Melatonin (N-acetyl-5-methoxytryptamine) is an indoleamine with antioxidant, chronobiotic and anti-inflammatory properties; reduced levels of this hormone are associated with higher risk of cancer. Several beneficial effects of melatonin have been described in a broad number of tumors, including liver cancers. In this work we systematically reviewed the publications of the last 15 years that assessed the underlying mechanisms of melatonin activities against liver cancers, and its role as coadjuvant in the treatment of these tumors. Literature research was performed employing PubMed, Scopus and Web of Science (WOS) databases and, after screening, 51 articles were included. Results from the selected studies denoted the useful actions of melatonin in preventing carcinogenesis and as a promising treatment option for the primary liver tumors hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), either alone or in combination with other compounds. Different processes were modulated by the indole, such as inhibition of oxidative stress, proliferation, angiogenesis and invasion, promotion of immune system response, cell cycle arrest and apoptosis, as well as recovery of circadian rhythms and autophagy modulation. Taken together, the present systematic review highlights the evidence that document the potential role of melatonin in improving the landscape of liver tumor treatment.

中文翻译：

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褪黑激素作为抗肝癌的抗肿瘤药物：最新的系统评价

褪黑激素（Ñ-乙酰基-5-甲氧基色胺）是一种具有抗氧化，生时作用和抗炎特性的吲哚胺；这种激素水平的降低与患癌症的风险增加有关。褪黑激素在包括肝癌在内的多种肿瘤中已经描述了几种有益的作用。在这项工作中，我们系统地回顾了过去15年的出版物，这些出版物评估了褪黑激素抗肝癌的潜在机制及其在治疗这些肿瘤中作为辅助药物的作用。文献研究使用PubMed，Scopus和Web of Science（WOS）数据库进行，筛选后纳入51篇文章。所选研究的结果表明，褪黑激素可以单独或与其他化合物联合使用，在预防癌变中发挥有益作用，并作为原发性肝肿瘤肝细胞癌（HCC）和胆管癌（CCA）的有前途的治疗选择。吲哚可调节不同的过程，例如抑制氧化应激，增殖，血管生成和侵袭，促进免疫系统应答，细胞周期停滞和细胞凋亡，以及昼夜节律的恢复和自噬调节。综上所述，本系统综述着重强调了证明褪黑激素在改善肝脏肿瘤治疗前景中潜在作用的证据。例如抑制氧化应激，增殖，血管生成和侵袭，促进免疫系统反应，细胞周期停滞和凋亡，以及昼夜节律的恢复和自噬调节。综上所述，本系统综述着重强调了证明褪黑激素在改善肝脏肿瘤治疗前景中潜在作用的证据。例如抑制氧化应激，增殖，血管生成和侵袭，促进免疫系统反应，细胞周期停滞和凋亡，以及昼夜节律的恢复和自噬调节。综上所述，本系统综述着重强调了证明褪黑激素在改善肝脏肿瘤治疗前景中潜在作用的证据。