title: The effects of L-arabinose on intestinal sucrase activity: dose-response studies in vitro and in humans.
abstract: BACKGROUND
  On the basis of results in cell cultures, rodents, and pigs, l-arabinose may inhibit intestinal sucrase activity and thereby delay sucrose digestion.
  
  
  OBJECTIVE
  The objective was to investigate the dose-response effects of l-arabinose on intestinal sucrase activity in vitro and glucose tolerance, appetite, and energy intake in humans.
  
  
  METHODS
  In vitro, Caco-2 cells were cultured for 21 d, homogenized, and used as an enzyme preparation with sucrose as substrate in concentrations from 7 to 280 mmol/L with 0.84, 1.4, and 2.8 mmol l-arabinose/L as inhibitor. Released glucose was measured after 30 min. In the human studies, 15 healthy men participated in a randomized, double-blind, crossover study. Sucrose beverages (75 g in 300 mL) supplemented with 0%, 1.3%, 2.7%, and 4% by weight of l-arabinose were tested at breakfast. Blood for the measurement of glucose, insulin, C-peptide, incretin hormones, and triacylglycerol was collected under fasting conditions and for 3 h postprandially. Postprandial appetite sensations and energy intake at lunch were registered.
  
  
  RESULTS
  In vitro, the addition of l-arabinose resulted in uncompetitive inhibition of sucrase activity. In the human studies, supplementation with 4% l-arabinose produced an 11% lower glucose peak, a 33% lower and delayed insulin peak, a 23% reduction in the incremental area under the curve (iAUC) for insulin, a 23% lower and delayed C-peptide peak, a 9% reduction in the iAUC for C-peptide, a 53% increase in the iAUC for glucagon-like peptide-1 (GLP-1), and a 28% reduction in the iAUC for glucose-dependent insulinotropic polypeptide. No effects on triacylglycerol, gastrointestinal symptoms, appetite ratings, or energy intake were observed.
  
  
  CONCLUSIONS
  l-Arabinose inhibits sucrase activity from Caco-2 cells; 4% l-arabinose in sucrose beverages reduces postprandial glucose, insulin, and C-peptide responses and enhances the GLP-1 response in humans without gastrointestinal adverse effects. This trial is registered at clinicaltrials.gov as NCT00302302.
authors.affiliation: Department of Human Nutrition, University of Copenhagen, Frederiksberg C, Denmark.
authors.forename: Inger
authors.initials: I
authors.lastname: Krog-Mikkelsen
authors.forename: Ole
authors.initials: O
authors.lastname: Hels
authors.forename: Inge
authors.initials: I
authors.lastname: Tetens
authors.forename: Jens Juul
authors.initials: JJ
authors.lastname: Holst
authors.forename: Jens Rikardt
authors.initials: JR
authors.lastname: Andersen
authors.forename: Klaus
authors.initials: K
authors.lastname: Bukhave
mesh_terms: D001089:Arabinose / Q000494:pharmacology*; D002096:C-Peptide / Q000032:analysis; D018938:Caco-2 Cells; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005749:Gastric Inhibitory Polypeptide / Q000097:blood; D052216:Glucagon-Like Peptide 1 / Q000097:blood; D006801:Humans; D007328:Insulin / Q000097:blood; D007422:Intestines / Q000187:drug effects* / Q000201:enzymology*; D008297:Male; D013393:Sucrase / Q000037:antagonists & inhibitors* / Q000378:metabolism
chemical_list: D002096:C-Peptide; D007328:Insulin; D005749:Gastric Inhibitory Polypeptide; D052216:Glucagon-Like Peptide 1; D001089:Arabinose; D013393:Sucrase