• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.4
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• pp.428-436
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• 2008

This study was carried out to compare the effects of whey protein concentrate, its hydrolysates and macropeptide fractions obtained from papain treatment of whey protein on lipid levels and appetite-related hormones in obesity model rats induced by high fat diet. Four week-old male Sprague-Dawley rats were fed high fat (18% w/w) and low protein (10% w/w) diet for 4 weeks and then divided into four groups (n=8/group). Rats were fed high fat diets containing various nitrogen sources; 10% whey protein concentrate (10WPC), 25% whey protein concentrate (25WPC), 25% whey protein hydrolysates (25WH), and 25% whey macropeptide fractions (25WP, MW$\geq$10,000), respectively for 6 weeks. There were no significant differences in body weight gain and food intake among groups. A significant decrease of total lipid, triglyceride in serum was observed in 25WH and 25WP groups. Total lipid and triglyceride contents of the liver were significantly decreased in 25WPC, 25WH and 25WP groups compared with 10WPC group. However, in the liver, there were no differences in the contents of total lipid and triglyceride among 25WPC, 25WH and 25WP groups. The daily amounts of feces were significantly increased in 25WH and 25WP groups and the excretion of total lipid and triglyceride were significantly increased in 25WH group. Serum glucose and insulin concentration were significantly decreased in 25WH group. The concentration of serum ghrelin was significantly decreased in the 25WPC, 25WH and 25WP groups compared with 10WPC group. However, there was no significant difference in the concentration of serum leptin among groups. These results suggest that whey protein hydrolysates and macropeptide fractions may show beneficial effects on the lipid profile in serum and liver, appetite regulation and insulin resistance in obesity model rats induced by high fat diet.

• Journal of Life Science
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• v.34 no.7
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• pp.509-519
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• 2024

A previous study showed that krill oil improved recognition and memory through anti-oxidative effects in an amyloid β model, but the authors noted that further investigations are necessary of alterations to neurotransmitters' states and of serum lipid profile improvements related to serum lipid peroxidation. Accordingly, in this study, ICR mice were pre-treated intraperitoneally with scopolamine prior to induced neurotransmission impairment, and the effects of krill oil provision on their capabilities of cognition were tested by performing a passive avoidance test (PAT), water maze test (WMT), and novel object recognition test. Then, parameters including the acetylcholine (ACh) concentration, acetylcholinesterase activity (AChE), lipid peroxidation, serum lipid levels, and nerve cell proliferation were investigated. The results showed that krill oil improved the mice's abilities in recognition and memory as the times taken to complete the PAT and WMT were reduced compared to the mice in a comparison scopolamine-treated group. Krill oil produced an increased concentration of Ach, and this was accompanied by a decrease in AChE. As shown in a scopolamine-treated SH-SY5Y cell line, krill oil reduced the activity of AChE. Moreover, the suppression of lipid peroxidation-reflected in the finding that malondialdehyde was decreased with krill oil provision-is speculated to affect the recorded serum triglyceride and cholesterol decreases and LDL cholesterol increase. The intake of krill oil was also found to produce an improvement in brain-derived neurotrophic factor expression by stimulating the activation of cyclic AMP response element binding protein in the brain tissue. Overall, the current results imply that the provision of krill oil raises the cognition and memory by elevating neurotransmitters and by improving the serum lipid profile and nerve cell proliferation, which occur as lipid peroxidation is suppressed in the brain tissue.

• Journal of Microbiology and Biotechnology
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• v.25 no.5
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• pp.687-695
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• 2015

Accumulating evidence indicates that lactic acid bacteria could improve host physiology and lipid metabolism. To investigate the effect of the gut microbiota on host lipid metabolism, a hyperlipidemic rat model was established by feeding rats a high-fat diet for 28 days, and the gut microbiota of the rats was analyzed using real-time PCR before and after administration of Lactobacillus rhamnosus hsryfm 1301 and its fermented milk for 28 days. The findings showed that the Lactobacillus spp., Bifidobacterium spp., Bacteroides spp., and Enterococcus spp. content in the hyperlipidemic rats gut was increased significantly (p < 0.05), while the Clostridium leptum and Enterobacter spp. content was decreased significantly after intervening with L. rhamnosus hrsyfm 1301 and its fermented milk for 28 days (p < 0.05). Furthermore, the lipid levels of the serum and the liver were decreased significantly (p < 0.05) and the fecal water content was increased significantly (p < 0.05) in the hyperlipidemic rats after the intervention, and hepatocyte fatty degeneration of liver tissues was also prevented. A positive correlation was observed between the Clostridium leptum content and the level of serum cholesterol, triglycerides, low-density lipoprotein, and high-density lipoprotein, and a negative correlation was observed between the Enterobacter spp. content and the Lactobacillus spp. and Bifidobacterium spp. content in the hyperlipidemic rats gut. These results suggest that the gut microbiota and lipid metabolism of hyperlipidemic rats could be improved by supplementation with L. rhamnosus hsryfm 1301 and its fermented milk.

