• Journal of Food Hygiene and Safety
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• v.28 no.2
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• pp.152-157
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• 2013

We evaluated the anti-diabetic effects of Isaria tenuipes in diabetes mellitus type 2. For the experiments, the diabetic animal model OLETF rats were divided to 4 groups: Isaria tenuipes was administered mixed with the high fat diet 45% at dose levels of 0.0%, 0.1%, 1.0%, and 5.0% for 4 weeks. All animals have free access to water and high fat diet 45%. The diabetic clinical markers, including clinical signs, body weight and food intake, organ weights, blood glucose level, insulin level and HOMA-IR index, oral glucose tolerance test, GLUT4 mRNA and protein were measured at a time. After administration for 4 weeks, the blood glucose levels, insulin levels and HOMA-IR index of test groups were decreased compared with control group in dose-dependent manner. The body weight and diet consumptions were reduced in control group at 4 weeks. The treatments of Isaria tenuipes also showed high expression of GLUT4 mRNA and protein in the muscle of OLETF rats. The results suggest that Isaria tenuipes has anti-hyperglycemic effect attenuating blood glucose in the animal model of type 2 diabetes and might be useful as a functional diet for human diabetic diseases.

• Journal of Life Science
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• v.18 no.1
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• pp.23-29
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• 2008

Panax ginseng C. A. MEYER is one of the most widely used herbal medicines in the Asian countries and has diverse functions including anti-diabetic action. The dysfunctions of mesangial cells in hyperglycemic conditions are implicated in the development of diabetic nephropathy. Insulin-like growth factors (IGFs) are also associated with the onset of diabetic nephropathy. Thus, we examined the effect of ginsenosides against high glucose-induced dysfunction of primary cultured rat mesangial cells. In the present study, high glucose increased IGF-I and IGF-II secretion in mesangial cells. Ginsenoside total saponin (GTS) prevented high glucose-induced increase of IGF-I and IGF-II secretion in mesangial cells. In addition, GTS prevented high glucose-induced increase of lipid peroxide formation and decrease of GSH contents. GTS also ameliorates high glucose-induced increase of arachidonic acid release and decrease of prostaglandin $E_2$. In conclusion, GTS prevented high glucose-induced dysfunction of mesangial cells via inhibition of oxidative stress and arachidonic acid pathways.

• Journal of Yeungnam Medical Science
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• v.36 no.1
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• pp.26-35
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• 2019

Background: Dysregulation of hepatic glucose production (HGP) contributes to the development of type 2 diabetes mellitus. Telmisartan, an angiotensin II type 1 receptor blocker (ARB), has various ancillary effects in addition to common blood pressure-lowering effects. The effects and mechanism of telmisartan on HGP have not been fully elucidated and, therefore, we investigated these phenomena in hyperglycemic HepG2 cells and high-fat diet (HFD)-fed mice. Methods: Glucose production and glucose uptake were measured in HepG2 cells. Expression levels of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase ${\alpha}$ ($G6Pase-{\alpha}$), and phosphorylation levels of insulin receptor substrate-1 (IRS-1) and protein kinase C ${\zeta}$ ($PKC{\zeta}$) were assessed by western blot analysis. Animal studies were performed using HFD-fed mice. Results: Telmisartan dose-dependently increased HGP, and PEPCK expression was minimally increased at a $40{\mu}M$ concentration without a change in $G6Pase-{\alpha}$ expression. In contrast, telmisartan increased phosphorylation of IRS-1 at Ser302 ($p-IRS-1-Ser^{302}$) and decreased $p-IRS-1-Tyr^{632}$ dose-dependently. Telmisartan dose-dependently increased $p-PKC{\zeta}-Thr^{410}$ which is known to reduce insulin action by inducing IRS-1 serine phosphorylation. Ectopic expression of dominant-negative $PKC{\zeta}$ significantly attenuated telmisartan-induced HGP and $p-IRS-1-Ser^{302}$ and -inhibited $p-IRS-1-Tyr^{632}$. Among ARBs, including losartan and fimasartan, only telmisartan changed IRS-1 phosphorylation and pretreatment with GW9662, a specific and irreversible peroxisome proliferator-activated receptor ${\gamma}$ ($PPAR{\gamma}$) antagonist, did not alter this effect. Finally, in the livers from HFD-fed mice, telmisartan increased $p-IRS-1-Ser^{302}$ and decreased $p-IRS-1-Tyr^{632}$, which was accompanied by an increase in $p-PKC{\zeta}-Thr^{410}$. Conclusion: These results suggest that telmisartan increases HGP by inducing $p-PKC{\zeta}-Thr^{410}$ that increases $p-IRS-1-Ser^{302}$ and decreases $p-IRS-1-Tyr^{632}$ in a $PPAR{\gamma}$-independent manner

• Nutrition Research and Practice
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• v.17 no.2
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• pp.241-256
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• 2023

