• Journal of Aquaculture
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• v.20 no.4
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• pp.219-225
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• 2007

This study investigated the correlationship between artificial maturation season and reproduction coefficient of cultured eel Anguilla japonica from May (spring) to next January (winter). The brood stock, female eels ($400{\sim}600\;g$) were artificially matured by weekly intramuscular injections of salmon pituitary extracts (SPE, 20 mg/fish) to induce a completion of vitellogenesis. After completion of vitellogenesis, final oocyte maturation and ovulation was induced by injection of $17{\alpha}$, $20{\beta}-dihydroxyprogesterone$ (DHP) at about $2\;{\mu}g/g$ body weight. Most fish ovulated $15{\sim}18\;h$ following the DHP injection. The ovulated fish were induced to natural spawning or artificial fertilization by the dry method. Males ($200{\sim}350\;g$) were received weekly intramuscular injections of human chorionic gonadotropin (HCG) at a dosage of 1 IU/g body weight to induce testicular maturation and spermiation. Seasonal reproduction coefficient which includes the rate of ovulation, buoyancy, fertilization and hatching of eggs in the artificially matured eel during spring to summer ($May{\sim}July$) were significantly higher than the other season, while there were no significant difference among spring and summer (P<0.05). Furthermore, the number of eggs spawned and larvae hatched in the artificially maturated eel during spring to summer ($May{\sim}July$) were significantly higher than the other season, while there were no significant difference in spring and summer (P<0.05). These results indicate that artificial maturation by hormone treatment of A. japonica was successful only during spring to summer, which is the maturation period in the wild stock in nature. Consequently, it is possible to determine the period of artificially induced sexual maturity by the reproduction coefficient which includes the rate of ovulation, buoyancy, fertilization and hatching of eggs in the cultured eel A. japonica.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.2
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• pp.210-218
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• 2010

This study was carried out to investigate the effect of Yacon (Polymnia sonchifolia Poepp. & Endl.) powder on cholesterol-lowering and anti-obesity effects in rats fed a high fat-high cholesterol diet for 4 weeks to induce hyperlipidemic and obese rat model. Weight-matched male Sprague-Dawley rats were assigned to four groups according to dietary fat, cholesterol levels and Yacon powder levels. Experimental groups were normal diet group (N), high fat-high cholesterol diet group (HFC), high fat-high cholesterol diet with 5% Yacon powder group (HFC-PSL) and high fat-high cholesterol diet with 10% Yacon powder group (HFC-PSH). The body weight gain and FER were increased by a high fat-high cholesterol diet, but gradually decreased in the Yacon powder fed groups compared with the HFC group. Food intake was lower in HFC groups compared with N group. The liver and adipose tissue weights of HFC group were heavier than those of N group, whereas those of groups administered Yacon powder were gradually decreased. The serum ALT, AST, ALP and LDH activities elevated by a high fat-high cholesterol diet were significantly decreased by Yacon powder administration. Levels of serum total cholesterol, LDL-cholesterol, atherogenic index and cardiac risk factor showed a decreasing tendency in the Yacon powder fed groups compared with HFC group. The serum HDL-cholesterol level decreased in the HFC group and markedly increased in the Yacon powder fed groups. Levels of total cholesterol and triglyceride in liver and adipose tissues were lower in Yacon powder administered groups than those in HFC group. These results suggest that Yacon powder may improve lipid metabolism of serum, liver, and adipose tissue and potentially reduce lipid storage.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.5
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• pp.641-649
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• 2014

This study was carried out to investigate the effects of Peucedanum japonicum Thunb. (PJT) powder on lipid metabolism and antioxidative activity in rats fed a high-fat/high-cholesterol diet for 4 weeks. Male Sprague-Dawley rats were assigned to four groups: normal diet group (N), high-fat/high-cholesterol group (HFC), high-fat/highcholesterol with 5% PJT powder (HFC-PBL), and high-fat/high-cholesterol with 10% PJT powder (HFC-PBH). Body weight gain and food efficiency ratio (FER) increased in the HFC group, whereas they gradually decreased in the PJT powder-fed groups. Food intake was not significantly different between the experimental groups. Liver and adipose tissue weights of the HFC group were heavier than that of the N group, whereas the groups fed PJT powder showed gradual reduction of tissue weights. Serum alkaline phosphatase (ALP) activity significantly decreased after PJT powder administration. Serum triglyceride level significantly decreased in groups fed PJT powder compared to the HFC group. The serum low density lipoprotein cholesterol (LDL-cholesterol) level of the HFC group increased by 73.70% than that of the N group, whereas serum high density lipoprotein (HDL-cholesterol) tended to decrease in groups fed PJT powder compared to the HFC group. Levels of triglycerides in epididymal and mesenteric adipose tissues, as well as cholesterol levels in liver and adipose tissues were lower in the groups fed 10% PJT powder compared to the HFC group. The liver glutathione (GSH) level increased in the groups fed PJT powder compare to the HFC group. The liver thiobarbituric acid reactive substances (TBARS) content significantly decreased in the groups fed PJT powder compared to the HFC group. These results suggest that PJT powder may improve lipid metabolism in the serum, liver, and adipose tissue and prevent oxidative stress by stimulating antioxidative systems in rats fed a high fat-high cholesterol diet.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.6
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• pp.1065-1070
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• 2002

