• Biomolecules & Therapeutics
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• v.28 no.2
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• pp.163-171
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• 2020

Silibinin exhibits antidiabetic potential by preserving the mass and function of pancreatic β-cells through up-regulation of estrogen receptor-α (ERα) expression. However, the underlying protective mechanism of silibinin in pancreatic β-cells is still unclear. In the current study, we sought to determine whether ERα acts as the target of silibinin for the modulation of antioxidative response in pancreatic β-cells under high glucose and high fat conditions. Our in vivo study revealed that a 4-week oral administration of silibinin (100 mg/kg/day) decreased fasting blood glucose with a concurrent increase in levels of serum insulin in high-fat diet/streptozotocin-induced type 2 diabetic rats. Moreover, expression of ERα, NF-E2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) in pancreatic β-cells in pancreatic islets was increased by silibinin treatment. Accordingly, silibinin (10 μM) elevated viability, insulin biosynthesis, and insulin secretion of high glucose/palmitate-treated INS-1 cells accompanied by increased expression of ERα, Nrf2, and HO-1 as well as decreased reactive oxygen species production in vitro. Treatment using an ERα antagonist (MPP) in INS-1 cells or silencing ERα expression in INS-1 and NIT-1 cells with siRNA abolished the protective effects of silibinin. Our study suggests that silibinin activates the Nrf2-antioxidative pathways in pancreatic β-cells through regulation of ERα expression.

• Korean journal of food and cookery science
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• v.10 no.4
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• pp.412-419
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• 1994

The Contents of proximate compositions, vitamin C and minerals(Ca, P, Fe and Zn) of five Korean wild vegetables were analyzed. Twenty four cooking recipes with three of the vegetables were developed and their taste characteristics were evaluated by 12-trained panels. The five Korean wild vegetables are Cassia tora(C.t.), Lycium chinese Mill(L.c.), Trichosanthes quadricirra MIQ(T.q.), Polygonatum japonicum MORR et DECAIS(P.j.) and Articum lappa L.(A.l.). They have been known as the efficacious plants agaginst diabetes mellitus. In our previous work, their hypoglycemic effects have been studied through streptozotocin-induced diabetic rats and fed on the wild vegetables. Contents of moisture were 14~86% in the samples and L.c. showed relatively higher content of crude protein(16.4%). High level of crude fat was seen in C.t.(9.4%). Contents of vitamin C were also relatively high in the wild vegetables(14.2~42.0 mg%). Analysis of minerals revealed the high level of Ca in L.c. leaves, P in A.l. and Fe in C.t. and L.c. leaves. All of the samples contained Zn in 5.0~14.6 mg%. Twelvetrained taste panels indicated that the 24-preparations of L.c. leaves, fruites and P.j. were well accepted in taste, color and odor. Although L.c. fruit gruel, L.c. cream soup and P.j. saute were evalulated as less acceptable, their sensory scores were in 3.6~5.4 which were not undesirable. The newly developed cooking recipes of L.c. fruits and leaves showed better scores in color and texture, P.j. in texture and odor.

• Journal of Nutrition and Health
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• v.31 no.5
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• pp.921-926
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• 1998

The purpose of this study was to investigate the potential hypolipidemic effect of adlay extract in streptozotocin-induced diabetic rats. Fifty six rats were fed either a control diet or adlay extract diets of : Methanol 1%(Ml%) ; Methanol 2%(M2%) ; Methanol 4%(M4%) ; Chloroform-Methanol 1%(CMl%) ; Chloroform-Methanol 2%(CM2%) ; Chloroform-Methanol 4%(CM4%) for 3 weeks. The amount of extracts added was 1%, 2% or 4% by diet weight respectively. The levels of glucose, total cholesterol(TC), high-density-lipoprotein cholesterol (HDL-C), free-fatty acid(FFA) and triglyceride(TG) in plasma, liver and skeletal muscle were compared. Among diabetic rats, there were no significant differences in the plasma level of glucose and TC regardless of a different extraction procedure or different amount of extracts added. While the plasma 7G level tended to increase with times passed in diabetic control group, was not increased with times passed in CM groups and was significantly lower in CM groups at 3rd week. Compared to the diabetic control group, the levels of FFA tended to be lower in all M groups and were not different in all CM groups. The levels of HDL-cholesterol were not different in all M groups and were significantly lower in all CM groups than diabetic control group. Compared to diabetic control group, liver triglyceride level was lower in M4% group and no significant difference was seen in Ml%, M2% and all CM groups. Muscle triglyceride level tended to be lower in Ml%, M2% and CM2% group and significantly was lower in M4% and CM4% group. Thus, it can be suggested that a CM extract of adllay could have a potential hypotriglyceridemic effect on diabetic subjects. (Korean J Nutrition 31(5) : 921∼926, 1998)

• Journal of the East Asian Society of Dietary Life
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• v.20 no.1
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• pp.46-53
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• 2010

