title: Antiobesity effects of the water-soluble fraction of the ethanol extract of Smilax china L. leaf in 3T3-L1 adipocytes.
abstract: OBJECTIVE
  Several medicinal properties of Smilax china L. have been studied including antioxidant, anti-inflammatory, and anti-cancer effects. However, the antiobesity activity and mechanism by which the water-soluble fraction of this plant mediates its effects are not clear. In the present study, we investigated the lipolytic actions of the water-soluble fraction of Smilax china L. leaf ethanol extract (wsSCLE) in 3T3-L1 adipocytes.
  
  
  METHODS
  The wsSCLE was identified by measuring the total polyphenol and flavonoid content. The wsSCLE was evaluated for its effects on cell viability, lipid accumulation, glycerol, and cyclic adenosine monophosphate (cAMP) contents. In addition, western blot analysis was used to evaluate the effects on protein kinase A (PKA), PKA substrates (PKAs), and hormone-sensitive lipase (HSL). For the lipid accumulation assay, 3T3-L1 adipocytes were treated with different doses of wsSCLE for 9 days starting 2 days post-confluence. In other cell experiments, mature 3T3-L1 adipocytes were treated for 24 h with wsSCLE.
  
  
  RESULTS
  Results showed that treatment with wsSCLE at 0.05, 0.1, and 0.25 mg/mL had no effect on cell morphology and viability. Without evidence of toxicity, wsSCLE treatment decreased lipid accumulation compared with the untreated adipocyte controls as shown by the lower absorbance of Oil Red O stain. The wsSCLE significantly induced glycerol release and cAMP production in mature 3T3-L1 cells. Furthermore, protein levels of phosphorylated PKA, PKAs, and HSL significantly increased following wsSCLE treatment.
  
  
  CONCLUSIONS
  These results demonstrate that the potential antiobesity activity of wsSCLE is at least in part due to the stimulation of cAMP-PKA-HSL signaling. In addition, the wsSCLE-stimulated lipolysis induced by the signaling is mediated via activation of the β-adrenergic receptor.
authors.affiliation: Research and Development Division, Korean Promotion Institute for Traditional Medicine Industry, Gyeongsan, 712-260, Korea.
authors.forename: Yun Hwan
authors.initials: YH
authors.lastname: Kang
authors.affiliation: Department of Bio-Health Technology, College of Biomedical Science, Kangwon National University, 1 Gangwondaehak-gil, Chuncheon, Gangwon 200-701, Korea.
authors.forename: Kyoung Kon
authors.initials: KK
authors.lastname: Kim
authors.affiliation: Well-Being Bioproducts R&D Regional Innovation Center, Kangwon National University, 1 Gangwondaehak-gil, Chuncheon, Gangwon 200-701, Korea.
authors.forename: Dae Jung
authors.initials: DJ
authors.lastname: Kim
authors.affiliation: Department of Bio-Health Technology, College of Biomedical Science, Kangwon National University, 1 Gangwondaehak-gil, Chuncheon, Gangwon 200-701, Korea. ; Well-Being Bioproducts R&D Regional Innovation Center, Kangwon National University, 1 Gangwondaehak-gil, Chuncheon, Gangwon 200-701, Korea.
authors.forename: Myeon
authors.initials: M
authors.lastname: Choe
keywords: Smilax china; antiobesity; hormone-sensitive lipase; lipolysis; protein kinase A