BACKGROUND/OBJECTIVES: Diabetes-specific oral nutritional supplements (ONS) have anti-hyperglycemic effects, while D-allulose exerts anti-diabetic and anti-obesity effects. In this study, we investigated the efficacy and safety of diabetes-specific ONS, including allulose, on glycemic and weight changes in overweight or obese patients with type 2 diabetes mellitus (T2DM). SUBJECTS/METHODS: A single-arm, historical-control pilot clinical trial was conducted on 26 overweight or obese patients with T2DM (age range: 30-70 yrs). The participants were administered 2 packs of diabetes-specific ONS, including allulose (200 kcal/200 mL), every morning for 8 weeks. The glycemic profiles, obesity-related parameters, and lipid profiles were assessed to evaluate the efficacy of ONS. RESULTS: After 8 weeks, fasting blood glucose (FBG) level significantly decreased from 139.00 ± 29.66 mg/dL to 126.08 ± 32.00 mg/dL (P = 0.007) and glycosylated hemoglobin (HbA1c) improved (7.23 ± 0.82% vs. 7.03 ± 0.69%, P = 0.041). Moreover, the fasting insulin (δ: -1.81 ± 3.61 μU/mL, P = 0.017) and homeostasis model assessment for insulin resistance (HOMA-IR) (δ: -0.87 ± 1.57, P = 0.009) levels decreased at 8 weeks, and body weight significantly decreased from 67.20 ± 8.29 kg to 66.43 ± 8.12 kg (P = 0.008). Body mass index (BMI) also decreased in accordance with this (from 25.59 ± 1.82 kg/m² to 25.30 ± 1.86 kg/m², P = 0.009), as did waist circumference (δ: -1.31 ± 2.04 cm, P = 0.003). CONCLUSIONS: The consumption of diabetes-specific ONS with allulose in overweight or obese patients with T2DM improved glycemic profiles, such as FBG, HbA1c, and HOMA-IR, and reduced body weight and BMI.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.12
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• pp.1716-1726
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• 2012

This study was undertaken to evaluate the antihyperglycemic, antilipid peroxidative, and antioxidant effects of the ethanol extracts of Artemisia iwayomogi (Ai) in streptozotocin (STZ)-induced diabetic rats. Diabetes was induced in Sprague-Dawley rats with a single intravenous injection (45 mg/kg b.w.) of STZ. The diabetic rats were then randomized to the diabetic and Ai extract therapy groups which were treated with Ai extract at doses of 1, 2, and 3 g/kg b.w./day, respectively, for 14 days. Oral administration of Ai (2 g/kg b.w.) significantly decreased their intake of food. Dosage of 2 g/kg of the extract significantly decreased blood glucose levels in the glucose level in diabetic rats after 4 day, there was no significant difference observed at 1 and 3 g/kg. A dose of 2 or 3 g/kg of the Ai extract significantly reduced plasma glucose levels in STZ-induced hyperglycemic rats at 7 days. The hypoglycemic effect of Ai at a dose of 2 g/kg was significantly more effective than that of STZ-control. The effect was more pronounced in 2 g/kg than 1 g and 3 g/kg. A significant reduction in triglycerides (TG) and free fatty acids (FFA), and a significant increase in liver glycogen were observed in treated diabetic rats at doses of 2 g/kg after 14 days of treatment. Administration of Ai extracts to diabetic rats showed a significant decrease in liver malondialdehyde (MDA) levels. The activity of superoxide dismutase (SOD) was significantly increased in the 3 g extract-supplemented groups. The activities of glutathione peroxidase (GSH-px) and catalase (CAT) were significantly increased in the 1 g and 3 g extract-supplemented groups. Ai extract significantly increased glutathione-S transferase (GST) activity in a dose-dependent manner compared with treatment in STZ-control rats. Our result supports the fact that the administration of Ai extract is able to reduce hyperglycemia and hyperlipidemia risk, and also reduce the oxidative stress in diabetic rats.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.11
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• pp.1401-1407
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• 2008

1-Deoxynojirimycin (DNJ) is a strong $\alpha$-glucosidase inhibitor which inhibits hyperglycemia in animals. To select the Bacillus strains highly producing DNJ, 4,000 strains were isolated from soil and grain samples. By the inhibitory activity against $\alpha$-glucosidase, nine Bacillus strains were selected and then identified by 16S rDNA sequencing. B. subtilis S10 was finally selected as the best strain for the production of DNJ. Various carbon sources and nitrogen sources in culture medium were evaluated for the highest production of DNJ. As the results, the optimized concentration of carbon source and nitrogen source was 1.0% galactose and 1.6% polypeptone and the concentration of DNJ produced was 0.75 g/L. The effect of culture supernatant of B. subtilis S10 on lowering blood glucose level was investigated in streptozotocin (STZ)-induced diabetic mice model. Mice were randomly assigned to control group (saline) and three test groups such as acarbose group, silkworm powder group and B. subtilis S10 group. After eight-week oral feeding, blood glucose levels of the B. subtilis S10 and silkworm powder groups were respectively $209.1{\pm}19.6\;mg/dL$ (59.1%) and $208.6{\pm}39.8\;mg/dL$ (59.0%) lower than $510{\pm}10\;mg/dL$ of the control group. These results indicated that the culture supernatant of B. subtilis S10 was able to reduce the blood glucose level in STZ-induced diabetic mice.

