SIRT2 (EC50 = 2 μM); SIRT1 (EC50 = 50~180 μM)

Type 2 diabetes was induced in Wistar rats by streptozotocin followed by nicotinamide. Test compounds and standard treatment were continued for 15 days. Results showed that there was significant normalisation of liver antioxidant enzymes compared to diabetic rats, suggesting all the tested compounds were beneficial in reducing oxidative stress

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.

Absorption, Distribution and Excretion
14(C)Niacinamide was incorporated into an oil-in-water (o/w) skin cream and into a 30% (w/w) soap base and applied to the skin of female Colworth Wistar rats. The final concentration of niacinamide in the soap solution was approximately 0.3% (w/v) and was 1% (w/w) in the skin cream. Application of the skin cream and soap paste was made to rat skin at approximately 20 mg/sq cm. The cream was carefully massaged over 10 sq cm of skin for up to 5 min before covering with polythene-lined occlusive protective patches. The rats were placed in metabolism cages for 48 hr during which time all excreta was collected. At 48 hr, the animals were killed and the patch, carcass, and treated area of skin were assayed for 14(C). Up to 32% 14(C) was recovered in excreta and in the carcasses from rats treated with skin cream containing 14(C)Niacinamide and up to 30% from those treated with soap paste.
Nicotinamide is efficiently absorbed from the gastrointestinal tract. At low doses, absorption is mediated via sodium-dependent facilitated diffusion. Passive diffusion is the principal mechanism of absorption at higher doses. Doses of up to three to four grams of nicotinamide are almost completely absorbed. Nicotinamide is transported via the portal circulation to the liver and via the systemic circulation to the various tissues of the body. Nicotinamide enters most cells by passive diffusion and enters erythrocytes by facilitated transport.
Niacinamide is widely distributed /throughout/ body tissues.
Niacin and niacinamide are readily absorbed from the GI tract following oral administration, and niacinamide (no longer commercially available in the US) is readily absorbed from subcutaneous and IM injection sites.
For more Absorption, Distribution and Excretion (Complete) data for Nicotinamide (16 total), please visit the HSDB record page.

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Metabolism / Metabolites
In amounts needed for physiologic function as a coenzyme (12-18 mg daily), niacin is converted to niacinamide; larger doses of niacin are converted to niacinamide to only a minor degree. Niacinamide is metabolized in the liver to N-methylniacinamide, other N-methylated derivatives, and nicotinuric acid (the glycine conjugate of niacin). These metabolites are excreted in urine. Following administration of physiologic doses of niacin or niacinamide, only a small amount of niacinamide is excreted unchanged in urine; however, following administration of larger doses, a greater proportion of niacin and niacinamide is excreted unchanged.
N1-Methyl-4-pyridone-3-carboxamide was detected on chromatograms of plasma extracts after oral administration of niacinamide to two human subjects.
6-Hydroxynicotinamide and 6-hydroxynicotinic acid /were detected/ as urinary metabolites by comparison of ultraviolet, infrared, and mass spectra following intraperitoneal injections of 14(C)Niacin or 14(C)Niacinamide into rats.
N1-methyl-4- pyridone-3-carboxamide is a major metabolite of niacin and niacinamide which has been found to be synthesized from N1- methylnicotinamide.
For more Metabolism/Metabolites (Complete) data for Nicotinamide (7 total), please visit the HSDB record page.
Uremic toxins tend to accumulate in the blood either through dietary excess or through poor filtration by the kidneys. Most uremic toxins are metabolic waste products and are normally excreted in the urine or feces.

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Biological Half-Life
The mean half life values were 2.7 hr, 5.9 hr, and 8.1 hr after taking 1, 3, or 6 g of Niacinamide, respectively.

