title: Polygonum cuspidatum inhibits pancreatic lipase activity and adipogenesis via attenuation of lipid accumulation.
abstract: BACKGROUND
  Obesity causes metabolic disease and is a serious health problem around the world. Polygonum cuspidatum (POCU1b) has been used clinically for the treatment of constipation, gallstones, hepatitis, and inflammation in East Asian countries. The principal aim of this study was to investigate for the first time whether the extract of Polygonum cuspidatum (POCU) biologically affects adipogenesis in 3 T3-L1 preadipocytes.
  
  
  METHODS
  Fractions (n-hexan, ethyl acetate, n-butanol, and water) of POCU ethanol extract were evaluated in vitro for their inhibitory activities on pancreatic lipase. Of the fractions, the n-butanol of POCU ethanol extract (POCU1b) was examined anti-obesity activity in 3 T3-L1 preadipocytes. To examine the inhibitory effect of POCU1b on adipogenesis, 3 T3-L1 preadipocytes were treated every the other day with POCU1b at various concentrations (0 ~ 25 μg/mL) for twelve days. Oil-red O staining and triglyceride content assay were performed to determine the lipid accumulation. The expression of mRNA and proteins associated lipid accumulation was measured using RT-PCR and Western blotting analysis. We also examined the effect of POCU1b on level of phosphorylated AMP-activated protein kinase (pAMPK) in 3 T3-L1 preadipocytes with POCU1b at various concentrations during adipocyte differentiation.
  
  
  RESULTS
  POCU1b exhibited the most pronounced inhibitory effects on pancreatic lipase activity. We found that POCU1b inhibited adipocyte differentiation in 3 T3-L1 preadipocytes in a dose-dependent manner, as evidenced by the reduced formation of lipid droplets and decreased glycerol-3-phosphate dehydrogenase (GPDH) activity. We also showed that the expression levels of adipocyte differentiation-related protein (ADRP) and perilipin (a protein that coats lipid droplets in adipocytes) were both reduced after POCU1b treatment. Peroxisome proliferator-activated receptor-gamma (PPAR-γ) and CCAAT/enhancer-binding protein-alpha (C/EBP-α) proteins, both major adipogenic transcription factors, were markedly reduced by POCU1b. Moreover, ADRP, perilipin, C/EBP-α, and PPAR-γ mRNA levels were also reduced by POCU1b. Levels of phosphorylated AMP-activated protein kinase (pAMPK) were elevated after POCU1b treatment (5, 10, and 25) in a dose-dependent manner.
  
  
  CONCLUSIONS
  Taken together, these results suggest that the anti-obesity effects of POCU1b involve the inhibition of pancreatic lipase activity and adipogenesis via the down-regulation of lipid accumulation.
authors.forename: Young Sook
authors.initials: YS
authors.lastname: Kim
authors.forename: Yun Mi
authors.initials: YM
authors.lastname: Lee
authors.forename: Joo Hwan
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Korean Medicine-Based Herbal Drug Development Group, Herbal Medicine Research Division, Korea Institute of Oriental Medicine (KIOM), Daejeon 305-811, Republic of Korea. jskim@kiom.re.kr.
authors.forename: Jin Sook
authors.initials: JS
authors.lastname: Kim
mesh_terms: D041721:3T3-L1 Cells; D055372:AMP-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D017667:Adipocytes / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D050156:Adipogenesis / Q000187:drug effects*; D000818:Animals; D022763:CCAAT-Enhancer-Binding Protein-alpha / Q000235:genetics / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D045468:Fallopia japonica / Q000737:chemistry*; D006801:Humans; D008049:Lipase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D050356:Lipid Metabolism / Q000187:drug effects; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D009765:Obesity / Q000188:drug therapy / Q000201:enzymology* / Q000378:metabolism / Q000503:physiopathology; D047495:PPAR gamma / Q000235:genetics / Q000378:metabolism; D010179:Pancreas / Q000187:drug effects / Q000201:enzymology*; D000070778:Perilipin-1; D000070780:Perilipin-2; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D010936:Plant Extracts / Q000494:pharmacology*; D013552:Swine; D014280:Triglycerides / Q000378:metabolism
chemical_list: D022763:CCAAT-Enhancer-Binding Protein-alpha; D002352:Carrier Proteins; D004791:Enzyme Inhibitors; D008565:Membrane Proteins; C000602982:PLIN2 protein, human; D047495:PPAR gamma; D000070778:Perilipin-1; D000070780:Perilipin-2; D010750:Phosphoproteins; D010936:Plant Extracts; C000602983:Plin2 protein, mouse; D014280:Triglycerides; D055372:AMP-Activated Protein Kinases; D008049:Lipase