Open AccessIn Vitro Studies on the Depigmenting Activity of 4‐( p ‐Hydroxyphenyl)‐2‐Butanone
Author(s) -
Fukuda Yoshiharu,
Nagano Megumi,
Tsukamoto Katsuhiko,
Futatsuka Makoto
Publication year - 1998
Publication title -
journal of occupational health
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.664
H-Index - 59
ISSN - 1348-9585
DOI - 10.1539/joh.40.137
Subject(s) - tyrosinase , in vitro , chemistry , melanin , melanoma , cytotoxic t cell , microbiology and biotechnology , tyrosine , enzyme , mtt assay , biochemistry , biology , cancer research
In Vitro Studies on the Depigmenting Activity of 4‐( p ‐Hydroxyphenyl)‐2‐Butanone: Yoshiharu F ukuda , et al. Department of Public Health, Kumamoto University School of Medicine —The aim of this study is to investigate the enzymatic properties and the depigmenting activity of 4‐( p ‐Hydroxyphenyl)‐ 2‐butanone (HPB) in vitro. The activity of HPB as a substrate of tyrosinase, its effect on tyrosinase enzymatic reactions, and its inhibition of the growth and the melanogenesis of cultured melanoma cells were examined. The HPB‐tyrosinase reaction and the effect of HPB on tyrosine‐tyrosinase and dopa‐tyrosinase reactions were followed spectrophotometrically. Fifty percent growth inhibition concentrations (IC 50 ) of several chemicals for melanoma cells and non‐pigmented cells were measured. Melanogenic activities in HPB‐treated melanoma cells were assayed. The results showed that HPB was oxidized by tyrosinase and stimulated tyrosine‐ tyrosinase and dopa‐tyrosinase reactions. The IC 50 of HPB for melanoma cells was higher than those of the established depigmenting agents but it was lower than that of HPB for non‐melanotic cells. Tyrosine hydroxylase in HPB‐treated melanoma cells was stimulated compared with the control, but melanin product in HPB‐treated cells was almost similar to the control. The results showed that HPB acts as a good substrate for tyrosinase and it stimulates tyrosinase enzymatic reactions, but it inhibits pigmented cell growth selectively. This study suggests that HPB‐induced depigmentation is due to a selective cytotoxic effect on pigmented cells rather than to the inhibition to melanogenesis.