Abstract:

The aim was to study and compare the effects of nicotinamide and its complexes with tea polyphenols on melanin biosynthesis and transport mechanism. Taking human skin melanocytes PIG1 cell line with high melanin expression induced by melanocyte-stimulating hormone （α-MSH） as the model, the effects of nicotinamide and its complexes matching with tea polyphenols on melanin content, intracellular tyrosinase activity and the key receptors in melanin biosynthesis and transport pathway were determined via western blot and colorimetric method with NaOH and L-DOPA. The results show that 2 g/L nicotinamide+0.5 g/L tea polyphenols, 3 g/L nicotinamide+0.3 mg/L tea polyphenols, 3 g/L nicotinamide+0.5 g/L tea polyphenols complexes show significantly inhibitory effects on melanin content, intracellular tyrosinase activity, the expression of tyrosinase-related protein-1 （TRP-1）, tyrosinase-related protein-2 （TRP-2）, melanocyte melanin cortisol receptor （MC1R） and human epidermal melanocyte transport-related proteins （Rab27a） protein in α-MSH-induced high melanin expression human PIG1 cell lines, which are stronger than that of 5 g/L nicotinamide. While 2 g/L nicotinamide only has the effects of suppressing intracellular tyrosinase activity. The combination of nicotinamide and tea polyphenols had more obvious effect to suppress the melanin biosynthesis and transport pathway in PIG1 cell lines.

Key words: melanin, PIG1 cell line, nicotinamide, tea polyphenols