• Journal of Life Science
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• v.19 no.4
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• pp.423-428
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• 2009

Selenium was investigated using human origin preadipocytes to see whether it possesses preventive or therapeutic effects for obesity. Unveiling the potential of selenium in the reduction of adipogenesis can help predict the therapeutic capabilities of selenium in obesity. In the present study, the molecular mechanism of the inhibition of adipogenesis by selenium was explored to unravel the involvement of the AMP-activated protein kinase. There is emerging evidence that AMPK, a sensor of cellular energy status, is a possible molecular target of controlling adipocyte differentiation on the basis of discovery that AMPK is responsible for the major metabolic responses to exercise, and integration of nutritional and hormonal signals to modulate feeding behavior or energy expenditure in the hypothalamus. Treatment of selenium resulted in inhibition of the adipocyte differentiation process and induction of mature apoptosis in 3T3-L1 adipocytes. We hypothesized that selenium may exert anti-adipogenic potential though modulating AMPK. We have found that selenium significantly activated AMPK and phosphorylated its substrate acetyl-CoA carboxylase ($ACC-serine^{79}$) during the inhibitory process of adipocytes. Also, the inhibition process of adipocyte differentiation by selenium was comparable to either reveratrol or a synthetic AMPK activator, AICAR (5-aminoimidazole-4-carboxamide-1-${\beta}$-D-ribofuranoside). To evaluate the involvement of AMPK in anti-lipogensis, we applied AICAR and Compound C, an AMPK inhibitor, to 3T3-L1-adipocytes and found that AMPK is required for the adipocyte differentiation blocking process. These results suggest that selenium has a potential to control adipogenesis and that this effect is mediated by AMPK, an essential kinase for both inhibition of adipocyte differentiation and apoptosis of mature adipocytes.

• Journal of Life Science
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• v.25 no.6
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• pp.663-672
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• 2015

The study was performed to investigate the effects of enzyme treated garlic (EG) and its natural resources composites on lipid levels in serum and liver of rats fed a high fat diet. Four different types of EG-composite extracts prepared: EG and EG + grape peel (EGG), EG + Persimmon (EGP) and EG + Catechu (EGC) by mixed 9.5:0.5, 9:1 and 8:2 (w/w) ratios, respectively. DPPH and ABTS radical scavenging activity in vitro, show the highest in EG + Catechu (EGC) composite by mixed 8:2 (w/w). EG and EG-composites extracts (8:2, w/w) were administered orally to SD-male rats at a concentration of 2.5 g/kg/day for 5 weeks. Total lipid and cholesterol contents in serum were significantly lower in EGC group than control group, and triglyceride content was the lowest in EGP group by 54.29 mg/dL. HDL-cholesterol contents were significantly higher in EGP and EGC groups. LDL-cholesterol content was lower in EG group than EG-composite groups, and VLDL cholesterol content was the lowest in EGP group. GOT, GPT and ALP activity was significantly lower in EGP group. Total lipid, cholesterol and triglyceride contents in liver were significantly lower in EGP and EGC group than control group. Antioxidant activity in serum was the highest in EGC groups by 50.86%, in liver was the highest in EGP groups. TBARS content in serum and liver was the lowest in EGP group. In these results, we suggest that EGP composites could have hypolipidemic and anti-obesity effects in rats fed a high fat diet.

• Journal of the Korean Society of Food Culture
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• v.23 no.2
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• pp.222-227
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• 2008

This study examined the chemical composition of lotus root and functionally evaluated a fermented lotus root drink. Electron-donating ability using DPPH along with nitrite-scavenging ability were used to compare the antioxidative activities of unfermented and fermented lotus root drinks. The electron-donating abilities of the unfermented lotus root drink (1%) and fermented lotusroot drink (1%) were 22.55% and 23.88%, respectively. At pH 6.0, the nitrite-scavenging abilities of the unfermented lotus root drink and the fermented lotus root drink (100%) were 27.64% and 40.3%, respectively, and their scavenging ability increased in a dose-dependent manner at all pH values. In order to study the anti-obesity effects of the two drinks, male Sprague-Dawley rats were divided into four groups (A: basal diet, B: high fat diet, C: high fat diet+unfermented lotus root drink, D: high fat diet+fermented lotus root drink). Net weight gains were not significantly different among the four groups. Plasma total cholesterol concentrations significantly decreased in the groups receiving the unfermented and fermented lotus root drinks. Also, plasma total lipid and triglyceride contents were lower in the groups receiving the unfermented and fermented lotus root drinks as compared to the high fat diet group; however, the differences among the three groups were not significant.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.7
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• pp.1043-1053
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• 2013

