Partially purified white bean amylase inhibitor reduces starch digestion in vitro and inactivates intraduodenal amylase in humans

  • Peter Layer
    Gastroenterology Unit, Mayo Clinic and Foundation, Rochester, Minnesota, USA

    S. C. Johnson and Son, Inc., Racine, Wisconsin, USA
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  • Gerald L. Carlson
    Gastroenterology Unit, Mayo Clinic and Foundation, Rochester, Minnesota, USA

    S. C. Johnson and Son, Inc., Racine, Wisconsin, USA
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  • Eugene P. Dimagno
    Address requests for reprints to: Eugene P. DiMagno, M.D., G.I. Diagnostic Unit, Mayo Clinic and Foundation, Rochester, Minnesota 55905.
    Gastroenterology Unit, Mayo Clinic and Foundation, Rochester, Minnesota, USA

    S. C. Johnson and Son, Inc., Racine, Wisconsin, USA
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      Whether commercial, bean-derived α-amylase inhibitor preparations failed to decrease starch digestion in humans because of insufficient antiamylase activity, destruction by gastrointestinal secretions, or decreased activity in the presence of starch is unknown. We used a simple partial purification procedure to markedly concentrate the inhibitor (sixfold to eightfold by total protein content, and 30–40-fold by dry weight). Compared with a commercial preparation and crude bean extract, this partially purified inhibitor inactivated intraduodenal, intraileal, and salivary amylase in vitro faster and more completely (p < 0.001); its specific activity was not affected by exposure to gastric juice and was only minimally reduced by duodenal juice. Whereas the rate of amylase inhibition by inhibitor was markedly slowed in the presence of nondietary liquid starch, dietary solid starch had only a minimal effect. Consequently, the partially purified inhibitor had no effect on liquid starch digestion, but decreased in vitro digestion of dietary starch in a dose-dependent manner (p < 0.001). Perfusion of the partially purified inhibitor (2.0, 3.5, or 5.0 mg/ml at 5 ml/min) into the duodenum of humans rapidly inhibited >94%, >99%, or >99.9% of intraluminal amylase activity. We conclude that commercial amylase inhibitors failed to decrease starch digestion in vivo mainly because they have insufficient antiamylase activity. However, a partially purified inhibitor with increased specific activity is stable in human gastrointestinal secretions, slows dietary starch digestion in vitro, rapidly inactivates amylase in the human intestinal lumen, and, at acceptable oral doses, may decrease intraluminal digestion of starch in humans. Such an inhibitor therefore deserves study.
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        • Kneen E
        • Sandstedt RM
        An amylase inhibitor from certain cereals (lett).
        J Am Chem Soc. 1943; 65: 1247
        • Bowman DE
        Amylase inhibitor of navy beans.
        Science. 1945; 102: 358-359
        • Puls W
        • Keup U
        Influence of an alpha-amylase inhibitor (BAY d 7791) on blood glucose, serum insulin and NEFA in starch loading tests in rats, dogs and man.
        Diabetologia. 1973; 9: 97-101
        • Marshall JJ
        • Lauda CM
        Purification and properties of phaseolamin, an inhibitor of alpha-amylase, from the kidney bean, Phaseolus vulgaris.
        J Biol Chem. 1975; 250: 8030-8037
        • Powers JR
        • Whitaker JR
        Purification and some physical and chemical properties of red kidney bean (Phaseolus vulgaris) alpha-amylase inhibitor.
        J Food Biochem. 1977; 1: 217-238
        • Powers JR
        • Whitaker JR
        Effect of several experimental parameters on combination of red kidney bean (Phaseolus vulgaris) alpha-amylase inhibitor with porcine pancreatic alpha-amylase.
        J Food Biochem. 1977; 1: 239-260
        • Bo-Linn GW
        • SantaAna CA
        • Morawski SG
        • Fordtran JS
        Starch blockers—their effect on calorie absorption from a high starcmeal.
        N Engl J Med. 1982; 307: 1413-1416
        • Carlson GL
        • Li BUK
        • Bass P
        • Olsen WA
        A bean alpha-amylase inhibitor formulation (starch blocker) is ineffective in man.
        Science. 1983; 219: 393-395
        • Hollenbeck CB
        • Coulston AM
        • Quan R
        • et al.
        Effects of a commercial starch blocker preparation on carbohydrate digestion and absorption: in vivo and in vitro studies.
        Am J Clin Nutr. 1983; 38: 498-503
        • Garrow JS
        • Scott PF
        • Heels S
        • Nair KS
        • Halliday D
        Starch blockers are ineffective in man.
