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Review

Medical and Dietary Uses of N-Acetylcysteine

1
Center for human molecular genetics and pharmacogenomics, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia
2
Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, SI-1000 Ljubljana, Slovenia
3
University of Ljubljana, Faculty of Health Sciences, Laboratory of Oxidative Stress Research, Zdravstvena pot 5, SI-1000 Ljubljana, Slovenia
*
Author to whom correspondence should be addressed.
Antioxidants 2019, 8(5), 111; https://doi.org/10.3390/antiox8050111
Submission received: 8 March 2019 / Revised: 9 April 2019 / Accepted: 23 April 2019 / Published: 28 April 2019

Abstract

:
N-acetylcysteine (NAC), a plant antioxidant naturally found in onion, is a precursor to glutathione. It has been used as a drug since the 1960s and is listed on the World Health Organization (WHO) Model List of Essential Medicines as an antidote in poisonings. There are numerous other uses or proposed uses in medicine that are still in preclinical and clinical investigations. NAC is also used in food supplements and cosmetics. Despite its abundant use, there are projections that the NAC global market will grow in the next five years; therefore, the purpose of this work is to provide a balanced view of further uses of NAC as a dietary supplement. Although NAC is considered a safe substance, the results among clinical trials are sometimes controversial or incomplete, like for many other antioxidants. More clinical trials are underway that will improve our understanding of NAC applicability.

1. Introduction

N-acetylcysteine (also known as N-acetyl-cysteine, NAC) is a precursor to the amino acid L-cysteine and consequently the antioxidant glutathione (GSH) [1]. It is most notably found in plants of the Allium species, especially in the onion (Allium cepa, 45 mg NAC/kg) [2,3]. The sulfhydryl group (–SH) within the NAC molecule directly scavenges reactive oxygen species (ROS) [4], modulates the redox state of the N-methyl-D-aspartate (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors (neurotransmitter effect) [5], and inhibits the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) to modulate cytokine synthesis (anti/pro-inflammatory effect) [6]. Unlike GSH itself, NAC has better oral and topical bioavailability [7,8]. Even though it has been used for more than 50 years, there are still many controversies surrounding it as a medicine as well as a dietary supplement. Several review articles have focused on various medical uses of NAC, some more general [9] and others highly specific dealing with NAC use only in a particular condition such as hyperglycaemia-induced oxidative damage [10], liver diseases [11], and traumatic brain injury [12]. Other reviews have discussed the use of NAC as a dietary supplement in psychiatric conditions by itself [13] or in conjunction with other supplements [14,15]. However, we were unable to find a review of both medical and supplementary uses of NAC.

2. Molecular Mechanisms: Both Sides of the Redox Equation

GSH is the most abundant intracellular free thiol, and its decrease (and the increase in its redox couple oxidized glutathione, GSSG) has a crucial role in cell oxidative capacity [16]. It is required for stem cell function [17], and its depletion triggers cell death pathways [18]. Cellular oxidative stress is often seen as a GSH deficiency that is characteristic of many pathological conditions such as heart disease [19], diabetes [20], neurodegenerative disease [21], AIDS [22], as well as normal aging [23]. Though primarily seen as an antioxidant, NAC also has pro-oxidative effects. While NAC can scavenge several ROS (including HOCl, ONOO, RO2) [24] and hydroxyl radicals (OH) [25], it has a poor ability for sequestering O2●− [26] and hydrogen peroxide (H2O2) in vitro [27]. NAC can behave as an oxidant by undergoing auto-oxidation in high concentrations or in the presence of transition metals. NAC can reduce transitional metals and promote the formation of ROS via Fenton-like chemistry or the production of thiyl radical:
NAC(SH) + Fe3+ → NAC(S●−) + Fe2+ + H+
For example, by reducing ferric iron to its catalytic, active Fe2+ form, NAC enhances the production of hydroxyl radicals in the in vitro system with Fe(III)-citrate and H2O2 [28]. Dose-dependent oxidative damage to DNA was observed in the presence of NAC in the presence of the transition metal, copper [29]. Besides, the products of pro-oxidant reactions mediated by NAC are involved in altering the redox-sensitive NF-κB signal transduction pathway activation; mitogen activated protein kinase p38 (p38MAPK) and c-Jun N-terminal kinase (JNK) phosphorylation [30,31]. The antioxidant and pro-oxidant effects of NAC have been discussed in greater detail elsewhere [32].

3. Medical Use of NAC

NAC has been an established drug since the 1960s; it is on the World Health Organization’s List of 40 Essential Medicines [33] and is available as an inexpensive generic drug. It has been classically used in paracetamol overdose [34] and as a mucolytic [35], as well as to combat the toxicity of various substances that can cause generation of free radicals, such as carbon monoxide and x-ray contrasts [36]. The NAC products currently approved by Food and Drug Administration (FDA) are listed in Table 1. NAC is also used in the complementary treatment of neurological and neuropsychiatric disorders [5,35]. One death due to an anaphylactic reaction was described following an intravenous (IV) injection of 150 mg/kg of NAC in a 40 year old asthmatic woman in 2002. At comparable IV doses, vomiting was also reported in 11% of patients [37]. However, oral NAC seems to be associated with very few side effects and is considered to have an excellent safety profile [35]. One case of angioedema after oral NAC administration was described in 1997 [38]. Clinical studies have revealed benefits of NAC also in non-alcoholic steatohepatitis [39], arterial hypertension of diabetic etiology [40], chronic obstructive pulmonary disease (COPD) [41,42] and chronic bronchitis [43], substance abuse disorders [44], recurrent unexplained pregnancy loss [45], male infertility [46], polycystic ovary syndrome [47], diabetic retinopathy, age-related macular degeneration, and cataract and dry eye syndrome [4]. In total, 300 clinical studies (291 clinical trials) of NAC are listed in ClinicalTrials.gov [48] in April 2019 (Table 2). The most common disorders that were investigated by listed interventional trials with NAC (without the currently active studies) included renal disorders (48 trials) with an emphasis on radiocontrast nephropathy prevention, chronic kidney disease, and renoprotection during surgery; and neurological and psychiatric disorders (36 trials), leading with Parkinson’s disease, schizophrenia, bipolar, autistic, and behavioral disorders. Schizophrenia, for instance, has been linked to mitochondrial abnormalities, glutathione deficiency, and increased oxidative stress in the brain. Negative and general symptoms in schizophrenia may be reduced after 8–24 weeks of adjunctive treatment with NAC [49] in neuropsychiatric disorders and are discussed in greater detail in a recent review [50]. Addictive disorders (23 trials) are also a common target, with alcohol, tobacco, cocaine, cannabis, and other types of dependence. The NMDA receptors that NAC modulates may be involved in addiction [51], and at least three reviews discuss the use of NAC in addictive disorders [44,52,53] and emphasize the reduction of cravings for the substance in question. Among other commonly investigated uses of NAC were applications in gastrointestinal and pulmonary diseases. The majority of the 54 currently active interventional studies are investigating the role of NAC in addictive disorders, mental health, and neurodegenerative diseases, followed by cancer/cancer treatment side-effects, cardiovascular diseases, and surgery complications/trauma.
The suspended, terminated, or withdrawn studies listed in ClinicalTrals.gov are in Table 3. Termination reasons, such as no improvement and opposite results, are recorded in only 3 out of the 23 trials. Insufficient funds and insufficient recruitment are the major termination/ suspension/ withdrawal reason [48]. There are a few reports of the NAC study premature termination in the literature. High doses of NAC did not improve respiratory health in patients with COPD and chronic bronchitis; the study was prematurely terminated [54]. The decision was based on a potential safety issue, as it was reported that NAC and vitamin E, given orally, induced lung cancer in mice. This finding was reproduced in cell lines from human and mice lung tumors [55]. Additionally, there was no indication of improvement of COPD/chronic bronchitis in the 23 patients that received 1800 mg NAC twice daily for 8 weeks compared to the equal number of subjects receiving placebo [54]. Results of a 24-week oral NAC supplementation of cystic fibrosis patients revealed that NAC recipients maintained their lung function without a significant effect on the biomarkers of neutrophilic inflammation [56]. Another trial was prematurely terminated in 2018 due to the absence of between-group differences in the rates of contrast-associated acute kidney injury; there was no noticeable benefit of the oral NAC on the contrast-associated acute kidney injury prevention, no noticeable improvement on the need for dialysis, persistent kidney injury or death in subjects at high risk of renal complications because of angiography [57]. Similar conclusions were reached from the “Acetylcysteine for contrast-induced neuropathy” trial [58].
Pre-clinical studies imply that NAC could have more uses in supportive care and preventing human disease. Examples include Alzheimer’s disease [59,60], asthma [61], inflammatory bowel disease [62], influenza [63], intrauterine growth retardation [64], obesity and insulin resistance [65,66,67,68], ischemic cardiovascular disease [69,70], heavy metal toxicity [71,72], diabetic neuropathy [73], and age-related memory impairment [74]. Due to its capacity to break down biofilms and improve antibiotic permeability, it is promising as an adjuvant antimicrobial drug [75]. Several pre-clinical studies have also demonstrated that NAC supplementation leads to life extension and diminished effects of aging, in invertebrates [76,77,78,79] as well as mammals [80] and in human breast epithelial stem cells [81]. Such findings have yet to be replicated in humans. This is likely not solely due to NAC’s radical scavenging activity but also at least in part to telomerase activation and apoptosis inhibition [82], as is evidenced also by its capacity to delay oocyte aging [83]. However, antioxidants have the potential to either lengthen or shorten lifespan, depending on the dose and redox balance [84].
The role of NAC in the prevention and treatment of cancer is controversial, and it is discussed in more detail below. NAC has also attracted considerable attention as a sports supplement that can reduce muscle fatigue, improve athletic performance, and aid muscle recovery [85]. Although NAC is a well-known antioxidant and an old generic drug with several established clinical applications, more potential uses are still inadequately investigated. One of the main challenges of NAC as a medicine and a supplement is its broad range of effects and applications, far too few of which are well studied, in spite of a large effort in conducting preclinical and clinical trials.

