Inhibitory effect of pine extract on α-glucosidase activity and postprandial hyperglycemia

• Published in: Nutrition (Burbank, Los Angeles County, Calif.) Los Angeles County, Calif.), 2005-06, Vol.21 (6), p.756-761
• Main Authors: Kim, Yong-Mu, Jeong, Youn-Kab, Wang, Myeong-Hyeon, Lee, Wi-Young, Rhee, Hae-Ik
• Format: Article
• Language: English
• Subjects: alpha-Amylases - antagonists & inhibitors; alpha-Amylases - metabolism; alpha-glucosidase; alpha-Glucosidases - metabolism; Animals; bark; Biological and medical sciences; Blood Glucose - drug effects; Blood Glucose - metabolism; Body Weight - drug effects; conifer needles; conifers; diabetes mellitus; Diabetes. Impaired glucose tolerance; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; enzyme activity; enzyme inhibition; enzyme inhibitors; Etiopathogenesis. Screening. Investigations. Target tissue resistance; Feeding. Feeding behavior; food conversion; Fundamental and applied biological sciences. Psychology; gene expression; glucose tolerance; glucose transporters; glycemic effect; Glycoside Hydrolase Inhibitors; hyperglycemia; Hyperglycemia - drug therapy; Intestinal Absorption - drug effects; long term effects; Medical sciences; medicinal properties; metabolic diseases; metabolic syndrome; Mice; Mice, Obese; nutrition-genotype interaction; Obesity - drug therapy; Phytotherapy; Pinus - chemistry; Pinus sp; plant extracts; Plant Extracts - pharmacology; Plant Extracts - therapeutic use; Postprandial hyperglycemia; Postprandial Period; postprandial state; Random Allocation; Vertebrates: anatomy and physiology, studies on body, several organs or systems; weight gain; α-glucosidase inhibitor
• ISSN: 0899-9007; 1873-1244
• DOI: 10.1016/j.nut.2004.10.014

This study investigated the inhibitory effect of pine bark extract (PBE) and needle extract on carbohydrate-hydrolyzing enzymes and the hypoglycemic effect in diabetic mice ( Lep ob [ ob/ob]). Pine bark and needle were dried and then placed in ethanol, and the extracts were assayed for the measurement of inhibition mode of PBE against α-amylase (EC 3.2.1.1) and α-glucosidase (EC 3.2.1.20). We also investigated the effect of long-term treatment with extracts on levels of postprandial blood glucose, body weight, food efficiency ratio, and gene expression of glucose transporter-4 in quadriceps muscle in diabetic mice ( Lep ob [ ob/ob]). The PBE showed competitive inhibition against salivary α-amylase and the combination of non-competitive and uncompetitive inhibition against yeast α-glucosidase. In animal experiments, PBE effectively suppressed the increase of postprandial blood glucose level by delaying absorption of diet, and body weights of the group that received PBE were significantly lower than that in the group administered 0.5% carboxylmethyl cellulose (control) 21 d after administration. PBE can be used to suppress postprandial hyperglycemia of diabetic patients. It also can be applied for control of obesity by decreasing the food efficiency ratio, especially carbohydrates.