ABSTRACT
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.
Subject(s)
Adipocytes/metabolism , Hemerocallis/chemistry , Intra-Abdominal Fat/metabolism , Lipolysis/drug effects , Norepinephrine/pharmacology , Plant Extracts/pharmacology , Sympathomimetics/pharmacology , Adipocytes/cytology , Animals , Cells, Cultured , Cyclic AMP/analogs & derivatives , Cyclic AMP/metabolism , Cyclic AMP/pharmacology , Cyclic AMP-Dependent Protein Kinases/metabolism , Drug Synergism , Intra-Abdominal Fat/cytology , Male , Norepinephrine/agonists , Phosphodiesterase Inhibitors/pharmacology , Plant Extracts/agonists , Plant Extracts/chemistry , Rats , Rats, Wistar , Sympathomimetics/agonistsABSTRACT
We have found natural products exhibiting lipolysis-promoting activity in subcutaneous adipocytes, which are less sensitive to hormones than visceral adipocytes. The activities and a action mechanisms of a novel plant extract of Cirsium oligophyllum (CE) were investigated in isolated adipocytes from rat subcutaneous fat, and its fat-reducing effects by peroral administration and topical application were evaluated in vivo. CE-induced lipolysis was synergistically enhanced by caffeine, a phosphodiesterase inhibitor, and was reduced by propranolol, a beta adrenergic antagonist. The peroral administration of 10% CE solution to Wistar rats for 32 days reduced body weight gain, subcutaneous, and visceral fat weights by 6.6, 26.2, and 3.0%, respectively, as compared to the control group. By the topical application of 2% of this extract to rats for 7 days, weight of subcutaneous fat in the treated skin was reduced by 23.2%. This fat mass reduction was accompanied by the up-regulation of uncoupling protein 1 (UCP), a principal thermogenic mitochondrial molecule related to energy dissipating, in subcutaneous fat and UCP3 in skin except for the fat layer. These results indicate that CE promotes lipolysis via a mechanism involving the beta adrenergic receptor, and affects the body fat mass. This fat reduction may be partially due to UCP up-regulation in the skin including subcutaneous fat. This is the first report showing that repeated lipolysis promotion through CE administration may be beneficial for the systematic suppression of body fat accumulation or the control of fat distribution in obesity.
Subject(s)
Adipocytes/drug effects , Adipose Tissue, White/drug effects , Cirsium , Ion Channels/metabolism , Mitochondrial Proteins/metabolism , Phytotherapy , Plant Extracts/administration & dosage , Adipocytes/metabolism , Adipose Tissue, White/metabolism , Adrenergic beta-Antagonists/pharmacology , Animals , Body Composition/drug effects , Body Weight/drug effects , Caffeine/pharmacology , Cells, Cultured , Drug Synergism , Lipolysis/drug effects , Male , Phosphodiesterase Inhibitors/pharmacology , Plant Extracts/antagonists & inhibitors , Propranolol/pharmacology , Rats , Rats, Wistar , Skin/drug effects , Skin/metabolism , Uncoupling Protein 1 , Uncoupling Protein 3 , Up-Regulation/drug effectsABSTRACT
We evaluated the usefulness of two-dimensional time-of-flight (2D TOF) MR venography (MRV) of the lower extremity using the respiratory compensation (RC) technique. In addition, six variations in patient positioning of the leg and knee were investigated to determine the best method of visualizing the deep popliteal veins and lower leg. All data sets were reviewed and graded for visualization of the deep veins at the pelvis, thigh, and leg portion (4-point scale) by two radiologists and three radiological technologists. The same veins demonstrated with various positions of the patient were also evaluated in the same manner. In conclusion, 2D TOF MRV with RC resulted in increased uniformity of vein signal in the pelvic area. Furthermore, we should position the patient's leg so as not to compress the vein at the posterior portion of the leg, and not to over-extend the knee joint. This enabled the best results to be obtained in MRV of the lower extremity.