Niacinamide Abstracts 2

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Aging

Inhibition of silencing and accelerated aging by nicotinamide, a putative negative regulator of yeast sir2 and human SIRT1

         (Bitterman, Anderson et al. 2002) Download

The Saccharomyces cerevisiae Sir2 protein is an NAD(+)-dependent histone deacetylase that plays a critical role in transcriptional silencing, genome stability, and longevity. A human homologue of Sir2, SIRT1, regulates the activity of the p53 tumor suppressor and inhibits apoptosis. The Sir2 deacetylation reaction generates two products: O-acetyl-ADP-ribose and nicotinamide, a precursor of nicotinic acid and a form of niacin/vitamin B(3). We show here that nicotinamide strongly inhibits yeast silencing, increases rDNA recombination, and shortens replicative life span to that of a sir2 mutant. Nicotinamide abolishes silencing and leads to an eventual delocalization of Sir2 even in G(1)-arrested cells, demonstrating that silent heterochromatin requires continual Sir2 activity. We show that physiological concentrations of nicotinamide noncompetitively inhibit both Sir2 and SIRT1 in vitro. The degree of inhibition by nicotinamide (IC(50) < 50 microm) is equal to or better than the most effective known synthetic inhibitors of this class of proteins. We propose a model whereby nicotinamide inhibits deacetylation by binding to a conserved pocket adjacent to NAD(+), thereby blocking NAD(+) hydrolysis. We discuss the possibility that nicotinamide is a physiologically relevant regulator of Sir2 enzymes.


Mechanism of nicotinamide inhibition and transglycosidation by Sir2 histone/protein deacetylases

         (Jackson, Schmidt et al. 2003) Download

Silent information regulator 2 (Sir2) enzymes catalyze NAD+-dependent protein/histone deacetylation, where the acetyl group from the lysine epsilon-amino group is transferred to the ADP-ribose moiety of NAD+, producing nicotinamide and the novel metabolite O-acetyl-ADP-ribose. Sir2 proteins have been shown to regulate gene silencing, metabolic enzymes, and life span. Recently, nicotinamide has been implicated as a direct negative regulator of cellular Sir2 function; however, the mechanism of nicotinamide inhibition was not established. Sir2 enzymes are multifunctional in that the deacetylase reaction involves the cleavage of the nicotinamide-ribosyl, cleavage of an amide bond, and transfer of the acetyl group ultimately to the 2'-ribose hydroxyl of ADP-ribose. Here we demonstrate that nicotinamide inhibition is the result of nicotinamide intercepting an ADP-ribosyl-enzyme-acetyl peptide intermediate with regeneration of NAD+ (transglycosidation). The cellular implications are discussed. A variety of 3-substituted pyridines was found to be substrates for enzyme-catalyzed transglycosidation. A Bronsted plot of the data yielded a slope of +0.98, consistent with the development of a nearly full positive charge in the transition state, and with basicity of the attacking nucleophile as a strong predictor of reactivity. NAD+ analogues including beta-2'-deoxy-2'-fluororibo-NAD+ and a His-to-Ala mutant were used to probe the mechanism of nicotinamide-ribosyl cleavage and acetyl group transfer. We demonstrate that nicotinamide-ribosyl cleavage is distinct from acetyl group transfer to the 2'-OH ribose. The observed enzyme-catalyzed formation of a labile 1'-acetylated-ADP-fluororibose intermediate using beta-2'-deoxy-2'-fluororibo-NAD+ supports a mechanism where, after nicotinamide-ribosyl cleavage, the carbonyl oxygen of acetylated substrate attacks the C-1' ribose to form an initial iminium adduct.

Cell Life versus cell longevity: the mysteries surrounding the NAD+ precursor nicotinamide

         (Li, Chong et al. 2006) Download

Nicotinamide, the amide form of niacin (vitamin B(3)), is the precursor for the coenzyme beta-nicotinamide adenine dinucleotide (NAD(+)) and plays a significant role during the enhancement of cell survival as well as cell longevity. Yet, these abilities of nicotinamide appear to be diametrically opposed. Here we describe the development of nicotinamide as a novel agent that is critical for modulating cellular metabolism, plasticity, longevity, and inflammatory microglial function as well as for influencing cellular life span. The capacity of nicotinamide to govern not only intrinsic cellular integrity, but also extrinsic cellular inflammation rests with the modulation of a host of cellular targets that involve mitochondrial membrane potential, poly(ADP-ribose) polymerase, protein kinase B (Akt), Forkhead transcription factors, Bad, caspases, and microglial activation. Further knowledge acquired in regards to the ability of nicotinamide to foster cellular survival and regulate cellular lifespan should significantly promote the development of therapies against a host of disorders, such as aging, Alzheimer's disease, diabetes, cerebral ischemia, Parkinson's disease, and cancer.

