Inhibitory effect of pine extract on alpha-glucosidase activity and postprandial hyperglycemia.
OBJECTIVE
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]).


METHODS
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 alpha-amylase (EC 3.2.1.1) and alpha-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]).


RESULTS
The PBE showed competitive inhibition against salivary alpha-amylase and the combination of non-competitive and uncompetitive inhibition against yeast alpha-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.


CONCLUSIONS
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.
Kim
Yong-Mu
YM
Division of Biotechnology, Kangwon National University, Chunchon, Korea.
Jeong
Youn-Kab
YK
Wang
Myeong-Hyeon
MH
Lee
Wi-Young
WY
Rhee
Hae-Ik
HI
D000818:Animals; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism; D001835:Body Weight / Q000187:drug effects; D065089:Glycoside Hydrolase Inhibitors; D006943:Hyperglycemia / Q000188:drug therapy*; D007408:Intestinal Absorption / Q000187:drug effects; D051379:Mice; D008820:Mice, Obese; D009765:Obesity / Q000188:drug therapy*; D008517:Phytotherapy; D028223:Pinus / Q000737:chemistry*; D010936:Plant Extracts / Q000494:pharmacology* / Q000627:therapeutic use; D019518:Postprandial Period; D011897:Random Allocation; D000516:alpha-Amylases / Q000037:antagonists & inhibitors / Q000378:metabolism; D000520:alpha-Glucosidases / Q000378:metabolism
D001786:Blood Glucose; D065089:Glycoside Hydrolase Inhibitors; D010936:Plant Extracts; D000516:alpha-Amylases; D000520:alpha-Glucosidases