Nicotinamide appears to play a role in protecting neurons from traumatic injury, ischemia, and stroke, as well as being implicated in 3 key neurodegenerative conditions: Alzheimer’s, Parkinson’s, and Huntington’s diseases. Nicotinamide, the amide form of vitamin B3 (niacin), has long been associated with neuronal development, survival, and function in the central nervous system (CNS), being implicated in both neuronal death and neuroprotection. Here, we summarise a body of research investigating the role of nicotinamide in neuronal health within the CNS, with a focus on studies that have shown a neuroprotective effect.
Nicotinamide is a pyridine carboxamide 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 pyridine carboxamide and a pyridine alkaloid. It is functionally related to 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.
A biologically active form of nicotinic acid; [Merck Index] A coenzyme composed of ribosyl nicotinamide 5′-diphosphate coupled to adenosine 5′-phosphate by pyrophosphate linkage. It is found widely in nature and is involved in numerous enzymatic reactions in which it serves as an electron carrier by being alternately oxidized (NAD+) and reduced (NADH). (Dorland, 27th ed) [ChemIDplus] Nicotinamide adenine dinucleotide, abbreviated NAD+, is a coenzyme found in all living cells
Indications
- 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.
- 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.
The thirteen recognized classes of vitamins and their roles.
| Vitamin | Other names | Examples of physiological functions |
|---|---|---|
| Vitamin A | Retinol, retinoic acid, retinal, carotenoid | Growth, maintenance of skin, bone development, maintenance of myelin, maintenance of vision |
| Vitamin B1 | Thiamine | Growth, appetite, digestion, nerve activity, energy production |
| Vitamin B2 | Riboflavin | Growth and development of fetus, redox systems, and respiratory enzymes; maintenance of mucosal, epithelial, and eye tissues |
| Vitamin B3 | Nicotinamide, niacinamide, nicotinic acid, niacin | Maintenance of NAD and NADP, coenzyme in lipid catabolism, oxidative deamination |
| Vitamin B5 | Pantothenic acid | Lipid metabolism, protein metabolism, part of coenzyme A in carbohydrate metabolism |
| Vitamin B6 | Pyridoxine, pyridoxol, adermine | Growth; protein, CHO, and lipid metabolism; coenzyme in amino acid metabolism |
| Vitamin B7 | Biotin, protective factor X | Growth; maintenance of skin, hair, bone marrow, and sex glands; biosynthesis of aspartate and unsaturated fatty acids |
| Vitamin B9 | Folic acid, folacin, folinic acid | Synthesis of nucleic acid, differentiation of embryonic nervous system |
| Vitamin B12 | Cobalamin | Coenzyme in nucleic acid, protein, and lipid synthesis; maintenance of epithelial cells and nervous system |
| Vitamin C | Ascorbic acid | Absorption of iron, antioxidants, growth, wound healing, formation of cartilage, dentine, bone and teeth, maintenance of capillaries |
| Vitamin D | Vitamin D3, cholecalciferol, calcitriol | Normal growth, Ca and P absorption maintains and activates alkaline phosphatase in bone, maintains serum calcium and phosphorus levels |
| Vitamin E | Tocopherol, Tokopharm, tocotrienols | Antioxidant, growth maintenance, aids absorption of unsaturated fatty acids, maintains muscular metabolism and integrity of the vascular system and central nervous system |
| Vitamin K | Prothrombin factor, menaquinones | Blood-clotting mechanisms, electron transport mechanisms, growth, and prothrombin synthesis in liver |