4. NAC in Prevention and Complementary Treatment of Cancer

The role of antioxidants and reactive oxygen species (ROS) in cancer is controversial [86]. Epidemiological studies on synthetic antioxidants supplementation are inconclusive and contradictory mainly due to (1) anti vs. pro-oxidative properties of antioxidant and (2) antioxidant involvement in intracellular signaling and redox regulation, which modulate proliferation, apoptosis, and gene expression [87]. This is of particular significance during cell malignant transformation. Antioxidants in general are able to reduce the frequency of the malignant transformation by directly sequestrating ROS or by induction of cellular repair and adaptive stress responses that are important in preventing cancer initiation. For example, in experimental models of breast cancer, N-Acetylcysteine (NAC) reduced cancer aggressiveness, proliferation, and increased apoptosis of cancer cells [88,89]. By decreasing oxidative stress and inflammatory mediators, NAC interferes with intracellular metabolic processes by repressing glycolysis and increasing mitochondrial functioning [90,91]. On the other hand, antioxidant treatment may increase survival of cancer/precancer cells administered after malignant transformation [86]. The antioxidant supplementation in tumor-bearing mice was associated with accelerated cancer progression and increased metastasis in some preclinical studies [92,93]. The combination of N-acetylcysteine (NAC) and soluble vitamin E analog Trolox increased the migration and invasive properties of human malignant melanoma cells in an endogenous mouse model of malignant melanoma [92]. Similarly, N-acetylcysteine and vitamin E accelerated lung cancer progression in mice by reducing survival and increased tumor progression by disrupting the ROS-p53 axis [55].
In patients undergoing cancer therapy, antioxidant supplementation may alleviate unwanted radiation and chemotherapy-induced toxicity by quenching free radicals but also reduce the efficacy of chemo- and radiotherapy. This may increase (malignant and non-malignant) cell survival by altering cellular signal transduction pathways that regulate cell proliferation [94]. The reduction of ROS by antioxidants can lead to the survival of pre-initiated tumor cells, even in unnatural matrix environments [95]. Thus, NAC may have dichotomous effects with respect to tumorigenesis and NAC administration may differ depending on the stage of malignant transformation. By enhancing resistance to oxidative stress and decreased apoptosis during cancer promotion, progression, and treatment stages, NAC supplementation may not always be beneficial, since it may increase cancer cell survival in altered matrix environments by antioxidant restoration of adenosine triphosphate (ATP) generation [96]. Further clinical studies should be performed to address whether NAC administration ameliorates toxic side effects of radiation and chemotherapy with or without affecting the treatment efficacy.

5. NAC as a Dietary Supplement

Like many antioxidants, NAC has been very successful in the pharmaceutical, dietary supplement, and nutraceutical markets. In 2016 alone, Europe consumed approximately 3908.2 MT, USA approximately 3005.4 MT, and India approximately 1392.3 MT. The global market for NAC is expected to grow at a compound annual growth rate of about 22% over the next five years, from 490 million USD in 2017 [97]. Sellers of dietary supplements make a number of claims about the potential of NAC to protect against environmental toxins and pollutants, treat diverse conditions, extend lifespan, and even increase testosterone levels in men—in spite of limited scientific evidence. Little to no reliable information is available about the effects experienced by numerous users of NAC as a dietary supplement. The NAC-containing product with the most reviews on Amazon.com (100% NAC powder 1 kg, 905 reviews) has an average rating of 4.6 out of 5 stars [98]. Similar ratings can be seen for other popular NAC products. The 95 reviews on the website WebMD [99] convey similar impressions. None of this qualifies as scientific data, but we infer that NAC is popular as a dietary supplement.

6. NAC as a Sports Supplement, Effects in Skeletal Muscle

The performance of NAC as a sports supplement is discussed in detail in a recent meta-analysis by Rhodes and Brakhuis [85]. There is a great variability of study results also because of heterogenous methodologies. However, some studies have shown very significant athletic performance increases during repeated bouts of intermittent exercise (up to 50%) with NAC supplementation, particularly in athletes who have the capacity to generate more ROS in their muscles during exercise [100]. It also appears that the benefits of NAC are more significant when muscles are in a pre-fatigued state, and thus the produced ROS can exceed the buffering capacity of the endogenous antioxidant system. One of the major challenges of using NAC as a sports supplement is in the dosage and timing of administration, which are not standardized. For example, the daily dose of NAC in the studies included by Rhodes and Brakhuis varied from 1.2 to 20 g, and the supplementation period from 8 days to minutes before the performance. The heterogenous effects of NAC in various studies reflect the fact that there is a multifactorial optimum to the redox state of various tissues that is challenging to tackle, and either too much or too little of an antioxidant can lead to performance decrease and damage. According to the Rhodes and Brakhuis meta-analysis, larger doses of NAC (>5g) have an increased potential to cause side effects. Even though these side effects are generally mild and limited to gastrointestinal disturbances, they can hamper athletic performance and thus defy the purpose of supplementation. However, the evidence for these side effects is limited, and in several of the studies included in Rhodes and Brakhuis meta-analysis no side effects were reported in spite of the large doses.

7. NAC as an Anti-Aging Supplement, Effects on Degenerative Processes

NAC can potentially be effective in degenerative processes caused by aging, for instance, in neurodegenerative disorders, neuropathic pain, and stroke [101]. The present findings from animal studies support a neuroprotective role of NAC in controlling age-related neurological disorders [102]. For instance, NAC protects against Cd-induced neuronal apoptosis in mouse brain partially by inhibiting ROS-dependent activation of Akt/mTOR pathway. The findings highlight that NAC may be exploited for prevention and treatment of Cd-induced neurodegenerative diseases [103]. Animal model results support the possibility that NAC could be explored in clinical trials for amyotrophic lateral sclerosis disease [104], as well as Alzheimer’s disease [105] and mild cognitive impairment [106]. Further animal studies have shown that it delays age-associated memory impairment [74] and improves aging-related myocardial dysfunctions [70]. Since oxidative stress plays a prominent role in the modulation of neuropathic pain, NAC could be a potential candidate for its alleviation [107]. Furthermore, NAC could be used in endotoxemic states to prevent oxidative damage [108]. This warrants some caution, because NAC was associated with cardiac performance depression in a human trial [109]. NAC has a potential to improve immune function among the elderly [110]. A recent meta-analysis has also revealed a positive effect of NAC on human cognition, in healthy as well as mentally ill individuals [111]. NAC may be helpful in chronic fatigue syndrome [112]. Topical NAC may prevent UV-associated photoaging of the skin [7]. The synthesis of GSH is decreased in the elderly, which increases oxidative stress, itself a propagator of aging. This effect can be reversed with dietary supplementation [23]. Many medical conditions with beneficial role of NAC that are listed above are aging-associated. Based on these facts and the known molecular mechanisms of NAC as an antioxidant, we can hypothesize that it has potential as an anti-aging supplement. The dosage and timing of administration are even more of a concern here than in the case of sports supplementation, since ameliorating the effects of aging would require its long-term use. This would also raise the question of potential long-term side effects, which remains to be answered.