Toxicity Summary
IDENTIFICATION AND USE: Nicotinamide is a white, crystalline powder. Nicotinamide is used to prevent niacin deficiency and to treat pellagra. Nicotinamide is also used in cosmetics as a hair and skin conditioning agent. It has been used in the enrichment of bread, flour, and other grain-derived products. Animal feed is routinely supplemented with nicotinamide. It is also used in multi-vitamin preparations. Nicotinamide and niacin are similarly effective as a vitamin because they can be converted into each other within the organism. The blanket term vitamin B(3) is used for both. Niacinamide is a component of important coenzymes involved in hydrogen transfer. HUMAN STUDIES: In humans, nicotinamide is required for lipid metabolism, tissue respiration, and glycogenolysis. In vivo, nicotinamide is formed from conversion of niacin. In addition, some dietary tryptophan is oxidized to niacin and then to nicotinamide in vivo. Nicotinamide is incorporated into 2 coenzymes: nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP). NAD and NADP act as hydrogen-carrier molecules in glycogenolysis, tissue respiration, and lipid metabolism. In a study with 6 volunteers (single dose between 3 and 9 g/day) toxic symptoms associated with nicotinamide were mild and consisted mainly of nausea. The effect of 2 mM nicotinamide on unscheduled DNA synthesis on resting human lymphocytes was studied. In cells treated with UV irradiation or with N-methyl-N-nitro- N-nitrosoguanidine, nicotinamide caused a two-fold stimulation of unscheduled DNA synthesis. ANIMAL STUDIES: Application of 0.1 g nicotinamide to the eyes of rabbits induced reversible irritation. It did not produced sensitization in guinea pig test. Single ip injection of nicotinamide (100 mg/kg) to male rats was shown to significantly induce all components of the hepatic microsomal mixed function oxidase system as well as activities of drug-metabolizing enzymes. Groups of 12 male rats were fed nicotinamide in their diet for a period of 8 to 12 weeks. At 0.1% of the diet (100 mg/kg bw per day), nicotinamide caused no significant change in the growth rate, at 0.2%, growth rate was enhanced, but at 0.4%, a marked inhibition of growth rate resulted. Almost complete growth inhibition occurred in rats fed 1% nicotinamide. Lifelong treatment with 1% nicotinamide had no carcinogenic effect in mice. However, nicotinamide promoted diethylnitrosamine-induced renal tubular cell tumorigenesis in rats. In mice nicotinamide in doses of 500-2000 mg/kg depresses orientation reflexes and exploring behavior, and has antiaggressive and anticonvulsant properties. Nicotinamide supplementation in pregnant rats led to a decrease in placental and fetal hepatic genomic DNA methylation and genomic uracil contents (a factor modifying DNA for diversity) in the placenta and fetal liver and brain, which could be completely or partially prevented by betaine. Moreover, nicotinamide supplementation induced tissue-specific alterations in the mRNA expression of the genes encoding nicotinamide N-methyltransferase, DNA methyltransferase 1, catalase and tumor protein p53 in the placenta and fetal liver. High-dose nicotinamide supplementation increased fetal hepatic a-fetoprotein mRNA level, which was prevented by betaine supplementation. It is concluded that maternal nicotinamide supplementation can induce changes in fetal epigenetic modification and DNA base composition. Nicotinamide was negative in an Ames test performed with Salmonella strains TA 98, TA 100, TA 1535, TA 1537 and TA 1538 both with and without metabolic activation. Nicotinamide was not mutagenic in Saccharomyces stain D4. It was reported that nicotinamide at concentrations of 3 mg/mL (25 mM) induced large structural chromosome aberrations in vitro in Chinese hamster ovary cells.
Uremic toxins such as nicotinamide are actively transported into the kidneys via organic ion transporters (especially OAT3). Increased levels of uremic toxins can stimulate the production of reactive oxygen species. This seems to be mediated by the direct binding or inhibition by uremic toxins of the enzyme NADPH oxidase (especially NOX4 which is abundant in the kidneys and heart) (A7868). Reactive oxygen species can induce several different DNA methyltransferases (DNMTs) which are involved in the silencing of a protein known as KLOTHO. KLOTHO has been identified as having important roles in anti-aging, mineral metabolism, and vitamin D metabolism. A number of studies have indicated that KLOTHO mRNA and protein levels are reduced during acute or chronic kidney diseases in response to high local levels of reactive oxygen species (A7869).

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Interactions
Addition of 0.5 mg of nicotinamide reduced the action of dicrotophos on cultured chick embryo tibiae.
Nicotinamide will prevent depletion of NAD coenzymes by alkylating agents.
Renal oncogenic activity of Streptozotocin in male rats was significantly decreased by nicotinamide.
Oral or iv administered nicotinamide prevented Streptozotocin-induced diabetes in Rhesus monkeys and dogs.
For more Interactions (Complete) data for Nicotinamide (25 total), please visit the HSDB record page.