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.3
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• pp.401-408
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• 2011

Type 2 diabetes mellitus (NIDDM) is a metabolic disorder that is characterized by high blood glucose in the context of insulin resistance and relative insulin deficiency. In order to control the type 2 diabetes mellitus, anti-hyperglycemic effect of Triticum aestivum L. water extracts (TAWE) was investigated in 7 week old male diabetic C57BL6/J-ob/ob mice. For the experiments, the diabetic animal model ob/ob mice and non-diabetic animal model lean mice were divided into 3 groups: non-treatment control group (Control), and two experimental groups orally treated with 25 or 100 mg/kg/day dose of TAWE (TAWE-25 and TAWE-100, respectively). The lean mice were used as the non-diabetic normal control. TAWE was orally administrated for 6 weeks and the diabetic clinical markers, including blood glucose level, body weight, organs weight and insulin level were determined. The oral administration of TAWE-100 in ob/ob diabetic mice significantly decreased blood glucose level (78.4%) and body weight (11.9%) compared with diabetic control group. The weights of organs, including spleen, liver, kidneys, heart and lung were not different among groups, while the treatments of TAWE-100 in ob/ob diabetic mice significantly reduced blood total cholesterol (24.35%) and triglyceride (23.97%) levels compared with the diabetic control group. The levels of serum insulin and glucose tolerance were improved after TAWE-100 treatment in ob/ob diabetic mice. Moreover, the immunohistochemical staining for insulin detection in pancreatic islet $\beta$-cells expressed high level of insulin in TAWE-100 treated ob/ob mice. From the above results, the intake of TAWE may be effective in anti-hyperglycemia by the attenuation of glucose and lipid levels. TAWE-containing diets or drugs may be beneficial for controlling diabetes mellitus type 2 in human.

• Korean Journal of Food Science and Technology
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• v.42 no.2
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• pp.204-209
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• 2010

This study was conducted to investigate the anti-diabetic activity of Kocat-D1, which is widely used in traditional medicine to treat diabetes in Shandong, China. Sprague Dawley rats (8 weeks of age) were separated into 4 groups: a normal control, streptozotocin (STZ)-induced diabetic rat group (DM control), Kocat-D1-1 (diabetic rat treated with 0.25 g/kg/day hot water extract), and Kocat-D1-2 (diabetic rat treated with 1 g/kg/day hot water extract). After eight weeks of treatment, the fasting blood glucose levels of the Kocat-D1-1 ($334.3{\pm}32.9\;mg/dL$) and Kocat-D1-2 group ($259.5{\pm}35.0\;mg/dL$) were significantly lower when compared to the DM control group ($451{\pm}42.6\;mg/dL$). Furthermore, the levels of glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), albumin and high-density lipoprotein (HDL) cholesterol in the serum of the Kocat-D1-2 group were significantly normalized when compared to the DM control group. However, significant differences were not observed between the Kocat-D1-1 group and the DM control group. Histochemical staining of the liver of the Kocat-D1-2 group revealed no fat accumulation. The insulin level was significantly upregulated in the Kocat-D1-2 group ($0.13{\pm}0.02\;ng/mL$) when compared to the DM control group ($0.05{\pm}0.04\;ng/mL$). The relative volume of $\beta$-cells in the pancreas of the Kocat-D1-2 group ($49.4{\pm}4.2%$) also increased significantly when compared to the DM control group ($12.9{\pm}7.9%$). These results suggest that Kocat-D1 exerts an anti-hyperglycemic effect through the enhancement of insulin secretion.

• Korean Journal of Food Science and Technology
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• v.48 no.5
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• pp.508-514
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• 2016

Effects of the ethyl acetate fraction from gomchwi (Ligularia fischeri) extract against high $glucose/H_2O_2-induced$ oxidative stress and in vitro neurodegeneration were investigated to confirm the physiological property of the extract. The ethyl acetate fraction of gomchwi extract showed the highest total phenolic contents than the other solvent fractions. An anti-hyperglycemic activity of the ethyl acetate fraction was evaluated using the ${\alpha}-glucosidase$ inhibitory assay, and the half maximal inhibitory concentration ($IC_{50}$) value for ${\alpha}-glucosidase$ was found to be $727.64{\mu}g/mL$. In addition, the ethyl acetate fraction showed excellent 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt radical scavenging activity, and inhibition of malondialdehyde production. The ethyl acetate fraction also decreased intracellular reactive oxygen species, whereas neuronal cell viability against high glucose/$H_2O_2$-induced cytotoxicity was found to be increased. Finally, 3,5-dicaffeoylquinic acid as a main phenolic compound in the ethyl acetate fraction was analyzed by high-performance liquid chromatography. These results suggest that gomchwi might be a good natural source of functional materials to prevent diabetic neurodegeneration.