Nicotinamide, NAD(P)(H), and Methyl-Group Homeostasis Evolved and Became a Determinant of Ageing Diseases: Hypotheses and Lessons from Pellagra

         (Williams, Hill et al. 2012) Download

Compartmentalized redox faults are common to ageing diseases. Dietary constituents are catabolized to NAD(H) donating electrons producing proton-based bioenergy in coevolved, cross-species and cross-organ networks. Nicotinamide and NAD deficiency from poor diet or high expenditure causes pellagra, an ageing and dementing disorder with lost robustness to infection and stress. Nicotinamide and stress induce Nicotinamide-N-methyltransferase (NNMT) improving choline retention but consume methyl groups. High NNMT activity is linked to Parkinson's, cancers, and diseases of affluence. Optimising nicotinamide and choline/methyl group availability is important for brain development and increased during our evolution raising metabolic and methylome ceilings through dietary/metabolic symbiotic means but strict energy constraints remain and life-history tradeoffs are the rule. An optimal energy, NAD and methyl group supply, avoiding hypo and hyper-vitaminoses nicotinamide and choline, is important to healthy ageing and avoids utilising double-edged symbionts or uncontrolled autophagy or reversions to fermentation reactions in inflammatory and cancerous tissue that all redistribute NAD(P)(H), but incur high allostatic costs.


Cancer

Nicotinamide phosphoribosyl-transferase/visfatin: a missing link between overweight/obesity and postmenopausal breast cancer? Potential preventive and therapeutic perspectives and challenges

(Dalamaga 2012) Download

Worldwide breast cancer (BC) constitutes a significant public health concern. Excess body weight is associated with postmenopausal BC (PBC) risk. Recent studies have shown that the constellation of obesity, insulin resistance and serum adipokine levels are associated with the risk and prognosis of PBC. Nicotinamide phosphoribosyl-transferase (Nampt), also known as visfatin and pre-B-cell-colony-enhancing factor, found in the visceral fat, represents a novel pleiotropic adipokine acting as a cytokine, a growth factor and an enzyme. It plays an important role in a variety of metabolic and stress responses as well as in the cellular energy metabolism, particularly NAD biosynthesis. Nampt exhibits proliferative, anti-apoptotic, pro-inflammatory and pro-angiogenic properties. Nampt's insulin-mimetic function remains a controversial issue. Circulating Nampt levels are increased in obese women. Also, Nampt levels are significantly elevated in women suffering from PBC than in healthy controls independently from known risk factors of BC, anthropometric and metabolic parameters as well as serum concentrations of well known adipokines. High expression of Nampt in BC tissues was reported to be associated with more malignant cancer behavior as well as adverse prognosis. Taking into account the mitogenicity of Nampt as well as its proliferative, anti-apoptotic and pro-angiogenic properties, a novel hypothesis is proposed whereas Nampt may be involved in the etiopathogenesis of PBC and may represent a missing link between overweight/obesity and PBC. Nampt could exert its effects on the normal and neoplastic mammary tissue by endocrine and paracrine mechanisms; Nampt could also be secreted by tumor epithelial cells in an autocrine manner. It could stimulate mammary epithelial cell proliferation, invasion, metastasis, and angiogenesis, which is essential for BC development and progression. Serum Nampt might be a novel risk factor as well as a potential diagnostic and prognostic biomarker in PBC. In addition, pharmacologic agents that neutralize biochemically Nampt or medications that decrease Nampt levels or downregulate signaling pathways downstream of Nampt may prove to be useful anti-cancer agents. The potential harmful effect on PBC risk due to vitamin B3 (nicotinic acid, a natural NAD precursor in the biosynthetic route leading to NAD) intake is speculated for the first time. In this hypothesis, the role of Nampt in BC carcinogenesis and progression is explored as well as the pathophysiological mechanisms that underlie the association between Nampt and PBC in the context of a dysfunctional adipose tissue in obesity. Understanding of these mechanisms may be important for the development of preventive and therapeutic strategies against PBC.

