Grapefruit Oil Attenuates Adipogenesis in Cultured Subcutaneous Adipocytes

Abstract

We investigated the effects of different essential oils on adipogenesis in rat subcutaneous adipocytes. Subcutaneous preadipocytes were cultured in Dulbecco's Modified Eagle Medium (DMEM) containing insulin, transferrin, fibroblast growth factor, dexamethasone, indomethacin, fetal bovine serum, and an essential oil at 37 °C in 5 % CO₂ to induce their differentiation. After 7 days, the number of viable cells and the amount of triglycerides accumulated in the cells were determined. Differentiation markers such as the enzymatic activity of glycerol-3-phosphate dehydrogenase (GPDH) and the expression of GPDH and peroxisome proliferator-activated receptor γ (PPARγ) genes were also measured, as well as the intracellular Ca²⁺ levels. We found that grapefruit oil inhibited the accumulation of triglycerides in a dose-dependent manner at concentrations of 50 to 400 µg/mL. Furthermore, it suppressed the expression of GPDH and caused a 70 % decrease in the enzymatic activity of GPDH at a concentration of 50 µg/mL. Grapefruit oil also caused a nearly 2-fold increase in the intracellular concentration of Ca²⁺ and suppressed the expression of PPARγ genes. Our results demonstrate that grapefruit oil efficiently inhibits adipogenesis in cultured subcutaneous preadipocytes and adipocytes.

Key words

grapefruit - Citrus paradise - Rutaceae - essential oil - adipogenesis - GPDH - PPARγ

References

• 1 Pairault J, Green H. A study of the adipose conversion of suspended 3T3 cells by using glycerophosphate dehydrogenase as differentiation marker.  Proc Natl Acad Sci USA. 1979;  76 5138-5142
• 2 Wise L, Green H. Participation of one isozyme of cytosolic glycerophosphate dehydrogenase in the adipose conversion of 3T3 cells.  J Biol Chem. 1979;  254 273-275
• 3 Lowell B. PPARgamma: an essential regulator of adipogenesis and modulator of fat cell function.  Cell. 1999;  99 239-242
• 4 Lane M, Tang Q, Jiang M. Role of the CCAAT enhancer binding proteins (C/EBPs) in adipocyte differentiation.  Biochem Biophy Res Commun. 1999;  266 677-683
• 5 Koh K J, Pearce A L, Marshman G, Finlay-Jones J J, Hart P H. Tea tree oil reduces histamine-induced skin inflammation.  Br J Dermatol. 2002;  147 1212-1217
• 6 Okugawa H, Ueda R, Matsumoto K, Kawanishi K, Kato A. Effect of jinkoh-eremol and agarospirol from agarwood on the central nervous system in mice.  Planta Med. 1996;  62 2-6
• 7 Umezu T. Anticonflict effects of plant-derived essential oils.  Pharmacol Biochem Behav. 1999;  64 35-40
• 8 Umezu T, Sakata A, Ito H. Ambulation-promoting effect of peppermint oil and identification of its active constituents.  Pharmacol Biochem Behav. 2001;  69 383-390
• 9 Yamada K, Mimaki Y, Sashida Y. Anticonvulsive effects of inhaling lavender oil vapour.  Biol Pharm Bull. 1994;  17 359-360
• 10 Takahashi N, Kawada T, Goto T, Yamamoto T, Taimatsu A, Matsui N, Kimura K, Saito M, Hosokawa M, Miyashita K, Fushiki T. Dual action of isoprenols from herbal medicines on both PPARgamma and PPARalpha in 3T3-L1 adipocytes and HepG2 hepatocytes.  FEBS Lett. 2002;  514 315-322
• 11 Shen J, Niijima A, Tanida M, Horii Y, Maeda K, Nagai K. Olfactory stimulation with scent of grapefruit oil affects autonomic nerves, lipolysis and appetite in rats.  Neurosci Lett. 2005;  380 289-294
• 12 Nilsson N O, Belfrage P. Effects of acetate, acetaldehyde, and ethanol on lipolysis in isolated rat adipocytes.  J Lipid Res. 1978;  19 737-741
• 13 Hsu C L, Yen G C. Effects of capsaicin on induction of apoptosis and inhibition of adipogenesis in 3T3-L1 cells.  J Agric Food Chem. 2007;  55 1730-1736
• 14 Shi H, Halvolren Y D, Ellis P N, Wilkison W O, Zemel M B. Role of intracellular calcium in human adipocyte differentiation.  Physiol Genomics. 2000;  3 75-82
• 15 Neal J W, Clipstone N A. Calcineurin mediates the calcium-dependent inhibition of adipocyte differentiation in 3T3-L1 cells.  J Biol Chem. 2002;  277 49776-49781
• 16 Liu L, Clipstone N A. Prostaglandin F2alpha inhibits adipocyte differentiation via a G alpha q-calcium-calcineurin-dependent signaling pathway.  J Cell Biochem. 2007;  100 161-173
• 17 Aoshima H, Hamamoto K. Potentiation of GABAA receptors expressed in Xenopus oocytes by perfume and phytoncid.  Biosci Biotechnol Biochem. 1999;  63 743-748