Glutathione (glutathione, r-glutamyl cysteingl + glycine, GSH) is a tripeptide containing γ-amide bonds and sulfhydryl groups. It is composed of glutamic acid, cysteine and glycine and exists in almost every cell of the body.
Glutathione can help maintain normal immune system function and has antioxidant and integrated detoxification effects. The sulfhydryl group on cysteine is its active group (so it is often abbreviated as G-SH), which is easy to combine with certain drugs, toxins, etc., giving it an integrated detoxification effect. Glutathione can not only be used in drugs, but also as a base material for functional foods. It is widely used in functional foods such as delaying aging, enhancing immunity, and anti-tumor.
Glutathione has two forms: reduced (G-SH) and oxidized (G-S-S-G). Under physiological conditions, reduced glutathione accounts for the vast majority. Glutathione reductase can catalyze the interconversion between the two forms, and the coenzyme of this enzyme can also provide NADPH for pentose phosphate bypass metabolism.
Mechanism of Action:
GSH is an important regulatory metabolite in cells. It is not only a cofactor of glyceraldehyde phosphate dehydrogenase, but also a coenzyme of glyoxalase and triose dehydrogenase. It participates in the tricarboxylic acid cycle and sugar metabolism in the body, and can activate a variety of enzymes, such as sulfhydryl (SH) enzyme-coenzyme, thereby promoting the metabolism of carbohydrates, fats and proteins. The characteristic of the GSH molecule is that it has an active sulfhydryl group (-SH), which is the most important functional group. It can participate in a variety of important biochemical reactions in the body, protect the sulfhydryl groups of important enzyme proteins in the body from oxidation and inactivation, and ensure energy metabolism and cell utilization. At the same time, it can directly reduce free radicals to acidic substances by combining with free radicals in the body through sulfhydryl groups, thereby accelerating the excretion of free radicals and counteracting the damage of free radicals to important organs. Haddad et al. found that GSH was involved in the regulation of lipopolysaccharide-induced cytokine transcription and the regulation of the I-KB/NF-KB signaling pathway. Armstrong et al. found that the reduction of GSH content is a potential early activation signal of apoptosis, and the subsequent oxygen free radicals promote cell apoptosis.
Main Applications:
1. Clinical drugs
Glutathione drugs are widely used in clinical practice. In addition to using its sulfhydryl group to chelate heavy metals, fluoride, mustard gas and other toxins, it is also used in hepatitis, hemolytic diseases, keratitis, cataracts and retinal diseases as a drug for treatment or auxiliary treatment. In recent years, Western scientists, especially Japanese scholars, have discovered that glutathione has the function of inhibiting HIV.
Latest research also shows that GSH can correct the imbalance of acetylcholine and cholinesterase, play an anti-allergic role, prevent skin aging and pigmentation, reduce the formation of melanin, improve skin antioxidant capacity and make the skin shiny. In addition, GSH also has a good effect in treating corneal diseases and improving sexual function.
2. Antioxidant effect
Glutathione, as an important antioxidant in the body, can remove free radicals in the human body; because GSH itself is susceptible to oxidation by certain substances, it can protect the sulfhydryl groups in many proteins and enzymes from being oxidized by harmful substances in the body, thereby ensuring the normal physiological functions of proteins and enzymes; the content of glutathione in human red blood cells is high, which is of great significance for protecting the sulfhydryl groups of proteins on the red blood cell membrane in a reduced state and preventing hemolysis.
3. Food additives
Adding glutathione to food can play an unexpected role:
1. Adding it to flour products can play a reducing role. Not only does it shorten the time for making bread to one-half or one-third of the original time, but it also greatly improves working conditions and plays a role in strengthening food nutrition and other functions.
2. Add it to yogurt and infant food, which is equivalent to vitamin C and can act as a stabilizer.
3. Mix it into fish cake to prevent the color from darkening.
4. Add it to meat products, cheese and other foods to enhance the flavor.