The purpose of this study was investigated the effects of YK-209 mulberry leaves on antioxidative defense system of liver in diabetic rats induced with streptozotocin (STZ). Male Sprague-Dawley rats weighing 100$\pm$10 g were randomly assigned to one normal and four STZ-induced diabetic groups; YK-209 mulberry leaves free diet (DM group),0.1% YK-209 mulberry leaves diet (DM-0.1Y group),0.2% YK-209 mulberry leaves diet (DM-0.2Y group) and 0.4% YK-209 mulberry leaves diet (DM-0.4Y group). Diabetes was induced by intravenous Injection of 55 mg/kg body weight of STZ in sodium citrate buffer (pH 4.3) via tail vein after 4 weeks feeding of experimental diets. Rats were sacrificed at the 9th day of diabetic states. Liver weight in all four diabetic groups were higher than normal group, but YK-209 mulberry supplementation groups were lower than DM group. Hepatic superoxide dismutase (SOD) activity was significantly decreased in all diabetic groups, compared with normal group. Hepatic glutathione peroxidase (GSHpx) activity was 7.3% decreased in DM group, compared with normal group, but those of DM-0.1Y and DM-0.2Y groups were maintained the normal level. The hepatic thiobarbituric acid reactive substances was markedly increased by 144% in DM group, compared with normal group, but those of DM-0. 1Y, DM-0.2Y groups were maintained the normal level. The contents of lipofuscin in liver were increased by 100% in DM group compared with normal group, but those of DM-0. 1Y, DM-0.2Y and DM-0.4Y groups were decreased to 42% 43% and 44%, respectively, compared with DM group. The hepatic superoxide radical (0$^2$-) contents in DM group were increased to 81%, compared with normal group, but those of DM-0.1Y and DM-0.4Y groups were similar to those of normal group. The present result indicate that YK-209 mulberry leaves regarded to suppress lipid peroxidation as an free radical scavenger system by the inhibition of oxidative stress.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.7
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• pp.943-949
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• 2012

This study investigated the effects of diets with a supplement of Job's tears (JT) and Cudrania tricuspidata leaf (CTL) powder as a functional food ingredient on obesity and lipid profiles in diet-induced obese rats. Male Sprague-Dawley rats were fed a high-fat diet (D12492, 45 kcal fat) for 5 weeks during the first phase. In the second phase, which lasted 5 weeks, the rats were divided into four experimental groups. The groups were a high-fat diet group as a control (HFD), a high-fat diet with 10% JT powder supplement group (JT-10), a 10% CTL powder supplement group (CTL-10), and a 20% JT and CTL 1:1 mixed-powder supplement group (MIX-20). The adipose tissue (RFP, EFP) weights were significantly decreased in the CTL-10 and MIX-20 groups than in the HFD group (p<0.05). The fecal weight produced by the MIX-20 group was highest among all experimental groups (p<0.05), and it was significantly increased during the second phase compared to the first phase (p<0.05). The serum total cholesterol content was significantly decreased in the CTL-10 and MIX-20 groups, and the LDL-cholesterol content was significantly low in the JT-10 and MIX-20 groups than in the HFD group (p<0.05). The blood glucose levels were significantly decreased in all experimental diet supplement groups than in the HFD group (p<0.05). The findings show that a diet of mixed JT and CTL could improve lipid metabolism.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.7
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• pp.950-956
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• 2012

Salicornia herbacea L. is an annual herb that grows in salt marshes and salt fields along the seashores. It is also commonly used as a folk remedy in Korea. The objective of this study was to investigate the beneficial effects of Salicorrnia herbacea L. (SH) hot water extract on obesity. Five-week old male Sprague-Dawley rats (n=36) were divided into two groups and provided either a normal fat diet (11.5% fat from kcal) or a high fat diet (40.5% fat from kcal) for 6 weeks to induce obesity. Then, rats were blocked into six groups of six mice each and provided either a diet containing SH (0.5% of diet; g/kg) or a normal diet for another 6 weeks. Final body weights were significantly reduced when rats were fed SH among the high fat diet groups (HNS and HHS). Serum triglyceride concentrations significantly decreased in every group provided SH. HDL-cholesterol concentrations significantly increased in SH-fed groups among the high fat diet groups. Further, atherogenic index significantly decreased when rats were fed SH diet (HHS). There were no differences in LDL-cholesterol between the high fat diet groups, and glucose concentrations decreased when rats were fed SH diet (HNS). These results indicate that dietary intake of Salicornia herbacea L. hot water extract might have beneficial effects on obesity by reducing body weight, fat weights, and improving blood lipid profile.

