Endogenous Metabolite

One of the most common non-protein thiols found in living cells is L-reduced glutathione. Important biological processes in organisms include the synthesis of proteins and DNA, enzyme activity, metabolism, and cell protection, all of which depend on L-reduced glutathione. L-reduced glutathione has been found to be a sign of oxidative stress and has the ability to scavenge oxygen free radicals [1].

The ROS were decreased after GSH treatment, and the mRNA levels of tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, IL-6, matrix metalloproteinase (MMP)-1, MMP-3, were also significantly inhibited after GSH stimulation. However, the IL-10 levels were enhanced, and GSH increased the expression of PTEN. The GSH suppressed the activation of phosphorylated (p)-PI3K and p-AKT. The supplementation of the BSO restored the activation of PI3K/AKT pathway with a high production of ROS. The levels of TNF-α, IL-1β and IL-6 were also elevated, when the BSO was added.[2]
Conclusion: These findings suggest that GSH can act as an inflammatory suppressor by downregulating the PTEN/PI3K/AKT pathway in MH7A cells. These data indicated a novel function of GSH for improving the inflammation of RA SFs and may help to alleviate the pathological process of RA.[2]

Modified electrodes coated by adsorbed cobalt phthalocyanines are known to show substantial electrocatalytic activity for the electro-oxidation of several thiols in alkaline aqueous solution. In this context, we explore in this study the electrocatalytic activity of adsorbed cobalt phthalocyanine (CoPc) on ordinary pyrolytic graphite electrode for the oxidation of reduced L-glutathione GSH and the reduction of its disulfide GSSG at physiological pH. To do so, cyclic and rotating disk voltammetries were performed and the amperometric results show that a stable electrochemical sensing material, with good reproducibility and sensitivity (in accordance with the concentrations of GSH expected in biological media), can be easily achieved. This opens the way for the design of an electrochemical sensor able to detect these two analytes in biologically relevant experimental conditions (in terms of pH)[1].

The MH7A cells and mouse SFs were treated with indicated concentrations of GSH (100 μg/mL) with or without Escherichia coli lipopolysaccharide (LPS) (100 ng/mL), the control group was treated with equal amount of phosphate buffered saline (PBS) for 24 h at 37°C. The supernatants were used to detect the protein levels of cytokines via enzymelinked immunosorbent assay (ELISA). The cells were used to detect the messenger ribonucleic acid (mRNA) expression levels of cytokines via reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and were used to measure the protein expression levels of PTEN, phosphorylated (p)-PI3K, and p-AKT via Western blotting[2].
The levels of ROS were determined using a ROS assay kit according to the manufacturer’s instructions. Cellular ROS production was measured using a 2´,7´-dichlorofluorescein diacetate (DCFDA) assay kit according to the manufacturer’s instructions. The DCFDA is a cell permeable fluorogenic dye that measures hydroxyl, peroxyl, and activity of ROS within the cell. Briefly, dilute DCFH-DA with serum-free culture medium at a ratio of 1:1000 to a final concentration of 10 μmoL/L. Remove the cell culture medium and add 500 µL diluted DCFH-DA in 24-well plate. Incubate for 20 min at 37°C in a humidified atmosphere (5% CO2). Wash the cells three times with serum-free cell culture medium to fully remove the redundant DCFH-DA. Finally, capture the figures with laser confocal microscope[2].
The RNA was isolated from MH7A cells and mouse SFs using TRIzol® reagent, and RT was conducted using PrimeScript™ RT Master mix. Then, complementary deoxyribonucleic acid (cDNA) was amplified using SYBR® Premix Ex Taq™ with gene-specific primers. The RT-qPCR analyses were performed in a LightCycler® 480 II detection system under the following thermal cycler conditions: initial denaturation for 5 min at 95°C, followed by 45 cycles for 15 sec at 95°C, 15 sec at 60°C and 15 sec at 72°C, using the primers listed in Tables 1 and 2. All experiments were performed in triplicate and the comparative cycling threshold values (Ct values) were normalized to endogenous reference (GAPDH). The levels of mRNA expression were calculated using the 2-ΔΔCq method[2].

A total of 30 DBA/1J female mice were used in this study. The release of ROS in MH7A cells was examined using a ROS assay kit. The effects of GSH on the messenger ribonucleic acid (mRNA) expression and protein levels of inflammatory cytokines were determined via reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA) in mouse SFs and MH7A cells, respectively. The PTEN/PI3K/AKT pathway was investigated via Western blotting. The effects of buthionine-sulfoximine (BSO), as an inhibitor of GSH, on these molecules were examined.[2]

Absorption, Distribution and Excretion
Studies have shown that glutathione has no biological activity when taken orally, and only a very small portion of orally administered glutathione tablets or capsules can be absorbed by the human body.

