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N-Acetyl Cysteine (NAC)

February 2, 2010

N-Acetyl Cysteine (NAC) is a metabolite of the sulfur-containing amino acid, Cysteine. Cysteine is found in high protein foods, N-Acetyl Cysteine is not. N-Acetyl Cysteine is produced within the human body. Cysteine plays a role in the sulfation cycle, acting as a sulfur donor in phase II detoxification and as a methyl donor in the conversion of homocysteine to methionine. Cysteine also helps synthesize glutathione, one of the body’s most important natural antioxidants and detoxifiers. N-Acetyl-Cysteine is the acetylated form of L-Cysteine.

N-Acetyl Cysteine Cautions

When taking N-acetyl cysteine it is recommended that two to three times as much vitamin C be taken at the same time. Failure to do so may result in more harm than good from taking this product because of the prolonged presence of the oxidized form of L-Cysteine. The vitamin C also helps keep the glutathione that is produced from the Cysteine in its reduced form so that it can continue acting as an antioxidant.

N-Acetyl Cysteine Dosage

Typical dosage recommendations are in the range of 250-1500mg of NAC daily for the majority of therapeutic benefits.

N-Acetyl Cysteine increases Glutathione Levels

N-Acetyl Cysteine is rapidly metabolized to intracellular glutathione. Glutathione acts as a powerful antioxidant in the body. Glutathione also detoxifies chemicals into less harmful compounds. N-Acetyl Cysteine also protects the body from acetaminophen toxicity and is used in hospitals for patients with acetaminophen poisoning. It has also been shown to be effective at treating liver failure from other causes as well.

N-Acetyl Cysteine Chelates Heavy Metals

Heavy metals like lead, mercury and arsenic are detoxified and removed from the body by N-Acetyl Cysteine . It also increases the excretion of zinc and other essential minerals when taken over an extended period. It is therefore necessary to supplement zinc, copper and other trace minerals when taking N-Acetyl Cysteine.

N-Acetyl Cysteine and the Immune System

Glutathione is known to aid in the transport of nutrients to lymphocytes and phagocytes, two major classes of immune cells, and to protect cell membranes. While purified glutathione is available as a dietary supplement, absorption is low, and N-Acetyl Cysteine is thought to be a better method of boosting cellular glutathione levels. N-Acetyl Cysteine is being investigated as a treatment for AIDS.

N-Acetyl Cysteine Breaks up Mucus

N-Acetyl Cysteine cleaves disulfide bonds by converting them to two sulfhydryl groups. This action results in the breakup of mucoproteins in lung mucus, reducing their chain lengths and thinning the mucus, improving conditions such as bronchitis and flu. Double-blind research has found that N-Acetyl Cysteine supplements improved symptoms and prevented recurrences in people with chronic bronchitis. N-Acetyl Cysteine at a dosage of 1,200 mg per day helps to prevent Influenza infection, reduces the symptoms of existing Influenza infection and reduces the duration of Influenza infections.

N-Acetyl Cysteine and Cancer

N-Acetyl CysteineN-Acetyl Cysteine has been shown to reduce the proliferation of certain cells lining the colon and may reduce the risk of colon cancer in people with recurrent polyps in the colon. Its action as an antioxidant and a glutathione precursor may also contribute to a protective effect against cancer.

3 Comments leave one →
  1. February 2, 2010 1:03 PM

    Eur J Med Res. 2009 Aug 12;14(8):352-8.
    A phase II study on safety and efficacy of high-dose N-acetylcysteine in patients with cystic fibrosis.

    Dauletbaev N, Fischer P, Aulbach B, Gross J, Kusche W, Thyroff-Friesinger U, Wagner TO, Bargon J.

    University Hospital, Frankfurt/Main, Germany.

    OBJECTIVE: We conducted a single-centre, randomised, double-blinded, placebo-controlled phase II clinical study to test safety and efficacy of a 12-week therapy with low-dose (700 mg/daily) or high-dose (2800 mg/daily) of NAC. METHODS: Twenty-one patients (DeltaF508 homo/heterozygous, FEV1>40% pred.) were included in the study. After a 3-weeks placebo run-in phase, 11 patients received low-dose NAC, and 10 patients received high-dose NAC. Outcomes included safety and clinical parameters, inflammatory (total leukocyte numbers, cell differentials, TNF-alpha, IL-8) measures in induced sputum, and concentrations of extracellular glutathione in induced sputum and blood. RESULTS: High-dose NAC was a well-tolerated and safe medication. High-dose NAC did not alter clinical or inflammatory parameters. However, extracellular glutathione in induced sputum tended to increase on high-dose NAC. CONCLUSIONS: High-dose NAC is a well-tolerated and safe medication for a prolonged therapy of patients with CF with a potential to increase extracellular glutathione in CF airways.

