Kazinol U inhibits melanogenesis through the inhibition of tyrosinase‐related proteins via AMP kinase activation. (28th January 2019)

• Record Type: Journal Article
• Authors: Lim, Jihyun; Nam, Sorim; Jeong, Ji Hye; Kim, Min Jung; Yang, Young; Lee, Myeong‐Sok; Lee, Hee Gu; Ryu, Jae‐Ha; Lim, Jong‐Seok
• Is Part Of: British journal of pharmacology. Volume 176:Number 5(2019)
• Page Start: 737
• Page End: 750
• Publication Date: 2019-01-28
• Subjects: Pharmacology -- Periodicals; Chemotherapy -- Periodicals; Drug Therapy -- Periodicals; Pharmacology -- Periodicals; 615.1
• DOI: 10.1111/bph.14560
• Languages: English
• ISSNs: 0007-1188

Abstract

Abstract : Background and Purpose: Kazinol U is a prenylated flavan isolated from an extract of Broussonetia kazinoki Sieb (Moraceae). Kazinol U has shown cytoprotective effects against cytokine‐induced apoptotic cell death and induces AMP kinase (AMPK) activation through LKB1 activation. However, kazinol U has not been tested as a regulator of melanogenesis, although bark extract of B. kazinoki has been used as a cosmetic ingredient for skin conditioning. Experimental Approach: We cultured mouse, human melanoma cells and normal human melanocytes to demonstrate anti‐melanogenic effects of kazinol U. A tyrosinase activity assay, Western blot, RT‐qPCR and a luciferase reporter gene assay were performed to determine the anti‐melanogenic mechanisms of kazinol U. We confirmed its effect on melanogenesis in vivo using zebrafish. Key Results: Kazinol U inhibited the expression and activity of tyrosinase, the rate‐limiting enzyme in melanogenesis, and reduced tyrosinase expression and activity in response to cAMP‐inducing agents. Kazinol U reduced the expression of other melanogenic enzymes, such as tyrosinase‐related protein (Tyrp) 1 and Tyrp2, and down‐regulated microphthalmia‐associated transcription factor (MITF), the master regulator of the tyrosinase gene family. Moreover, kazinol U induced phosphorylation of AMPK and MAPK proteins, which are MITF inhibitors. It also exhibited anti‐melanogenic effects in zebrafish, a recently developed in vivo model. Conclusions and Implications: Our findings suggest that kazinol U reduces melanogenesis via its inhibitory effect on MITF and its downstream target genes, tyrosinase, Tyrp1 and Tyrp2. This work may provide a basis for the application of kazinol U for the treatment of hyperpigmentation skin disorders. Abstract :