Melanin-concentrating hormone-1 receptor binding activity of pheophorbides isolated from Morus alba leaves.
The time-resolved fluorescence technique based on melanin-concentrating hormone (MCH) receptor subtype-1 (MCH-1 receptor) binding assay was adopted to carry out a bioassay-guided fractionation of the methanol extract of Morus alba leaves. This fractionation and purification led to the isolation of two compounds identified as pheophorbide a methyl ester and 13(2)(S)-hydroxypheophorbide a methyl ester. These active pheophorbides exhibited potent inhibitory activity in binding of europium-labeled MCH to the human recombinant MCH-1 receptor (IC(50) value; 4.03 and 0.33 microM, respectively). Besides binding activity, the pheophorbides inhibited MCH-mediated extracellular signal-regulated kinase (ERK) phosphorylation in Chinese hamster ovary cells expressing human MCH-1 receptor. These results suggest that pheophorbide a methyl ester and 13(2)(S)-hydroxypheophorbide a methyl ester act as modulators of MCH-1 receptor and MCH-mediated ERK signaling.
Oh
Byung Koo
BK
Bio-Organic Science Division, Korea Research Institute of Chemical Technology, Yuseong, Daejeon, Republic of Korea.
Oh
Kwang-Seok
KS
Kwon
Kwang-il
KI
Ryu
Shi Yong
SY
Kim
Young Sup
YS
Lee
Byung Ho
BH
D000818:Animals; D016466:CHO Cells; D002734:Chlorophyll / Q000031:analogs & derivatives* / Q000494:pharmacology; D006224:Cricetinae; D003412:Cricetulus; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D006801:Humans; D015394:Molecular Structure; D031625:Morus / Q000737:chemistry*; D010766:Phosphorylation; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D011979:Receptors, Pituitary Hormone / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D015398:Signal Transduction
D010936:Plant Extracts; D011979:Receptors, Pituitary Hormone; D011994:Recombinant Proteins; C092274:melanin-concentrating hormone receptor; D002734:Chlorophyll; D048049:Extracellular Signal-Regulated MAP Kinases; C032623:pheophorbide a