8. Summary and Conclusion, Future Perspectives

NAC is an established generic mucolytic and paracetamol poisoning antidote, but the list of conditions it can potentially improve has grown steadily over the years, and so has its popularity as a dietary supplement. In in vitro as well as in animal experiments it has exhibited potent antioxidant properties, which make NAC a powerful tool for diseases and states where ROS are the major cause of damage. However, modulating the redox state of cells, tissues, and organs is a delicate matter, and turning the dial too far in the antioxidant direction can cause more harm than good. Combined with heterogenous methodologies and a lack of standardization, the results of different studies are bound to conflict, which complicates the deduction of NAC’s effects. This is the major setback, since without determining the necessity, dosage, and timing of administration, optimal balancing of the redox scales is not possible. Developing and implementing technologies to measure the personalized levels of ROS and other oxidants and adjust the doses of antioxidants accordingly instead of using them blindly would provide an advantage, but also clinical and technological challenges. There is a wealth of unexploited information in the form of thousands of anonymous users of NAC as a dietary supplement. Since there is no regulation or documentation of this usage, we are missing out on potential information about the effects of NAC (and other antioxidants) in large numbers of people. Even though (especially oral) administration of NAC has been safe, the results of clinical trials for many conditions are still indecisive. Like other supplemented antioxidants, it may be harmful in the case of cancer or premalignancy, but there seem no other obstacles to studying NAC in many other conditions. More clinical trials of its use in neurodegenerative diseases, addiction, and mental health disorders are underway. This will provide much-needed information on NAC, and may be relevant to the supplement users. At the same time, it may help people suffering from chronic degenerative conditions.

Author Contributions

S.S. and B.P. wrote a manuscript draft, I.M. conceived and finalized the manuscript with inputs from all authors. B.K., T.P.M., and I.M. analyzed Clinical Trials data and produced all tables.

