• Food Science and Preservation
• /
• v.19 no.1
• /
• pp.123-130
• /
• 2012

In this study, 80% ethanolic extracts of tartary and common buckwheats were assessed for their total phenol content, total flavonoids content, antioxidant activity (DPPH, ABTS radical scavenging activity and reducing power), and anti-adipogenic effects. Our results show that total phenol contents of 80% ethanolic extract from tartary and common buckwheats were $17.35{\pm}0.41$ and $8.20{\pm}0.28\;{\mu}g$ GAE/g, respectively. Antioxidant activities of 80% ethanolic extract from tartary buckwheat were significantly higher than that of common buckwheat extract (p<0.05). During adipocyte differentiation, 80% ethanolic extracts of tartary and common buckwheat significantly inhibited lipid accumulation compared to control cells. We further evaluated the effect of buckwheat extracts on the changes of key gene expression associated with 3T3-L1 adipogenesis and ROS production. Tartary buckwheat extract was more suppressed the mRNA expressions ($PPAR{\gamma}$ and aP2) than that of common buckwheat extract. Moreover, tartary buckwheat inhibited the mRNA expression of both NOX4 (NADPH oxidase 4) and G6PDH (glucose-6-phosphate dehydrogenase). These results indicate that anti-adipogenesis effect of tartary buckwheat can be attributed to phenolic compound that may potentially inhibit ROS production.

• Journal of Ginseng Research
• /
• v.31 no.2
• /
• pp.79-85
• /
• 2007

Compound K (CK) is a final metabolite of panaxadiol ginsenosides. Although panax ginseng is known to have anti-diabetic activity, the active ingredient is not yet fully identified. Therefore, it would be interesting to know whether and how CK has an anti-diabetic activity. First, insulin secretion-stimulating activity of CK was examined using RIN-m5F cell line and primary cultured islets. CK enhanced the insulin secretion in a concentration dependent manner. This effect, however, was almost completely abolished in the presence of diazoxide, $K^+$ channel opener, indicating that the insulin secretion-stimulating activity of CK is presumably due to blockade of ATP sensitive $K^+$ channel. In addition, effects of CK on gene expressions of hepatic enzymes (phosphoenolpyruvate carboxykinase[PEPCK], glucose-6-phos-phatase[G6Pase]) and on adipocyte differentiation in H4IIE and 3T3-Ll cells, respectively, were examined. CK suppressed the induction of PEPCK and G6Pase mRNA expressions under the dexamethasone/cAMP stimulation condition. CK also reduced the $PPAR-{\gamma}$ mRNA expression and triglyceride accumulation in a dose dependent manner as compared to the control. The present study suggests that CK deserves to examine whether it shows an anti-diabetic activity in animal and human studies.