|Publication Type:||Journal Article|
|Year of Publication:||2010|
|Authors:||An, SMi, Koh, J-S, Boo, YChool|
|Keywords:||human epidermal melanocytes, human tyrosinase, melanin, p-coumaric acid, tyrosine, UVB|
Tyrosinase (TYR) catalyzes rate-limiting steps of melanogenesis and thus its inhibitors are potentially useful as hypopigmenting agents. Recently, p-coumaric acid (p-CA) has been suggested to interfere with the pro-melanogenic actions of tyrosine due to its structural similarity with tyrosine (An SM et al., Br J Dermatol 2008. 159: 292). In this study, we compared the inhibitory effects of p-CA and two other well known TYR inhibitors used in cosmetics – arbutin and kojic acid – on the catalytic activities of mushroom, murine and human TYRs in vitro, using tyrosine and 3,4-dihydroxyphenylalanine (DOPA) as substrates. The results showed that p-CA is a weaker inhibitor of mushroom TYR but much stronger inhibitor of human or murine TYR in comparison with kojic acid and arbutin. In addition, p-CA inhibited human TYR at much lower concentrations than those required for the inhibition of murine or mushroom TYRs. Enzyme kinetics analysis indicated that p-CA is a mixed type (for tyrosine) or competitive inhibitor (for DOPA) of human TYR. Potent antimelanogenic effects of p-CA were observed in human epidermal melanocytes exposed to UVB. The present study demonstrated that p-CA is a potent and selective inhibitor of human TYR and is potentially useful as a hypopigmenting agent. Copyright © 2010 John Wiley & Sons, Ltd.
|Short Title:||Phytotherapy Research|