Effects of grape seed extract and its ethylacetate/ethanol fraction on blood glucose levels in a model of type 2 diabetes

Abstract

The present study observed the effects of grape seed extract (GSE) and its ethylacetate (E) and ethylacetate/ethanol (EE) fractions on blood glucose levels in C57BL/KsJ-lepr(db)/lepr(db) (db/db) mice at 4-12 weeks of age. In the GSE- and EE fraction-treated db/db group, the blood glucose concentration began to be lower than that in the vehicle-treated db/db group at 6 weeks after treatment, while the blood glucose concentration in the E fraction-treated db/db group was similar to that in the vehicle-treated db/db group. The glycosylated hemoglobin (HbA1c) level in the vehicle-treated db/db groups was 9.3%, whereas HbA1c levels in the GSE- and EE fraction-treated db/db group decreased significantly to 5.7% and 6.1%, respectively, at 8 weeks after treatment. However, administration of GSE and its EE fraction did not show any significant effects on body weights and food consumption in db/db mice. These results suggest that GSE and its EE fraction have a potential to decrease the blood glucose and HbA1c level, which is applicable to good healthy foods for reducing blood glucose levels.

Hypocholesterolemic activity of grape seed proanthocyanidin is mediated by enhancement of bile acid excretion and up-regulation of CYP7A1

“…GSP has been a subject of the extensive investigations for its various biological activities. It has been reported that GSP is anti-atherosclerosis [1,2], anti-carcinogenesis [3], hypotensive [4] anti-lipogenesis [5], antioxidant [6,7] and antihyperglycemic [8]. GSP has been shown to be hypocholesterolemic in both humans and animals [1,9], although the underlying mechanism remains poorly understood.…”

Microwave‐assisted aqueous two‐phase extraction of phenolics from grape (Vitis vinifera) seed

“…GSEs are usually extracted using conventional organic solvents, and studies have been conducted to determine the effect of extraction solvent on the phenolic antioxidant activity of GSEs . The traditional method requires a large amount of solvent and prolonged extraction time.…”

Oligomeric Cocoa Procyanidins Possess Enhanced Bioactivity Compared to Monomeric and Polymeric Cocoa Procyanidins for Preventing the Development of Obesity, Insulin Resistance, and Impaired Glucose Tolerance during High-Fat Feeding

“…Hwang et al investigated the effects of GSE in genetically modified mice with T2D 89 . After a daily oral administration of 50 mg/kg*BW GSE, a significant reduction in blood glucose levels began to occur in mice at 4 weeks compared to the control group and this significance steadily increased in magnitude throughout the 8 week study 89 . Moreover, 8 weeks of this GSE treatment effectively reduced mice HbA1c levels to 5.7% compared to the control group level of 9.3% 89 .…”

“…In the same respect, research specifically evaluating the beneficial attributes of polyphenols derived from materials such as GSE is also extensive. GSE-derived polyphenols have been shown to combat obesity and T2D by alleviating HF DIO, decreasing blood glucose and insulin resistance, and reducing the expression of obesity biomarkers [89][90][91][92][93] . In contrast, studies of the anti-obesity and anti-diabetic effects of cocoa polyphenols are comparatively few.…”