The potential effects of ethyl acetate fraction from Curcuma longa L. on lipolysis in differentiated 3T3-L1 adipocytes.
The effects of the turmeric ethyl acetate fraction (TEF) from the methanolic extract from Curcuma longa L. on lipid metabolism and underlying mechanisms of lipolysis were investigated in 3T3-L1 adipocytes. The intracellular lipid droplets were stained with Oil red O dye and quantified. Compared to the control, lipid accumulation was significantly decreased by 46.6% with treatment by TEF at the concentration of 20 microg/mL. The intracellular triglyceride (TG) level was also reduced by 37.9% at the concentration of 20 microg/mL. To determine the mechanism for TG content reduction, levels of glucose uptake and glycerol release were measured. Incubation of the 3T3-L1 adipocytes with TEF for 4 hours significantly lowered the cellular level of glucose in a dose-dependent manner. Furthermore, cellular expression of insulin-responsive glucose transporter (GLUT)-4 was decreased by 46%, indicating that reduced glucose uptake was due to a decrease in cellular GLUT-4 expression. In addition, the level of free glycerol released into the cultured medium was increased by 36.4% with the treatment by TEF. In subsequent measurements using quantitative real-time polymerase chain reaction, mRNA levels of hormone-sensitive lipase (HSL) and adipose TG lipase (ATGL) were elevated by 34.8% and 16.9%, respectively, at the concentration of 20 microg/mL. These results suggest that TEF partially inhibits lipogenesis by the suppression of glucose uptake via the decreased expression of cellular GLUT-4 and stimulates lipolysis through the induction of HSL and/or ATGL gene expression, resulting in the increased glycerol release.
Lee
Jeongmin
J
Clinical Research Center, Department of Medical Nutrition, Kyung Hee University, Yongin, Republic of Korea.
Yoon
Ho-Geun
HG
Lee
Yoo-Hyun
YH
Park
Jeongjin
J
You
Yanghee
Y
Kim
Kyungmi
K
Jang
Ja-Young
JY
Yang
Ji-Won
JW
Jun
Woojin
W
D041721:3T3-L1 Cells; D017667:Adipocytes / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D001692:Biological Transport; D030024:Curcuma / Q000737:chemistry*; D004305:Dose-Response Relationship, Drug; D005947:Glucose / Q000378:metabolism*; D051275:Glucose Transporter Type 4 / Q000378:metabolism*; D005990:Glycerol / Q000378:metabolism; D008049:Lipase / Q000235:genetics / Q000378:metabolism; D008066:Lipolysis / Q000187:drug effects*; D051379:Mice; D015388:Organelles / Q000187:drug effects / Q000378:metabolism; D010936:Plant Extracts / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D002787:Sterol Esterase / Q000235:genetics / Q000378:metabolism; D014280:Triglycerides / Q000378:metabolism
D051275:Glucose Transporter Type 4; D010936:Plant Extracts; D012333:RNA, Messenger; D014280:Triglycerides; D002787:Sterol Esterase; D008049:Lipase; D005947:Glucose; D005990:Glycerol