Studies on the extraction of pumpkin components and their biological effects on blood glucose of diabetic mice

Pumpkin crude extract (PCE) was extracted from pumpkin powder with water and 95% ethanol at 60 degrees C. Several components were isolated and further purified by solvents purification and dialysis as well as column chromatography. The anti-diabetic activities of the hypoglycemic components extracted from pumpkin were identified using diabetic model mice which were induced by alloxan intraperitoneal injection. The diabetic mice were treated with pumpkin extracts by intraperitoneal injection at dosages of 100, 200 and 400 mg/kg body weight. Blood samples for glucose assays were taken from the diabetic mice before injection and 4, 7 and 11 hours after injection. The results showed that the blood glucose levels in the diabetic mice were significantly reduced by PCE-C from 15.32 +/- 4.38 mM to 5.77 +/- 1.46 mM (p < 0.001) in 7 hours. PCE-C was further purified by deproteinization, dialysis and Sephadex G-100 column chromatography and a fraction as PCE-F was collected. Seven hours after PCE-F injection at a dosage of 200 mg/kg body weight, blood glucose levels dropped significantly from 15.90 +/- 3.21 mM to 7.19 +/- 2.54 mM (p < 0.01). PCE-F was identified by gas chromatography as a polysaccharide consisting of heterogeneous monosaccharides, such as glucose, galactose, arabinose and rhamnose. Copyright (C) 2013, Food and Drug Administration, Taiwan. Published by Elsevier Taiwan LLC. All rights reserved.