Toxicity Summary
Glutathione (GSH) participates in leukotriene synthesis and is a cofactor of glutathione peroxidase. As a hydrophilic molecule, it plays an important role in liver biotransformation by binding to lipophilic toxins and waste products, preventing them from entering bile. Glutathione also participates in the detoxification of methylglyoxal, a metabolic byproduct and toxin. This detoxification reaction is catalyzed by the glyoxase system. Glyoxase I catalyzes the conversion of methylglyoxal and reduced glutathione to SD-lactylglutathione. Glyoxase II catalyzes the conversion of SD-lactylglutathione to reduced glutathione and D-lactic acid. Glutathione (GSH) is a cofactor in binding and reduction reactions catalyzed by glutathione S-transferases in the cytosol, microsomes, and mitochondria. However, it can also participate in non-enzymatic binding reactions of certain chemicals; for example, its binding with N-acetyl-p-benzoquinone imine (NAPQI) is presumably particularly significant. NAPQI is an active cytochrome P450 reactive metabolite produced by acetaminophen overdose. In this case, glutathione binds to NAPQI, acting as a suicide substrate and detoxifying it in the process, replacing the thiol groups of cellular proteins that would otherwise be adducted by the toxicity. The preferred treatment for such overdose is the administration (usually in nebulized form) of N-acetylcysteine, the efficacy of which has been consistently demonstrated in the literature. N-acetylcysteine can be used by cells to replenish depleted GSSG, thereby maintaining a usable GSH pool.

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Toxicity Data
ORL-MUS LD50 5000 mg/kg, IPR-MUS LD50 4020 mg/kg, SCU-MUS LD50 5000 mg/kg, IVN-RBT LD50 > 2000 mg/kg, IMS-MUS LD50 4000 mg/kg

[1]. Electrocatalytic activity of cobalt phthalocyanine CoPc adsorbed on a graphite electrode for the oxidation of reduced L-glutathione (GSH) and the reduction of its disulfide (GSSG) at physiological pH. Bioelectrochemistry. 2007 Jan;70(1):147-54.

Glutathione is a tripeptide compound composed of glutamic acid linked to the N-terminus of cysteine via its side chain. It has multiple functions, including acting as a skin whitening agent, a human metabolite, an E. coli metabolite, a mouse metabolite, an anti-aging agent, an antioxidant, and a cofactor. It is a tripeptide, a thiol, and an L-cysteine derivative, and is also the conjugate acid of glutathione(1-). It is a tripeptide that plays multiple roles in cells. Glutathione can bind to drugs, increasing their solubility and facilitating excretion; it is a cofactor for certain enzymes; it participates in protein disulfide rearrangement; and it can reduce peroxides. Glutathione is present in or produced by E. coli (K12 strain, MG1655 strain). It has also been reported to exist in corn, fruit flies, and other organisms with relevant data. Glutathione is a tripeptide composed of three amino acids (cysteine, glutamic acid, and glycine) and is present in most mammalian tissues. Glutathione possesses antioxidant, free radical scavenging, and detoxifying properties. Furthermore, it is a cofactor of glutathione peroxidase, participating in amino acid absorption and leukotriene synthesis. As a substrate for glutathione S-transferase, glutathione can react with various harmful chemicals (such as halides, epoxides, and free radicals) to produce harmless, inactive products. In red blood cells, these reactions prevent oxidative damage by reducing methemoglobin and peroxides. Glutathione also participates in the formation and maintenance of disulfide bonds in proteins, as well as the transport of amino acids across cell membranes. Glutathione is a compound synthesized from cysteine, which may be the most important member of the body's toxin removal system. Like cysteine, glutathione also contains a key sulfhydryl group (-SH), making it a potent antioxidant. Glutathione is present in the cells of almost all living organisms on Earth—both animal and plant. Scientists speculate that glutathione was crucial to the origin of life on Earth. Glutathione has multiple functions, but it does not act alone. Glutathione is a coenzyme in many enzymatic reactions. Among the most important are redox reactions, where the sulfhydryl group on the cysteine residues of glutathione in the cell membrane prevents cell membrane peroxidation; and binding reactions, where glutathione (especially in the liver) binds to toxic chemicals, thus playing a detoxifying role. Glutathione also plays an important role in the production of red and white blood cells and in the entire immune system. Clinical applications of glutathione include preventing oxygen toxicity in hyperbaric oxygen therapy, treating lead and other heavy metal poisoning, reducing the toxicity of chemotherapy and radiotherapy in cancer treatment, and reversing cataracts. Glutathione participates in the synthesis of leukotrienes and is a cofactor of glutathione peroxidase. Furthermore, as a hydrophilic molecule, glutathione plays an important role in liver biotransformation by binding to lipophilic toxins and waste products, preventing them from entering the bile. Glutathione is also essential for the detoxification of methylglyoxal, a metabolic byproduct and a toxin. This detoxification reaction is catalyzed by the glyoxase system. Glyoxalase I (EC 4.4.1.5) catalyzes the conversion of methylglyoxal and reduced glutathione to SD-lactylglutathione. Glyoxalase II (EC 3.1.2.6) catalyzes the hydrolysis of SD-lactylglutathione to glutathione and D-lactic acid. Glutathione is a substrate for both binding and reduction reactions catalyzed by glutathione S-transferases in the cytosol, microsomes, and mitochondria. However, glutathione can also bind non-enzymatically to certain chemicals, such as N-acetyl-p-benzoquinone imine (NAPQI), an active cytochrome P450 metabolite produced from acetaminophen. NAPQI can be toxic when glutathione (GSH) is depleted due to overdose (acetaminophen). Glutathione binds to NAPQI during this process, acting as a suicide substrate and detoxifying it by replacing the sulfhydryl groups of cellular proteins that would otherwise be covalently modified. When all GSH is depleted, NAPQI begins to react with cellular proteins, ultimately leading to cell death. The preferred treatment for this analgesic overdose is administration of N-acetylcysteine (usually in nebulized form), which cells can use to replenish depleted GSSG, thereby renewing the available GSH pool. It binds to the drug, making it more soluble in water for excretion; it is a cofactor for certain enzymes; it participates in protein disulfide rearrangement and peroxide reduction.
A tripeptide that plays multiple roles in cells. It binds to the drug, making it more soluble in water for excretion; it is a cofactor for certain enzymes; it participates in protein disulfide rearrangement and peroxide reduction. See also: Glutathione; Nonapeptide-1 (components)...View more...