• The Korea Journal of Herbology
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• v.22 no.4
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• pp.127-135
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• 2007

Objectives : In this study we investigated the antiobese effects of mixed pills of pickled black soybeans with herbs(herbal Chokong pill, hereafter HCKP) in rats fed high-fat diet. It was evaluated by measuring the changes of body weight, adipose tissues weight and lipid profiles in serum. Methods : Black soybeans were pickled in vinegar for 15 days to prepare Chokong, at room temperature. For treatment group, HCKP was prepared, which five kinds of medicinal herbs(Rhynchosia nulubilis, Glycyrrhiza uralensis, Zizyphus vulgaris, Atractylodes macrocephala K, Astragalus membranaceus and Cornus officinalis) were added to dried Chokong. Four groups of male Sprague-Dawley rats were fed different diets during 9 weeks: normal diet containing 5%(w/w) com oil, high-fat diet containing 10%(w/w) lard plus 5%(w/w) corn oil (HF), high-fat diet supplemented with 1%(T1) and 5%(T5) HCKP powder, respectively. Results : The T5 group had markedly lower body weight gain and weights of epididymal adipose tissue when compared with HF group. There were significant differences in visceral adipose tissue weights, serum total cholesterol and triglyceride concentrations between the HF and T5 group. Then, the efficacy of powered HCKP on body weight and lipid profiles change in rats fed high-fat diet were induced dose dependantly. Conclusion : These results suggest that the possibility of HCKP, as an antiobese functional formula, by suppression of body weight gain and improved lipid profiles.

• Biomedical Science Letters
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• v.16 no.3
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• pp.151-159
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• 2010

The peroxisome proliferator-activated receptor $\alpha$ (PPAR$\alpha$) is a nuclear transcription factor that plays a central role in lipid metabolism and obesity. Exercise also is a powerful modifier of the manifestations of the lipid metabolism and obesity in animal models and humans with obesity and metabolic syndrome. However, effects of exercise on lipid metabolism and obesity in normal-weight younger female subjects, having functional ovaries and not metabolic disease, remain unexplained. To explore the effects of exercise on the development of obesity and its molecular mechanism in high fat diet-fed female C57BL/6J mice, we experimented the effects of swim training on body weight, adipose tissue mass, serum lipid levels, morphological changes of adipocytes and the expression of PPAR$\alpha$ target genes involved in fat oxidation in skeletal muscle tissue of female C57BL/6J mice. Swim-trained mice had significantly decreased body weight, adipose tissue mass, serum triglycerides compared with female control mice. Histological studies showed that swim training significantly decreased the average size of adipoctyes in parametrial adipose tissue. Swim training did not affect the expression of PPAR$\alpha$ mRNA in skeletal muscle. Concomitantly, swim training did not increase mRNA levels of PPAR$\alpha$ target genes responsible for fatty acid $\beta$-oxidation, such as carnitine palmitoyltransferase 1, medium chain acyl-CoA dehydrogenase, enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase, and thiolase in skeletal muscle. In conclusion, these results indicate that swim training regulates lipid metabolism and obesity in high fat diet fed-female mice although swim training did not increase mRNA levels of PPAR$\alpha$ target genes involved in fatty acid $\beta$-oxidation in skeletal muscle, suggesting that swim training may prevent obesity and improve fitness through other mechanisms in female with ovaries, not through the activation of skeletal muscle PPAR$\alpha$.