The study examined the effects of dietary green tea powder supplementation on blood glucose, and plasma and liver lipid concentrations in diabetic rats. Twenty-five male Sprague-Dawley rats (body weight $200{\pm}5\;g$) were divided into two groups (diabetic and non-diabetic), which were each randomly divided into two subgroups that were fed a control and 1% green tea powder-supplemented diet. Serum and liver lipid concentrations were measured by established techniques. Low density lipoprotein-cholesterol (LDL-C) was calculated from an established equation. Body weight gain and feed efficiency ratio were lower in diabetic rats than in non-diabetic rats regardless of diet. There were no differences in weight gain in diabetic and non-diabetic rats consuming the control and green tea powder-supplemented diets. The levels of fasting plasma glucose, serum total cholesterol, triglyceride, LDL-C and atherogenic index of diabetic rats were significantly higher than that of non-diabetic rats. Conversely, the levels of high density lipoprotein-cholesterol (HDL-C) of diabetic rats was significantly lower than that of non-diabetic rats. Fasting plasma glucose, serum total cholesterol, triglyceride, LDL-C and atherogenic index were significantly lower in diabetic rats fed the green tea powder diet than in rats fed the control diet, and HDL-C was significantly higher in rats fed the green tea powder diet than in rats fed the control diet. The content of liver total cholesterol and triglyceride of diabetic rats were significantly higher than that of non-diabetic rats. Liver total cholesterol and triglyceride were significantly lower in diabetic rats fed green tea powder-supplemented diet than in rats fed the control diet. It is concluded that green tea powder supplementation positively influences blood glucose and lipid metabolism in diabetic rats. The present study, although not directly applicable to humans, may have some implications for individuals who habitually consume green tea powder.

• KSBB Journal
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• v.26 no.1
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• pp.41-48
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• 2011

To enhance cyclo-His-Pro (CHP) content, soybean hydrolysate was obtained using the strains isolated from Chungkukjang and further purified by various purification steps. First, twenty two strains were screened from Chungkukjang containing high level of CHP. Among them, the strain No. 12, which showed higher productivity of CHP from soybean ferment and have homologous sequence with 16S rDNA of Bacillus amyloliquefaciens, was named B. amyloliquefaciens CHP-12. Through various purification processes, CHP was concentrated from soybean ferment using ultrafiltration, which showed the best efficiency of CHP production, with the yield (71.3%) and CHP content (2.14 mg/g). Moreover, when glucose tolerance test was performed in Type I Sprague-Dawley rat induced by streptozotocin using the soybean ferments [0.5 g soybean ferment/kg body weight (CHP-0.5 group)] and 1.0 g soybean ferment/kg body weight (CHP-1.0 group), there were significant differences in glucose levels between diabetes-control group (265.3 mg/dL) and soybean ferment-treated groups (CHP-0.5 group: 84.3 mg/dL and CHP-1.0 group: 85.3 mg/dL) 120 min after glucose injection (2 g/kg body weight) (p < 0.05). Accordingly, it is suggested that the soybean ferment containing high level of CHP might be a candidate material as an anti-diabetic supplement for manufacturing functional healthy foods.

• The Korean Journal of Physiology and Pharmacology
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• v.3 no.2
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• pp.175-182
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• 1999

In the present study, the underlying mechanisms for diabetic functional derangement and insulin effect on diabetic cardiomyopathy were investigated with respect to sarcoplasmic reticulum (SR) $Ca^{2+}-ATPase$ and phospholamban at the transcriptional and translational levels. The maximal $Ca^{2+}$ uptake and the affinity of $Ca^{2+}-ATPase$ for $Ca^{2+}$ were decreased in streptozotocin-induced diabetic rat cardiac SR, however, even minimal amount of insulin could reverse both parameters. Levels of both mRNA and protein of phospholamban were significantly increased in diabetic rat hearts, whereas the mRNA and protein levels of SR $Ca^{2+}-ATPase$ were significantly decreased. In case of phospholamban, insulin treatment reverses these parameters to normal levels. Minimal amount of insulin could reverse the protein levels; however, it could not reverse the mRNA level of SR $Ca^{2+}-ATPase$ at all. Thus, the decreased SR $Ca^{2+}$ uptake appear to be largely attributed to the decreased SR $Ca^{2+}-ATPase$ level, which is further impaired due to the inhibition by the increased level of phospholamban. These results indicate that insulin is involved in the control of intracellular $Ca^{2+}$ in the cardiomyocyte through multiple target proteins via multiple mechanisms for the decrease in the mRNA for both SR $Ca^{2+}-ATPase$ and phospholamban which are unknown and needs further study.

