplemented with 20% unsalted Doenjang group (NS). During the study period, food intake and body weight were measured daily and weekly, respectively. The animals were sacrificed after 12 weeks. Body weight gain, epididymal fat pad weight and serum triglyceride levels of DJ group were found to be significantly lower than those of the HD and NS groups. Serum total-cholesterol levels of DJ and NS groups were significantly lower as compared to the HD group. There were significant decreases in plasma insulin and leptin levels in DJ group compared with the HD and NS groups. We did not observe any significant changes in the expression of hepatic lipogenic-related gene among the HD, DJ and NS groups. However, ACC expression was found to be significantly decreased in DJ group. Lipolysis-related gene ( and CPT-1) expression was significantly higher in the DJ group as compared to HD and NS groups. In conclusion, the results of this study showed that Doenjang supplementation lowers body weight gain and improves obesity-related parameters.
    Journal of the Korean Society of Food Science and Nutrition 01/2013; 42(7).
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    ABSTRACT: Jerusalem artichoke (Helianthus tuberosus Linne, HTL) and chungkookjang (CKJ; fermented soybeans) both modulate energy and glucose metabolism. However, the mechanism and their additive effects are unknown. We investigated whether the consumption of HTL and CKJ altered insulin sensitivity, insulin secretion capacity and beta-cell survival in type 2 diabetic animals. Rats were divided into partially pancreatectomized (Px) diabetic rats, and sham operated non-diabetic control rats and all fed high fat diets. Diabetic rats were sub-divided into an untreated diabetic control group and those fed 5% HTL, 5% CKJ or 5% HTL+5% CKJ for 8 weeks. HTL+CKJ treatment reduced visceral fat without modulating energy intake compared to the diabetic-control. Glucose tolerance was improved in an ascending order of diabetic-control, CKJ, HTL, HTL+CKJ, and normal-control, but by different mechanisms. CKJ and CKJ+HTL, but not HTL, increased first and second phase insulin secretion in comparison to the diabetic-control at hyperglycemic clamp. However, glucose infusion rates (mg/kg bw/min) were increased by and CKJ+HTL (13.5), but not HTL (9.4) or CKJ (9.5) alone, and HTL and CKJ+ HTL decreased hepatic glucose compared to diabetic-control during the hyperinsulinemic euglycemic study and were associated with decreased triglyceride accumulation and increased glycogen storage. The improved hepatic insulin sensitivity by HTL and CKJ+HTL was explained by potentiated insulin signaling (tyrosine phosphorylation of insulin receptor substrate 2[rightwards arrow]phosphorylation of Akt) and phosphorylation of AMPK[rightwards arrow]phosphorykation of acetyl Co carboxlase in comparison to diabetic-control and decreased PEPCK expression. Absolute beta-cell mass was increased by CKJ (23.4mg) and CKJ+HTL (26.3 mg) by increasing proliferation compared to the diabetic-control (21.26 mg). Although HTL lowered beta-cell apoptosis, it did not increase beta-cell mass (20.8 mg). In conclusions, HTL and CKJ enhanced glucose tolerance in different manners, and exhibited partially additive and complementary effects by reversing insulin resistance and enhancing beta-cell function in diabetic rats.
    Nutrition & Metabolism 12/2012; 9(1):112. · 3.16 Impact Factor
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    ABSTRACT: Abstract We investigated the hepatoprotective effects of the extract of dandelion leaves (EDL) on a murine model of methionine- and choline-deficient (MCD) diet-induced nonalcoholic steatohepatitis (NASH). C57BL/6 mice were fed for 4 weeks with one of the following diets: control diet (Cont), MCD diet (MCD), MCD diet supplemented with EDL at 200 mg/kg body weight·daily (MCD+D200), and MCD diet supplemented with EDL at 500 mg/kg body weight·daily (MCD+D500). Hepatic function was assessed by evaluating the following parameters: liver histology; plasma levels of alanine aminotransferase (ALT), triglyceride (TG), malondialdehyde (MDA), and reduced glutathione (GSH); expression levels of TNF-α and IL-6; and levels of caspase-3 and pJNK/JNK protein. Histopathological evaluations revealed that addition of EDL to the MCD diet dampens the severity of the clinical signs of NASH. Moreover, EDL led to a significant decrease in the serum levels of ALT, hepatic TG, and MDA, and in the expression levels of TNF-α, and IL-6; on the contrary, the levels of reduced GSH increased. At the post-transcriptional level, EDL significantly decreased the activation of procaspase-3 to active caspase-3, and the phosphorylation of JNK. These results suggest that the beneficial effects of EDL on NASH are mainly due to its antioxidant and anti-inflammatory activities.
    Journal of medicinal food 12/2012; · 1.39 Impact Factor
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    ABSTRACT: Korean Red Ginseng (KRG) is a functional food and has been well known for keeping good health due to its anti-fatigue and immunomodulating activities. However, there is no data on Korean red ginseng for its preventive activity against acute respiratory illness (ARI). The study was conducted in a randomized, double-blinded, placebo-controlled trial in healthy volunteers (Clinical Trial Number: NCT01478009). Our primary efficacy end point was the number of ARI reported and secondary efficacy end point was severity of symptoms, number of symptoms, and duration of ARI. A total of 100 volunteers were enrolled in the study. Fewer subjects in the KRG group reported contracting at least 1 ARI than in the placebo group (12 [24.5%] vs 22 [44.9%], P = 0.034), the difference was statistically significant between the two groups. The symptom duration of the subjects who experienced the ARI, was similar between the two groups (KRG vs placebo; 5.2 ± 2.3 vs 6.3 ± 5.0, P = 0.475). The symptom scores were low tendency in KRG group (KRG vs placebo; 9.5 ± 4.5 vs 17.6 ± 23.1, P = 0.241). The study suggests that KRG may be effective in protecting subjects from contracting ARI, and may have the tendency to decrease the duration and scores of ARI symptoms.
    Journal of Korean medical science 12/2012; 27(12):1472-8. · 0.84 Impact Factor
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    ABSTRACT: Red peppers and red pepper paste are reported to have anti-obesity, analgesic and anti-inflammatory effects in animals and humans due to the capsaicin in red pepper. We investigated whether consuming capsaicin and capsiate, a nonpungent capsaicin analogue, modifies glucose-stimulated insulin secretion, pancreatic β-cell survival and insulin sensitivity in 90% pancreatectomized (Px) diabetic rats, a moderate and non-obese type 2 diabetic animal model. Px diabetic rats were divided into 3 treatment groups: 1) capsaicin (Px-CPA), 2) capsiate (Px-CPI) or 3) dextrose (Px-CON) and provided high fat diets (40 energy % fat) containing assigned components (0.025% capsaicin, capsiate, or dextrose) for 8 weeks. Both capsaicin and capsiate reduced body weight gain, visceral fat accumulation, serum leptin levels and improved glucose tolerance without modulating energy intake in diabetic rats. In comparison to the control, both capsaicin and capsiate potentiated first and second and phase insulin secretion during hyperglycemic clamp. Both also increased β-cell mass by increasing proliferation and decreasing apoptosis of β-cells by potentiating insulin/IGF-1 signaling. However, only capsiate enhanced hepatic insulin sensitivity during euglycemic hyperinuslinemic clamp. Capsiate reduced hepatic glucose output and increased triglyceride accumulation in the hyperinsulinemic state and capsiate alone significantly increased glycogen storage. This was related to enhanced pAkt→PEPCK and pAMPK signaling. Capsaicin and capsiate reduced triglyceride storage through activating pAMPK. In conclusion, capsaicin and capsiate improve glucose homeostasis but they differently enhance insulin sensitivity in the liver, insulin secretion patterns, and islet morphometry in diabetic rats. Capsiate has better anti-diabetic actions than capsaicin.
    The Journal of nutritional biochemistry 09/2012; · 4.29 Impact Factor
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    ABSTRACT: Recent studies suggest that phytoestrogens may exert a protective effect against osteoporosis. This study examined whether treatment with phytoestrogen extracts from Saururus chinensis (SC) exerted a preventive effect on estrogen-deficiency-induced osteoporosis. Six- to seven-month-old female Sprague-Dawley rats were randomly assigned into either a sham-operated group or one of three ovariectomy (OVX) subgroups: OVX treated with vehicle, OVX with alendronate, and OVX with SC extract (SC). Rats began receiving treatment 4 weeks before the OVX treatment and continued receiving treatment for an additional 10 weeks after OVX (for a combined total of 14 weeks). The results showed that the SC treatment prevented loss of femur bone mineral density after OVX, as determined by a significant decrease in the levels of serum bone turnover markers osteocalcin and alkaline phosphatase as well as urinary deoxypyridinoline. Micro-computed tomography analysis showed that the SC treatment significantly prevented decreases in bone volume/tissue volume, trabecular number and trabecular thickness, while also preventing an increase in trabecular separation. It was concluded that SC treatment could prevent OVX-induced loss of bone mass and deterioration in trabecular microarchitecture by suppressing bone turnover, thereby maintaining bone structural integrity. Further, no stimulation of proliferation of uterine tissue was noted. Therefore, it is suggested that treatment with S. chinensis extracts might be a potential alternative therapy for treating postmenopausal osteoporosis.
    Phytotherapy Research 08/2012; 26(8):1182-8. · 2.40 Impact Factor

