Multiple Important Functions of Glutathione

Glutathione is the most common non-protein thiol molecule found mainly in eukaryotic cells. It is widely distributed in all living species. Although the reduced form of glutathione accounts for more than 90% of the prevalent glutathione, a variety of other forms may be found in microbial cells, tissues and plasma. Glutathione is oxidized to produce glutathione disulfide GSSG (oxidized glutathione). This oxidized glutathione may then be reduced back to glutathione by the enzyme glutathione reductase, although the process depletes NADPH.

In addition to GSSG, glutathione may exist in the form of several different mixed disulfide bonds, such as GS-S-CoA, GS-S-Cys, and GS-S-protein, which are produced through the process of glutathionylation.

Although glutathione has been revealed to be involved in a large number of physiological processes and to perform a variety of important functions, the main and general roles of glutathione can be summarized in three main areas: as an antioxidant, as an enhancer of the immune system, and as a detoxifier of higher eukaryotes.

First, glutathione's powerful ability to provide electrons and its relatively high intracellular concentration (possibly up to millimolar levels) make it possible to maintain a reducing environment within the cell. Thus, glutathione is an important antioxidant that protects DNA, proteins, and other macromolecules from oxidative damage caused by reactive oxygen species (ROS), among other things.

Secondly, glutathione is one of the most powerful antiviral chemicals found in research, and it is also important for the function of the immune system by promoting the formation of white blood cells. In conclusion, in order to accomplish the detoxification process, glutathione can bind to a variety of exogenous electrophilic reagents and exogenous substances through the action of glutathione-S-transferase. As a result, glutathione is often considered to be one of the most potent, adaptive, and important natural defense chemicals.

Glutathione deficiency has been associated with a variety of disease states in humans, including HIV infection, cirrhosis of the liver, lung disease, gastrointestinal and pancreatic inflammation, diabetes mellitus, neurodegenerative diseases, and aging.

Glutathione has the potential to be used as an additive in the food and cosmetic industries. Glutathione is most commonly used as a chemical in the pharmaceutical industry; nevertheless, it also has the potential to be used in the other industries mentioned above. In fact, the reason why glutathione has such a wide range of applications in the industry is that this chemical is usually considered risk-free when consumed in the form of nutritional supplements. On the other hand, there are several reports of oral acute toxicity studies of glutathione in mice that show a lethal dose 50 (LD 50) of greater than 5 grams per kilogram, indicating that glutathione is harmless. No significant adverse effects have also been documented in a considerable number of clinical trials.

References: Al-Temimi AA, Al-Hilifi SA, Al-Mossawi AE. An investigation on glutathione derived from spinach and red cabbage leaves and their effects of adding to meat patties. Saudi J Biol Sci. 2023 May;30(5):103632. doi: 10.1016/j.sjbs.2023.103632. Epub 2023 Mar 31. PMID: 37123535; PMCID: PMC10140161.