• The Journal of Internal Korean Medicine
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• v.31 no.2
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• pp.212-223
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• 2010

Objectives : The aims of this study were to evaluate whether gastric contractility could be measured by bowel sound of rats, and whether gastrointestinal side effect of any herbal restoratives would be related with their inhibition of gastric contraction. Methods : Streptozotocin (STZ)-induced diabetic rats were used as a gastric hypocontraction model. At the time of 6 weeks after induction of diabetes, 2mL of normal saline (NS) and 2mL of extract solution each containing 125mg/kg of Bojoongikki-tang (BJ), Sipjeondaebo-tang (SJ), Youngkaechulgam-tang (YG) were given to Normal (NR) and diabetic rats (DR), respectively. Bowel sound was recorded for 30 minute in fasting, and 120 minute of their administration. Gastric motility index was serially calculated with the ratio of accumulated potentials of post-administration/fasting state every 10 minutes. Results : Gastric contractility between NR and DR could be significantly distinguished by bowel sound auscultation. BJ had a decreasing effect, SJ had a bidirectional effect, and YG had an increasing effect on gastric contractility measured by bowel sound auscultation. Conclusions : BJ showed the possibility of inhibitory effects on gastric contraction. So, before administration, a gastric motility test should be recommended to prevent possible side effects in patients with gastric hypocontractility.

• Biomolecules & Therapeutics
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• v.5 no.4
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• pp.364-368
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• 1997

Onion (Allium cepa Linn) has been reported to have hypoglycemic activity in human and several animal models. In the present study, we performed intraperitoneal glucose tolerance test (IPGTT) in young (1.5mo) and aged (5 mo) rats treated with onion in order to determine whether aging can influence on the anti-hy-perglycemic effect of onion. In addition, we investigated the hypoglycemic effect of onion in streptozotocin- induced diabetic rats treated with aqueous extracts of onion (500 mg/kg, i.p., daily) for 4 weeks. Blood glucose level was determined in fasted and fed rats by using a glucometer (Johnson & Johnson). In glucose tolerance test, blood glucose level was maximally increased 15 min after glucose load (2 g/kg, i.p.), and recovered to the basal level 3 hr after glucose challenge in young and old rats. The maximum blood glucose levels of young and aged rat were 184$\pm$7.49 and 225.2$\pm$ 12.55 mg/dl, respectively. A single i.p. injection of aqueous extract of onion (1 g/kg) 30 min before glucose challenge significantly decreased blood glucose levels at 15, 30, 60, 90 min after glucose load in aged rats, while the administration of onion did not show any significant effect in young rats. In onion-treated diabetic rats, significant hypoglycemic effect (p<0.05) was observed, and the effect was greater in fasted rats than in fed. In conclusion, these results suggest that anti-hyperlycemic effect of onion can be changed by age and fasting.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2002.07a
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• pp.219-219
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• 2002

The SPP003 is a mixture of water extract from Schizandrae Fructus, Poligoni multiflori Radix, Ginseng Radix Akba and Hoelen. The aim of this study was to investigate the anti-hyperglycemic effect of SPP003 in normal and streptozotocin (STZ)-induced diabetic rats, and to monitor the toxicity of SPP003. Oral glucose tolerance test (OGTT) was performed after oral administration of SPP003 100, 300, 600 and 900 mg/kg in normal rats. Blood glucese concentration was measured at -30 min (vehicle, SPP003 or tolbutamide 60 mg/kg, 0 min (glucose treatment), 60, 120 and 180 min. Rats were administerd STZ 65mg/kg (0.1M citrate buffer, pH 4.5) intraperitoneally to induce diabetes and administered vehicle, Spp003 (100, 300 and 600 mg/kg) or tolbutamide (60 mg/kg) orally once a day for 4 weeks. Blood glucose level was measured a 0, 4, 7, 14, 21 and 29 day after initial drug administration. A single oral toxicity of SPP003 was studied in Sprague-Dawley rats of both sexes. In this study, rats were administered with doses of 1, 2 and 5 g/kg of SPP003. In glucose tolerance test, SPP003 900 mg/kg markedly decreased glucose concentration at 1 hr after glucose treatment. Blood glucose levels were much higher in STZ-diabetic rats. These increases were significantly attenuated by SPP003 600 mg/kg. SPP003 did not show any signigicant toxicity. These findings suggest that SPP003 has hypoglycemic properties in STZ-diabetic rats.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.808-812
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• 2009

The ${\alpha}-glucosidase$ inhibitory and antioxidant effects of water chestnut (Trapa japonica Flerov.) were assessed to explore its possible use as an anti-diabetic agent. Methanol extracts of the fruit shell and meat of water chestnut were assayed for inhibitory activity against yeast ${\alpha}-glucosidase$ and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. Effect of fruit shell extract on postprandial glucose response was assessed. Compared with fruit meat, shell extract showed stronger inhibition against ${\alpha}-glucosidase$ with an $IC_{50}$ of 273 ${\mu}g/mL$. Oral administration of fruit shell extract (500 mg/kg) significantly lowered the postprandial area under the glucose response curve to starch (1 g/kg) in streptozotocin (STZ)-induced diabetic rats (p<0.01). Compared with fruit meat, shell extract showed stronger scavenging activity against DPPH, with an $IC_{50}$ of 27.1 ${\mu}g/mL$. The results indicate that the fruit shell of water chestnut was effective in controlling postprandial hyperglycemia and exerted an antioxidant effect. Therefore, water chestnut may be useful in treating diabetes.