7H-Dibenzo[c,g]carbazole (DBC), a local and systemic carcinogen in animal studies, is a common environmental pollutant. It generally co-occurs in a variety of organic complex mixtures derived from incomplete combustion of organic matter. Despite high lipophilicity, DBC is more water-soluble and faster metabolized than the homocyclic aromatics. Moreover, greater polarity, high bioaccumulation potential, and persistence in the environment may imply DBC's higher biological significance and impact on human health, even at lower concentrations. The biotransformation pathways of DBC are incompletely known and the ultimate carcinogenic metabolite(s) are not clearly identified as yet. Structure-biological studies suggest two ways of activation: at the ring carbon atoms and at the pyrrole nitrogen. It is supposed that the particular pathway of biotransformation might be connected with the tissue/organ specificity of DBC. Cytochrome P450 (CYP) family of enzymes plays a pivotal role in the metabolism of DBC; though, the one-electron activation and the aldo-keto reductase-catalyzed oxidation are also involved in metabolic activation. Additionally, DBC can be photoactivated even at physiologically relevant doses of UVA light due to the extended aromatic ring system resulting in strong genotoxicity and oxidative stress. The goal of this review is to summarize current knowledge on mechanisms of DBC activation and possible implications for toxicity, genotoxicity, and carcinogenicity.

中文翻译：

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7H-二苯并[c，g]咔唑：代谢途径和毒性。

7H-二苯并[c，g]咔唑（DBC）是动物研究中的一种局部和全身性致癌物，是一种常见的环境污染物。它通常同时存在于源自有机物不完全燃烧的各种有机复合混合物中。尽管亲脂性很高，但DBC比同环芳族化合物更易溶于水且代谢更快。此外，更大的极性，更高的生物蓄积潜力和在环境中的持久性可能意味着DBC的生物学意义更高，即使浓度较低也对人体健康产生影响。DBC的生物转化途径尚不完全清楚，最终致癌代谢物尚不清楚。结构生物学研究提出了两种激活方式：在环碳原子处和在吡咯氮处。据推测，生物转化的特定途径可能与DBC的组织/器官特异性有关。细胞色素P450（CYP）酶家族在DBC的代谢中起着关键作用。但是，单电子激活和醛酮还原酶催化的氧化也参与代谢激活。另外，由于芳香环系统的扩展，DBC甚至在生理相关剂量的UVA光下也可以被光活化，从而导致强烈的遗传毒性和氧化应激。这篇综述的目的是总结有关DBC激活机制的最新知识，以及对毒性，遗传毒性和致癌性的潜在影响。单电子激活和醛酮还原酶催化的氧化也参与代谢激活。另外，由于芳香环系统的扩展，DBC甚至在生理相关剂量的UVA光下也可以被光活化，从而导致强烈的遗传毒性和氧化应激。这篇综述的目的是总结有关DBC激活机制的最新知识，以及对毒性，遗传毒性和致癌性的潜在影响。单电子激活和醛酮还原酶催化的氧化也参与代谢激活。另外，由于芳香环系统的扩展，DBC甚至在生理相关剂量的UVA光下也可以被光活化，从而导致强烈的遗传毒性和氧化应激。这篇综述的目的是总结有关DBC激活机制的最新知识，以及对毒性，遗传毒性和致癌性的潜在影响。