Glutathione is a protein that is produced naturally in the body. As a tripeptide it encompasses three amino–acids, namely L-cysteine, L-glutamic and glycine in most of the animal species and also in plants. As such, glutathione is synthesized by all normal cells from the three amino-acid components. Despite being a non-essential nutrient reduced levels can occur in immunocompromised states hence necessitating supplementation. Also, although glutathione is found in all cells, the highest concentration is found in the liver that also acts as a storage site for glutathione. Glutathione exists in main two forms, the reduced form known as L-glutathione (GSH) and oxidized form (GSSH). L-glutathione forms the largest percentage of the total glutathione pool in the body, reaching up to 90 %. Glutathione has three crucial functions; it functions as an antioxidant, immunosupportive function and detoxification function. Glutathione levels tend to get depleted with age.
Glutathione is one of the antioxidants that is manufactured by the body. It the most abundant cellular thiol. Glutathione functions as a water-soluble antioxidant when it counteracts oxidative attack by free radicals. Specifically it neutralizes toxic peroxides such as hydrogen peroxide. It normally exists in the reduced form (GSH) which readily receives reactive radicals and is reduced to (GSSG) within the cells. Even in the oxidized state glutathione has the ability to non-enzymatic ally reduce free radical species and reactive oxygen and nitrite compounds by acting as a substrate for conjugation and reduction courtesy of the thiol group of the cysteine amino acid. It is commonly referred to as the “master antioxidant” as other antioxidants depend on it to function properly. Glutathione also functions as a cofactor. It potentiates the action of glutathione peroxidase that is also an antioxidant. It also helps maintain the levels of ascorbate and tocopherol through its reducing properties.
Glutathione plays an immunosupportive role. The healthy growth and activity of immune cells is dependent on glutathione. Glutathione enhances the immune system by stimulating the body to produce more white blood cells which are the main components of the immune system. Another immune function is that glutathione is necessary for maintaining immune mediated T-cell activation and the process of phagocytosis through which macrophages take up and eliminate foreign organisms from the body. Additionally, it helps maintain balance between various T-helper cells such as IL-2, IL-12 and gamma-interferon, IL-6, IL-4 to maintain an effective cytokine response profile.
Glutathione also maintains skin health. It lowers melanin production by inhibiting tyrosinase activity and increasing the levels if colorless pheromelanin, that is responsible for the bright skin. This has a therapeutic function for the skin as it helps remove any form of hyperpigmentation such as dark spots or pimple marks leaving the skin soft and supple. The antioxidation property also helps prevents aging by making the skin smooth, fresh and radiant. The fact that glutathione also enhances the healing of wounds prevents skin scarring that can occur as a result of sun burn.
Additionally, glutathione has a role in detoxification function. It is directly involved in the specific detoxification reactions that protect the body against the toxins. Glutathione that is highly concentrated in the liver also removes toxins that circulate in the body thus preventing damage to the body cells. According to research low glutathione levels induces poor liver function hence paralyzing its detoxification function.
Lastly, glutathione takes part in the DNA synthesis and repair as well as protein synthesis hence facilitating growth and development. It also influences male fertility by determining the quality of sperms produced. The most effective way of increasing depleted glutathione levels in the body is to ingest its precursor, such as N-Acetyl-Cysteine (NAC). Additionally one should maintain a healthy balanced diet and engage in regular exercise (L-glutathione. (n.d.).