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Non-Human Toxicity Values
LD50 Rat oral 3500 mg/kg
LD50 Rat sc 1680 mg/kg
LD50 Mouse oral 2500 mg/kg
LD50 Mouse ip 2050 mg/kg
For more Non-Human Toxicity Values (Complete) data for Nicotinamide (9 total), please visit the HSDB record page.

J Biol Chem.2002 Nov 22;277(47):45099-107.

Nicotinamide is a white powder. (NTP, 1992)
Nicotinamide is a pyridinecarboxamide that is pyridine in which the hydrogen at position 3 is replaced by a carboxamide group. It has a role as an EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor, a metabolite, a cofactor, an antioxidant, a neuroprotective agent, an EC 3.5.1.98 (histone deacetylase) inhibitor, an anti-inflammatory agent, a Sir2 inhibitor, a Saccharomyces cerevisiae metabolite, an Escherichia coli metabolite, a mouse metabolite, a human urinary metabolite and a geroprotector. It is a vitamin B3, a pyridinecarboxamide and a pyridine alkaloid. It is functionally related to a nicotinic acid.
An important compound functioning as a component of the coenzyme NAD. Its primary significance is in the prevention and/or cure of blacktongue and pellagra. Most animals cannot manufacture this compound in amounts sufficient to prevent nutritional deficiency and it therefore must be supplemented through dietary intake.
Niacinamide is a metabolite found in or produced by Escherichia coli (strain K12, MG1655).
Nicotinamide has been reported in Lactarius subplinthogalus, Taraxacum formosanum, and other organisms with data available.
Niacinamide is the active form of vitamin B3 and a component of the coenzyme nicotinamide adenine dinucleotide (NAD). Niacinamide acts as a chemo- and radio-sensitizing agent by enhancing tumor blood flow, thereby reducing tumor hypoxia. This agent also inhibits poly(ADP-ribose) polymerases, enzymes involved in the rejoining of DNA strand breaks induced by radiation or chemotherapy.
Nicotinamide is a uremic toxin. Uremic toxins can be subdivided into three major groups based upon their chemical and physical characteristics: 1) small, water-soluble, non-protein-bound compounds, such as urea; 2) small, lipid-soluble and/or protein-bound compounds, such as the phenols and 3) larger so-called middle-molecules, such as beta2-microglobulin. Chronic exposure of uremic toxins can lead to a number of conditions including renal damage, chronic kidney disease and cardiovascular disease.
Niacinamide or vitamin B3 is an important compound functioning as a component of the coenzyme NAD. Its primary significance is in the prevention and/or cure of blacktongue and pellagra. Most animals cannot manufacture this compound in amounts sufficient to prevent nutritional deficiency and it therefore must be supplemented through dietary intake. Niacinamide is used to increase the effect of radiation therapy on tumor cells. Niacin (nicotinic acid) and niacinamide, while both labeled as vitamin B3 also have different applications. Niacinamide is useful in arthritis and early-onset type I diabetes while niacin is an effective reducer of high cholesterol levels.
Niacinamide is a metabolite found in or produced by Saccharomyces cerevisiae.
An important compound functioning as a component of the coenzyme NAD. Its primary significance is in the prevention and/or cure of blacktongue and PELLAGRA. Most animals cannot manufacture this compound in amounts sufficient to prevent nutritional deficiency and it therefore must be supplemented through dietary intake.
See also: Niacinamide ascorbate (is active moiety of); Dapsone; niacinamide (component of); Adenosine; Niacinamide (component of) ... View More ...

