Compendio degli studi più significativi con riferimento a proprietà, assunzione, effetti.

Fania L, Mazzanti C, Campione E, Candi E, Abeni D, Dellambra E. Role of Nicotinamide in Genomic Stability and Skin Cancer Chemoprevention. Int J Mol Sci. 2019 Nov 26;20(23):5946. doi: 10.3390/ijms20235946.

Abstract. Nicotinamide (NAM) is an amide form of vitamin B3 and the precursor of nicotinamide adenine dinucleotide (NAD+), an essential co-enzyme of redox reactions for adenosine triphosphate (ATP) production and for other metabolic processes. As NAD+ status is critical in maintaining cellular energy, vitamin B3 deficiency mainly affects tissues that need high cellular energy causing pellagra and skin sun sensitivity. In animal models, NAD+ deficiency leads to UV sensitivity of the skin, impairs DNA damage response, and increases genomic instability and cancer incidence. Furthermore, NAD+ depletion is associated with human skin aging and cancer. NAM prevents the UV-induced ATP depletion boosting cellular energy and enhances DNA repair activity in vitro and in vivo. Moreover, NAM reduces skin cancer incidence and prevents the immune-suppressive effects of UV in mice. Thus, NAM is involved in the maintenance of genomic stability and may have beneficial effects against skin aging changes and tumor development. Clinical studies showed that topical use of NAM reduces cutaneous aging. Furthermore, oral NAM administration reduces the level of UV-mediated immunosuppression and lowers the rate of non-melanoma skin cancers in high-risk patients. Therefore, NAM replenishment strategy may be a promising approach for skin cancer chemoprevention.

Doroftei B, Ilie OD, Cojocariu RO, Ciobica A, Maftei R, Grab D, Anton E, McKenna J, Dhunna N, Simionescu G. Minireview Exploring the Biological Cycle of Vitamin B3 and Its Influence on Oxidative Stress: Further Molecular and Clinical Aspects. Molecules. 2020 Jul 22;25(15):3323. doi: 10.3390/molecules25153323. 

Abstract. Vitamin B3, or niacin, is one of the most important compounds of the B-vitamin complex. Recent reports have demonstrated the involvement of vitamin B3 in a number of pivotal functions which ensure that homeostasis is maintained. In addition, the intriguing nature of its synthesis and the underlying mechanism of action of vitamin B3 have encouraged further studies aimed at deepening our understanding of the close link between the exogenous supply of B3 and how it activates dependent enzymes. This crucial role can be attributed to the gut microflora and its ability to shape human behavior and development by mediating the bioavailability of metabolites. Recent studies have indicated a possible interconnection between the novel coronavirus and commensal bacteria. As such, we have attempted to explain how the gastrointestinal deficiencies displayed by SARS-CoV-2-infected patients arise. It seems that the stimulation of a proinflammatory cascade and the production of large amounts of reactive oxygen species culminates in the subsequent loss of host eubiosis. Studies of the relationhip between ROS, SARS-CoV-2, and gut flora are sparse in the current literature. As an integrated component, oxidative stress (OS) has been found to negatively influence host eubiosis, in vitro fertilization outcomes, and oocyte quality, but to act as a sentinel against infections. In conclusion, research suggests that in the future, a healthy diet may be considered a reliable tool for maintaining and optimizing our key internal parameters.

Novak Kujundžić R. COVID-19: Are We Facing Secondary Pellagra Which Cannot Simply Be Cured by Vitamin B3? Int J Mol Sci. 2022 Apr 13;23(8):4309. doi: 10.3390/ijms23084309. 

Abstract. Immune response to SARS-CoV-2 and ensuing inflammation pose a huge challenge to the host’s nicotinamide adenine dinucleotide (NAD+) metabolism. Humans depend on vitamin B3 for biosynthesis of NAD+, indispensable for many metabolic and NAD+-consuming signaling reactions. The balance between its utilization and resynthesis is vitally important. Many extra-pulmonary symptoms of COVID-19 strikingly resemble those of pellagra, vitamin B3 deficiency (e.g., diarrhoea, dermatitis, oral cavity and tongue manifestations, loss of smell and taste, mental confusion). In most developed countries, pellagra is successfully eradicated by vitamin B3 fortification programs. Thus, conceivably, it has not been suspected as a cause of COVID-19 symptoms. Here, the deregulation of the NAD+ metabolism in response to the SARS-CoV-2 infection is reviewed, with special emphasis on the differences in the NAD+ biosynthetic pathway’s efficiency in conditions predisposing for the development of serious COVID-19. SARS-CoV-2 infection-induced NAD+ depletion and the elevated levels of its metabolites contribute to the development of a systemic disease. Acute liberation of nicotinamide (NAM) in antiviral NAD+-consuming reactions potentiates “NAM drain”, cooperatively mediated by nicotinamide N-methyltransferase and aldehyde oxidase. “NAM drain” compromises the NAD+ salvage pathway’s fail-safe function. The robustness of the host’s NAD+ salvage pathway, prior to the SARS-CoV-2 infection, is an important determinant of COVID-19 severity and persistence of certain symptoms upon resolution of infection.

