Nicotinamide, a vitamin B3 derivative, is an inhibitor of SIRT1 (IC50=50-180 μM) and SIRT2 (IC50=2 μM). Nicotinamide can be used as a precursor of nicotinamide adenine dinucleotide or NAD+, which can be supplemented by dietary intake and can prevent or treat melanoglossia and pellagra.

RAW264.7 cells:> 10 μM, Sir2Tm-D101N mutant:14.6 ± 3.4 mM, SIRT1:50-180 μM, BL21 cells:6.2 μM, SK-MEL-28 cells:100 μM, MDA-MB-436 cells:30.09 mM, SIRT2:2 μM (EC50), HEK293T cells:43.8 μM, MDA-MB-231 cells:20.09 mM, MCF-7 cells:20.01 mM

METHODS: A375, SK-MEL-28, and mouse B16-F10 cells were treated with Nicotinamide (0, 1, 20, and 50 mM) for 24 or 48 hours.
RESULTS: Nicotinamide reduced cell numbers ina dose-dependent manner, with a strong inhibitory effect at 20mM and almost full effect at 50mM. [1]

METHODS: To study the anti-tumor activity of Nicotinamide, mice were intraperitoneally injected with Nicotinamide (1500 and 1800 mg/Kg, 5 days a week).
RESULTS: Nicotinamide inhibited tumor growth ina mouse model of metastatic melanoma. [1]
METHODS: To study the antiviral activity of Nicotinamide, Nicotinamide (0-200 mg/kg, 5 days) was intraperitoneally injected into HBV transgenic mice.
RESULTS: Nicotinamide inhibited HBV replication in HBV transgenic mice. [2]