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Drug Indications
For nutritional supplementation, and also for treating dietary deficiencies or imbalances.

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Mechanism of Action
Glutathione (GSH) participates in leukotriene synthesis and is a cofactor of glutathione peroxidase. It also plays a role in liver biotransformation and detoxification; as a hydrophilic molecule, it binds with other lipophilic toxins or wastes before entering bile excretion. It participates in the detoxification of the toxic metabolic byproduct methylglyoxal, a process mediated by glyoxase. Glyoxase I catalyzes the conversion of methylglyoxal and reduced glutathione to SD-lactylglutathione. Glyoxase II catalyzes the conversion of SD-lactylglutathione to reduced glutathione and D-lactate. Glutathione (GSH) is a cofactor for the binding and reduction reactions catalyzed by glutathione S-transferase expressed in the cytosol, microsomes, and mitochondria. However, GSH can also bind non-enzymatically to certain chemicals; for example, it is presumably particularly potent in its binding to N-acetyl-p-benzoquinone imine (NAPQI). NAPQI is an active cytochrome P450 reactive metabolite produced by acetaminophen overdose. In this case, glutathione binds to NAPQI, acting as a suicide substrate and detoxifying it during the binding process, thereby replacing the thiol groups of cellular proteins that would otherwise be adducted by the toxicity. For such overdose, the preferred treatment is administration of N-acetylcysteine (usually in nebulized form), the efficacy of which has been well-documented in the literature. N-acetylcysteine can be used by cells to replenish depleted GSSG, thereby maintaining the available GSH pool.

C10H17N3O6S

307.32

307.083

C, 39.08; H, 5.58; N, 13.67; O, 31.24; S, 10.43

70-18-8

L-Glutathione reduced-13C2,15N;815610-65-2; 20167-21-9 (sodium); 34212-83-4 (disodium); 70-18-8 (free acid)

124886

Typically exists as white to off-white solids at room temperature

1.4±0.1 g/cm3

754.5±60.0 °C at 760 mmHg

182-192ºC

410.1±32.9 °C

0.0±5.5 mmHg at 25°C

1.572

-0.87

6

8

9

20

389

2

S([H])C([H])([H])[C@@]([H])(C(N([H])C([H])([H])C(=O)O[H])=O)N([H])C(C([H])([H])C([H])([H])[C@@]([H])(C(=O)O[H])N([H])[H])=O

RWSXRVCMGQZWBV-WDSKDSINSA-N

InChI=1S/C10H17N3O6S/c11-5(10(18)19)1-2-7(14)13-6(4-20)9(17)12-3-8(15)16/h5-6,20H,1-4,11H2,(H,12,17)(H,13,14)(H,15,16)(H,18,19)/t5-,6-/m0/s1

(2S)-2-amino-5-[[(2R)-1-(carboxymethylamino)-1-oxo-3-sulfanylpropan-2-yl]amino]-5-oxopentanoic acid

GSH; NSC-400639; NSC400639; Glutatiol; NSC 400639; L-Glutathione; Glutathione;glutathione; 70-18-8; L-Glutathione; Glutathion; L-Glutathione reduced; Isethion; Tathion; Glutathione-SH;

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: (1). This product requires protection from light (avoid light exposure) during transportation and storage.  (2). Please store this product in a sealed and protected environment (e.g. under nitrogen), avoid exposure to moisture.  (3). This product is not stable in solution, please use freshly prepared working solution for optimal results.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

H2O : ~62.5 mg/mL (~203.37 mM)

Solubility in Formulation 1: 100 mg/mL (325.39 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with sonication (<60°C).

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 (Please use freshly prepared in vivo formulations for optimal results.)