    PMID: 19666395 [PubMed – indexed for MEDLINE]

  2. February 2, 2010 1:07 PM

    Perspect Dev Neurobiol. 1996;3(2):121-31.
    On the track of cell survival pharmaceuticals in the oligodendrocyte type-2 astrocyte lineage.

    Noble M, Mayer-Próschel M.

    Ludwig Institute for Cancer Research, London, United Kingdom.

    The identification of compounds that can protect cells against death induced by exposure to noxious stimuli and against programmed cell death (apoptosis) associated with exposure to inadequate amounts of trophic factors is of great interest in contemporary biology. We have found that N-acetyl-L-cysteine (NAC) is able to promote cell survival in these two distinct experimental paradigms of, respectively, “death by murder” and “death by neglect.” In the former case, NAC prevented the death of oligodendrocytes induced by glutamate or tumor necrosis factor-alpha (TNF-alpha), and also prevented TNF-alpha-induced death of L929 cells. NAC also acted in synergy with ciliary neurotrophic factor (CNTF) to prevent killing of oligodendrocytes by TNF-alpha. In analysis of “death by neglect,” NAC markedly enhanced the extent of spinal ganglion neuron survival obtained with suboptimal concentrations of nerve growth factor and of oligodendrocyte survival obtained with suboptimal concentrations of CNTF or insulin-like growth factor-1. Surprisingly, significant rescue of oligodendrocytes from apoptosis was also observed with combinations of NAC with progesterone, vitamin C, or Trolox, a water-soluble vitamin E analogue, although not with any of these compounds applied individually. These results demonstrate that cocktails of small molecules such as those we have studied may have beneficial effects not predictable from the action of any individual member of the cocktail. In light of the long clinical history of therapeutic use of NAC and the other compounds identified in our studies, we suggest that it may be of interest to examine use of NAC alone, or combinations of NAC with the other small molecules we have studied, in conditions in which certain toxin-mediated forms of cell death or apoptosis contribute significantly to disease.

    PMID: 8826530 [PubMed – indexed for MEDLINE]

  3. February 2, 2010 1:14 PM

    Anticancer Res. 2009 Nov;29(11):4571-4.
    Reduction of oxidative DNA fragmentation by ascorbic acid, zinc and N-acetylcysteine in nasal mucosa tissue cultures.

    Baumeister P, Huebner T, Reiter M, Schwenk-Zieger S, Harréus U.

    Department of Otolaryngology, University of Munich, Marchioninistr. 15, 81377 Munich, Germany.

    Oxidative stress is one major factor in upper aerodigestive tract carcinogenesis. Reactive oxygen species derived from environmental sources, cigarette smoke or cellular metabolism, constantly attack large molecules within the cell. While damaged lipids and proteins can be replaced, oxidative DNA damage needs to be repaired. Damage exceeding DNA repair capacity might lead to permanent mutations. Ascorbic acid, zinc and N-acetylcysteine are widely used as supplementations during upper aerodigestive tract infections. Therefore we chose to investigate their potential in DNA protection. We produced so called “mini-organ” cultures of nasal mucosa, three-dimensional tissue cubes coated with ciliated epithelium, for repeated incubation with ascorbic acid, zinc and N-acetylcysteine at different concentrations. This model has several advantages with respect to repeated incubations, metabolic competence of cells and standardized conditions compared to cell line experiments or animal models. After washing twice, oxidative damage was induced by hydrogen peroxide. Resulting DNA fragmentation was analyzed using the FPG-comet assay, a special modification of the alkaline single-cell microgel electrophoresis for the detection of the most prevalent oxidative DNA base modification. DNA damage was reduced within a range of 45-60%. Cell viability after incubations with hydrogenperoxide was >90%. Our results show strong DNA protective effects of the substances tested in accordance with epidemiological studies linking a diet rich in antioxidative micronutrients with a lowered risk for cancer development. The reasons for the failure of large antioxidant supplementation interventional trials need to be further investigated.

    PMID: 20032405 [PubMed – indexed for MEDLINE]

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