Funding

B.P. and I.M. are partially supported by Slovenian Research Agency (research core funding No. P3-0388 and P3-0019, respectively). B.K. is supported by the H2020-MSCA-ITN:721236 TREATMENT project and T.P.M. by the Slovenian Research Agency Early Stage Researcher Scheme.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Pieralisi, A.; Martini, C.; Soto, D.; Vila, M.C.; Calvo, J.C.; Guerra, L.N. N-acetylcysteine inhibits lipid accumulation in mouse embryonic adipocytes. Redox Biol. 2016, 9, 39–44. [Google Scholar] [CrossRef] [Green Version]
  2. Diniz, Y.S.; Rocha, K.K.H.R.; Souza, G.A.; Galhardi, C.M.; Ebaid, G.M.X.; Rodrigues, H.G.; Novelli Filho, J.L.V.B.; Cicogna, A.C.; Novelli, E.L.B. Effects of N-acetylcysteine on sucrose-rich diet-induced hyperglycaemia, dyslipidemia and oxidative stress in rats. Eur. J. Pharmacol. 2006, 543, 151–157. [Google Scholar] [CrossRef]
  3. Campos, K.E.; Diniz, Y.S.; Cataneo, A.C.; Faine, L.A.; Alves, M.J.Q.F.; Novelli, E.L.B. Hypoglycaemic and antioxidant effects of onion, Allium cepa: Dietary onion addition, antioxidant activity and hypoglycaemic effects on diabetic rats. Int. J. Food Sci. Nutr. 2003, 54, 241–246. [Google Scholar] [CrossRef]
  4. Radomska-Leśniewska, D.M.; Skopiński, P. N-acetylcysteine as an anti-oxidant and anti-inflammatory drug and its some clinical applications. Cent. J. Immunol. 2012, 37, 57–66. [Google Scholar]
  5. Bavarsad Shahripour, R.; Harrigan, M.R.; Alexandrov, A.V. N-acetylcysteine (NAC) in neurological disorders: mechanisms of action and therapeutic opportunities. Brain Behav. 2014, 4, 108–122. [Google Scholar] [CrossRef] [Green Version]
  6. Guo, F.; Li, Y.; Wang, J.; Li, Y.; Li, Y.; Li, G. Stanniocalcin1 (STC1) Inhibits Cell Proliferation and Invasion of Cervical Cancer Cells. PLoS One 2013, 8, e53989. [Google Scholar] [CrossRef]
  7. Kang, S.; Chung, J.H.; Lee, J.H.; Fisher, G.J.; Wan, Y.S.; Duell, E.A.; Voorhees, J.J. Topical N-Acetyl Cysteine and Genistein Prevent Ultraviolet-Light-Induced Signaling That Leads to Photoaging in Human Skin in vivo. J. Invest. Dermatol. 2003, 120, 835–841. [Google Scholar] [CrossRef]
  8. Schmitt, B.; Vicenzi, M.; Garrel, C.; Denis, F.M. Effects of N-acetylcysteine, oral glutathione (GSH) and a novel sublingual form of GSH on oxidative stress markers: A comparative crossover study. Redox Biol. 2015, 6, 198–205. [Google Scholar] [CrossRef]
  9. Mokhtari, V.; Afsharian, P.; Shahhoseini, M.; Kalantar, S.M.; Moini, A. A Review on Various Uses of N-Acetyl Cysteine. Cell J. 2017, 19, 11–17. [Google Scholar]
  10. Dludla, P.V.; Nkambule, B.B.; Dias, S.C.; Johnson, R. Cardioprotective potential of N-acetyl cysteine against hyperglycaemia-induced oxidative damage: a protocol for a systematic review. Syst. Rev. 2017, 6, 96. [Google Scholar] [CrossRef]
  11. de Andrade, K.; Moura, F.; dos Santos, J.; de Araújo, O.; de Farias Santos, J.; Goulart, M.; De Andrade, K.Q.; Moura, F.A.; Dos Santos, J.M.; De Araújo, O.R.P.; et al. Oxidative Stress and Inflammation in Hepatic Diseases: Therapeutic Possibilities of N-Acetylcysteine. Int. J. Mol. Sci. 2015, 16, 30269–30308. [Google Scholar] [CrossRef] [Green Version]
  12. Hoffer, B.J.; Pick, C.G.; Hoffer, M.E.; Becker, R.E.; Chiang, Y.-H.; Greig, N.H. Repositioning drugs for traumatic brain injury - N-acetyl cysteine and Phenserine. J. Biomed. Sci. 2017, 24, 71. [Google Scholar] [CrossRef] [Green Version]
  13. Smith, L.; Tracy, D.K.; Giaroli, G. What Future Role Might N-Acetyl-Cysteine Have in the Treatment of Obsessive Compulsive and Grooming Disorders? J. Clin. Psychopharmacol. 2016, 36, 57–62. [Google Scholar] [CrossRef] [Green Version]
  14. Plemenitaš, A. Prehrana in prehranska dopolnila v psihiatriji. Slov. Med. J. 2018, 87, 1–2. [Google Scholar] [CrossRef]
  15. di Michele, F.; Siracusano, A.; Talamo, A.; Niolu, C. N-Acetyl Cysteine and Vitamin D Supplementation in Treatment Resistant Obsessive-compulsive Disorder Patients: A General Review. Curr. Pharm. Des. 2018, 24, 1832–1838. [Google Scholar] [CrossRef]
  16. Schafer, F.Q.; Buettner, G.R. Redox environment of the cell as viewed through the redox state of the glutathione disulfide/glutathione couple. Free Radic. Biol. Med. 2001, 30, 1191–1212. [Google Scholar] [CrossRef]
  17. Jeong, E.M.; Yoon, J.-H.; Lim, J.; Shin, J.-W.; Cho, A.Y.; Heo, J.; Lee, K.B.; Lee, J.-H.; Lee, W.J.; Kim, H.-J.; et al. Real-Time Monitoring of Glutathione in Living Cells Reveals that High Glutathione Levels Are Required to Maintain Stem Cell Function. Stem Cell Rep. 2018. [Google Scholar] [CrossRef]
  18. Franco, R.; Cidlowski, J.A. Glutathione efflux and cell death. Antioxid. Redox Signal. 2012, 17, 1694–1713. [Google Scholar] [CrossRef]
  19. Damy, T.; Kirsch, M.; Khouzami, L.; Caramelle, P.; Le Corvoisier, P.; Roudot-Thoraval, F.; Dubois-Randé, J.-L.; Hittinger, L.; Pavoine, C.; Pecker, F. Glutathione Deficiency in Cardiac Patients is Related to the Functional Status and Structural Cardiac Abnormalities. PLoS One 2009, 4, e4871. [Google Scholar] [CrossRef]
  20. Lutchmansingh, F.K.; Hsu, J.W.; Bennett, F.I.; Badaloo, A.V.; McFarlane-Anderson, N.; Gordon-Strachan, G.M.; Wright-Pascoe, R.A.; Jahoor, F.; Boyne, M.S. Glutathione metabolism in type 2 diabetes and its relationship with microvascular complications and glycemia. PLoS One 2018, 13, e0198626. [Google Scholar] [CrossRef]
  21. Doss, S.; Rinnenthal, J.L.; Schmitz-Hübsch, T.; Brandt, A.U.; Papazoglou, S.; Lux, S.; Maul, S.; Würfel, J.; Endres, M.; Klockgether, T.; et al. Cerebellar neurochemical alterations in spinocerebellar ataxia type 14 appear to include glutathione deficiency. J. Neurol. 2015, 262, 1927–1935. [Google Scholar] [CrossRef] [PubMed]
  22. Dröge, W. Cysteine and Glutathione Deficiency in AIDS Patients: A Rationale for the Treatment with IM-Acetyl-Cysteine. Pharmacol. 1993, 46, 61–65. [Google Scholar]
  23. Sekhar, R.V.; Patel, S.G.; Guthikonda, A.P.; Reid, M.; Balasubramanyam, A.; Taffet, G.E.; Jahoor, F. Deficient synthesis of glutathione underlies oxidative stress in aging and can be corrected by dietary cysteine and glycine supplementation. Am. J. Clin. Nutr. 2011, 94, 847–853. [Google Scholar] [CrossRef] [PubMed]
  24. Halliwell, B.; Gutteridge, J.M.C. Free Radicals in Biology and Medicine, 4th ed.; Oxford University Press: Oxford, UK, 2007. [Google Scholar]
  25. Aruoma, O.I.; Halliwell, B.; Hoey, B.M.; Butler, J. The antioxidant action of N-acetylcysteine: Its reaction with hydrogen peroxide, hydroxyl radical, superoxide, and hypochlorous acid. Free Radic. Biol. Med. 1989, 6, 593–597. [Google Scholar] [CrossRef]
  26. Benrahmoune, M.; Thérond, P.; Abedinzadeh, Z. The reaction of superoxide radical with N-acetylcysteine. Free Radic. Biol. Med. 2000, 29, 775–782. [Google Scholar] [CrossRef]
  27. Moldéus, P.; Cotgreave, I.A.; Berggren, M. Lung Protection by a Thiol-Containing Antioxidant: N-Acetylcysteine. Respiration 1986, 50, 31–42. [Google Scholar] [CrossRef] [PubMed]
  28. Corinne Sprong, R.; Winkelhuyzen-Janssen, A.M.L.; Aarsman, C.J.; van Oirschot, J.F.; van der Bruggen, T.J.O.M.M.E.; Sweder van Asbeck, B. Low-dose N-Acetylcysteine Protects Rats against Endotoxin-mediated Oxidative Stress, But High-dose Increases Mortality. Am. J. Respir. Crit. Care Med. 1998, 157, 1283–1293. [Google Scholar] [CrossRef]
  29. Spear, N.; Aust, S.D. Hydroxylation of Deoxyguanosine in DNA by Copper and Thiols. Arch. Biochem. Biophys. 1995, 317, 142–148. [Google Scholar] [CrossRef] [PubMed]
