Inhibition of two stages of melanin synthesis by sesamol, sesamin and sesamolin

ABSTRACT

Objective To investigate the antimelanogenesis properties of three sesame compounds-sesamol, sesamin and sesamolin via two stages of melanin synthesis vis-à-vis sunscreen function and enzyme inhibition in melanoma cell line in order to search for alternative depigmenting agents. Methods Antimelanogenic effects of sesame lignans were assessed in SK-MEL2 compared with the reference depigmenting agents, kojic acid and β-arbutin, in order to evaluate (a) the sunscreen function of sesamol, sesamin and sesamolin by measurement of UV absorbtion property; (b) the inhibition of tyrosinase activity through mushroom and cellular tyrosinase; and (c) the effect on melanin content and melanogenic protein expression (tyrosinase, TRP-1 and TRP-2) by Western blot analysis; and (d) the toxicity of sesamol, sesamin and sesamolin to cells using cell cytotoxicity assay. Results The results showed that sesamin, sesamolin and sesamol exerted satisfiable sunscreen function by absorbed UVB at 290 nm. Sesamol exhibited the highest inhibition of mushroom tyrosinase activity, but lipophilic sesamolin exhibited the highest cellular tyrosinase inhibition (IC