Abstract

Exogenous insulin, used as a therapeutic agent for diabetes, forms insoluble deposits containing amyloid fibrillar structures near the administration site. We have analyzed the in vitro anti-amyloid activity of four green tea constituents: (-)-epigallocatechin gallate (EGCG), (-)-epicatechin (EC), gallic acid (GA), caffeine (CF), and their equimolar mixtures. Regarding individually tested compounds, only EGCG inhibited the fibrillization process. The individual EC, GA, and CF molecules were ineffective. The presence of EGCG in equimolar combinations with GA, EC, or CF was required for the inhibitory activity of most mixtures. Molecular docking revealed that EGCG interacts with an essential amyloidogenic region of insulin chain B. Individually inactive GA had a potentiating effect on the activity of EGCG. In contrast, EC and CF had a negative impact on the activity of the mixtures. We have observed diverse morphology and the amount of insulin amyloid aggregates formed in the presence of studied compounds. The distinct types of amyloid aggregates created in vitro in the presence of EGCG and other green tea constituents were characterized. Results indicate that the biological activity of individual molecules is not directly applicable to the pooled samples effects prediction.

Details

Title
Amyloid Aggregation of Insulin: An Interaction Study of Green Tea Constituents
Author
Gancar Miroslav 1 ; Kurin Elena 2 ; Bednarikova Zuzana 1 ; Marek Jozef 1 ; Mucaji Pavel 2 ; Nagy, Milan 2 ; Gazova Zuzana 1 

 Institute of Experimental Physics, Slovak Academy of Sciences, Department of Biophysics, Kosice, Slovakia (GRID:grid.435184.f) (ISNI:0000 0004 0488 9791) 
 Comenius University in Bratislava, Department of Pharmacognosy and Botany, Faculty of Pharmacy, Bratislava, Slovakia (GRID:grid.7634.6) (ISNI:0000000109409708) 
Publication year
2020
Publication date
2020
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2409608234
Copyright
© The Author(s) 2020. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.