Enhancement of lipolytic responsiveness of adipocytes by novel plant extract in rat.
Subcutaneous adipocytes accumulate excess energy as triglycerides, but lipolytic response is less sensitive to catecholamines than visceral adipocytes. Obesity also induces catecholamine resistance of adipocytes. We have searched for crude drugs that could enhance the lipolytic response to noradrenalin. In this study, the lipolysis-promoting activities and action mechanisms of a novel plant extract from Hemerocallis fulva (HE) were investigated in isolated adipocytes from rat subcutaneous fat. HE exhibited no lipolysis-promoting activity alone but markedly promoted lipolysis when combined with noradrenaline; however, this synergistic activity was accompanied by no increase of intracellular cAMP production. This activity of HE was also observed when combined with cAMP analogue and was further enhanced by phosphodiesterase inhibitor. PKA inhibitor could reduce these activities of HE. These results indicate that HE is a novel lipolysis-promoting material that can sensitize the lipolytic response of adipocytes to catecholamine and suggest that HE can amplify the intra-cellular signaling pathway related to PKA or modify the other mechanism-regulating lipase activity. This characteristic material could contribute to improvement of adipose mobility in obesity-related disorder or in subcutaneous adiposity and to suppression of body fat accumulation.
Mori
Shinobu
S
Biological Science Laboratories, Kao Corporation, 2606 Akabane, Ichikai-Machi, Haga-gun, Tochigi, 321-3497, Japan. mori.shinobu@kao.co.jp
Takizawa
Minoru
M
Satou
Mayumi
M
Sakasai
Mitsuyoshi
M
Kusuoku
Hiroshi
H
Nojiri
Hiroshi
H
Yoshizuka
Naonobu
N
Hotta
Mitsuyuki
M
Kitahara
Takashi
T
Hase
Tadashi
T
Takema
Yoshinori
Y
Saito
Masayuki
M
Yada
Toshihiko
T
D017667:Adipocytes / Q000166:cytology / Q000378:metabolism*; D000818:Animals; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D004357:Drug Synergism; D031421:Hemerocallis / Q000737:chemistry*; D050152:Intra-Abdominal Fat / Q000166:cytology / Q000378:metabolism*; D008066:Lipolysis / Q000187:drug effects*; D008297:Male; D009638:Norepinephrine / Q000819:agonists / Q000494:pharmacology*; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D010936:Plant Extracts / Q000819:agonists / Q000737:chemistry / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013566:Sympathomimetics / Q000819:agonists / Q000494:pharmacology*
D010726:Phosphodiesterase Inhibitors; D010936:Plant Extracts; D013566:Sympathomimetics; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D009638:Norepinephrine