Glycosidic inhibitors of melanogenesis from leaves of Momordica charantia.
Eight glycosidic compounds, 1-8, including two new compounds, (4ξ)-α-terpineol 8-O-[α-L-arabinopyranosyl-(1→6)-β-D-glucopyranoside] (5) and myrtenol 10-O-[β-D-apiofuranosyl-(1→6)-β-D-glucopyranoside] (7), were isolated from the BuOH-soluble fraction of a MeOH extract of Momordica charantia leaves. The structures of the new compounds were elucidated on the basis of extensive spectroscopic analyses and comparison with literature. Upon evaluation of compounds 1-8 on the melanogenesis in B16 melanoma cells induced with α-melanocyte-stimulating hormone (α-MSH), these compounds were found to exhibit inhibitory activities with 7.1-27.0% and 23.6-46.4% reduction of melanin content at 30 μM and 100 μM, respectively, with no or almost no toxicity to the cells (80.0-103.5% of cell viability at 100 μM). Western blot analysis showed that compound 7 reduced the protein levels of MITF, tyrosinase, TRP-1, and TRP-2 mostly in a concentration-dependent manner, suggesting that this compound inhibits melanogenesis on the α-MSH-stimulated B16 melanoma cells by, at least in part, inhibiting the expression of MITF, followed by decreasing the expression of tyrosinase, TRP-1, and TRP-2.
College of Science and Technology, Nihon University, Tokyo, Japan.
Takashi
T
Kikuchi
Jie
J
Zhang
Yan
Y
Huang
Kensuke
K
Watanabe
Kenta
K
Ishii
Ayako
A
Yamamoto
Makoto
M
Fukatsu
Reiko
R
Tanaka
Toshihiro
T
Akihisa
D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D006027:Glycosides / Q000737:chemistry / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy; D008543:Melanins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D051379:Mice; D029777:Momordica charantia / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry*
D000970:Antineoplastic Agents; D006027:Glycosides; D008543:Melanins