We investigated the ability of soybean curd residue (SCR) and its fermented products to inhibit obesity and improve the blood lipid profiles of obese mice fed a high-fat diet. Samples were prepared by fermenting SCR with Aspergillus oryzae var effuses KACC 44990 (ASCR), a microbe used for the fermentation of traditional Korean Meju, and with Monascus pilosus IFO 4480 (MSCR), a microbe used for the production of red rice. In addition, AMSCR, a mixture composed of equal amounts of ASCR and MSCR, was also prepared. Male mice were divided into six groups and fed with either a normal diet, a high-fat diet, or a high-fat diet supplemented with SCR, ASCR, MSCR, or AMSCR. After 8 weeks, body weight gain, serum and hepatic lipid profiles, and the activities of enzymes that generate or scavenge reactive oxygen species (ROS) were evaluated. Compared with the high-fat diet group, all the test groups showed a significant reduction in body, organ, and epididymal fat weight gain. These effects were observed with supplements in the order AMSCR>ASCR>MSCR>SCR. Similarly, supplements of test samples reduced high levels of serum and hepatic triglycerides (TG), total cholesterol, and low-density lipoprotein (LDL) cholesterol caused by hight-fat diet, while high-density lipoprotein (HDL) cholesterol was increased. Interestingly, the ability of ASCR to lower serum TG was stronger than that of MSCR, while MSCR showed a stronger hypocholesterolemic effect than ASCR. Meanwhile, AMSCR returned comprehensively serum lipid levels to normal. In addition, hepatic damage was prevented with effects in the order AMSCR>ASCR>MSCR>SCR. Hepatic ROS generating system including xanthine oxidase (XO) and ROS scavenging system including superoxide dismutase (SOD), glutathione peroxidase (GPX) and glutathione S-transferase (GST) were recovered to normal level by all test diets. In conclusion, this study suggests that SCR and its fermented products can inhibit obesity and improve lipid profiles.

• Journal of Life Science
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• v.25 no.1
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• pp.62-67
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• 2015

Myelophycus simplex Papenfuss is distributed over the northern Pacific and southern coast of Korea, and is a member of the brown algae family. The objective of this study was to investigate the effect of M. simplex methanol extract on adipocyte differentiation and adipogenesis in 3T3-L1 preadipocytes. Treatment with M. simplex methanol extract significantly suppressed terminal differentiation of 3T3-L1 preadipocytes in a dose-dependent manner, as confirmed by a decrease in lipid droplet content observed by Oil Red O staining. Also, the M. simplex methanol extract significantly suppressed the triglyceride content of 3T3-L1 preadipocytes in a dose-dependent manner. Treatment with 300 and $500{\mu}g/ml$ of M. simplex methanol extract caused a 42% and 76% reduction in lipid droplet content, respectively. In order to understand the anti-adipogenic effects of M. simplex methanol extract, the changes in the expression of several adipogenic transcription factors, including peroxisome proliferator-activated receptor (PPAR) ${\gamma}$-cytidine-cytidine-adenosine-adenosine-thymidine (CCAAT)/enhancer binding protein (C/EBP) ${\alpha}$ and ${\beta}$, were investigated using immunoblotting. M. simplex suppressed the expression of $PPAR{\gamma}$, $C/EBP{\alpha}$, and $C/EBP{\beta}$ proteins compared with control. Therefore, the results of this study suggest that M. simplex methanol extract inhibits adipocyte differentiation and thus may have applications as a potential source for an anti-obesity functional food agent.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.7
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• pp.969-974
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• 2011

This study was performed to investigate the inhibitory activity of Ecklonia cava (EC) against lipase and the stability of this activity under various heat and pH conditions. As a result, EC ethanol extract showed lipase inhibitory activity of 59, 34 and 19% at concentrations of 5, 2.5 and 1 mg/mL, whereas the water extract showed low inhibitory activity at all concentrations compared to that of the ethanol extracts. In a heat and pH stability test, the inhibitory activity of the EC ethanol extract increased with heat treatment at $121^{\circ}C$ for 15 min compared with the control and was stable in the pH range of 2~10. Therefore, the EC ethanol extract could be useful as a natural anti-obesity agent.