Lorenzen A, Stannek C, Lang H, Andrianov V, Kalvinsh I, Schwabe U. Characterization of a G protein-coupled receptor for nicotinic acid. Mol Pharmacol. 2001 Feb;59(2):349-57. doi: 10.1124/mol.59.2.349. 

Abstract. Nicotinic acid is a lipid-lowering agent widely used to treat hypertriglyceridemia and to elevate low high density lipoprotein levels. However, the underlying mechanisms are poorly understood. In this study, G protein activation by nicotinic acid and derivatives was assessed as stimulation of guanosine 5'-(gamma-[(35)S]-thio)triphosphate ([(35)S]GTPgammaS) binding, and [(3)H]nicotinic acid was used for specific labeling of binding sites. Nicotinic acid (EC(50) approximately 1 microM) stimulated [(35)S]GTPgammaS binding in membranes from rat adipocytes and spleen, but not from other tissues. G protein activation in adipocyte membranes in the presence of maximally activating concentrations of the selective A(1) adenosine receptor agonist 2-chloro-N(6)-cyclopentyladenosine and nicotinic acid was almost additive, indicating that G proteins of mostly distinct pools were activated by these agonists. G protein activation by nicotinic acid and related substances in spleen and adipocytes revealed identical pharmacological profiles. [(3)H]Nicotinic acid specifically detected guanine nucleotide-sensitive binding sites of identical pharmacology in adipocyte and spleen membranes. The site of action of nicotinic acid is distinct from other G protein-coupled receptors. These data indicate that nicotinic acid most probably acts on a specific G protein-coupled receptor.

Sallabi SM, Alhmoudi A, Alshekaili M, Shah I. Determination of Vitamin B3 Vitamer (Nicotinamide) and Vitamin B6 Vitamers in Human Hair Using LC-MS/MS. Molecules. 2021 Jul 25;26(15):4487. doi: 10.3390/molecules26154487. 

Abstract. Water-soluble B vitamins participate in numerous crucial metabolic reactions and are critical for maintaining our health. Vitamin B deficiencies cause many different types of diseases, such as dementia, anaemia, cardiovascular disease, neural tube defects, Crohn's disease, celiac disease, and HIV. Vitamin B3 deficiency is linked to pellagra and cancer, while niacin (or nicotinic acid) lowers low-density lipoprotein (LDL) and triglycerides in the blood and increases high-density lipoprotein (HDL). A highly sensitive and robust liquid chromatography-tandem mass spectroscopy (LC/MS-MS) method was developed to detect and quantify a vitamin B3 vitamer (nicotinamide) and vitamin B6 vitamers (pyridoxial 5'-phosphate (PLP), pyridoxal hydrochloride (PL), pyridoxamine dihydrochloride (PM), pridoxamine-5'-phosphate (PMP), and pyridoxine hydrochloride (PN)) in human hair samples of the UAE population. Forty students' volunteers took part in the study and donated their hair samples. The analytes were extracted and then separated using a reversed-phase Poroshell EC-C18 column, eluted using two mobile phases, and quantified using LC/MS-MS system. The method was validated in human hair using parameters such as linearity, intra- and inter-day accuracy, and precision and recovery. The method was then used to detect vitamin B3 and B6 vitamers in the human hair samples. Of all the vitamin B3 and B6 vitamers tested, only nicotinamide was detected and quantified in human hair. Of the 40 samples analysed, 12 were in the range 100-200 pg/mg, 15 in the range 200-500 pg/mg, 9 in the range of 500-4000 pg/mg. The LC/MS-MS method is effective, sensitive, and robust for the detection of vitamin B3 and its vitamer nicotinamide in human hair samples. This developed hair test can be used in clinical examination to complement blood and urine tests for the long-term deficiency, detection, and quantification of nicotinamide.

Williams PA, Harder JM, Foxworth NE, Cochran KE, Philip VM, Porciatti V, Smithies O, John SW. Vitamin B3 modulates mitochondrial vulnerability and prevents glaucoma in aged mice. Science. 2017 Feb 17;355(6326):756-760. doi: 10.1126/science.aal0092. 