• Nutrition Research and Practice
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• v.11 no.3
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• pp.198-205
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• 2017

BACKGROUND/OBJECTIVES: The anti-diabetic activity of pear through inhibition of ${\alpha}-glucosidase$ has been demonstrated. However, little has been reported about the effect of pear on insulin signaling pathway in obesity. The aims of this study are to establish pear pomace 50% ethanol extract (PPE)-induced improvement of insulin sensitivity and characterize its action mechanism in 3T3-L1 cells and high-fat diet (HFD)-fed C57BL/6 mice. MATERIALS/METHODS: Lipid accumulation, monocyte chemoattractant protein-1 (MCP-1) secretion and glucose uptake were measure in 3T3-L1 cells. Mice were fed HFD (60% kcal from fat) and orally ingested PPE once daily for 8 weeks and body weight, homeostasis model assessment of insulin resistance (HOMA-IR), and serum lipids were measured. The expression of proteins involved in insulin signaling pathway was evaluated by western blot assay in 3T3-L1 cells and adipose tissue of mice. RESULTS: In 3T3-L1 cells, without affecting cell viability and lipid accumulation, PPE inhibited MCP-1 secretion, improved glucose uptake, and increased protein expression of phosphorylated insulin receptor substrate 1 [p-IRS-1, ($Tyr^{632})$)], p-Akt, and glucose transporter type 4 (GLUT4). Additionally, in HFD-fed mice, PPE reduced body weight, HOMA-IR, and serum lipids including triglyceride and LDL-cholesterol. Furthermore, in adipose tissue, PPE up-regulated GLUT4 expression and expression ratio of p-IRS-1 ($Tyr^{632})/IRS$, whereas, down-regulated p-IRS-1 ($Ser^{307})/IRS$. CONCLUSIONS: Our results collectively show that PPE improves glucose uptake in 3T3-L1 cells and insulin sensitivity in mice fed a HFD through stimulation of the insulin signaling pathway. Furthermore, PPE-induced improvement of insulin sensitivity was not accompanied with lipid accumulation.

• Preventive Nutrition and Food Science
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• v.20 no.1
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• pp.43-51
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• 2015

${\varepsilon}$-Polylysine (EPL) is used as a natural preservative in food. However, few studies have been conducted to assess the beneficial functions of dietary EPL. The purpose of this study was to elucidate the mechanism underlying the inhibition of neutral and acidic sterol absorption and hepatic enzyme activity-related fatty acid biosynthesis following EPL intake. EPL digest prepared using an in vitro digestion model had lower lipase activity and micellar lipid solubility and higher bile acid binding capacity than casein digest. Male Wistar rats were fed an AIN-93G diet containing 1% (wt/wt) EPL or L-lysine. After 4 weeks of feeding these diets, the marked decrease in serum and liver triacylglycerol contents by the EPL diet was partly attributed to increased fecal fatty acid excretion. The activities of hepatic acetyl-coenzyme A carboxylase and glucose-6-phosphate dehydrogenase, which are key enzymes of fatty acid biosynthesis, were enhanced in rats fed EPL diet. The increased fatty acid biosynthesis activity due to dietary EPL may be prevented by the enhancement of fecal fatty acid excretion. The hypocholesterolemic effect of EPL was mediated by increased fecal neutral and acidic sterol excretions due to the EPL digest suppressing micellar lipid solubility and high bile acid binding capacity. These results show that dietary EPL has beneficial effects that could help prevent lifestyle-related diseases such as hyperlipidemia and atherosclerosis.

• Food Science of Animal Resources
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• v.30 no.4
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• pp.582-589
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• 2010

The current study was designed to assess the effects of emulsified sausage supplemented with ginseng saponin on lipid metabolism by applying a rat model. Four groups of 8 rats (5 wk old) were each allocated one of 4 treatments: basal feed (C), and basal feed with 20% sausage powder containing 0% (S0), 2% (S2) and 4% (S4) ginseng saponin. The experiment was conducted for 4 wk. The results did not differ among the treatments with different amounts of sausage (ST), but daily feed intake (p<0.01) and feed conversion (p<0.001) were significantly increased in STs compared to C. Both total serum cholesterol and triglyceride concentrations were significantly (p<0.001) reduced, by 45 and 46%, and 48 and 46%, in S2 and S4, respectively, compared to S0. In the liver, the total cholesterol level was dramatically (p<0.05) decreased according to increasing sausage powder levels. In particular, S4 showed approximately 14% reduction compared to S0 (p<0.05). Liver triglyceride content also showed a similar tendency, where S2 and S4 resulted in 7% and 31% reduction. With regard to fatty acid composition in the liver tissues, palmitic acid (16:0), oleic acid (18:1), eicosanoic acid (20:1), and eicosatrienoic acid (20:3) did not differ among the STs, whereas both linoleic acid (18:2) (p<0.01) and linolenic acid (18:3) (p<0.001) showed significant increases in S2 compared to S0. The current data demonstrated that emulsified sausages supplemented with ginseng saponin effectively reduce total cholesterol and triglyceride concentrations in the serum and liver, and increase unsaturated and essential fatty acid in the liver. These data collectively imply that the sausage improved the overall lipid profile in a rat model, and can be further generalized to the result that emulsified sausage can improve lipid metabolism depending on the products' formula.