The nicotinamide phosphoribosyltransferase: a molecular link between metabolism, inflammation, and cancer

(Galli, Van Gool et al. 2010) Download

Beyond its well-described role in cellular metabolism, intracellular nicotinamide adenine dinucleotide (NAD) levels have been shown to affect the enzymatic activity of a series of NAD-dependent enzymes, influencing biological responses such as cell survival and inflammation. Nicotinamide phosphoribosyl transferase activity has been shown to be essential for maintaining adequate intracellular NAD levels, suggesting that this enzyme may in fact play a central role in modulating the activity of a wide range of NAD-dependent enzymes. Several recent observations concur with this hypothesis and suggest that by regulating NAD availability, Nampt is able to control both cell viability and the inflammatory response. Nampt may thus represent a novel pharmacological target with valuable anti-inflammatory and antitumor properties.

Topical nicotinamide modulates cellular energy metabolism and provides broad-spectrum protection against ultraviolet radiation-induced immunosuppression in humans

         (Sivapirabu, Yiasemides et al. 2009) Download

BACKGROUND: Ultraviolet (UV) radiation can profoundly suppress the cutaneous immune system, thus enhancing carcinogenesis. Agents that prevent UV-induced immunosuppression may thus reduce skin cancer. Nicotinamide (vitamin B3) prevents UV-induced immunosuppression and carcinogenesis in mice, and solar-simulated (ss) UV-induced immunosuppression in humans. Its effectiveness against different UV wavebands and mechanism of action is as yet unknown. OBJECTIVES: To determine the effects and mechanisms of topical nicotinamide on UV-induced suppression of delayed type hypersensitivity (DTH) responses in humans. METHODS: Healthy Mantoux-positive volunteers in four randomised, double-blinded studies were irradiated with solar-simulated (ss)UV (UVB + UVA) or narrowband UVB (300 nm) or UVA (385 nm). Topical nicotinamide (0.2% or 5%) or its vehicle were applied immediately after each irradiation. Mantoux testing was performed at irradiated sites and adjacent unirradiated control sites 48 h after the first irradiation and measured 72 h later. Immunosuppression was calculated as the difference in Mantoux-induced erythema and induration at test sites compared to control sites. Human keratinocyte cell cultures, with and without ssUV and nicotinamide, were used for quantitative real-time reverse transcriptase-polymerase chain reaction assessment of TP53 and enzymes that regulate oxidative phosphorylation. RESULTS: Nicotinamide cooperated with ssUV to increase enzymes involved in cellular energy metabolism and p53, and significantly protected against immunosuppression caused by UVB, longwave UVA and single and repeated ssUV exposures. CONCLUSIONS: Longwave UVA, which is poorly filtered by most sunscreens, was highly immune suppressive even at doses equivalent to 20 min of sun exposure. Nicotinamide, which protected against both UVB and UVA, is a promising agent for skin cancer prevention.

Role of nicotinamide in DNA damage, mutagenesis, and DNA repair

(Surjana, Halliday et al. 2010) Download

Nicotinamide is a water-soluble amide form of niacin (nicotinic acid or vitamin B3). Both niacin and nicotinamide are widely available in plant and animal foods, and niacin can also be endogenously synthesized in the liver from dietary tryptophan. Nicotinamide is also commercially available in vitamin supplements and in a range of cosmetic, hair, and skin preparations. Nicotinamide is the primary precursor of nicotinamide adenine dinucleotide (NAD(+)), an essential coenzyme in ATP production and the sole substrate of the nuclear enzyme poly-ADP-ribose polymerase-1 (PARP-1). Numerous in vitro and in vivo studies have clearly shown that PARP-1 and NAD(+) status influence cellular responses to genotoxicity which can lead to mutagenesis and cancer formation. This paper will examine the role of nicotinamide in the protection from carcinogenesis, DNA repair, and maintenance of genomic stability.