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Therapeutic Uses
Vitamin B Complex
/CLINICAL TRIALS/ ClinicalTrials.gov is a registry and results database of publicly and privately supported clinical studies of human participants conducted around the world. The Web site is maintained by the National Library of Medicine (NLM) and the National Institutes of Health (NIH). Each ClinicalTrials.gov record presents summary information about a study protocol and includes the following: Disease or condition; Intervention (for example, the medical product, behavior, or procedure being studied); Title, description, and design of the study; Requirements for participation (eligibility criteria); Locations where the study is being conducted; Contact information for the study locations; and Links to relevant information on other health Web sites, such as NLM's MedlinePlus for patient health information and PubMed for citations and abstracts for scholarly articles in the field of medicine. Nicotinamide is included in the database.
Niacin and niacinamide are used to prevent niacin deficiency and to treat pellagra. Some clinicians prefer niacinamide for the treatment of pellagra because it lacks vasodilating effects. Pellagra may result from dietary deficiency, isoniazid therapy, or from decreased conversion of tryptophan to niacin in Hartnup disease or carcinoid tumors. /Included in US product label/
Although niacin and niacinamide have not been shown by well-controlled trials to have therapeutic value, the drugs have been used for the management of schizophrenic disorder, drug-induced hallucinations, chronic brain syndrome, hyperkinesis, unipolar depression, motion sickness, alcohol dependence, livedoid vasculitis, acne, and leprosy. /NOT included in US product label/
For more Therapeutic Uses (Complete) data for Nicotinamide (14 total), please visit the HSDB record page.

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Drug Warnings
Blood glucose concentration should be monitored periodically in patients receiving niacin or niacinamide, especially early in the course of therapy. Dosage requirements for antidiabetic agents (e.g., insulin, oral sulfonylureas) may change in diabetic patients.
Potential adverse effects on fetus: Higher levels in fetus than mother, but no fetal anomalies reported. Potential side effects on breast-fed infant: No adverse effects known . FDA Category: C (C = Studies in laboratory animals have revealed adverse effects on the fetus (teratogenic, embryocidal, etc.), but there are no controlled studies in pregnant women. The benefits from use of the drug in pregnant women may be acceptable despite its potential risks, or there are no laboratory animal studies or adequate studies in pregnant women.) /from table II/
Niacinamide /was administered/ daily as a liquid formulation to head and neck cancer patients receiving a 5- to 7-week course of radiotherapy. Niacinamide was administered orally 1.5 hr before irradiation. The daily dose was 80 mg/kg bw to a maximum of 6 g. A dose reduction to 60 mg/kg was introduced for patients with severe side-effects. ... Side-effects of niacinamide were monitored. In all patients, peak concentrations greater than 700 nM/mL could be obtained 0.25-3 hr after drug intake. During the first week of treatment, plasma concentrations at the time of irradiation were adequate in 82% of the samples. Nausea, with or without vomiting, occurred in 65% of patients. Tolerance improved after a 25% reduction of the dose in six of seven patients but plasma concentrations at the time of irradiation decreased below 700 nM/mL in four out of six patients. Other niacinamide side effects included gastrointestinal symptoms, flushing, dizziness, sweating, fatigue, and headache. The most powerful single predictor for severe niacinamide toxicity was the mean of the plasma concentration measured at the time of irradiation during the first week.
Abnormal liver function test results (including increased serum concentrations of bilirubin, AST [SGOT], ALT [SGPT], and LDH), jaundice, and chronic liver damage have occurred during niacin and niacinamide therapy. Abnormal prothrombin time and hypoalbuminemia have also been reported.
For more Drug Warnings (Complete) data for Nicotinamide (6 total), please visit the HSDB record page.

C6H6N2O

122.12

122.048

C, 59.01; H, 4.95; N, 22.94; O, 13.10

98-92-0

25334-23-0; Nicotinamide;98-92-0

936

White to off-white solid

1.2±0.1 g/cm3

257.7±32.0 °C at 760 mmHg

128-131 °C(lit.)

109.7±25.1 °C

0.0±0.6 mmHg at 25°C

1.590

Endogenous Metabolite

-0.24

1

2

1

9

114

0

O=C(C1=C([H])N=C([H])C([H])=C1[H])N([H])[H]

DFPAKSUCGFBDDF-UHFFFAOYSA-N

InChI=1S/C6H6N2O/c7-6(9)5-2-1-3-8-4-5/h1-4H,(H2,7,9)

3-Pyridinecarboxylic acid amide

2934.99.03.00

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: This product requires protection from light (avoid light exposure) during transportation and storage.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.

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Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)
*Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution.
Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)
Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil)
Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals).

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Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)]
*Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

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Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium)
Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose
Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals).

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Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders

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Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

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 (Please use freshly prepared in vivo formulations for optimal results.)