        Lancet. 1983; i: 60-61
        • Rosenberg IH
        Starch-blockers—still no calorie-free lunch.
        N Engl J Med. 1982; 307: 1444-1445
        • DiMagno EP
        • Go VLW
        • Summerskill WHJ
        Relations between pancreatic enzyme outputs and malabsorption in severe pancreatic insufficiency.
        N Engl J Med. 1973; 288: 813-815
        • French D
        Chemistry and biochemistry of starch.
        in: 2nd ed. MTP international review of science, biochemistry. Series. Vol 5.. Butterworths, London1975: 269-335
        • Jenkins DFA
        • Wolever TMS
        • Taylor RH
        • et al.
        Rate of digestion of foods and postprandial glycaemia in normal and diabetic subjects.
        Br Med J. 1980; 281: 14-17
        • Keane FB
        • DiMagno EP
        • Malagelada J-R
        Duodenogastric reflux in humans: its relationship to fasting antroduodenal motility and gastric, pancreatic, and biliary secretion.
        Gastroenterology. 1981; 81: 726-731
        • Go VLW
        • Hofmann AF
        • Summerskill WHJ
        Simultaneous measurements of total pancreatic, biliary, and gastric outputs in man using a perfusion technique.
        Gastroenterology. 1970; 58: 638
        • Lowry OH
        • Rosebrough NJ
        • Farr AL
        • Randall RJ
        Protein measurement with the Folin phenol reagent.
        J Biol Chem. 1951; 193: 265-275
        • Bondar RFL
        • Mead D
        Evaluation of glucose-b-phosphate dehydrogenase from leucostoc mesenteroides in the hexokinase method for determining glucose in serum.
        Clin Chem. 1974; 20: 586-590
        • Bird R
        • Hopkins RH
        The action of some alpha-amylases on amylase.
        Biochem J. 1954; 56: 86-99
        • Solomons NW
        • Hamilton NH
        • Christman NT
        • Rothman D
        Evaluation of a rapid breath hydrogen analysis for clinical studies of carbohydrate absorption.
        Dig Dis Sci. 1983; 28: 397-404
        • Box GEP
        • Hunter WG
        • Hunter JS
        Statistics for experimenters.
        in: John Wiley & Sons, New York1978: 306-342
        • Gray GM
        Carbohydrate digestion and absorption. Role of the small intestine.
        N Engl J Med. 1975; 292: 1225-1230
        • Regan PT
        • Malagelada J-R
        • DiMagno EP
        • Go VLW
        Rationale for the use of cimetidine in pancreatic insufficiency.
        in: 2nd ed. Mayo Clin Proc. 53. 1978: 79-83
        • Regan PT
        • Malagelada J-R
        • DiMagno EP
        • Go VLW
        Postprandial gastric function in pancreatic insufficiency.
        Gut. 1979; 20: 249-254
        • Malagelada J-R
        • Go VLW
        • Summerskill WHJ
        Different gastric, pancreatic and biliary responses to solid-liquid or homogenized meals.
        Dig Dis Sci. 1979; 24: 101-110
        • Anderson IH
        • Levine AS
        • Levitt MD
        Incomplete absorption of the carbohydrate in all-purpose wheat flour.
        N Engl J Med. 1981; 304: 891-892
        • Levine AS
        • Levitt MD
        Malabsorption of starch moiety of oats, corn and potatoes (abstr).
        Gastroenterology. 1981; 80: 1209
        • Stephen AM
        • Haddad AC
        • Phillips SF
        Passage of carbohydrate into the colon.
        Gastroenterology. 1983; 85: 589-595
        • Bond Jr, JH
        • Levitt MD
        Fate of soluble carbohydrate in the colon of rats and man.
        J Clin Invest. 1976; 57: 1158-1164
        • Argenzio RA
        • Southworth M
        • Lowe JE
        • Stevens CE
        Interrelationships of Na, HCO3 and volatile fatty acid transport by equine large intestine.
        Am J Physiol. 1977; 233: E469-E478
        • Kim K-I
        • Jewell DE
        • Benevenga NJ
        • Grummer RH
        The fraction of dietary lactose available for fermentation in the cecum and colon of pigs.
        J Anim Sci. 1978; 46: 1658-1665
        • Bond JH
        • Currier BE
        • Buchwald H
        • Levitt MD
        Colonic conservation of malabsorbed carbohydrate.
        Gastroenterology. 1980; 78: 444-447
        • Ruppin H
        • Bar-Meir S
        • Soergel KH
        • Wood CM
        • Schmitt Jr, MG
        Absorption of short-chain fatty acids by the colon.
        Gastroenterology. 1980; 78: 1500-1507
        • Stephen AM
        • Cummings JH
        The microbial contribution to human faecal mass.
        J Med Microbiol. 1980; 13: 45-56
        • O'Dea K
        • Snow P
        • Nestel P
        Rate of starch hydrolysis in vitro as a predictor of metabolic response to complex carbohydrate in vivo.
        Am J Clin Nutr. 1981; 34: 1991-1993