Tags

Type your tag names separated by a space and hit enter

Different polyphenolic components of soft fruits inhibit alpha-amylase and alpha-glucosidase.
J Agric Food Chem. 2005 Apr 06; 53(7):2760-6.JA

Abstract

Polyphenol-rich extracts from soft fruits were tested for their ability to inhibit alpha-amylase and alpha-glucosidase. All extracts tested caused some inhibition of alpha-amylase, but there was a 10-fold difference between the least and most effective extracts. Strawberry and raspberry extracts were more effective alpha-amylase inhibitors than blueberry, blackcurrant, or red cabbage. Conversely, alpha-glucosidase was more readily inhibited by blueberry and blackcurrant extracts. The extent of inhibition of alpha-glucosidase was related to their anthocyanin content. For example, blueberry and blackcurrant extracts, which have the highest anthocyanin content, were the most effective inhibitors of alpha-glucosidase. The extracts most effective in inhibiting alpha-amylase (strawberry and raspberry) contain appreciable amounts of soluble tannins. Other tannin-rich extracts (red grape, red wine, and green tea) were also effective inhibitors of alpha-amylase. Indeed, removing tannins from strawberry extracts with gelatin also removed inhibition. Fractionation of raspberry extracts on Sephadex LH-20 produced an unbound fraction enriched in anthocyanins and a bound fraction enriched in tannin-like polyphenols. The unbound anthocyanin-enriched fraction was more effective against alpha-glucosidase than the original extract, whereas the alpha-amylase inhibitors were concentrated in the bound fraction. The LH-20 bound sample was separated by preparative HPLC, and fractions were assayed for inhibition of alpha-amylase. The inhibitory components were identified as ellagitannins using LC-MS-MS. This study suggests that different polyphenolic components of fruits may influence different steps in starch digestion in a synergistic manner.

Authors+Show Affiliations

McDougall GJ
Quality, Health and Nutrition Programme, Genes to Products Theme, Scottish Crop Research Institute, Invergowrie, Dundee, DD2 5DA, UK. gmcdou@scri.sari.ac.uk
Shpiro F
No affiliation info available
Dobson P
No affiliation info available
Smith P
No affiliation info available
Blake A
No affiliation info available
Stewart D
No affiliation info available

MeSH

AnthocyaninsChromatography, High Pressure LiquidEnzyme InhibitorsFlavonoidsFragariaFruitGlycoside Hydrolase InhibitorsMass SpectrometryPhenolsPlant ExtractsPolyphenolsRosaceaeTanninsalpha-Amylases

Pub Type(s)

Comparative Study
Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

15796622

Clinical Trial Links

Blood Glucose and Body Fat Regulatory Effect of Peanut Skin Extract

Citation

McDougall, Gordon J., et al. "Different Polyphenolic Components of Soft Fruits Inhibit Alpha-amylase and Alpha-glucosidase." Journal of Agricultural and Food Chemistry, vol. 53, no. 7, 2005, pp. 2760-6.
McDougall GJ, Shpiro F, Dobson P, et al. Different polyphenolic components of soft fruits inhibit alpha-amylase and alpha-glucosidase. J Agric Food Chem. 2005;53(7):2760-6.
McDougall, G. J., Shpiro, F., Dobson, P., Smith, P., Blake, A., & Stewart, D. (2005). Different polyphenolic components of soft fruits inhibit alpha-amylase and alpha-glucosidase. Journal of Agricultural and Food Chemistry, 53(7), 2760-6.
McDougall GJ, et al. Different Polyphenolic Components of Soft Fruits Inhibit Alpha-amylase and Alpha-glucosidase. J Agric Food Chem. 2005 Apr 6;53(7):2760-6. PubMed PMID: 15796622.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Different polyphenolic components of soft fruits inhibit alpha-amylase and alpha-glucosidase. AU - McDougall,Gordon J, AU - Shpiro,Faina, AU - Dobson,Patricia, AU - Smith,Pauline, AU - Blake,Alison, AU - Stewart,Derek, PY - 2005/3/31/pubmed PY - 2005/5/19/medline PY - 2005/3/31/entrez SP - 2760 EP - 6 JF - Journal of agricultural and food chemistry JO - J Agric Food Chem VL - 53 IS - 7 N2 - Polyphenol-rich extracts from soft fruits were tested for their ability to inhibit alpha-amylase and alpha-glucosidase. All extracts tested caused some inhibition of alpha-amylase, but there was a 10-fold difference between the least and most effective extracts. Strawberry and raspberry extracts were more effective alpha-amylase inhibitors than blueberry, blackcurrant, or red cabbage. Conversely, alpha-glucosidase was more readily inhibited by blueberry and blackcurrant extracts. The extent of inhibition of alpha-glucosidase was related to their anthocyanin content. For example, blueberry and blackcurrant extracts, which have the highest anthocyanin content, were the most effective inhibitors of alpha-glucosidase. The extracts most effective in inhibiting alpha-amylase (strawberry and raspberry) contain appreciable amounts of soluble tannins. Other tannin-rich extracts (red grape, red wine, and green tea) were also effective inhibitors of alpha-amylase. Indeed, removing tannins from strawberry extracts with gelatin also removed inhibition. Fractionation of raspberry extracts on Sephadex LH-20 produced an unbound fraction enriched in anthocyanins and a bound fraction enriched in tannin-like polyphenols. The unbound anthocyanin-enriched fraction was more effective against alpha-glucosidase than the original extract, whereas the alpha-amylase inhibitors were concentrated in the bound fraction. The LH-20 bound sample was separated by preparative HPLC, and fractions were assayed for inhibition of alpha-amylase. The inhibitory components were identified as ellagitannins using LC-MS-MS. This study suggests that different polyphenolic components of fruits may influence different steps in starch digestion in a synergistic manner. SN - 0021-8561 UR - https://www.unboundmedicine.com/medline/citation/15796622/Different_polyphenolic_components_of_soft_fruits_inhibit_alpha_amylase_and_alpha_glucosidase_ DB - PRIME DP - Unbound Medicine ER -