• Journal of Life Science
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• v.27 no.9
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• pp.1052-1058
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• 2017

Gelidium amansii shows antioxidant and anti-obesity effects; however, the effect on postprandial blood glucose levels is not known. The objective of the present study was to investigate the inhibitory effect of Gelidium amansii extract (GAE) on carbohydrate-digesting enzymes and its ability to alleviate postprandial hyperglycemia in streptozotocin (STZ)-induced diabetic mice. Gelidium amansii was extracted with 80% ethanol and concentrated for use in this study. The ${\alpha}-glucosidase$ and ${\alpha}-amylase$ inhibition assays were performed using the colorimetric method. ICR normal and STZ-induced diabetic mice were orally administered GAE (300 mg/kg body weight) or acarbose (100 mg/kg body weight) alone or soluble starch (2 g/kg body weight). Blood samples were taken from the tail vein at 0, 30, 60 and 120 min. Our results indicated that GAE markedly inhibited ${\alpha}-glucosidase$ and ${\alpha}-amylase$ activities with $IC_{50}$ values of $0.099{\pm}0.009mg/ml$ and $0.178{\pm}0.038mg/ml$, respectively, and was a more effective inhibitor than acarbose, the positive control. Further, the postprandial blood glucose levels of STZ-induced diabetic mice in the GAE-administered group were significantly lower than those of control group mice (p<0.05). Moreover, the area under the curves (AUC) significantly decreased with GAE administration in STZ-induced diabetic mice (p<0.05). These results indicate that GAE may be effective in decreasing postprandial blood glucose levels by inhibiting carbohydrate-digesting enzymes such as ${\alpha}-amylase$ and ${\alpha}-glucosidase$. Therefore, GAE could be used as a potential functional food for alleviating postprandial hyperglycemia.

• Korean Journal of Plant Resources
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• v.34 no.2
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• pp.186-196
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• 2021

In this study, we investigated inhibitory effect of red sweet pepper (Capsicum annuum L.) on triglyceride biosynthesis in Rhodosporidium toruloides. There was no significant difference in the total lipid content of all the experimental groups including 0.02, 0.1 and 0.5% (w/v) of red sweet pepper 70% ethanol extract treatment (RSPE). However, the triglyceride content was significantly decreased in RSPE group campared to the control group. When the formation of lipid droplet in the oleaginous yeast was examined, a small amount of fluorescence was observed compared to the control as the concentration of RSPE increased. The number of cells and free fatty acid increased in a concentration-dependent manner. These results suggest that RSPE has an anti-obesity effect.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.1
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• pp.39-46
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• 2009

This study investigated the beneficial effects of crude saponins from soybean cake on body weight and glucose tolerance in high-fat (37% calories from fat) diet fed C57BL/6 mice. The mice were supplemented with three doses of saponins (0.5%, 1.0%, and 1.5%, wt/wt) and 1.0% Garcinia cambogia (wt/wt), positive control for 9 weeks. The body weight, visceral fat weight and epididymal adipocyte area were significantly reduced in the saponin supplemented groups in a dose dependent manner compared to the high-fat group. Saponins did not significantly affect food intake; however, cambogia significantly lowered food intake compared to the high-fat fed control group. The crude saponins from soybean cake supplement significantly lowered plasma leptin, triglyceride and total cholesterol levels, whereas they significantly elevated the fecal excretion of triglyceide in a dose dependent manner compared to the high-fat group. Cambogia did not affect the fecal excretion of lipid in the diet-induced obese mice. Supplementation of 1.5% saponin reduced the hepatic triglyceride content compared to the high-fat group. High-fat induced glucose intolerance with the elevation of blood glucose levels compared to the normal group; however, the saponins supplement significantly improved postprandial glucose levels. After 9 weeks of being fed a high-fat diet, the mice presented with significantly increased activities of hepatic fatty acid synthase and fatty acid ${\beta}$-oxidation; however, saponins and cambogia normalized these activities. These results indicate that saponins from soybean cake exhibit a potential anti-obesity effect and may prevent glucose intolerance by reducing body weight and plasma lipids, increasing fecal lipid excretion and regulating hepatic lipid metabolism in high-fat fed mice.

• Korean Journal of Food Science and Technology
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• v.51 no.1
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• pp.81-89
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• 2019

This study was performed to confirm the influence of chlorogenic acid (CGA) and 3,5-dicaffeyolquinic acid (3,5-diCQA) intake on problems caused by high-fat diet. CGA was more effective in suppressing weight gain than 3,5-diCQA. In contrast, 3,5-diCQA was more effective in improving glucose tolerance than CGA. In the biopsy, it was confirmed that CGA inhibited visceral fat and liver fat accumulation. 3,5-diCQA also inhibited visceral fat accumulation, but 3,5-diCQA increased liver fat accumulation. The liver fat accumulation induced oxidative stress, but 3,5-diCQA reduced oxidative damage through its antioxidant activity. The increased liver fat accumulation was because a 3,5-diCQA greatly increased Akt phosphorylation and decreased AMPK phosphorylation in the liver. Consequently, CGA was effective in alleviating the problems caused by high-fat diets, while maintaining normal balance. 3,5-diCQA also showed a positive effect on problems caused by high-fat diets, but it increased liver fat accumulation and thereby had negative consequences.