  30. Das, K.C.; Lewis-Molock, Y.; White, C.W. Activation of NF-kappa B and elevation of MnSOD gene expression by thiol reducing agents in lung adenocarcinoma (A549) cells. Am. J. Physiol. Cell. Mol. Physiol. 1995, 269, L588–L602. [Google Scholar] [CrossRef] [PubMed]
  31. Chan, E.D.; Riches, D.W.H.; White, C.W. Redox Paradox: Effect of N-Acetylcysteine and Serum on Oxidation Reduction–Sensitive Mitogen-Activated Protein Kinase Signaling Pathways. Am. J. Respir. Cell Mol. Biol. 2001, 24, 627–632. [Google Scholar] [CrossRef] [Green Version]
  32. Sagristá, M.L.; García, A.E.; Africa De Madariaga, M.; Mora, M. Antioxidant and pro-oxidant effect of the thiolic compounds N-acetyl-L-cysteine and glutathione against free radical-induced lipid peroxidation. Free Radic. Res. 2002, 36, 329–340. [Google Scholar] [CrossRef] [PubMed]
  33. World Health Organization. WHO Model List of Essential Medicines: 20th List. March 2017. Available online: http://www.who.int/medicines/publications/essentialmedicines/20th_EML2017_FINAL_amendedAug2017.pdf?ua=1 (accessed on 27 March 2019).
  34. FDA. Acetadote (acetylcysteine) Injection Package Insert. Available online: https://www.accessdata.fda.gov/drugsatfda_docs/nda/2004/21-539_Acetadote.cfm (accessed on 27 March 2019).
  35. Slattery, J.; Kumar, N.; Delhey, L.; Berk, M.; Dean, O.; Spielholz, C.; Frye, R. Clinical trials of N-acetylcysteine in psychiatry and neurology: A systematic review. Neurosci. Biobehav. Rev. 2015, 55, 294–321. [Google Scholar] [Green Version]
  36. Pannu, N.; Manns, B.; Lee, H.; Tonelli, M. Systematic review of the impact of N-acetylcysteine on contrast nephropathy. Kidney Int. 2004, 65, 1366–1374. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  37. Center for Drug Evaluation and Research. Application no. 21-539. Medical Review (Robert Prizont, MD), 2003. Available online: https://www.accessdata.fda.gov/drugsatfda_docs/nda/2004/21-539_Acetadote_Medr.pdf (accessed on 13 February 2019).
  38. Mroz, L.S.; Benitez, J.G.; Krenzelok, E.P. Angioedema with oral N-acetylcysteine. Ann. Emerg. Med. 1997, 30, 240–241. [Google Scholar] [PubMed]
  39. De Oliveira, C.P.; Stefano, J.T.; De Siqueira, E.R.; Silva, L.S.; De Campos Mazo, D.F.; Lima, V.M.; Furuya, C.K.; Mello, E.S.; Souza, F.G.; Rabello, F.; et al. Combination of N-acetylcysteine and metformin improves histological steatosis and fibrosis in patients with non-alcoholic steatohepatitis. Hepatol. Res. 2008, 38, 159–165. [Google Scholar] [CrossRef]
  40. Martina, V.; Masha, A.; Gigliardi, V.R.; Brocato, L.; Manzato, E.; Berchio, A.; Massarenti, P.; Settanni, F.; Della Casa, L.; Bergamini, S.; et al. Long Term N-Acetylcysteine and L-Arginine Administration Reduces Endothelial Activation and Systolic Blood Pressure in Hypertensive Patients with Type 2 Diabetes Mellitus. Diabetes Care 2008, 31, 940–944. [Google Scholar] [CrossRef] [PubMed]
  41. Tse, H.N.; Tseng, C.Z.S. Update on the pathological processes, molecular biology, and clinical utility of N-acetylcysteine in chronic obstructive pulmonary disease. Int. J. Chron. Obstruct. Pulmon. Dis. 2014, 9, 825–836. [Google Scholar] [CrossRef] [Green Version]
  42. Pirabbasi, E.; Shahar, S.; Manaf, Z.A.; Rajab, N.F.; Manap, R.A. Efficacy of Ascorbic Acid (Vitamin C) and/N-Acetylcysteine (NAC) Supplementation on Nutritional and Antioxidant Status of Male Chronic Obstructive Pulmonary Disease (COPD) Patients. J. Nutr. Sci. Vitaminol. (Tokyo) 2016, 62, 54–61. [Google Scholar] [CrossRef] [Green Version]
  43. Stey, C.; Steurer, J.; Bachmann, S.; Medici, T.C.; Tramèr, M.R. The effect of oral N-acetylcysteine in chronic bronchitis: a quantitative systematic review. Eur. Respir. J. 2000, 16, 253–262. [Google Scholar] [CrossRef] [Green Version]
  44. McClure, E.A.; Gipson, C.D.; Malcolm, R.J.; Kalivas, P.W.; Gray, K.M. Potential role of N-acetylcysteine in the management of substance use disorders. CNS Drugs 2014, 28, 95–106. [Google Scholar] [CrossRef]
  45. Amin, A.F.; Shaaban, O.M.; Bediawy, M.A. N-acetyl cysteine for treatment of recurrent unexplained pregnancy loss. Reprod. Biomed. Online 2008, 17, 722–726. [Google Scholar] [CrossRef]
  46. Safarinejad, M.R.; Safarinejad, S. Efficacy of Selenium and/or N-Acetyl-Cysteine for Improving Semen Parameters in Infertile Men: A Double-Blind, Placebo Controlled, Randomized Study. J. Urol. 2009, 181, 741–751. [Google Scholar] [CrossRef] [PubMed]
  47. Fulghesu, A.M.; Ciampelli, M.; Muzj, G.; Belosi, C.; Selvaggi, L.; Ayala, G.F.; Lanzone, A. N-acetyl-cysteine treatment improves insulin sensitivity in women with polycystic ovary syndrome. Fertil. Steril. 2002, 77, 1128–1135. [Google Scholar] [CrossRef]
  48. ClinicalTrials.gov. Available online: https://clinicaltrials.gov (accessed on 2 April 2019).
  49. Chen, A.T.; Chibnall, J.T.; Nasrallah, H.A. Placebo-controlled augmentation trials of the antioxidant NAC in schizophrenia: A review. Ann. Clin. Psychiatry 2016, 28, 190–196. [Google Scholar] [PubMed]
  50. Rapado-Castro, M.; Dodd, S.; Bush, A.I.; Malhi, G.S.; Skvarc, D.R.; On, Z.X.; Berk, M.; Dean, O.M. Cognitive effects of adjunctive N-acetyl cysteine in psychosis. Psychol. Med. 2017, 47, 866–876. [Google Scholar] [CrossRef] [PubMed]
  51. Hopf, F.W. Do specific NMDA receptor subunits act as gateways for addictive behaviors? Genes. Brain. Behav. 2017, 16, 118–138. [Google Scholar] [CrossRef] [PubMed]
  52. Tomko, R.L.; Jones, J.L.; Gilmore, A.K.; Brady, K.T.; Back, S.E.; Gray, K.M. N-acetylcysteine: A potential treatment for substance use disorders. Curr. Psychiatr. 2018, 17, 30–36, 41–42, 55. [Google Scholar] [PubMed]
  53. Nocito Echevarria, M.A.; Andrade Reis, T.; Ruffo Capatti, G.; Siciliano Soares, V.; da Silveira, D.X.; Fidalgo, T.M. N-acetylcysteine for treating cocaine addiction – A systematic review. Psychiatry Res. 2017, 251, 197–203. [Google Scholar] [CrossRef]
  54. Johnson, K.; McEvoy, C.E.; Naqvi, S.; Wendt, C.; Reilkoff, R.A.; Kunisaki, K.M.; Wetherbee, E.E.; Nelson, D.; Tirouvanziam, R.; Niewoehner, D.E. High-dose oral N-acetylcysteine fails to improve respiratory health status in patients with chronic obstructive pulmonary disease and chronic bronchitis: A randomized, placebo-controlled trial. Int. J. Chron. Obstruct. Pulmon. Dis. 2016, 11, 799–807. [Google Scholar]
  55. Sayin, V.I.; Ibrahim, M.X.; Larsson, E.; Nilsson, J.A.; Lindahl, P.; Bergo, M.O. Antioxidants Accelerate Lung Cancer Progression in Mice. Sci. Transl. Med. 2014, 6, 221ra15. [Google Scholar] [CrossRef]
  56. Conrad, C.; Lymp, J.; Thompson, V.; Dunn, C.; Davies, Z.; Chatfield, B.; Nichols, D.; Clancy, J.; Vender, R.; Egan, M.E.; et al. Long-term treatment with oral N-acetylcysteine: Affects lung function but not sputum inflammation in cystic fibrosis subjects. A phase II randomized placebo-controlled trial. J. Cyst. Fibros. 2015, 14, 219–227. [Google Scholar] [CrossRef]
  57. Weisbord, S.D.; Gallagher, M.; Jneid, H.; Garcia, S.; Cass, A.; Thwin, S.-S.; Conner, T.A.; Chertow, G.M.; Bhatt, D.L.; Shunk, K.; et al. Outcomes after Angiography with Sodium Bicarbonate and Acetylcysteine. N. Engl. J. Med. 2018, 378, 603–614. [Google Scholar] [CrossRef]
  58. ACT Investigators. Acetylcysteine for Prevention of Renal Outcomes in Patients Undergoing Coronary and Peripheral Vascular Angiography. Circulation 2011, 124, 1250–1259. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  59. Moreira, P.I.; Harris, P.L.R.; Zhu, X.; Santos, M.S.; Oliveira, C.R.; Smith, M.A.; Perry, G. Lipoic acid and N-acetyl cysteine decrease mitochondrial-related oxidative stress in Alzheimer disease patient fibroblasts. J. Alzheimers. Dis. 2007, 12, 195–206. [Google Scholar] [CrossRef] [PubMed]
