Character of a wheat amylase inhibitor preparation and effects on fasting human pancreaticobiliary secretions and hormones.

Abstract

Amylase inhibition induces carbohydrate tolerance, satiety, and weight loss and prolongs gastric emptying, effects that may be useful in the treatment of obesity and non-insulin-dependent diabetes mellitus. The aim of this study was to determine (1) purity of a wheat amylase inhibitor preparation, (2) intraduodenal concentration of the wheat amylase inhibitor preparation that inhibits > 90% amylase activity (which causes carbohydrate malabsorption), and (3) if the inhibitor alters pancreaticobiliary secretions or intraluminal pH. High-performance liquid chromatography followed by electrophoresis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis were used for characterization. Groups of 3 subjects received intraduodenal infusions of 3.0, 4.5, or 6.0 mg/mL of the inhibitor for 90 minutes during the middle of a 270-minute essential amino acid solution infusion (which stimulates 50% maximal pancreatic enzyme secretion). Pancreatic enzyme and bile acid delivery to the duodenum were measured for a 270-minute period. The inhibitor is 96% protein, 59% containing 0.19, 0.28, 0.38, and 0.53 inhibitors. The 0.38 inhibitor has the most antipancreatic alpha-amylase activity. The inhibitor reduced amylase activity in the duodenum dose dependently (r = 0.7; P = 0.04); > 4 mg/mL inhibited > 90% amylase activity but did not affect delivery of other enzymes or bile acids to the duodenum or gastric or duodenal pH. The preparation has a high protein purity and a high specific activity against alpha-amylase activity and effectively inhibits human pancreatic amylase activity secreted into the duodenum.