Effects of steamed Polygonatum odoratum extract on inhibition of adipocyte differentiation and lowing lipid in 3T3-L1 adipocytes

ABSTRACT 1)Objectives : The purpose of this study was to investigate inhibitory effects of steamed Polygonatum odoratum extract (POE) on differentiation and adipogenesis in 3T3-L1 adipocytes.Methods : Polygonatum odoratum (P. odoratum) extract was extracted with ethyl acetate. Total phenolic and flavonoid contents in POE were measured for antioxidant activit y. The spectrophotometric method was used to determine the DPPH and ABTS radical scavenging activity and fer ric-reducing antioxidant potential (FRAP). MTT assay was examined for cell toxicity, oil red O staining wa s performed for intracelluar adipogenesis in differentiated 3T3-L1 adipocytes. Western blot analysis for mea surement of CCAAT/enhancer-binding protein α (C/EBPα), peroxisome proliferator-activated receptorγ (PPARγ) and AMP-activated protein kinase (AMPK) expressions were performed.Results : The results revealed that POE has antioxidant activities. Cont ents of total polyphenolics and flavonoids were 50.83±1.52 GAE mg/100g dry weight of POE and 17 .05±2.47 RE mg/100g dry weight of POE, respectively. DPPH radical scavenging activity, and FRAP in 10 mg/ml concentration were 92.1±0.6%, 244.8±9.0 µM Fe(II) and ABTS inhibition in 5 mg/ml concentration was 84.8± 4.1%. Treatment of POE in adipocytes inhibited the differentiation and adipogenesis of 3T 3-L1 adipocytes compared to those of vehicle control. Additionally, protein expressions of C/EBPα and PPARγ, major transcription factor for the adipogenic genes, were significantly decreased compared to those of vehicl e control (p<0.05). Futhermore, phosphorylation of AMPK was increased in 3T3-L1 adipocytes treated with POE com pared to that of vehicle control (p<0.05).Conclusions : we demonstrate that steamed P. odoratum extract (POE) has potentiating antioxidant activities,