The anthocyanins in black currants regulate postprandial hyperglycaemia primarily by inhibiting α-glucosidase while other phenolics modulate salivary α-amylase, glucose uptake and sugar transporters

Sisir Kumar Barik, Wendy Russell, Kim M Moar, Morven Cruickshank, Lorraine Scobbie, Gary Duncan, Nigel Hoggard* (Corresponding Author)

*Corresponding author for this work

Research output: Contribution to journalArticle

Abstract

The hypoglycaemic effects of two Ribes sp. i.e. anthocyanin-rich black currants (BC) were compared to green currants (GC), which are low in anthocyanins to establish which compounds are involved in the regulation of postprandial glycaemia. We determined the effect of the currants on inhibiting carbohydrate digestive enzymes (α-amylase, α-glucosidase), intestinal sugar absorption and transport across CaCo-2 cells. The digestion of these currants was modelled using in vitro gastrointestinal digestion (IVGD) to identify the metabolites present in the digested extracts by LC–MS/MS. Freeze-dried BC and IVDG extracts inhibited yeast α-glucosidase activity (P<.0001) at lower concentrations than acarbose, whereas GC and IVDG GC at the same concentrations showed no inhibition. BC and GC both showed significant inhibitory effects on salivary α-amylase (P<.0001), glucose uptake (P<.0001) and the mRNA expression of sugar transporters (P<.0001). Taken together this suggests that the anthocyanins which are high in BC have their greatest effect on postprandial hyperglycaemia by inhibiting α-glucosidase activity. Phytochemical analysis identified the phenolics in the currants and confirmed that freeze-dried BC contained higher concentrations of anthocyanins compared to GC (39.80 vs. 9.85 g/kg dry weight). Specific phenolics were also shown to inhibit salivary α-amylase, α-glucosidase, and glucose uptake. However, specific anthocyanins identified in BC which were low in GC were shown to inhibit α-glucosidase. In conclusion the anthocyanins in BC appear to regulate postprandial hyperglycaemia primarily but not solely by inhibiting α-glucosidase while other phenolics modulate salivary α-amylase, glucose uptake and sugar transporters which together could lower the associated risk of developing type-2 diabetes.
Original languageEnglish
Article number108325
JournalThe Journal of Nutritional Biochemistry
Volume78
Early online date26 Dec 2019
DOIs
Publication statusE-pub ahead of print - 26 Dec 2019

Fingerprint

Ribes
Glucosidases
Anthocyanins
Amylases
Sugars
Hyperglycemia
Glucose
Acarbose
Phytochemicals
Medical problems
Metabolites
Hypoglycemic Agents
Yeast
Carbohydrates
Messenger RNA
Digestion
Enzymes

Keywords

  • black currants
  • anthocyanins
  • LC–MS/MS
  • Alpha-Glucosidase
  • glucose uptake
  • Glucose Transporter

Cite this

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title = "The anthocyanins in black currants regulate postprandial hyperglycaemia primarily by inhibiting α-glucosidase while other phenolics modulate salivary α-amylase, glucose uptake and sugar transporters",
abstract = "The hypoglycaemic effects of two Ribes sp. i.e. anthocyanin-rich black currants (BC) were compared to green currants (GC), which are low in anthocyanins to establish which compounds are involved in the regulation of postprandial glycaemia. We determined the effect of the currants on inhibiting carbohydrate digestive enzymes (α-amylase, α-glucosidase), intestinal sugar absorption and transport across CaCo-2 cells. The digestion of these currants was modelled using in vitro gastrointestinal digestion (IVGD) to identify the metabolites present in the digested extracts by LC–MS/MS. Freeze-dried BC and IVDG extracts inhibited yeast α-glucosidase activity (P<.0001) at lower concentrations than acarbose, whereas GC and IVDG GC at the same concentrations showed no inhibition. BC and GC both showed significant inhibitory effects on salivary α-amylase (P<.0001), glucose uptake (P<.0001) and the mRNA expression of sugar transporters (P<.0001). Taken together this suggests that the anthocyanins which are high in BC have their greatest effect on postprandial hyperglycaemia by inhibiting α-glucosidase activity. Phytochemical analysis identified the phenolics in the currants and confirmed that freeze-dried BC contained higher concentrations of anthocyanins compared to GC (39.80 vs. 9.85 g/kg dry weight). Specific phenolics were also shown to inhibit salivary α-amylase, α-glucosidase, and glucose uptake. However, specific anthocyanins identified in BC which were low in GC were shown to inhibit α-glucosidase. In conclusion the anthocyanins in BC appear to regulate postprandial hyperglycaemia primarily but not solely by inhibiting α-glucosidase while other phenolics modulate salivary α-amylase, glucose uptake and sugar transporters which together could lower the associated risk of developing type-2 diabetes.",
keywords = "black currants, anthocyanins, LC–MS/MS, Alpha-Glucosidase, glucose uptake, Glucose Transporter",
author = "Barik, {Sisir Kumar} and Wendy Russell and Moar, {Kim M} and Morven Cruickshank and Lorraine Scobbie and Gary Duncan and Nigel Hoggard",
note = "We are grateful to the Scottish Government Rural and Environment Science and Analytical Services (RESAS), the University of Aberdeen and Nutricia Research Foundation for funding. We thank Graham Horgan from Biomathematics and Statistics Scotland for their assistance with the statistical analysis. We thank Gordon J. McDougall and Rex M. Brennan, from The James Hutton Institute for supplying the currants. None of the authors had any conflicts of interest.",
year = "2019",
month = "12",
day = "26",
doi = "10.1016/j.jnutbio.2019.108325",
language = "English",
volume = "78",
journal = "The Journal of Nutritional Biochemistry",
issn = "0955-2863",
publisher = "Elsevier Inc.",