• The Journal of Korean Medicine
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• v.23 no.4
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• pp.64-72
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• 2002

Objective: Ramulus mori (RM) has been known to be effective for the treatment of obesity. To show the effectiveness of RM in a more scientific way, RM extract was prepared and evaluated in high fat diet rats by measuring the changes of body weight and lipid metabolism as described briefly below. Methods: 200 g of crushed RM was extracted withmethyl alcohol. The extract was evaporated under reduced pressure to give 33.4 g. For 10 weeks, control group rats were fed a high fat diet, while the test group rats were fed with the same diet plus RM extract. The normal group was fed with a normal diet. 150 mg of RM extract per 1 kg of body weight was added to the diet in the test group rats. Results: The control group rats on the high fat diet gained weight significantly, whereas the test group rats on the high fat diet plus RM extract gamed less weight. The significant increase of liver weight caused by the high fat diet was also inhibited by the RM extract treatment. Total lipid, triglyceride and total cholesterol levels of serum in the high fat diet rats were remarkably increased, whereastheir levels on the high fat diet plus RM extract were less increased. While serum HDL-cholesterol levels were remarkably decreased in the high fat diet, its level was less decreased in the high fat diet plus RM extract. Furthermore, we observed that the activities of hepatic acetyl-CoA carboxylase and fatty acid synthetase increased under the high fat diet, while their activities under the high fat diet plus RM extract were getting back nearly to the normal levels of the normal diet rats. Conclusions: These result show that the obesity caused by a high fat diet was effectively inhibited by an RM extract. Our results also showed that the abnormal lipid metabolism caused by a high fat diet was effectively cured by adding RM extract.

• Nutrition Research and Practice
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• v.7 no.6
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• pp.481-487
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• 2013

High-fat diet up-regulates either insulin resistance or triglycerides, which is assumed to be related to the expression of peroxisome proliferator-activated receptor (PPAR)-${\alpha}$ and PPAR-${\gamma}$. The beneficial effects of vitamin E on insulin resistance are well known; however, it is not clear if vitamin E with a high-fat diet alters the expression of PPAR-${\alpha}$ and PPAR-${\gamma}$. We investigated the effects of d-${\alpha}$-tocopherol supplementation on insulin sensitivity, blood lipid profiles, lipid peroxidation, and the expression of PPAR-${\alpha}$ and PPAR-${\gamma}$ in a high-fat (HF) diet-fed male C57BL/6J model of insulin resistance. The animals were given a regular diet (CON; 10% fat), a HF diet containing 45% fat, or a HF diet plus d-${\alpha}$-tocopherol (HF-E) for a period of 20 weeks. The results showed that the HF diet induced insulin resistance and altered the lipid profile, specifically the triglyceride (TG) and total cholesterol (TC) levels (P < 0.05). In this animal model, supplementation with d-${\alpha}$-tocopherol improved insulin resistance as well as the serum levels of TG and very-low-density lipoprotein-cholesterol (VLDL-C) (P < 0.05). Moreover, the treatment decreased the levels of malondialdehyde (MDA) in the serum and liver while increasing hepatic PPAR-${\alpha}$ expression and decreasing PPAR-${\gamma}$ expression. In conclusion, the oral administration of d-${\alpha}$-tocopherol with a high-fat diet had positive effects on insulin resistance, lipid profiles, and oxidative stress through the expression of PPAR-${\alpha}$ and PPAR-${\gamma}$ in a high-fat diet-fed male mice.