p-Hydroxybenzoic Acid β-d-Glucosyl Ester and Cimidahurinine with Antimelanogenesis and Antioxidant Effects from Pyracantha angustifolia via Bioactivity-Guided Fractionation

Abstract

This study evaluated bioactivity-guided fractionation as a means to identify therapeutic phytochemicals from <i>Pyracantha angustifolia</i> that can attenuate melanogenesis and oxidation. Seven compounds with inhibitory effects on melanin production and tyrosinase (TYR) activity, and ABTS and DPPH radical-scavenging activities, which have not been reported as whitening materials, were isolated from the <i>n</i>-butanol fraction from <i>P. angustifolia</i> leaves (PAL). Among the seven compounds, <i>p</i>-hydroxybenzoic acid β-d-glucosylester (HG), and cimidahurinine (CH) had strong inhibitory effects on melanin production and TYR activity, as well as ABTS and DPPH radical-scavenging activities. Western blot analysis showed that HG and CH suppressed tyrosinase-related protein (TYRP)-1 and TYRP-2 expression. Moreover, HG and CH inhibited reactive oxygen species (ROS) generation in tert-butyl hydroperoxide (<i>t</i>-BHP)-treated B16F10 cells. These results suggest that <i>P. angustifolia</i> containing active compounds, such as HG and CH, is a potent therapeutic candidate for the development of hypopigmenting agents.