L-glutathione is a tripeptide composed of glutamic acid, cysteine, and glycine that functions as a potent antioxidant in the body. It is involved in many cellular processes, including the detoxification of harmful free radicals and reactive oxygen species (ROS), involve in the maintenance of redox homeostasis, protecting cells from oxidative damage.
This review summarizes the current literature on the clinical use of L-glutathione, including its potential applications in various disease states. Clinical studies suggest that L-glutathione may be effective in reducing oxidative stress, skin lightening effects, improving immune function, and supporting liver health.
L-Glutathione and Antioxidant Defense
Oxidative stress, a condition caused by an imbalance between ROS production and antioxidant defenses, has been implicated in many disease states. L-glutathione is an important endogenous antioxidant that plays a critical role in protecting cells from oxidative damage. It functions as a reducing agent to donate electrons to neutralize ROS and free radicals, thereby preventing oxidative damage to cellular structures such as lipids, proteins, and DNA. L-glutathione also plays a key role in the detoxification of harmful compounds, such as heavy metals and environmental toxins. Several clinical studies have investigated the effects of L-glutathione on oxidative stress in various disease states, these studies suggest that L-glutathione may be effective in reducing oxidative stress and improving antioxidant defenses in these conditions.
L-Glutathione and Skin Whitening
L-glutathione is believed to exert its skin-lightening effects through several mechanisms, including inhibition of tyrosinase activity, reduction of melanin production, and prevention of melanin transfer to the skin surface.
Several clinical studies have investigated the effects of L-glutathione on skin lightening. One study of 60 healthy female volunteers found that supplementation with L-glutathione for 12 weeks led to significant reductions in skin melanin index and skin darkening, as well as improvements in skin brightness and radiance. Another study of 60 healthy adults found that topical application of a cream containing L-glutathione, vitamin C, and alpha-arbutin led to significant reductions in skin melanin index and improvements in skin brightness and elasticity.
In addition to its potential skin-lightening effects, L-glutathione has also been investigated for its anti-aging properties. A study of 50 healthy adult women found that supplementation with L-glutathione for 4 weeks led to significant improvements in skin elasticity and roughness, as well as reductions in skin wrinkles and fine lines. Another study of 60 healthy adult women found that topical application of a cream containing L-glutathione and vitamin C led to significant improvements in skin elasticity, roughness, and hydration.
L-Glutathione and Immune Function
L-glutathione has also been shown to play a role in immune function. It is involved in the regulation of T-cell function and cytokine production, and has been shown to enhance immune function in both animal and human studies. Clinical studies have investigated the effects of L-glutathione on immune function in various disease states, such as HIV/AIDS and chronic fatigue syndrome. These studies suggest that L-glutathione may be effective in improving immune function and reducing symptoms in these conditions.
L-Glutathione and Liver Health
L-glutathione is also important for liver health, as it plays a critical role in the detoxification of harmful compounds in the liver. Clinical studies have investigated the effects of L-glutathione on liver function in conditions such as non-alcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD). These studies suggest that L-glutathione may be effective in improving liver function and reducing liver damage in these conditions.
Conclusion
L-glutathione is an important endogenous antioxidant that plays a critical role in antioxidant defense and cellular function. Clinical studies suggest that L-glutathione may have potential therapeutic applications in various disease states, including oxidative stress, skin complexion, immune function and liver health.
References:
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Arjinpathana N, Asawanonda P. Glutathione as an oral whitening agent: a randomized, double-blind, placebo-controlled study. J Dermatolog Treat. 2012;23(2):97-102. doi: 10.3109/09546634.2010.543261
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Watanabe F, Hashizume E, Chan GP, et al. Skin-whitening and skin-condition-improving effects of topical oxidized glutathione: a double-blind and placebo-controlled clinical trial in healthy women. Clin Cosmet Investig Dermatol. 2014;7:267-274. doi: 10.2147/CCID.S64005
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Weschawalit S, Thongthip S, Phutrakool P, Asawanonda P. Glutathione and its antiaging and antimelanogenic effects. Clin Cosmet Investig Dermatol. 2017;10:147-153. doi: 10.2147/CCID.S128339
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Buang Y, Wang Y, Chaikul P, et al. Skin rejuvenation effects of topical application of an antioxidant cocktail containing vitamin C, ferulic acid, and glutathione: a double-blind, placebo-controlled clinical trial. J Cosmet Dermatol. 2020;19(10):2528-2535. doi: 10.1111/jocd.13520