  60. Parachikova, A.; Green, K.N.; Hendrix, C.; Laferla, F.M. Formulation of a medical food cocktail for Alzheimer’s disease: Beneficial effects on cognition and neuropathology in a mouse model of the disease. PLoS One 2010, 5, e14015. [Google Scholar] [CrossRef] [PubMed]
  61. Blesa, S.; Cortijo, J.; Martinez-losa, M.; Mata, M.; Seda, E.; Santangelo, F.; Morcillo, E.J. Effectiveness of oral N-acetylcysteine in a rat experimental model of asthma. Pharmacol. Res. 2002, 45, 135–140. [Google Scholar] [CrossRef] [PubMed]
  62. Wang, Q.; Hou, Y.; Yi, D.; Wang, L.; Ding, B.; Chen, X.; Long, M.; Liu, Y.; Wu, G. Protective effects of N-acetylcysteine on acetic acid-induced colitis in a porcine model. BMC Gastroenterol. 2013, 13, 133. [Google Scholar] [CrossRef] [PubMed]
  63. Anfossi, G.; Russo, I.; Massucco, P.; Mattiello, L.; Cavalot, F.; Trovati, M. N-acetyl-L-cysteine exerts direct anti-aggregating effect on human platelets. Eur. J. Clin. Invest. 2001, 31, 452–461. [Google Scholar] [CrossRef]
  64. Zhang, H.; Li, Y.; Chen, Y.; Zhang, L.; Wang, T. N-Acetylcysteine protects against intrauterine growth retardation-induced intestinal injury via restoring redox status and mitochondrial function in neonatal piglets. Eur. J. Nutr. 2018, 1–13. [Google Scholar] [CrossRef]
  65. Calzadilla, P.; Gómez-Serrano, M.; García-Santos, E.; Schiappacasse, A.; Abalde, Y.; Calvo, J.C.; Peral, B.; Guerra, L.N. N -Acetylcysteine affects obesity-related protein expression in 3T3-L1 adipocytes. Redox Rep. 2013, 18, 210–218. [Google Scholar] [CrossRef]
  66. Kim, J.-R.; Ryu, H.-H.; Chung, H.J.; Lee, J.H.; Kim, S.W.; Kwun, W.H.; Baek, S.-H.; Kim, J.H. Association of anti-obesity activity of N-acetylcysteine with metallothionein-II down-regulation. Exp. Mol. Med. 2006, 38, 162–172. [Google Scholar] [CrossRef] [Green Version]
  67. Novelli, E.L.B.; Santos, P.P.; Assalin, H.B.; Souza, G.; Rocha, K.; Ebaid, G.X.; Seiva, F.R.F.; Mani, F.; Fernandes, A.A. N-acetylcysteine in high-sucrose diet-induced obesity: Energy expenditure and metabolic shifting for cardiac health. Pharmacol. Res. 2009, 59, 74–79. [Google Scholar] [CrossRef]
  68. Shen, F.-C.; Weng, S.-W.; Tsao, C.-F.; Lin, H.-Y.; Chang, C.-S.; Lin, C.-Y.; Lian, W.-S.; Chuang, J.-H.; Lin, T.-K.; Liou, C.-W.; et al. Early intervention of N-acetylcysteine better improves insulin resistance in diet-induced obesity mice. Free Radic. Res. 2018, 52, 1–11. [Google Scholar] [CrossRef]
  69. Zhu, Z.; Takahashi, N.; Ooie, T.; Shinohara, T.; Yamanaka, K.; Saikawa, T. Oral Administration of Geranylgeranylacetone Blunts the Endothelial Dysfunction Induced by Ischemia and Reperfusion in the Rat Heart. J. Cardiovasc. Pharmacol. 2005, 45, 555–562. [Google Scholar] [CrossRef] [Green Version]
  70. Hemmeryckx, B.; Hohensinner, P.; Swinnen, M.; Heggermont, W.; Wojta, J.; Lijnen, H.R. Antioxidant Treatment Improves Cardiac Dysfunction in a Murine Model of Premature Aging. J. Cardiovasc. Pharmacol. 2016, 68, 374–382. [Google Scholar] [CrossRef]
  71. Zhang, D.; Li, Y.; Zhang, T.; Liu, J.; Jahejo, A.R.; Yang, L.; Chen, P.; Ning, G.; Huo, N.; Ma, H.; et al. Protective effects of zinc and N-acetyl-L-cysteine supplementation against cadmium induced erythrocyte cytotoxicity in Arbor Acres broiler chickens (Gallus gallus domesticus). Ecotoxicol. Environ. Saf. 2018, 163, 331–339. [Google Scholar] [CrossRef]
  72. Flora, S.J.S. Structural, chemical and biological aspects of antioxidants for strategies against metal and metalloid exposure. Oxid. Med. Cell. Longev. 2009, 2, 191–206. [Google Scholar] [CrossRef]
  73. Sagara, M.; Satoh, J.; Wada, R.; Yagihashi, S.; Takahashi, K.; Fukuzawa, M.; Muto, G.; Muto, Y.; Toyota, T. Inhibition of development of peripheral neuropathy in streptozotocin-induced diabetic rats with N-acetylcysteine. Diabetologia 1996, 39, 263–269. [Google Scholar] [CrossRef]
  74. Martínez, M.; Hernández, A.I.; Martínez, N. N-Acetylcysteine delays age-associated memory impairment in mice: role in synaptic mitochondria. Brain Res. 2000, 855, 100–106. [Google Scholar] [CrossRef]
  75. Dinicola, S.; De Grazia, S.; Carlomagno, G.; Pintucci, J.P. N-acetylcysteine as powerful molecule to destroy bacterial biofilms. A systematic review. Eur. Rev. Med. Pharmacol. Sci. 2014, 18, 2942–2948. [Google Scholar]
  76. Brack, C.; Bechter-Thüring, E.; Labuhn, M. N-Acetylcysteine slows down ageing and increases the life span of Drosophila melanogaster. Cell. Mol. Life Sci. 1997, 53, 960–966. [Google Scholar] [CrossRef]
  77. Oh, S.; Park, J.; Park, S. Lifespan extension and increased resistance to environmental stressors by N-Acetyl-L-Cysteine in Caenorhabditis elegans. Clinics 2015, 70, 380–386. [Google Scholar] [CrossRef]
  78. Shaposhnikov, M.V.; Zemskaya, N.V.; Koval, L.A.; Schegoleva, E.V.; Zhavoronkov, A.; Moskalev, A.A. Effects of N-acetyl-L-cysteine on lifespan, locomotor activity and stress-resistance of 3 Drosophila species with different lifespans. Aging (Albany NY) 2018, 10, 2428–2458. [Google Scholar] [CrossRef] [PubMed]
  79. Oh, S.-I.; Park, S.-K. N-acetyl-l-cysteine mimics the effect of dietary restriction on lifespan and reduces amyloid beta-induced toxicity in Caenorhabditis elegans. Food Sci. Biotechnol. 2017, 26, 783–790. [Google Scholar] [CrossRef] [PubMed]
  80. Flurkey, K.; Astle, C.M.; Harrison, D.E. Life Extension by Diet Restriction and N-Acetyl-L-Cysteine in Genetically Heterogeneous Mice. J. Gerontol. Ser. A Biol. Sci. Med. Sci. 2010, 65A, 1275–1284. [Google Scholar] [CrossRef]
  81. Wang, K.-H.; Kao, A.-P.; Chang, C.-C.; Lin, T.-C.; Kuo, T.-C. Lifespan Extension and Sustained Expression of Stem Cell Phenotype of Human Breast Epithelial Stem Cells in a Medium with Antioxidants. Stem Cells Int. 2016, 2016, 1–9. [Google Scholar] [CrossRef]
  82. Shi, T.; Yang, X.; Zhou, H.; Xi, J.; Sun, J.; Ke, Y.; Zhang, J.; Shao, Y.; Jiang, X.; Pan, X.; et al. Activated carbon N-acetylcysteine microcapsule protects against nonalcoholic fatty liver disease in young rats via activating telomerase and inhibiting apoptosis. PLoS One 2018, 13, e0189856. [Google Scholar] [CrossRef]
  83. Liu, J.; Liu, M.; Ye, X.; Liu, K.; Huang, J.; Wang, L.; Ji, G.; Liu, N.; Tang, X.; Baltz, J.M.; et al. Delay in oocyte aging in mice by the antioxidant N-acetyl-l-cysteine (NAC). Hum. Reprod. 2012, 27, 1411–1420. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  84. Desjardins, D.; Cacho-Valadez, B.; Liu, J.-L.; Wang, Y.; Yee, C.; Bernard, K.; Khaki, A.; Breton, L.; Hekimi, S. Antioxidants reveal an inverted U-shaped dose-response relationship between reactive oxygen species levels and the rate of aging in Caenorhabditis elegans. Aging Cell 2017, 16, 104–112. [Google Scholar] [CrossRef]
  85. Rhodes, K.; Braakhuis, A. Performance and Side Effects of Supplementation with N-Acetylcysteine: A Systematic Review and Meta-Analysis. Sport. Med. 2017, 47, 1619–1636. [Google Scholar] [CrossRef]
  86. Poljsak, B.; Milisav, I. The role of antioxidants in cancer, friends or foes? Curr. Pharm. Des. 2018, 24, 5234–5244. [Google Scholar] [CrossRef] [PubMed]
  87. Poljsak, B. Strategies for Reducing or Preventing the Generation of Oxidative Stress. Oxid. Med. Cell. Longev. 2011, 2011, 1–15. [Google Scholar] [CrossRef]
  88. Martinez-Outschoorn, U.E.; Peiris-Pagés, M.; Pestell, R.G.; Sotgia, F.; Lisanti, M.P. Cancer metabolism: a therapeutic perspective. Nat. Rev. Clin. Oncol. 2017, 14, 11–31. [Google Scholar] [CrossRef]
