A Bean α-Amylase Inhibitor Formulation (Starch Blocker) Is Ineffective in Man

Gl, Carlson; Li, Bu; Bass, Paul; Wa, Olsen

doi:10.1126/science.6184780

Cited by 58 publications

(22 citation statements)

References 14 publications

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“…162 Studies performed in humans have shown contradictory results. For instance, three studies have failed to show any measurable inhibition of starch hydrolysis or significant weight loss in vivo, 155,[163][164][165] suggesting either the existence of an alternate route capable of degrading starch or insufficient amounts of inhibitors reaching the substrate. Subsequent studies showed that intraduodenal administration of the partially purified inhibitor significantly inhibited α-amylase activity during the ingestion of a starch diet.…”

Section: Phaseolus Vulgaris Lmentioning

confidence: 99%

The role of lipid and carbohydrate digestive enzyme inhibitors in the management of obesity: a review of current and emerging therapeutic agents

Tucci¹

2010

DMSO

117

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Section: Phaseolus Vulgaris Lmentioning

confidence: 99%

The role of lipid and carbohydrate digestive enzyme inhibitors in the management of obesity: a review of current and emerging therapeutic agents

Tucci¹

2010

DMSO

117

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“…The consumption of ␣AI-1 protein (marketed as a weight-loss aid in the United States in the 1980s) by humans (35,36) or rats (37) also has been shown to have no effect on their carbohydrate metabolism. Several factors probably contribute to the lack of inhibition in mammals: the inhibitor may be inactivated by gastric juices (35), the pH optimum for inhibition is lower (pH 4.5-5.0) than the pH that prevails in the duodenum (pH 6-7) (38), and ␣-amylase is produced in vast excess in the human gut (39). We therefore are proceeding with the further development of pea weevil-resistant peas containing the bean ␣AI-1 protein.…”

Section: Relationship Between Inhibitor Effectiveness In the Field Trmentioning

confidence: 99%

Bean α-amylase inhibitor 1 in transgenic peas ( Pisum sativum ) provides complete protection from pea weevil ( Bruchus pisorum ) under field conditions

Morton

Schroeder

Bateman

et al. 2000

Proc. Natl. Acad. Sci. U.S.A.

237

125

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Two ␣-amylase inhibitors, called ␣AI-1 and ␣AI-2, that share 78% amino acid sequence identity and have a differential specificity toward mammalian and insect ␣-amylases are present in different accessions of the common bean (Phaseolus vulgaris). Using greenhouse-grown transgenic peas (Pisum sativum), we have shown previously that expression of ␣AI-1 in pea seeds can provide complete protection against the pea weevil (Bruchus pisorum). Here, we report that ␣AI-1 also protects peas from the weevil under field conditions. The high degree of protection is explained by our finding that ␣AI-1 inhibits pea bruchid ␣-amylase by 80% over a broad pH range (pH 4.5-6.5). ␣AI-2, on the other hand, is a much less effective inhibitor of pea bruchid ␣-amylase, inhibiting the enzyme by only 40%, and only in the pH 4.0 -4.5 range. Nevertheless, this inhibitor was still partially effective in protecting field-grown transgenic peas against pea weevils. The primary effect of ␣AI-2 appeared to be a delay in the maturation of the larvae. This contrasts with the effect of ␣AI-1, which results in larval mortality at the first or second instar. These results are discussed in relationship to the use of amylase inhibitors with different specificities to bring about protection of crops from their insect pests or to decrease insect pest populations below the economic injury level.

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“…Carlson et al (1983) found that despite high in vitro activity of a bean amylase inhibitor, in humans, glycemic response was not reduced by addition of the amylase inhibitor supplement to a high starch meal. Similarly, Bo-Linn et al (1982) found that calories absorbed were not reduced by amylase inhibitor supplements given in conjunction with a high starch meal.…”

Section: Resultsmentioning

confidence: 99%

“…In order to function as an inhibitor of intestinal digestive enzymes in vivo, a protein must survive gastric digestion. Several studies found high in vitro inhibitory activities, but then failed to find the same inhibitory activities in vivo (Bo-Linn et al 1982; Carlson et al 1983), possibly due to susceptibility of the inhibitor to digestion. Therefore, in this study, extracts were subjected to in vitro gastric digestion prior to assaying for amylase inhibitory activity.…”

Section: Introductionmentioning

confidence: 99%

Susceptibility of sweet potato (Ipomoea batatas) peel proteins to digestive enzymes

Maloney

Trương

Allen

2014

Food Science & Nutrition

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Sweet potato proteins have been shown to possess antioxidant and antidiabetic properties in vivo. The ability of a protein to exhibit systemic effects is somewhat unusual as proteins are typically susceptible to digestive enzymes. This study was undertaken to better understand how digestive enzymes affect sweet potato proteins. Two fractions of industrially processed sweet potato peel, containing 6.8% and 8.5% protein and 80.5% and 83.3% carbohydrate, were used as a source of protein. Sweet potato proteins were incubated with pepsin, trypsin, and chymotrypsin and protein breakdown was visualized with SDS-PAGE. After pepsin digestion, samples were assayed for amylase inhibitory activity. Sporamin, the major storage protein in sweet potatoes, which functions as a trypsin inhibitor as well, exhibited resistance to pepsin, trypsin, and chymotrypsin. Sporamin from blanched peel of orange sweet potatoes was less resistant to pepsin digestion than sporamin from outer peel and from extract of the white-skinned Caiapo sweet potato. Trypsin inhibitory activity remained after simulated gastric digestion, with the Caiapo potato protein and peel samples exhibiting higher inhibitory activity compared to the blanched peel sample. Amylase and chymotrypsin inhibitory activity was not present in any of the samples after digestion.

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A Bean α-Amylase Inhibitor Formulation (Starch Blocker) Is Ineffective in Man

Cited by 58 publications

References 14 publications

The role of lipid and carbohydrate digestive enzyme inhibitors in the management of obesity: a review of current and emerging therapeutic agents

The role of lipid and carbohydrate digestive enzyme inhibitors in the management of obesity: a review of current and emerging therapeutic agents

Bean α-amylase inhibitor 1 in transgenic peas ( Pisum sativum ) provides complete protection from pea weevil ( Bruchus pisorum ) under field conditions

Susceptibility of sweet potato (Ipomoea batatas) peel proteins to digestive enzymes

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