L-arabinose selectively inhibits intestinal sucrase in an uncompetitive manner and suppresses glycemic response after sucrose ingestion in animals

Metabolism. 1996 Nov;45(11):1368-74. doi: 10.1016/s0026-0495(96)90117-1.

Abstract

The objective of this study was to investigate the effects of L-arabinose on intestinal alpha-glucosidase activities in vitro and to evaluate its effects on postprandial glycemic responses in vivo. L-Arabinose inhibited the sucrase activity of intestinal mucosa in an uncompetitive manner (Ki, 2 mmol/L). Neither the optical isomer D-arabinose nor the disaccharide L-arabinobiose inhibited sucrase activity, whereas D-xylose was as potent as L-arabinose in inhibiting this activity. L-Arabinose and D-xylose showed no inhibitory effect on the activities of intestinal maltase, isomaltase, trehalase, lactase, and glucoamylase, or pancreatic amylase. In contrast, a known alpha-glucosidase inhibitor, acarbose, competitively inhibited (Ki, 1.1 mumol/L) sucrase activity and also inhibited intestinal maltase, glucoamylase, and pancreatic amylase. L-Arabinose suppressed the increase of blood glucose after sucrose loading dose-dependently in mice (ED50, 35 mg/kg), but showed no effect after starch loading. The suppressive effect of D-xylose on the increase of blood glucose after sucrose loading was 2.4 times less than that of L-arabinose, probably due to intestinal absorption of the former. Acarbose strongly suppressed glycemic responses in both sucrose loading (ED50, 1.1 mg/kg) and starch loading (ED50, 1.7 mg/kg) in mice. L-Arabinose suppressed the increase of plasma glucose and insulin in rats after sucrose loading, the suppression of the former being uninterruptedly observed in mice for 3 weeks. Thus, the results demonstrated that L-arabinose selectively inhibits intestinal sucrase activity in an uncompetitive manner and suppresses the glycemic response after sucrose ingestion by inhibition of sucrase activity.

MeSH terms

  • Acarbose
  • Amylases / antagonists & inhibitors
  • Animals
  • Arabinose / metabolism
  • Arabinose / pharmacology*
  • Blood Glucose / analysis*
  • Glycoside Hydrolase Inhibitors
  • Insulin / blood
  • Intestinal Mucosa / enzymology*
  • Male
  • Mice
  • Mice, Inbred ICR
  • Rats
  • Rats, Wistar
  • Sucrase / antagonists & inhibitors*
  • Sucrose / pharmacology*
  • Swine
  • Trisaccharides / pharmacology
  • Xylose / pharmacology
  • Xylose / urine

Substances

  • Blood Glucose
  • Glycoside Hydrolase Inhibitors
  • Insulin
  • Trisaccharides
  • Sucrose
  • Xylose
  • Arabinose
  • Amylases
  • Sucrase
  • Acarbose