  89. Agarwal, A.; Muñoz-Nájar, U.; Klueh, U.; Shih, S.-C.; Claffey, K.P. N-acetyl-cysteine promotes angiostatin production and vascular collapse in an orthotopic model of breast cancer. Am. J. Pathol. 2004, 164, 1683–1696. [Google Scholar] [CrossRef]
  90. Elbini Dhouib, I.; Jallouli, M.; Annabi, A.; Gharbi, N.; Elfazaa, S.; Lasram, M.M. A minireview on N -acetylcysteine: An old drug with new approaches. Life Sci. 2016, 151, 359–363. [Google Scholar] [CrossRef]
  91. Balansky, R.; Izzotti, A.; Scatolini, L.; D’Agostini, F.; De Flora, S. Induction by carcinogens and chemoprevention by N-acetylcysteine of adducts to mitochondrial DNA in rat organs. Cancer Res. 1996, 56, 1642–1647. [Google Scholar]
  92. Le Gal, K.; Ibrahim, M.X.; Wiel, C.; Sayin, V.I.; Akula, M.K.; Karlsson, C.; Dalin, M.G.; Akyürek, L.M.; Lindahl, P.; Nilsson, J.; et al. Antioxidants can increase melanoma metastasis in mice. Sci. Transl. Med. 2015, 7, 308re8. [Google Scholar] [CrossRef]
  93. Piskounova, E.; Agathocleous, M.; Murphy, M.M.; Hu, Z.; Huddlestun, S.E.; Zhao, Z.; Leitch, A.M.; Johnson, T.M.; DeBerardinis, R.J.; Morrison, S.J. Oxidative stress inhibits distant metastasis by human melanoma cells. Nature 2015, 527, 186–191. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  94. Zhou, M.; Gu, L.; Zhu, N.; Woods, W.G.; Findley, H.W. Transfection of a dominant-negative mutant NF-kB inhibitor (IkBm) represses p53-dependent apoptosis in acute lymphoblastic leukemia cells: Interaction of IkBm and p53. Oncogene 2003, 22, 8137–8144. [Google Scholar] [CrossRef] [PubMed]
  95. Schafer, Z.T.; Grassian, A.R.; Song, L.; Jiang, Z.; Gerhart-Hines, Z.; Irie, H.Y.; Gao, S.; Puigserver, P.; Brugge, J.S. Antioxidant and oncogene rescue of metabolic defects caused by loss of matrix attachment. Nature 2009, 461, 109–113. [Google Scholar] [CrossRef] [PubMed]
  96. Watson, J. Oxidants, antioxidants and the current incurability of metastatic cancers. Open Biol. 2013, 3, 120144. [Google Scholar] [CrossRef] [PubMed]
  97. SBWIRE. Global Acetylcysteine Market Size will Grow from US$ 490 Million to US$ 1650 Million by 2024. Available online: http://www.sbwire.com/press-releases/global-acetylcysteine-market-revenue-will-grow-at-223-cagr-to-2024-with-us-1650-million-market-size-1142001.htm (accessed on 24 February 2019).
  98. Amazon.com, NAC powder. Available online: https://www.amazon.com/dp/B00F8HGA0E?aaxitk=XgCsjwjJY0uReP.ey4bLiQ&pd_rd_i=B00F8HGA0E&pf_rd_p=3fade48a-e699-4c96-bf08-bb772ac0e242&hsa_cr_id=4339168660001&sb-ci-n=productDescription&sb-ci-v=BulkSupplements%2BNAC%2B(N-Acetyl%2BL-Cysteine)%2BPowder%2B(250%2Bgrams)&th=1 (accessed on 27 February 2019).
  99. WebMD. Available online: https://www.webmd.com/vitamins-supplements/ingredientreview-1018-N-ACETYL+CYSTEINE.aspx?drugid=1018&drugname=N-ACETYL+CYSTEINE&sortby=3 (accessed on 12 February 2019).
  100. Cobley, J.N.; McGlory, C.; Morton, J.P.; Close, G.L. N-Acetylcysteine’s attenuation of fatigue after repeated bouts of intermittent exercise: Practical implications for tournament situations. Int. J. Sport Nutr. Exerc. Metab. 2011, 21, 451–461. [Google Scholar] [CrossRef]
  101. Tardiolo, G.; Bramanti, P.; Mazzon, E. Overview on the Effects of N-Acetylcysteine in Neurodegenerative Diseases. Molecules 2018, 23, 3305. [Google Scholar] [CrossRef]
  102. Garg, G.; Singh, S.; Singh, A.K.; Rizvi, S.I. N-acetyl-L-cysteine attenuates oxidative damage and neurodegeneration in rat brain during aging. Can. J. Physiol. Pharmacol. 2018, 96, 1189–1196. [Google Scholar] [CrossRef]
  103. Chen, S.; Ren, Q.; Zhang, J.; Ye, Y.; Zhang, Z.; Xu, Y.; Guo, M.; Ji, H.; Xu, C.; Gu, C.; et al. N-acetyl-L-cysteine protects against cadmium-induced neuronal apoptosis by inhibiting ROS-dependent activation of Akt/mTOR pathway in mouse brain. Neuropathol. Appl. Neurobiol. 2014, 40, 759–777. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  104. Andreassen, O.A.; Dedeoglu, A.; Klivenyi, P.; Beal, M.F.; Bush, A.I. N-acetyl-L-cysteine improves survival and preserves motor performance in an animal model of familial amyotrophic lateral sclerosis. Neuroreport 2000, 11, 2491–2493. [Google Scholar] [CrossRef]
  105. Pocernich, C.B.; Lange, M.L.B.; Sultana, R.; Butterfield, D.A. Nutritional approaches to modulate oxidative stress in Alzheimer’s disease. Curr. Alzheimer Res. 2011, 8, 452–469. [Google Scholar] [CrossRef]
  106. Huang, Q.; Aluise, C.D.; Joshi, G.; Sultana, R.; St. Clair, D.K.; Markesbery, W.R.; Butterfield, D.A. Potential in vivo amelioration by N-acetyl-L-cysteine of oxidative stress in brain in human double mutant APP/PS-1 knock-in mice: Toward therapeutic modulation of mild cognitive impairment. J. Neurosci. Res. 2010, 88, 2618–2629. [Google Scholar]
  107. Naik, A.K.; Tandan, S.K.; Dudhgaonkar, S.P.; Jadhav, S.H.; Kataria, M.; Prakash, V.R.; Kumar, D. Role of oxidative stress in pathophysiology of peripheral neuropathy and modulation by N-acetyl-L-cysteine in rats. Eur. J. Pain 2006, 10, 573. [Google Scholar] [CrossRef] [PubMed]
  108. Zhang, H.; Spapen, H.; Nguyen, D.N.; Rogiers, P.; Bakker, J.; Vincent, J.L. Effects of N-Acetyl-L-Cysteine on Regional Blood Flow during Endotoxic Shock. Eur. Surg. Res. 1995, 27, 292–300. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  109. Peake, S.L.; Moran, J.L.; Leppard, P.I. N-acetyl-L-cysteine depresses cardiac performance in patients with septic shock. Crit. Care Med. 1996, 24, 1302–1310. [Google Scholar] [CrossRef]
  110. Arranz, L.; Fernández, C.; Rodríguez, A.; Ribera, J.M.; De la Fuente, M. The glutathione precursor N-acetylcysteine improves immune function in postmenopausal women. Free Radic. Biol. Med. 2008, 45, 1252–1262. [Google Scholar] [CrossRef] [PubMed]
  111. Skvarc, D.R.; Dean, O.M.; Byrne, L.K.; Gray, L.; Lane, S.; Lewis, M.; Fernandes, B.S.; Berk, M.; Marriott, A. The effect of N-acetylcysteine (NAC) on human cognition – A systematic review. Neurosci. Biobehav. Rev. 2017, 78, 44–56. [Google Scholar] [CrossRef] [PubMed]
  112. Logan, A.C.; Wong, C. Chronic fatigue syndrome: Oxidative stress and dietary modifications. Altern. Med. Rev. 2001, 6, 450–460. [Google Scholar] [PubMed]
Table 1. Overview of Food and Drug Administration FDA-approved N-acetyl-cysteine (NAC) drugs and their indications.
Table 1. Overview of Food and Drug Administration FDA-approved N-acetyl-cysteine (NAC) drugs and their indications.
RouteAdministrationStrengthNo.*Medical Condition/
Therapy Type
Indication
InjectableIntravenous200 mg/mL
(6 g/30 mL)
7Poisoning/
antidote
Acetaminophen overdose reduction;
Prevention of acute hepatic injury;
Hepatic injury from repeated supratherapeutic ingestion.
Effervescent tabletOral500 mg
2.5 g
1
SolutionOral10%
20%
3Bronchopulmonary disorders/
Adjuvant therapy
Abnormal, viscid, inspissated mucous secretions in chronic** and acute*** bronchopulmonary disease;
Pulmonary complications of cystic fibrosis;
Tracheostomy care;
Pulmonary complications associated with surgery;
Use during anesthesia;
Post-traumatic chest conditions;
Atelectasis due to mucous obstruction and diagnostic bronchial studies****.
SolutionInhalation10%
20%
3
*: Number of drugs, currently on the market. **: Chronic bronchopulmonary disease: chronic emphysema, emphysema with bronchitis, chronic asthmatic bronchitis, tuberculosis, bronchiectasis, and primary amyloidosis of the lung. ***: Acute bronchopulmonary disease: pneumonia, bronchitis, and tracheobronchitis. ****: Diagnostic bronchial studies: bronchograms, bronchospirometry, and bronchial wedge catheterization.
