RRC ID 63686
Author Ukiya M, Sato D, Kimura H, Hirai Y, Nishina A.
Title Tokoronin Contained in Dioscorea tokoro Makino ex Miyabe Suppressed α-MSH-Induced Melanogenesis in B16 Cells via Suppression of Classical MAPK Pathway Activation.
Journal Chem Biodivers
Abstract In this study, melanogenesis inhibition in B16 cells by eight compounds, namely, tokorogenin, tokoronin, yononin, gracillin, proto-yonogenin, proto-tokoronin, proto-yononin, and proto-gracillin, isolated from Dioscorea tokoro Makino ex Miyabe were evaluated. The results of the cytotoxicity and α-MSH-induced melanogenesis inhibition effects of the eight compounds revealed that tokoronin was the most effective in terms of low-cytotoxicity and melanogenesis inhibition. Tokoronin downregulated α-MSH-induced melanogenesis via suppression of the expression of the three types of melanogenesis-related enzymes [tyrosinase, tyrosinase-related protein-1 (TRP-1), TRP-2] by the inhibition of phospho-microphthalmia-associated transcription factor (p-MITF) and cAMP response element binding protein (CREB) levels. p-MITF and CREB are regulated by various kinases [Akt, mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK), p38 mitogen-activated protein kinase (MAPK), and c-jun N-terminal kinase (JNK)]. As the results of measurement of the combined effects of tokoronin with inhibitors or promoters of these kinases, no change in the biological activity of tokoronin by Akt inhibitor (wortmannin) or p38 MAPK inhibitor (SB202190) was observed, however, the effect of tokoronin was reduced by the MEK/ERK inhibitor (U0126) and promoted by the MEK/ERK activator (FGF2). Therefore, it was deduced that tokoronin first inactivated ERK; then, it suppressed p-MITF and CREB levels; and finally, α-MSH-induced melanogenesis was suppressed.
Volume 17(6)
Pages e2000077
Published 2020-6-1
DOI 10.1002/cbdv.202000077
PMID 32378303
MeSH Animals Cell Line, Tumor Cell Survival / drug effects Dioscorea / chemistry* Dioscorea / metabolism Down-Regulation / drug effects Extracellular Signal-Regulated MAP Kinases / metabolism Imidazoles / pharmacology MAP Kinase Signaling System / drug effects* Melanins / metabolism* Melanoma, Experimental / metabolism Melanoma, Experimental / pathology Phosphatidylinositol 3-Kinases / metabolism Protein Kinase Inhibitors / pharmacology Proto-Oncogene Proteins c-akt / metabolism Pyridines / pharmacology Wortmannin / pharmacology alpha-MSH / pharmacology*
IF 2.039
Human and Animal Cells B16 melanoma(RCB1283)