Differential impact of cold and hot tea extracts on tyrosine phosphatases regulating insulin receptor activity: a

Related Experiment Video

Updated: Oct 5, 2025

Co-immunoprecipitation Assay for Studying Functional Interactions Between Receptors and Enzymes
09:40

Co-immunoprecipitation Assay for Studying Functional Interactions Between Receptors and Enzymes

Published on: September 28, 2018

15.3K

Massimo Genovese1, Simone Luti1, Elisa Pardella2

  • 1Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Viale Morgagni 50, 50134, Florence, Italy.

European Journal of Nutrition
|January 23, 2022
PubMed
Abstract

Insights

Tea catechins like EGCG inhibit key enzymes (LMW-PTP and PTP1B) that negatively regulate insulin signaling, improving insulin sensitivity in liver cells.

Area of Science:

  • Biochemistry
  • Pharmacology
  • Cell Biology

Background:

  • The role of tea constituents in modulating the insulin-signaling pathway is not fully understood.
  • Previous research suggests some tea components may inhibit Protein Tyrosine Phosphatase 1B (PTP1B), a negative regulator of insulin signaling.

Purpose of the Study:

  • To investigate the effects of tea extracts and their constituents on Low-Molecular-Weight Protein Tyrosine Phosphatase (LMW-PTP) and PTP1B.
  • To clarify the antidiabetic activity and mechanism of action of tea components on the insulin-signaling pathway.

Main Methods:

  • In vitro enzyme activity assays were performed on cold and hot tea extracts.
  • Gas chromatography-mass spectrometry (GC-MS) was used to identify active components.
  • Insulin-signaling pathway modulation was assessed in liver and muscle cells using tea extracts and identified components.

Main Results:

  • Both cold and hot tea extracts inhibited LMW-PTP and PTP1B through distinct mechanisms.
  • Galloyl moiety-bearing catechins, particularly epigallocatechin gallate (EGCG), were identified as the inhibitory components.
  • EGCG demonstrated mixed-type non-competitive inhibition of PTP1B (nanomolar IC50) and acted as an insulin-sensitizing agent, enhancing insulin receptor levels and sensitivity in liver cells.

Conclusions:

  • Tea components, especially EGCG, effectively modulate PTP1B activity.
  • These findings suggest a mechanism by which tea consumption may improve insulin sensitivity and regulate insulin receptor function.
Keywords:
Epigallocatechin gallateInsulin resistancePTP1B inhibitorsTea extractsType 2 diabetes

More Related Videos

An Adipocyte Cell Culture Model to Study the Impact of Protein and Micro-RNA Modulation on Adipocyte Function09:20

An Adipocyte Cell Culture Model to Study the Impact of Protein and Micro-RNA Modulation on Adipocyte Function

Published on: May 4, 2021

3.8K
Measuring the Rate of Lipolysis in Ex Vivo Murine Adipose Tissue and Primary Preadipocytes Differentiated In Vitro09:41

Measuring the Rate of Lipolysis in Ex Vivo Murine Adipose Tissue and Primary Preadipocytes Differentiated In Vitro

Published on: March 17, 2023

3.1K

Related Concept Videos

Transducer Mechanism: Enzyme-Linked Receptors01:27

Transducer Mechanism: Enzyme-Linked Receptors

Enzyme-linked receptors are cell-surface receptors acting as an enzyme or associating with an enzyme intracellularly. They make excellent drug targets. Drugs can bind to the extracellular ligand-binding domain or directly affect their enzymatic domain and alter their activity.
Major types that are helpful drug targets include:
3.1K
PI3K/mTOR/AKT Signaling Pathway01:22

PI3K/mTOR/AKT Signaling Pathway

The mammalian target of rapamycin  (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1  (mTORC1) and mTOR complex 2  (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast,  mTORC2 consists of a...
4.1K
Insulin: The Receptor and Signaling Pathways01:28

Insulin: The Receptor and Signaling Pathways

Insulin action is mediated through a receptor tyrosine kinase, akin to the IGF-1 receptor. The number of receptors per cell varies significantly, from 40 on erythrocytes to 300,000 on adipocytes and hepatocytes. The insulin receptor consists of linked α/β subunit dimers, forming a heterotetramer glycoprotein with two extracellular α subunits and two β subunits spanning the membrane. The α subunits inhibit the inherent tyrosine kinase activity of the β subunits, but...
1.7K
Responses to Heat and Cold Stress02:45

Responses to Heat and Cold Stress

Every organism has an optimum temperature range within which healthy growth and physiological functioning can occur. At the ends of this range, there will be a minimum and maximum temperature that interrupt biological processes.
14.0K