Coptis chinensis inhibits melanogenesis increasing miR-340-mediated suppression of microphathalmia-associated transcription factor

Abstract

Background: Coptis chinensis (C. chinensis) contains various antioxidants, including berberine, epiberberlin, ferulic acid, magnoflorine, palmatine, and worenine, which have antibacterial, anti-inflammatory, haemostatic, hypotensive, and anticancer effects. In the present study, the melanogenesis-inhibiting effects of C. chinensis were investigated and the molecular mechanisms were elucidated. Methods: The melanogenesis-inhibiting effect of C. chinensis was verified by measuring melanin contents, melanogenesisrelated tyrosinase activities, and mRNA and protein expression levels of tyrosinase and microphthalmia-associated transcription factor (MITF). In addition, changes in miR-340 expression by C. chinensis were verified, and the activity of the miR-340 binding site of the target MITF gene was determined using luciferase reporter assays.