Nicotinamide

Nicotinamide, commonly known as niacinamide and nicotinic amide, belongs to the vitamin B group and is a water-soluble amide form of nicotinic acid (vitamin B3 or niacin). In the human body, nicotinic acid is converted to nicotinamide, which, while sharing identical vitamin functions, does not have the same pharmacological and toxic effects. Importantly, unlike niacin, nicotinamide neither lowers cholesterol nor induces flushing. However, it should be noted that doses exceeding 3g/day can be toxic to the liver.

Nicotinamid

Biochemical Role

Inside cells, niacin is incorporated into nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP), essential coenzymes in a multitude of enzymatic oxidation-reduction reactions. Both the pathways for nicotinic acid amide and nicotinic acid are remarkably similar. Nicotinamide is produced through the aqueous aminolysis of 3-cyanopyridine (nicotinonitrile) and subsequent crystallization.

Medical Uses

Skin Conditions

Nicotinamide has shown anti-inflammatory properties beneficial to patients with inflammatory skin conditions, including acne vulgaris. It can suppress antigen-induced, lymphocytic transformation and inhibit 3',5'-cyclic-AMP phosphodiesterase. Notably, nicotinamide can block the inflammatory actions of iodides known to precipitate or exacerbate inflammatory acne.

Oral acne medications NicAzel and Nicomide primarily contain nicotinamide, drawing from its anti-acne properties. Nicotinamide is also a key component in an adjunct supplement called Azerizin™, which purportedly aids in managing inflammatory skin conditions. Apart from oral administration, nicotinamide is also used topically in the form of 4% or 5% gel or cream, proving as effective as topical 1% clindamycin. Importantly, unlike topical Erythromycin or Clindamycin, it does not develop any bacterial resistance in treating inflammatory acne.

In addition to its anti-inflammatory properties, topical application of nicotinamide has been reported to effectively lighten skin.

Anxiety

Research indicates that nicotinamide may exhibit anxiolytic, or anti-anxiety, properties, possibly functioning similarly to benzodiazepines.

Alzheimer's Disease

Nicotinamide, an activator of sirtuins at lower doses but an inhibitor at higher doses, has been reported to restore cognition in Alzheimer's disease transgenic mice. A safety study for the treatment of Alzheimer's disease using niacinamide is currently being conducted at the University of California, Irvine.

Cancer

Nicotinamide acts as a chemo- and radio-sensitizing agent by enhancing tumor blood flow, thereby reducing tumor hypoxia. It inhibits poly(ADP-ribose) polymerases (PARP-1), enzymes involved in the rejoining of DNA strand breaks induced by radiation or chemotherapy. PARP-1 appears to be an important target for triple negative breast cancers. Moreover, some patients combine nicotinamide with intravenous vitamin C therapy for cancer treatment. It also prevents immunosuppression caused by UVA and UVB radiation.

Apoptosis

Nicotinamide can prevent apoptosis, or programmed cell death, in cells exposed to oxidative stress-inducing agents. For instance, it prevents apoptosis in human cortical neuronal cells and Jurkat cells when oxidative stress is induced by certain agents.

Other Uses and Toxicity

Research indicates that nicotinamide can increase the endurance of mice. However, it should be noted that while nicotinamide does not produce the flushing, itching, and burning sensations of the skin that are commonly seen with large oral doses of nicotinic acid, high-dose nicotinamide should still be considered a drug with toxic potential. Adult doses in excess of 3g/day could potentially lead to liver toxicity. Yet, overall, it is generally safe and rarely causes side effects when used as a food additive, as well as a component in cosmetics and medication.

References

• [1] Knip M, Douek IF, Moore WP, et al. (2000). "Safety of high-dose nicotinamide: a review". Diabetologia. 43 (11): 1337–45.
• [2] "Niacinamide". DrugBank. Retrieved April 1, 2021.
• [3] Kirkland JB (2012). "Niacin requirements for genomic stability". Mutat Res. 733 (1–2): 14–20.

Vitamins A Vitamin A B Biotin Vitamin B1 (see Thiamin) Vitamin B12 Vitamin B6 C Calcium Choline Chromium Copper Vitamin C D Vitamin D

E Energy Drinks Exercise and Athletic Performance Vitamin E F Fluoride Folate I Iodine Iron K Vitamin K

M Magnesium Multivitamin/mineral Supplements N Niacin P Pantothenic Acid Phosphorus Potassium Primary Mitochondrial Disorders R Riboflavin

S Selenium T Thiamin V Vitamin A Vitamin B1 (see Thiamin) Vitamin B12 Vitamin B6 Vitamin C Vitamin D Vitamin E Vitamin K Z Zinc

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