• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.6
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• pp.774-781
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• 2012

This study investigated dose-response effects of chlorogenic acid (CA) on glucose metabolism and the antioxidant system in streptozotocin (STZ)-induced diabetic mice with a high-fat diet (HFD). Male ICR mice were fed with a HFD (37% calories from fat) for 4 weeks prior to intraperitoneal injection with STZ (100 mg/kg body weight). Diabetic mice were supplemented with two doses of CA (0.02% and 0.05%, wt/wt) for 6 weeks. Both doses of CA significantly improved fasting blood glucose level, glucose tolerance and insulin tolerance without any changes in plasma insulin and C-peptide levels. Plasma leptin concentration was significantly higher in the CA-supplemented groups than in the diabetic control group. Both doses of CA significantly increased hepatic glucokinase activity and decreased glucose-6-phosphatase activity compared to the diabetic control group. The ratio of glucokinase/glucose-6-phosphatase was dose-independently higher in CA-supplemented mice than in diabetic control mice. CA supplementation dose-independently elevated superoxide dismutase and catalase activities, whereas it lowered lipid peroxide levels compared to the diabetic control mice in the liver and erythrocyte. These results suggest that low-dose CA may be used as a hypoglycemic agent in a high-fat diet and STZ-induced diabetic mice.

• The Korea Journal of Herbology
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• v.32 no.2
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• pp.25-32
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• 2017

Objectives : This study was conducted to investigate candidate materials as anti-inflammatory agent from extracts of Korean medicinal plants in Hwaak mountain. Ligustrum obtusifolium (LO) is a Korea medicinal plants that commonly used for robustness and hemostasis. It has been reported that LO has exhibited anti-ischemic, anti-oxidative, anti-hypolipidemic, anti-tumor and hypoglycemic effects. However, LO has not been previously reported to have an anti-inflammatory effect. Therefore, we have evaluated the anti-inflammatory effects of LO and its underlying molecular mechanisms in LPS-induced RAW 264.7 macrophages. Methods : Cell viability was determined by MTT assay in RAW 264.7 macrophages. Nitric Oxide (NO) was measured with Griess reagent and pro-inflammatory cytokines were detected by ELISA in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Protein expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and p65 subunit of nuclear $factor-{\kappa}B$ ($NF-{\kappa}B$) were determined by Western blot analysis. Results : Among 15 extracts of Korean medicinal plants tested, Ligustrum obtusifolium (LO) showed the inhibition of NO production without cytotoxicity. LO reduced the expression levels of iNOS and COX-2 proteins in LPS-simulated RAW 264.7 macrophages in dose-dependent manner. Consistent with these data, LO inhibited the productions of $TNF-{\alpha}$, IL-6, and $IL-1{\beta}$ in LPS-simulated RAW 264.7 macrophages. Furthermore, LO attenuated the LPS-induced nuclear translocation of p65 $NF-{\kappa}B$ in RAW 264.7 macrophages involving suppression of $NF-{\kappa}B$ activation. Conclusions : Taken together, these results suggest that the anti-inflammatory effects of LO is associated with regulation of inflammatory mediators via inhibition of $NF-{\kappa}B$ activation in LPS-treated RAW 264.7 macrophages.

• 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 Ginseng Research
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• v.26 no.4
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• pp.191-195
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• 2002

In this study, we like to examine whether Panax ginseng water extract (PGWE) exerts antidiabetic activities in prevention and treatment modes in multiple low dose (MLD) streptozotocin (STZ) (20 mg/kg i.p injection for 5 days) induced diabetic SD rats. In the prevention mode,150 mg/kg of GRWE was administered intraperitoneally with STG for 3 weeks, and this group is called CO 150. In the treatment mode, we started to administer the same dose of PGWE on day 8 and for 3 weeks, and this group is called POST150. PGWE exerted significant hypoglycemic activities in both prevention (normal control, 97 ${\pm}$ 6 mg/dl; diabetic control, 331${\pm}$23; CO150, 211${\pm}$37) and treatment groups (normal control, 128${\pm}$4 mg/dl; diabetic control, 392${\pm}$33: POST150, 263${\pm}$44). Of great importance is the fact that plasma insulin levels in both groups were markedly increased as compared to the diabetic control (normal control,428.7${\pm}$62.1 pg/dl; diabetic control, 167.0${\pm}$91.7; CO150, 377.6${\pm}$68.7 in prevention mode, and in treatment mode normal control 417.9${\pm}$84.6 pg/dl; diabetic control, 166.1${\pm}$104.7; POST150, 315.2${\pm}$47.4). Blood glucose levels were closely associated with plasma insulin levels, and this result may suggest that PGWE showed the activity to enhance insulin secretion as well as preventing destruction of pancreatic islet cells. Food and water intakes were also determined at the last week of treatment i n both groups. Characteristic symptoms of diabetes were significantly improved in both groups. In the prevention mode, water intake (ml/rat/day) in normal control was increased from 30.6${\pm}$1.5 to 122.2${\pm}$3.4 in diabetic control rats. In the CO150-treated group, water intake was dramatically reduced to 68.3${\pm}$4.4 (p<0.001 vs. diabetic control). In the treatment mode, POST-treated group also reduced the water intake from 128.9${\pm}$2.2 to 113.3${\pm}$1.7. Taken together, our data suggest that PGWE showed comparable antidiabetic activities in prevention and treatment modes. Therefore, PGWE may have a potential as a prophylactic as well as therapeutic agent fur type 2 diabetes mellitus (T2DM).