「N-acetyl-cysteine (NAC)」の編集履歴（バックアップ）一覧に戻る
N-acetyl-cysteine (NAC)--is an anticarcinogenic and antimutagenic agent; it inhibits IL-6 as well as invasion and metastasis of malignant cells
N-acetyl-cysteine (NAC) is the acetylated precursor of the amino acids L-cysteine and reduced glutathione. Historically, it is used as a mucolytic agent in respiratory illnesses as well as an antidote for acetaminophen hepatotoxicity, but more recently its credits have grown. Animal and human studies have shown it to be a powerful antioxidant and a potential therapeutic agent in the treatment of cancer (Bongers et al. 1995; van Zandwijk 1995).
The biological value of NAC is attributed to its sulfhydryl group, while its acetyl-substituted amino group offers protection against oxidative and metabolic processes (Bonanomi et al. 1980; Sjodin et al. 1989). In vitro studies showed NAC to be directly antimutagenic and anticarcinogenic; in vivo, NAC inhibited mutagenicity of a number of mutagenic materials (De Flora et al. 1986, 1992).
NAC has both chemopreventive and therapeutic potential in malignancies arising in the lung, skin, breast, liver, head, and neck (van Zandwijk 1995; Izzotti 1998). NAC is effective in inhibiting tumor cell growth in melanoma, prostate cells, and astrocytoma cell lines (the latter is a primary tumor in the brain) (Albini et al. 1995; Arora-Kuruganti et al. 1999; Chiao et al. 2000). Neovascularization (new blood vessel growth) is crucial for tumor mass expansion and metastasis. NAC inhibited invasion and metastasis of malignant cells by up to 80% by preventing angiogenesis (De Flora et al. 1996).
A number of cancers express IL-6 and other potentially dangerous cytokines. NAC inhibited (in a dose-dependent manner) the synthesis of IL-6 by alveolar macrophage (Munoz et al. 1996; Gosset et al. 1999).
Peak plasma levels of NAC occur approximately 1 hour after an oral dose; 12 hours after dosing, it is undetectable. Despite a relatively low bioavailability (4-10%), research has shown NAC to be clinically effective (Borgstrom et al. 1986). A suggested NAC therapeutic dosage is usually in the range of 600 mg per day.