Infections

C/EBPepsilon mediates nicotinamide-enhanced clearance of Staphylococcus aureus in mice

         (Kyme, Thoennissen et al. 2012) Download

The myeloid-specific transcription factor, CCAAT/enhancer-binding protein epsilon (C/EBPepsilon) is a critical mediator of myelopoiesis. Mutation of this gene is responsible for neutrophil-specific granule deficiency in humans, a condition that confers susceptibility to Staphylococcus aureus infection. We found that C/EBPepsilon-deficient mice are severely affected by infection with S. aureus, and C/EBPepsilon deficiency in neutrophils contributes to the infectious phenotype. Conversely, exposure to the epigenetic modulator nicotinamide (vitamin B3) increased expression of C/EBPepsilon in WT myeloid cells. Further, nicotinamide increased the activity of C/EBPepsilon and select downstream antimicrobial targets, particularly in neutrophils. In a systemic murine infection model as well as in murine and human peripheral blood, nicotinamide enhanced killing of S. aureus by up to 1,000 fold but had no effect when administered to either C/EBPepsilon-deficient mice or mice depleted of neutrophils. Nicotinamide was efficacious in both prophylactic and therapeutic settings. Our findings suggest that C/EBPepsilon is an important target to boost killing of bacteria by the innate immune system.

Nicotinamide: an oral antimicrobial agent with activity against both Mycobacterium tuberculosis and human immunodeficiency virus

         (Murray 2003) Download

Coinfection with Mycobacterium tuberculosis and human immunodeficiency virus (HIV) is responsible for one-third of all deaths due to acquired immunodeficiency syndrome. More than 99% of cases of HIV-M. tuberculosis coinfection occur in the developing world, where limited resources add urgency to the search for effective and affordable therapies. Although antimicrobial agents against each of these infections are available, single agents that have activity against both M. tuberculosis and HIV are uncommon. The activity of nicotinamide has been evaluated in 2 different eras: in anti-M. tuberculosis studies performed during 1945-1961 and in anti-HIV studies performed from 1991 to the present. This review brings together these 2 bodies of inquiry and raises the possibility that, with more study, this small molecule could emerge at the beginning of the 21st century either as a therapeutic agent in itself or as the lead compound for a new class of agents with activity against both M. tuberculosis and HIV.

Inflammation

Nicotinamide is a potent inhibitor of proinflammatory cytokines

         (Ungerstedt, Blomback et al. 2003) Download

The present study investigates the modulating effects of nicotinamide on the cytokine response to endotoxin. In an in vitro model of endotoxaemia, human whole blood was stimulated for two hours with endotoxin at 1 ng/ml, achieving high levels of the proinflammatory cytokines IL-1 beta, IL-6, IL-8 and TNF alpha. When coincubating whole blood, endotoxin and the vitamin B3 derivative nicotinamide, all four cytokines measured were inhibited in a dose dependent manner. Inhibition was observed already at a nicotinamide concentration of 2 mmol/l. At a concentration of 40 mmol/l, the IL-1 beta, IL-6 and TNF alpha responses were reduced by more than 95% and the IL-8 levels reduced by 85%. Endotoxin stimulation activates poly(ADP-ribose)polymerase (PARP), a nuclear DNA repair enzyme. It has been hypothesized that the anti-inflammatory properties of nicotinamide are due to PARP inhibition. In the present study, the endotoxin induced PARP activation was dose dependently decreased with 4-40 mmol/l nicotinamide or 4-100 micro mol/l 6(5H) phenanthridinone, a specific PARP inhibitor. 6(5H)phenanthridinone however, failed to inhibit the proinflammatory cytokines. Thus, the mechanism behind the cytokine inhibition in our model seems not to be due to PARP inhibition. In conclusion, the present study could not only confirm previous reports of a down-regulatory effect on TNFalpha, but demonstrates that nicotinamide is a potent modulator of several proinflammatory cytokines. These findings demonstrate that nicotinamide has a potent immunomodulatory effect in vitro, and may have great potential for treatment of human inflammatory disease.


Negative transcriptional regulation of inflammatory genes by group B3 vitamin nicotinamide

         (Zhang, Jing et al. 2012) Download

The water-soluble group B3 vitamin nicotinamide (NAM) is involved in a wide range of physical processes through biosynthetically converted to nicotinamide adenine dinucleotide (NAD(+)). In addition to its pivotal role in energy metabolism, NAD(+) is also the indispensable substrate of poly (ADP-ribose) polymerase-1 (PARP-1) and sirtuin 1 (SIRT1). PARP-1 and SIRT1 may catalyze the posttranslational poly(ADP-ribosyl)ation and acetylation of histones as well as non-histone proteins, such as nuclear factor kappa B and activator protein 1, which play crucial roles in transcriptional regulation of inflammatory genes. The NAD(+)-dependent modifications catalyzed by PARP-1 and SIRT1 liberate NAM, and NAM acts as feedback inhibitor of PARP-1 and SIRT1 through interacting with the enzymes at the binding site for NAD(+). There is increasing evidence that NAM effectively suppresses the expression of inflammatory genes and provides therapeutic benefits in various inflammation-based diseases. The mechanisms underlie the anti-inflammatory properties of NAM might involve the inhibition of PARP-1 and SIRT1.