Publication Stats

1k Citations
329.74 Total Impact Points

Institutions

  • 1997–2014
    • Korea Food Research Institute
      Sŏul, Seoul, South Korea
  • 2008–2012
    • Hoseo University
      • College of Natural Sciences
      Onyang, South Chungcheong, South Korea
    • The University of Arizona
      • School of Plant Sciences
      Tucson, AZ, United States
    • Sunchon National University
      • Department of Food Science and Technology
      Sunchun, South Jeolla, South Korea
    • Suzuka University of Medical Science
      Kambe, Mie, Japan
  • 2005–2012
    • Hallym University
      • • Department of Food Science and Nutrition
      • • College of Medicine
      Seoul, Seoul, South Korea
  • 2008–2011
    • Chonbuk National University
      • Department of Food Science and Technology
      Tsiuentcheou, North Jeolla, South Korea
  • 2007–2011
    • Gyeongsang National University
      • • Graduate School
      • • Division of Applied Life Science
      Chinju, South Gyeongsang, South Korea
    • Ewha Womans University
      Sŏul, Seoul, South Korea
  • 2010
    • Konkuk University
      • Department of Bioscience and Technology
      Sŏul, Seoul, South Korea
  • 2008–2009
    • Seoul National University
      • College of Veterinary Medicine
      Seoul, Seoul, South Korea
  • 2007–2008
    • Sungkyunkwan University
      • Department of Biological Science
      Seoul, Seoul, South Korea
  • 2006
    • Wonkwang University
      Riri, North Jeolla, South Korea