Planta Med 2020; 86(11): 790-799
DOI: 10.1055/a-1164-8152
Biological and Pharmacological Activity
Original Papers
Georg Thieme Verlag KG Stuttgart · New York

Wild Strawberry, Blackberry, and Blueberry Leaf Extracts Alleviate Starch-Induced Hyperglycemia in Prediabetic and Diabetic Mice

István Takács
1   Department of Microbiology, University of Szeged, Szeged, Hungary
,
András Szekeres
1   Department of Microbiology, University of Szeged, Szeged, Hungary
,
Ákos Takács
2   Department of Food Engineering, University of Szeged, Szeged, Hungary
,
Dávid Rakk
1   Department of Microbiology, University of Szeged, Szeged, Hungary
,
Miklós Mézes
3   Department of Nutrition, Szent István University, Gödöllő, Hungary
,
Ágnes Polyák
4   Laboratory of Molecular Neuroendocrinology, Institute of Experimental Medicine, Budapest, Hungary
,
Lóránt Lakatos
5   Department of Dermatology and Allergology, University of Szeged, Szeged, Hungary
6   Present address: Biological Research Center, Szeged, Hungary
,
Gyöngyi Gyémánt
7   Department of Inorganic and Analytical Chemistry, University of Debrecen, Debrecen, Hungary
,
Dezső Csupor
8   Department of Pharmacognosy, Faculty of Pharmacy, University of Szeged, Szeged, Hungary
,
Krisztina J. Kovács*
4   Laboratory of Molecular Neuroendocrinology, Institute of Experimental Medicine, Budapest, Hungary
,
Szilamér Ferenczi*
4   Laboratory of Molecular Neuroendocrinology, Institute of Experimental Medicine, Budapest, Hungary
› Author Affiliations

Supported by: GINOP GINOP-2.3.2-15-2016-00012 Supported by: National Research Development and Innovation Office of Hungary 109622 Supported by: National Research Development and Innovation Office of Hungary 109744 Supported by: National Research Development and Innovation Office of Hungary 124424 Supported by: National Research Development and Innovation Office of Hungary NN107787 Supported by: National Research Development and Innovation Office of Hungary NN11024
Further Information

Publication History

received 17 October 2019
revised 15 April 2020

accepted 23 April 2020

Publication Date:
25 May 2020 (online)

Preview

Abstract

Intestinal α-glucosidase and α-amylase break down nutritional poly- and oligosaccharides to monosaccharides and their activity significantly contributes to postprandial hyperglycemia. Competitive inhibitors of these enzymes, such as acarbose, are effective antidiabetic drugs, but have unpleasant side effects. In our ethnopharmacology inspired investigations, we found that wild strawberry (Fragaria vesca), blackberry (Rubus fruticosus), and European blueberry (Vaccinium myrtillus) leaf extracts inhibit α-glucosidase and α-amylase enzyme activity in vitro and are effective in preventing postprandial hyperglycemia in vivo. Toxicology tests on H9c2 rat embryonic cardiac muscle cells demonstrated that berry leaf extracts have no cytotoxic effects. Oral administration of these leaf extracts alone or as a mixture to normal (control), obese, prediabetic, and streptozotocin-induced diabetic mice attenuated the starch-induced rise of blood glucose levels. The efficiency was similar to that of acarbose on blood glucose. These results highlight berry leaf extracts as candidates for testing in clinical trials in order to assess the clinical significance of their effects on glycemic control.

* Joint senior authors.


Supporting Information