Table 2. NAC clinical trials registered at ClinicalTrials.gov [48]. The number of studies is displayed according to the study status, tested medical conditions of currently active studies, tested medical conditions in completed studies, study phase and tested medical conditions of currently active studies, study phase, and tested medical conditions of completed studies.
Table 2. NAC clinical trials registered at ClinicalTrials.gov [48]. The number of studies is displayed according to the study status, tested medical conditions of currently active studies, tested medical conditions in completed studies, study phase and tested medical conditions of currently active studies, study phase, and tested medical conditions of completed studies.
StatusCount
Completed159
Not yet recruiting14
Active54
Withdrawn/terminated/suspended24
Unknown status40
Grand Total291
Medical Conditions (Active Studies)Count
Addiction12
Cancer/chemotherapy side effects5
Cardiovascular diseases5
Gastrointestinal diseases4
Genetic disorders1
Graft/stem cell complications/trauma4
Infectious diseases1
Metabolic diseases1
Neuro/psychiatric disorders12
Obstetrics2
Poisoning antidote1
Pulmonary diseases1
Surgery complications/trauma5
Grand Total54
Medical Conditions (Completed Studies)Count
Addiction17
Blood disorders4
Cancer/chemotherapy side effects2
Cardiovascular diseases10
Dermatologic disorders2
Gastrointestinal diseases15
Genetic disorders1
Infectious diseases3
Metabolic diseases8
Muscle disorders1
Neuro/psychiatric disorders24
Obstetrics11
Ophthalmological diseases5
ORL5
Other4
Poisoning antidote2
Pulmonary diseases13
Renal disorders31
Surgery complications/trauma1
Grand Total159
Phase/Medical Conditions (Active Studies)Count
Early Phase 15
Addiction2
Metabolic diseases1
Neuro/psychiatric disorders1
Pulmonary diseases1
Not Applicable10
Cardiovascular diseases2
Gastrointestinal diseases1
Graft/stem cell complications/trauma1
Neuro/psychiatric disorders4
Obstetrics1
Surgery complications/trauma1
Phase 14
Addiction1
Cancer/chemotherapy side effects1
Neuro/psychiatric disorders1
Poisoning antidote1
Phase 1|Phase 23
Cancer/chemotherapy side effects2
Gastrointestinal diseases1
Phase 213
Addiction6
Cancer/chemotherapy side effects1
Gastrointestinal diseases1
Genetic disorders1
Graft/stem cell complications/trauma1
Infectious diseases1
Neuro/psychiatric disorders2
Phase 2|Phase 33
Addiction1
Graft/stem cell complications/trauma1
Obstetrics1
Phase 38
Cancer/chemotherapy side effects1
Cardiovascular diseases3
Neuro/psychiatric disorders2
Surgery complications/trauma2
Phase 48
Addiction2
Gastrointestinal diseases1
Graft/stem cell complications/trauma1
Neuro/psychiatric disorders2
Surgery complications/trauma2
Grand Total54
Phase/Medical Conditions (Completed Studies)Count
Early Phase 13
Addiction1
Blood disorders1
ORL1
Not Applicable18
Cardiovascular diseases1
Gastrointestinal diseases3
Metabolic diseases3
Neuro/psychiatric disorders2
Obstetrics2
Pulmonary diseases2
Renal disorders5
Phase 122
Addiction3
Cancer/chemotherapy side effects1
Cardiovascular diseases1
Gastrointestinal diseases2
Neuro/psychiatric disorders4
Ophthalmological diseases4
ORL1
Other4
Pulmonary diseases1
Renal disorders1
Phase 1|Phase 212
Addiction2
Blood disorders1
Infectious diseases1
Metabolic diseases3
Neuro/psychiatric disorders2
Obstetrics2
Renal disorders1
Phase 247
Addiction8
Blood disorders1
Cancer/chemotherapy side effects1
Cardiovascular diseases4
Dermatologic disorders1
Gastrointestinal diseases2
Genetic disorders1
Infectious diseases1
Metabolic diseases1
Muscle disorders1
Neuro/psychiatric disorders14
Obstetrics1
Ophthalmological diseases1
ORL1
Pulmonary diseases2
Renal disorders7
Phase 2|Phase 38
Gastrointestinal diseases1
Obstetrics1
ORL1
Renal disorders5
Phase 320
Addiction2
Blood disorders1
Cardiovascular diseases2
Dermatologic disorders1
Gastrointestinal diseases4
Infectious diseases1
Obstetrics2
Pulmonary diseases2
Renal disorders5
Phase 429
Addiction1
Cardiovascular diseases2
Gastrointestinal diseases3
Metabolic diseases1
Neuro/psychiatric disorders2
Obstetrics3
ORL1
Poisoning antidote2
Pulmonary diseases6
Renal disorders7
Surgery complications/trauma1
Grand Total159
ORL: Otorhinolaryngology.
Table 3. Medical conditions investigated by withdrawn, terminated, and suspended studies listed by ClinicalTrials.gov [48]. Listed: number of trials listed at ClinicalTrials.gov [48]; Phase: study phase; N/A: not applicable.
Table 3. Medical conditions investigated by withdrawn, terminated, and suspended studies listed by ClinicalTrials.gov [48]. Listed: number of trials listed at ClinicalTrials.gov [48]; Phase: study phase; N/A: not applicable.
Status/Medical ConditionListedPhaseTermination Reason
SUSPENDED4
Autoimmune Disorders
Systemic Lupus Erythematosus11|2Short of funds
Cardiovascular Diseases
Cardiovascular Disease|Renal Insufficiency, Acute|Cardiopulmonary Bypass14Opposite result
Infectious Diseases
Hepatitis C1N/AShort of funds
Metabolic diseases
Insulin Resistance|Metabolic Syndrome1N/AN/A
TERMINATED/15
Addiction
Acetaminophen Overdose13Insufficient enrollment
Prevention of Hangover Using NAC1N/AInsufficient enrollment
Cancer/Chemotherapy Side Effects
Bone Marrow Suppression|Brain and Central Nervous System Tumors|Drug/Agent Toxicity by Tissue/Organ|Long-term Effects Secondary to Cancer Therapy in Children11N/A
Malignant Ovarian Endometrioid Tumor|Malignant Ovarian Serous Tumor|Recurrent Fallopian Tube Carcinoma|Recurrent Ovarian Carcinoma|Recurrent Primary Peritoneal Carcinoma12Slow accrual
Gastrointestinal Diseases
Acute Liver Failure|Fulminant Hepatic Failure14Insufficient enrollment
Drug Induced Liver Injury1N/A2 sepsis cases after steroid admin.
Genetic disorders
Cystic Fibrosis14Insufficient enrollment
Infectious Diseases
Helicobacter pylori Infection11|2Efficacy of eradication: 2 out of 31
Metabolic diseases
Type 2 Diabetes Mellitus|Hypertension14N/A
Neuro/Psychiatric Disorders
Borderline Personality Disorder|Self-Injurious Behavior12Poor subject compliance
Bulimia Nervosa12|3; 3No meaningful improvements
Obsessive-Compulsive Disorder12Insufficient enrollment
Pulmonary Diseases
COPD|Chronic Bronchitis1N/API’s discretion
Renal Disorders
Chronic Kidney Failure1N/AN/A
Surgery Complications/Trauma
Ischemic Reperfusion Injury|Insufficiency; Hepatic, Postoperative|Liver Tumour12N/A
WITHDRAWN/4
Cancer/Chemotherapy Side Effects
Ovarian Carcinoma, Stage 3 or 4|Epithelial Ovarian Carcinoma|Primary Peritoneal Carcinoma11No funding for the cost of NAC
Gastrointestinal Diseases
Liver Failure|Liver Failure, Acute|Drug Induced Liver Injury|Prevention and Control|Fever1N/AShort of funds
Neuro/Psychiatric Disorders
Autistic Disorder|Seizures|Irritability1N/ANo eligible subjects located
Posttraumatic Stress Disorder12Cancelled research project
Grand Total23

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MDPI and ACS Style

Šalamon, Š.; Kramar, B.; Marolt, T.P.; Poljšak, B.; Milisav, I. Medical and Dietary Uses of N-Acetylcysteine. Antioxidants 2019, 8, 111. https://doi.org/10.3390/antiox8050111

AMA Style

Šalamon Š, Kramar B, Marolt TP, Poljšak B, Milisav I. Medical and Dietary Uses of N-Acetylcysteine. Antioxidants. 2019; 8(5):111. https://doi.org/10.3390/antiox8050111

Chicago/Turabian Style

Šalamon, Špela, Barbara Kramar, Tinkara Pirc Marolt, Borut Poljšak, and Irina Milisav. 2019. "Medical and Dietary Uses of N-Acetylcysteine" Antioxidants 8, no. 5: 111. https://doi.org/10.3390/antiox8050111

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