• 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 the Korean Society of Food Science and Nutrition
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• v.41 no.6
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• pp.766-773
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• 2012

This study investigates the effects of diets with mulberry leaf and Cudrania tricuspidata leaf supplements on blood glucose-related biomarkers in streptozotocin-induced diabetic rats. Male diabetic Sprague-Dawley rats were divided into groups and fed several diets. Group A was fed a diet with a 10% supplement of mulberry leaves. Group B was fed a diet with a 10% supplement of mulberry leaves and an additional 10% supplement of Cudrania tricuspidata leaves. Group C was fed a diet with a 10% supplement of mulberry leaves and an additional 30% supplement of Cudrania tricuspidata leaves. Group D was fed a diet with a 10% supplement of Cudrania tricuspidata leaves. Group E was the DM control. All diets were based on AIN-93G diet and they all lasted 6 weeks. The blood glucose levels of groups B and C stayed similar to initial levels (reference blood glucose) for the experimental period, which was significantly lower than levels in groups A, D, and E at the 6th week (p<0.05). And the area under the blood glucose curve (AUC) was also significantly lower in groups B and C than in groups D and E (p<0.05). The fasting blood glucose level after the experiment was significantly lower in groups B and C (p<0.05), and the C-peptide content of group C was as high as 50 pmol/L on average. The HbA1c content was also significantly lower in groups A and B than in group E (p<0.05). The serum TG, AST, and ALT levels were significantly decreased in groups A, B, and D than in group E (p<0.05). From the findings, it is shown that a diet of 1:1 mulberry and Cudrania tricuspidata leaf supplements could improve blood glucose-related biomarkers.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.10
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• pp.1536-1544
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• 2005

We have investigated physiological effects of soy ice cream with oligosaccharide on oxidative stress and fecal microflora in streptozotocin-induced diabetic rats. Parched soybean powder (7.6$\%$, w/w) substituted skimmed milk and cream, soybean oil (7.6$\%$, w/w) for milk oil, and fructooligosaccharide (9.5$\%$, w/w) for sucrose. Five types of ice cream were prepared: regular, oligosaccharide-supplemented regular, soy, oligosaccharide - supplemented soy, and oligosaccharide - supplemented black soybean ice cream . Freeze - dried ice cream was supplemented to AIN93-based diets at 30$\%$ (w/w) containing 6.5$\%$ soy and 4.5$\%$ fructooligosaccharide. Diabetes was induced by intramuscular administration of streptozotocin, and experimental diets were given for 4 weeks. Plasma concentration of thiobarbituric acid reactive substances (TBARS) was significantly increased in the diabetic rats compared with the normal rats, then was significantly decreased with feeding soy ice cream containing diet compared with regular ice cream containing diet among the diabetic groups. The levels of TBARS in liver were decreased in the rats that were fed either soy or oligosaccharide ice cream compared with the rats that were fed regular ice cream. Erythrocyte superoxide dismutase activity was significantly increased in the rats fed soy ice cream compared with the rats fed regular ice cream. Erythrocyte glutathione peroxidase and catalase activities were significantly increased in the rats fed black soybean ice cream. Fecal concentrations of Lactobacilli were significantly higher in the rats fed soy ice cream and oligosaccharide- supplemented soy ice cream than that of the rats fed regular ice cream. Fecal concentrations of Bifidobacteria were significantly higher in the rats fed oligosaccharide- supplemented soy ice cream than that of the rats fed regular ice cream. In conclusion, oligosaccharide- supplemented soy ice cream suppressed lipid peroxidation and improved the got microbiota in diabetic rats compared with milk-based regular ice cream.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.3
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• pp.321-327
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• 2006

This study was performed to investigate the hypoglycemic effect of pine needle extract oil against type 2 diabetes. Six-week-old male C57BL/Ks(db/db) mice were divided into four groups : negative control, pine needle extract oil low dose, high dose and positive control groups, which fed daily for 6 weeks with corn oil, pine needle extract oil 112.5 mg/kg, 450 mg/kg or metformin (150 mg/kg ), respectively. The oral administration of the pine needle extract oil resulted in the significant and dose-dependent decreases of blood glucose levels in comparison with corn oil treatment. The levels of HbAlc showed a tendency of the decrease by the high dose treatment of the pine needle extract oil and were positively correlated with blood glucose levels (r=0.5046, p=0.0023) . However, the levels of serum insulin and C-peptide were not affected by pine needle extract oil or metformin treatments. The levels of serum leptin, which is related with the insulin sensitivity, showed a tendency of the increases by pine needle extract oil treatment and were negatively correlated to blood glucose levels (r=-0.4754, p=0.0052). In conclusion, these results suggest that the pine needle extract oil have a potential for the oral anti-hyperglycemic agent and the mode of action may be related with the improvement of the insulin sensitivity through blood leptin.