Misc

Niacinamide. Monograph

         (2002) Download

Niacin versus niacinamide

         (Jaconello 1992) Download

The vitamin nicotinamide: translating nutrition into clinical care

         (Maiese, Chong et al. 2009) Download

Nicotinamide, the amide form of vitamin B(3) (niacin), is changed to its mononucleotide compound with the enzyme nicotinic acide/nicotinamide adenylyltransferase, and participates in the cellular energy metabolism that directly impacts normal physiology. However, nicotinamide also influences oxidative stress and modulates multiple pathways tied to both cellular survival and death. During disorders that include immune system dysfunction, diabetes, and aging-related diseases, nicotinamide is a robust cytoprotectant that blocks cellular inflammatory cell activation, early apoptotic phosphatidylserine exposure, and late nuclear DNA degradation. Nicotinamide relies upon unique cellular pathways that involve forkhead transcription factors, sirtuins, protein kinase B (Akt), Bad, caspases, and poly (ADP-ribose) polymerase that may offer a fine line with determining cellular longevity, cell survival, and unwanted cancer progression. If one is cognizant of the these considerations, it becomes evident that nicotinamide holds great potential for multiple disease entities, but the development of new therapeutic strategies rests heavily upon the elucidation of the novel cellular pathways that nicotinamide closely governs.

Nicotinic acid receptor subtypes and their ligands

         (Soudijn, van Wijngaarden et al. 2007) Download

Half a century ago, nicotinic acid (niacin) was introduced into the clinic as the first orally available drug to treat high cholesterol levels and to improve the balance between (V)low density lipoproteins (LDL) and high density lipoproteins (HDL). Remarkably, its putative mechanism of action has only been recently elucidated, particularly because of the cloning of a G protein-coupled receptor (HM74A or GPR109A). This receptor responds to both nicotinic acid and the ketone body beta-hydroxybutyrate, the latter thought to be the more probable endogenous ligand for HM74A. In this review, we will discuss the pharmacology and medicinal chemistry of this receptor subtype and a related one (HM74 or GPR109B). Although still in its infancy, the ligand repertoire is developing, and a number of compound classes have now been described, among which are both full and partial agonists. Antagonists, however, are still lacking, thus compromising thorough pharmacological studies. Mutagenesis experiments have provided clues regarding the ligand binding site; in particular, an arginine residue in transmembrane domain 3 of the receptor seems to recognize the acidic moiety present in nicotinic acid and related substances. HM74A has also been linked to one of the major side effects of nicotinic acid, that is, flushing, since this receptor subtype also occurs in skin immune cells. It is not known yet whether HM74 is also present on these cells. Since nicotinic acid is one of the few available medicines that raise HDL ("good cholesterol") levels, HM74A and HM74 appear promising targets for future pharmacotherapy.


The effect of oral niacinamide on plasma phosphorus levels in peritoneal dialysis patients

         (Young, Cheng et al. 2009) Download

BACKGROUND: Hyperphosphatemia remains a significant problem for patients requiring dialysis and is associated with increased mortality. Current treatment options include dietary restriction, dialysis, and phosphate binders. Treatment using the latter is frequently limited by cost, tolerability, and calcium loading. One open-label trial found niacinamide to be effective at decreasing serum phosphorus values in hemodialysis patients. Niacinamide may effectively reduce phosphorus levels in peritoneal dialysis (PD) patients already receiving standard phosphorus-lowering therapies. METHODS: An 8 week, randomized, double blind, placebo-controlled trial to evaluate the effectiveness of niacinamide to reduce plasma phosphorus levels in PD patients. Patients had to demonstrate a baseline phosphorus value > 4.9 mg/dL. Patients were randomized to niacinamide or placebo and prescribed 250 mg twice daily, with titration to 750 mg twice daily, as long as safety parameters were not violated. Phosphate binders, active vitamin D, and cinacalcet were kept constant during the study. The primary end point was change in plasma phosphorus. Secondary end points included changes in lipid parameters. RESULTS: 15 patients started on the study drug (8 niacinamide, 7 placebo) and 7 in each arm had at least one on-study phosphorus measurement. The niacinamide treatment group experienced an average 0.7 +/- 0.9 mg/dL decrease in plasma phosphorus and the placebo-treated group experienced an average 0.4 +/- 0.8 mg/dL increase. The treatment effect difference (1.1 mg/dL) was significant (p = 0.037). No significant changes in high- or low-density lipoproteins or triglycerides were demonstrated. Two of the 8 patients randomized to the niacinamide treatment arm had to withdraw from the study due to drug-related adverse effects. Adverse effects may limit the use of niacinamide in PD patients. CONCLUSION: Niacinamide, when added to standard phosphorus-lowering therapies, resulted in a modest yet statistically significant reduction in plasma phosphorus levels at 8 weeks. [ClinicalTrials.gov number NCT00508885].


