title: Inhibition of melanogenic activity by 4,4'-dihydroxybiphenyl in melanoma cells.
abstract: In our previous study, we showed that 4,4'-dihydroxybiphenyl (44'-BP) reduced melanin content via the inhibition of tyrosinase. In the current study, we utilized 44'-BP treated B16 melanoma cells (B16 cells) to measure several key cellular parameters known to be involved in melanogenic activity. Included in these measurements were tyrosinase and microphthalmia transcription factor (MITF) protein levels, cyclic AMP levels, protein kinase A (PKA) activation, and reduced glutathione (GSH) and oxidized glutathione (GSSG) levels. Results showed that 44'-BP effectively suppressed the amounts of tyrosinase and MITF proteins, cAMP levels, and PKA activation. In addition, 44'-BP enhanced the GSH/GSSG ratio. In conclusion, our data provide an evidence that 44'-BP suppressed several cellular key parameters in the melanogenic pathway by downregulating the cAMP-dependent PKA signaling pathway and decreasing MITF gene expression (implied from the reduced protein levels), which in turn suppressed tyrosinase. We propose that the antimelanogenic action of 44'-BP is likely carried out by a combined effect of its anti-oxidant property and its ability to enhance intracellular GSH levels.
authors.affiliation: College of Pharmacy, Aging Tissue Bank, Pusan National University, Korea.
authors.forename: Jae Kyung
authors.initials: JK
authors.lastname: No
authors.forename: You Jung
authors.initials: YJ
authors.lastname: Kim
authors.forename: Jun Sik
authors.initials: JS
authors.lastname: Lee
authors.forename: Hae Young
authors.initials: HY
authors.lastname: Chung
mesh_terms: D001713:Biphenyl Compounds / Q000494:pharmacology*; D015153:Blotting, Western; D045744:Cell Line, Tumor; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D015536:Down-Regulation / Q000187:drug effects; D016166:Free Radical Scavengers / Q000494:pharmacology*; D005786:Gene Expression Regulation; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D008543:Melanins / Q000096:biosynthesis*; D008546:Melanoma, Experimental / Q000378:metabolism*; D051739:Microphthalmia-Associated Transcription Factor / Q000235:genetics / Q000378:metabolism; D014442:Monophenol Monooxygenase / Q000378:metabolism; D010084:Oxidation-Reduction
chemical_list: D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D008543:Melanins; D051739:Microphthalmia-Associated Transcription Factor; D000242:Cyclic AMP; D014442:Monophenol Monooxygenase; D017868:Cyclic AMP-Dependent Protein Kinases; D005978:Glutathione; C027439:4,4'-dihydroxybiphenyl