Abstract. Glaucomas are neurodegenerative diseases that cause vision loss, especially in the elderly. The mechanisms initiating glaucoma and driving neuronal vulnerability during normal aging are unknown. Studying glaucoma-prone mice, we show that mitochondrial abnormalities are an early driver of neuronal dysfunction, occurring before detectable degeneration. Retinal levels of nicotinamide adenine dinucleotide (NAD+, a key molecule in energy and redox metabolism) decrease with age and render aging neurons vulnerable to disease-related insults. Oral administration of the NAD+ precursor nicotinamide (vitamin B3), and/or gene therapy (driving expression of Nmnat1, a key NAD+-producing enzyme), was protective both prophylactically and as an intervention. At the highest dose tested, 93% of eyes did not develop glaucoma. This supports therapeutic use of vitamin B3 in glaucoma and potentially other age-related neurodegenerations.  Copyright © 2017, American Association for the Advancement of Science.

Huber R, Wong A. Nicotinamide: An Update and Review of Safety & Differences from Niacin. Skin Therapy Lett. 2020 Nov;25(5):7-11. 

Abstract. Nicotinamide (or niacinamide), a form of vitamin B3 that is often confused with its precursor nicotinic acid (or niacin), is a low-cost, evidence-based oral treatment option for actinic keratosis, squamous cell carcinomas, basal cell carcinomas, and bullous pemphigoid. Despite its favorable safety profile and affordability, the integration of nicotinamide into clinical practice is an ongoing process, and like many over-the-counter supplements it has faced some barriers. The purpose of this article is to address some of those barriers by reviewing its efficacy, safety profile, and emphasizing the difference between nicotinamide and niacin. Lastly, we offer practical guidance around recommendations and the availability of nicotinamide, which can be hard to find for patients and providers alike.

Zandona A, Lihtar G, Maraković N, Miš K, Bušić V, Gašo-Sokač D, Pirkmajer S, Katalinić M. Vitamin B3-Based Biologically Active Compounds as Inhibitors of Human Cholinesterases. Int J Mol Sci. 2020 Oct 29;21(21):8088. doi: 10.3390/ijms21218088.

Abstract. We evaluated the potential of nine vitamin B3 scaffold-based derivatives as acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitors, as a starting point for the development of novel drugs for treating disorders with cholinergic neurotransmission-linked pathology. As the results indicate, all compounds reversibly inhibited both enzymes in the micromolar range pointing to the preference of AChE over BChE for binding the tested derivatives. Molecular docking studies revealed the importance of interactions with AChE active site residues Tyr337 and Tyr124, which dictated most of the observed differences. The most potent inhibitor of both enzymes with Ki of 4 μM for AChE and 8 μM for BChE was the nicotinamide derivative 1-(4'-phenylphenacyl)-3-carbamoylpyridinium bromide. Such a result places it within the range of several currently studied novel cholinesterase inhibitors. Cytotoxicity profiling did not classify this compound as highly toxic, but the induced effects on cells should not be neglected in any future detailed studies and when considering this scaffold for drug development.

Tykhonenko T, Guzyk M, Tykhomyrov A, Korsa V, Yanitska L, Kuchmerovska T. Modulatory effects of vitamin B3 and its derivative on the levels of apoptotic and vascular regulators and cytoskeletal proteins in diabetic rat brain as signs of neuroprotection. Biochim Biophys Acta Gen Subj. 2022 Nov;1866(11):130207. doi: 10.1016/j.bbagen.2022.130207. 

Abstract. Background: Beneficial effects of nicotinamide (NAm) and its derivates have been earlier shown in animal models of diabetes mellitus (DM), but the mechanisms of their neuroprotective activities are still largely unknown. The aim of the present study was to investigate if NAm and conjugate of nicotinic acid with gamma-aminobutyric acid (N-GABA) are able to modulate expression levels of apoptosis regulators, angiogenesis-related molecules, and specific cytoskeletal proteins in diabetic rat brain....Conclusion: Thus, NAm and N-GABA may exert neuroprotective effects by decreasing pro-apoptotic regulators levels and improving expression of angiogenic and cytoskeletal proteins impaired by hyperglycemia in rat brain. Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.

Nazarali S, Kuzel P. Vitamin B Derivative (Nicotinamide)Appears to Reduce Skin Cancer Risk. Skin Therapy Lett. 2017 Sep;22(5):1-4.

Abstract. Nicotinamide, an amide form of vitamin B3, has shown the potential to treat a variety of dermatological conditions, including acne, rosacea, and atopic dermatitis. Recent studies have demonstrated the role of nicotinamide, in both topical and oral forms, as a chemopreventive agent against skin cancer. Its anti-carcinogenic role may be due to its ability to enhance DNA repair and prevent ultraviolet (UV)-induced immunosuppression, which is known to contribute to the progression of pre-malignant lesions. Furthermore, nicotinamide is a precursor of essential coenzymes for many important reactions in the body, including the production of nicotinamide adenine dinucleotide (NAD). NAD is a key coenzyme in the synthesis of adenosine triphosphate (ATP), which transports chemical energy within cells. Therefore, nicotinamide plays a significant role in supporting energy-dependent cellular processes, including DNA repair.