References

(2002). "Niacinamide. Monograph." Altern Med Rev 7(6): 525-9. [PMID: 12495377]

Bitterman, K. J., R. M. Anderson, et al. (2002). "Inhibition of silencing and accelerated aging by nicotinamide, a putative negative regulator of yeast sir2 and human SIRT1." J Biol Chem 277(47): 45099-107. [PMID: 12297502]

Dalamaga, M. (2012). "Nicotinamide phosphoribosyl-transferase/visfatin: a missing link between overweight/obesity and postmenopausal breast cancer? Potential preventive and therapeutic perspectives and challenges." Med Hypotheses 79(5): 617-21. [PMID: 22922056]

Galli, M., F. Van Gool, et al. (2010). "The nicotinamide phosphoribosyltransferase: a molecular link between metabolism, inflammation, and cancer." Cancer Res 70(1): 8-11. [PMID: 20028851]

Jackson, M. D., M. T. Schmidt, et al. (2003). "Mechanism of nicotinamide inhibition and transglycosidation by Sir2 histone/protein deacetylases." J Biol Chem 278(51): 50985-98. [PMID: 14522996]

Jaconello, P. (1992). "Niacin versus niacinamide." CMAJ 147(7): 990. [PMID: 1393911]

Kyme, P., N. H. Thoennissen, et al. (2012). "C/EBPepsilon mediates nicotinamide-enhanced clearance of Staphylococcus aureus in mice." J Clin Invest 122(9): 3316-29. [PMID: 22922257]

Li, F., Z. Z. Chong, et al. (2006). "Cell Life versus cell longevity: the mysteries surrounding the NAD+ precursor nicotinamide." Curr Med Chem 13(8): 883-95. [PMID: 16611073]

Maiese, K., Z. Z. Chong, et al. (2009). "The vitamin nicotinamide: translating nutrition into clinical care." Molecules 14(9): 3446-85. [PMID: 19783937]

Murray, M. F. (2003). "Nicotinamide: an oral antimicrobial agent with activity against both Mycobacterium tuberculosis and human immunodeficiency virus." Clin Infect Dis 36(4): 453-60. [PMID: 12567303]

Sivapirabu, G., E. Yiasemides, et al. (2009). "Topical nicotinamide modulates cellular energy metabolism and provides broad-spectrum protection against ultraviolet radiation-induced immunosuppression in humans." Br J Dermatol 161(6): 1357-64. [PMID: 19804594]

Soudijn, W., I. van Wijngaarden, et al. (2007). "Nicotinic acid receptor subtypes and their ligands." Med Res Rev 27(3): 417-33. [PMID: 17238156]

Surjana, D., G. M. Halliday, et al. (2010). "Role of nicotinamide in DNA damage, mutagenesis, and DNA repair." J Nucleic Acids 2010. [PMID: 20725615]

Ungerstedt, J. S., M. Blomback, et al. (2003). "Nicotinamide is a potent inhibitor of proinflammatory cytokines." Clin Exp Immunol 131(1): 48-52. [PMID: 12519385]

Williams, A. C., L. J. Hill, et al. (2012). "Nicotinamide, NAD(P)(H), and Methyl-Group Homeostasis Evolved and Became a Determinant of Ageing Diseases: Hypotheses and Lessons from Pellagra." Curr Gerontol Geriatr Res 2012: 302875. [PMID: 22536229]

Young, D. O., S. C. Cheng, et al. (2009). "The effect of oral niacinamide on plasma phosphorus levels in peritoneal dialysis patients." Perit Dial Int 29(5): 562-7. [PMID: 19776051]

Zhang, X. M., Y. P. Jing, et al. (2012). "Negative transcriptional regulation of inflammatory genes by group B3 vitamin nicotinamide." Mol Biol Rep 39(12): 10367-71. [PMID: 23053940]