BACKGROUND Nicotinamide (NAM) is a form of vitamin B3 that, when administered at near-gram doses, has been shown or suggested to be therapeutically effective against many diseases and conditions. The target conditions are incredibly diverse ranging from skin disorders such as bullous pemphigoid to schizophrenia and depression and even AIDS. Similar diversity is expected for the underlying mechanisms. In a large portion of the conditions, NAM conversion to nicotinamide adenine dinucleotide (NAD+) may be a major factor in its efficacy. The augmentation of cellular NAD+ level not only modulates mitochondrial production of ATP and superoxide, but also activates many enzymes. Activated sirtuin proteins, a family of NAD+-dependent deacetylases, play important roles in many of NAM's effects such as an increase in mitochondrial quality and cell viability countering neuronal damages and metabolic diseases. Meanwhile, certain observed effects are mediated by NAM itself. However, our understanding on the mechanisms of NAM's effects is limited to those involving certain key proteins and may even be inaccurate in some proposed cases. AIM OF REVIEW This review details the conditions that NAM has been shown to or is expected to effectively treat in humans and animals and evaluates the proposed underlying molecular mechanisms, with the intention of promoting wider, safe therapeutic application of NAM. KEY SCIENTIFIC CONCEPTS OF REVIEW NAM, by itself or through altering metabolic balance of NAD+ and tryptophan, modulates mitochondrial function and activities of many molecules and thereby positively affects cell viability and metabolic functions. And, NAM administration appears to be quite safe with limited possibility of side effects which are related to NAM's metabolites.

中文翻译：

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烟酰胺的治疗效果各异，机理也更多样化。

背景技术烟酰胺（NAM）是维生素B3的一种形式，当以近克的剂量给药时，已显示或暗示其对许多疾病和病症具有治疗效果。从皮肤疾病（如大疱性类天疱疮到精神分裂症和抑郁症，甚至艾滋病），目标疾病的范围令人难以置信。潜在的机制也预期会有类似的多样性。在大部分情况下，NAM转化为烟酰胺腺嘌呤二核苷酸（NAD +）可能是其功效的主要因素。细胞中NAD +水平的增加不仅调节线粒体ATP和超氧化物的产生，而且还激活了许多酶。活化的瑟土因蛋白是NAD +依赖性脱乙酰基酶家族，在许多NAM'中起重要作用 抗线粒体质量和细胞活力增强等抗神经元损伤和代谢性疾病的作用。同时，某些观察到的效果是由NAM本身介导的。但是，我们对NAM的作用机理的理解仅限于涉及某些关键蛋白质的机制，在某些建议的情况下甚至可能是不准确的。综述的目的本综述详细介绍了NAM已被证明或有望在人和动物中有效治疗的疾病，并评估了拟议的潜在分子机制，旨在促进NAM的更广泛，安全的治疗应用。NAM的主要科学评论概念，无论是通过本身还是通过改变NAD +和色氨酸的代谢平衡，调节线粒体功能和许多分子的活性，从而积极影响细胞活力和代谢功能。而且，NAM给药似乎是非常安全的，与NAM代谢物有关的副作用可能性很小。