Preface

Reduced glutathione (GSH) is a water-soluble tripeptide with the structure of g-glutamylcysteinyl-glycine. GSH is the most important thiol in living organisms. It is the key compo‐ nent of antioxidant system, serves as a free radical scavenger and can be effective against the attacks of many reactive species, including electrophilic substances and epoxides. Upon con‐ tact with reactive species, GSH is converted to oxidized glutathione (GSSG) by glutathione peroxidases and later can be reduced to GSH again by glutathione reductase. Therefore, there is a cycle of GSH and this cycle provides higher intracellular levels of GSH. GSH levels are depleted to different degrees if the cellular death mechanisms are triggered. GSH deple‐ tion and apparent oxidative stress may also cause cytotoxicity. GSH was shown to be pre‐ ventive against aging, cancer, heart disease and dementia. Moreover, GSH supplementation (mainly as cysteine) can help to reduce the symptoms of many diseases and can be beneficial in different conditions like autism, Alzheimer's disease, Parkinson's disease, HIV/AIDS, hepatitis, type 2 diabetes, cystic fibrosis and certain infections. This book is mainly focused on GSH in health and disease. The readers will receive information on the diverse functions of GSH and GSH-related enzymes, the importance of GSH status against oxidative stress and the interaction between GSH and nervous system-related infections. We believe that readers will get qualified scientific knowledge and a general overview of the importance of GSH and GSH-related enzymes in health and in different pathological conditions from this book.

### **Assoc.Prof.Dr. Pinar Erkekoglu**

Hacettepe University Faculty of Pharmacy Department of Toxicology Ankara, Turkey

### **Prof.Dr. Belma Kocer-Gumusel**

Hacettepe University Faculty of Pharmacy Department of Toxicology Ankara, Turkey

**Section 1**

**Glutathione - Evolution and Functions**

**Glutathione - Evolution and Functions**

VIII Preface

**Chapter 1**

**Provisional chapter**

**Introductory Chapter: A General Overview of**

**Introductory Chapter: A General Overview of** 

Additional information is available at the end of the chapter

Pinar ErkekogluAdditional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.81594

tions are at micromolar concentrations [2].

**Applications**

**Applications**

Pinar Erkekoglu

**1. Introduction**

α-peptidases [1].

turic acid [3].

environment as well [4].

**Glutathione, Glutathione Transport, and Glutathione**

**Glutathione, Glutathione Transport, and Glutathione** 

Reduced glutathione (GSH) is a water-soluble tripeptide with the structure of γ-glutamylcysteinyl-glycine. The gamma bond between glutamic acid and cysteine provides stability to GSH as there are lower amounts of γ-peptidases in biological systems when compared to

GSH is the most important thiol in living organisms. GSH is a catalyst, reductant, and reactant. This molecule is found in large quantities (millimolar concentrations) in organs exposed to toxins such as liver, kidney, lungs, and intestines. However, in body fluids, GSH concentra-

GSH is synthesized in the cell cytosol. In a reaction catalyzed by "γ-glutamylcysteine synthetase," L-cysteine and L-glutamate form "γ-glutamylcysteine." By the addition of glycine, GSH is formed in a reaction catalyzed by "glutathione synthetase." The catabolism of GSH is mainly catalyzed by "γ-glutamyl transpeptidase" (forming glutamate and cysteinylglycine) and "dipeptidases" (forming cysteine and glycine). Cysteine is then catabolized to mercap-

GSH plays a role in amino acid transport, protein synthesis, DNA synthesis and protection, and more generally, in cellular detoxification. The main source of plasma GSH is liver. As part of their physiological functions, viable cells such as hepatocytes and macrophages extrude this particular thiol. This phenomenon supplies antioxidant protection for the extracellular

> © 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

distribution, and reproduction in any medium, provided the original work is properly cited.

DOI: 10.5772/intechopen.81594

### **Introductory Chapter: A General Overview of Glutathione, Glutathione Transport, and Glutathione Applications Introductory Chapter: A General Overview of Glutathione, Glutathione Transport, and Glutathione Applications**

DOI: 10.5772/intechopen.81594

Pinar Erkekoglu Pinar Erkekoglu

Additional information is available at the end of the chapter Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.81594
