Down-regulation of MITF, TRP-1, TRP-2, and tyrosinase expressions by compounds isolated from Pruni persicae Flos in murine B16F10 melanoma

Three single compounds were isolated by the fractionation from Pruni persicae Flos, and its chemical structure was analyzed using 1H-, 13C-nuclear magnetic resonance, fast atom bombardment -Mass, and fourier transform infrared spectrometer analyses. The compounds were determined as quercetin 3-O-rhamnoside, kaempferol 3-O-¥�-neohesperidoside, and kaempferol 3-O-¥�-d-glucoside. To prove the whitening effect of these compounds, B16F10 melanoma was treated with quercetin-3-O-rhamnoside, kamferol-3-O-¥�-neohesperidoside or kaemferol-3-O-¥�-d-glucoside to confirm cell cytotoxicity using 3-[4,5-dimethylthiazol-2yl]-2,5-diphenyl-tetrazolium-bromide assay. As a result, cell cytotoxicity was examined at more than 20% in 20 ¥�g/mL of compounds isolated from Pruni persicae Flos. Tyrosinase activity and melanin production were examined at 10 ¥�g/mL of each compounds. Results showed quercetin-3-O-rhamnoside, kamferol-3-O-¥�-neohesperidoside or kaemferol-3-O-¥�-d-glucoside reduced tyrosinase activity in a dose-dependent manner. Moreover, quercetin-3-O-rhamnoside showed reduction of tyrosinase activity by 37.6% at 10 ¥�g/mL of quercetin-3-O-rhamnoside as well as the reduction of melanin contents by 58.8%. In addition, quercetin-3-O-rhamnoside, kamferol-3-O-¥�-neohesperidoside, and kaemferol-3-O-¥�-d-glucoside reduced tyrosinase, tyrosinase-related proteins 1, and 2, microphthalmia associated transcription factor expressions, which were related to whitening effect, as well as both of mRNA and protein level of cyclic adenosine monophosphate as upstream signals. More interestingly, quercetin-3-O-rhamnoside strongly reduced both mRNA and protein expressions than other compounds. Therefore, we determined the whitening effect from isolated compound fractionated from Pruni persicae Flos. Moreover, strong whitening activity of quercetin-3-O-rhamnoside was examined, which suggested the potential application of this compound in functional cosmetic development.