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TY - JOUR

T1 - The anthocyanins in black currants regulate postprandial hyperglycaemia primarily by inhibiting α-glucosidase while other phenolics modulate salivary α-amylase, glucose uptake and sugar transporters

AU - Barik, Sisir Kumar

AU - Russell, Wendy

AU - Moar, Kim M

AU - Cruickshank, Morven

AU - Scobbie, Lorraine

AU - Duncan, Gary

AU - Hoggard, Nigel

N1 - We are grateful to the Scottish Government Rural and Environment Science and Analytical Services (RESAS), the University of Aberdeen and Nutricia Research Foundation for funding. We thank Graham Horgan from Biomathematics and Statistics Scotland for their assistance with the statistical analysis. We thank Gordon J. McDougall and Rex M. Brennan, from The James Hutton Institute for supplying the currants. None of the authors had any conflicts of interest.

PY - 2019/12/26

Y1 - 2019/12/26

N2 - The hypoglycaemic effects of two Ribes sp. i.e. anthocyanin-rich black currants (BC) were compared to green currants (GC), which are low in anthocyanins to establish which compounds are involved in the regulation of postprandial glycaemia. We determined the effect of the currants on inhibiting carbohydrate digestive enzymes (α-amylase, α-glucosidase), intestinal sugar absorption and transport across CaCo-2 cells. The digestion of these currants was modelled using in vitro gastrointestinal digestion (IVGD) to identify the metabolites present in the digested extracts by LC–MS/MS. Freeze-dried BC and IVDG extracts inhibited yeast α-glucosidase activity (P<.0001) at lower concentrations than acarbose, whereas GC and IVDG GC at the same concentrations showed no inhibition. BC and GC both showed significant inhibitory effects on salivary α-amylase (P<.0001), glucose uptake (P<.0001) and the mRNA expression of sugar transporters (P<.0001). Taken together this suggests that the anthocyanins which are high in BC have their greatest effect on postprandial hyperglycaemia by inhibiting α-glucosidase activity. Phytochemical analysis identified the phenolics in the currants and confirmed that freeze-dried BC contained higher concentrations of anthocyanins compared to GC (39.80 vs. 9.85 g/kg dry weight). Specific phenolics were also shown to inhibit salivary α-amylase, α-glucosidase, and glucose uptake. However, specific anthocyanins identified in BC which were low in GC were shown to inhibit α-glucosidase. In conclusion the anthocyanins in BC appear to regulate postprandial hyperglycaemia primarily but not solely by inhibiting α-glucosidase while other phenolics modulate salivary α-amylase, glucose uptake and sugar transporters which together could lower the associated risk of developing type-2 diabetes.

AB - The hypoglycaemic effects of two Ribes sp. i.e. anthocyanin-rich black currants (BC) were compared to green currants (GC), which are low in anthocyanins to establish which compounds are involved in the regulation of postprandial glycaemia. We determined the effect of the currants on inhibiting carbohydrate digestive enzymes (α-amylase, α-glucosidase), intestinal sugar absorption and transport across CaCo-2 cells. The digestion of these currants was modelled using in vitro gastrointestinal digestion (IVGD) to identify the metabolites present in the digested extracts by LC–MS/MS. Freeze-dried BC and IVDG extracts inhibited yeast α-glucosidase activity (P<.0001) at lower concentrations than acarbose, whereas GC and IVDG GC at the same concentrations showed no inhibition. BC and GC both showed significant inhibitory effects on salivary α-amylase (P<.0001), glucose uptake (P<.0001) and the mRNA expression of sugar transporters (P<.0001). Taken together this suggests that the anthocyanins which are high in BC have their greatest effect on postprandial hyperglycaemia by inhibiting α-glucosidase activity. Phytochemical analysis identified the phenolics in the currants and confirmed that freeze-dried BC contained higher concentrations of anthocyanins compared to GC (39.80 vs. 9.85 g/kg dry weight). Specific phenolics were also shown to inhibit salivary α-amylase, α-glucosidase, and glucose uptake. However, specific anthocyanins identified in BC which were low in GC were shown to inhibit α-glucosidase. In conclusion the anthocyanins in BC appear to regulate postprandial hyperglycaemia primarily but not solely by inhibiting α-glucosidase while other phenolics modulate salivary α-amylase, glucose uptake and sugar transporters which together could lower the associated risk of developing type-2 diabetes.

KW - black currants

KW - anthocyanins

KW - LC–MS/MS

KW - Alpha-Glucosidase

KW - glucose uptake

KW - Glucose Transporter

U2 - 10.1016/j.jnutbio.2019.108325

DO - 10.1016/j.jnutbio.2019.108325

M3 - Article

C2 - 31952012

VL - 78

JO - The Journal of Nutritional Biochemistry

JF - The Journal of Nutritional Biochemistry

SN - 0955-2863

M1 - 108325

ER -