Effects and mechanisms of the Toona sinensis extract on improving insulin resistance and inhibiting unilocular lipid droplet formation in adipocytes

• Main Authors: Ming-Ren Kang, 康銘仁
• Other Authors: Tusty-Jiuan Hsieh
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/80513751442633322550

碩士 === 高雄醫學大學 === 醫學系基因體醫學科研究所 === 102 === Obesity and type II diabetes are growing health issue and life threatening event worldwide, including Taiwan. Toona sinensis Roem leaf (TSL) has been used as nutritious food and been suggested for several medical applications. In the past studies, TSL extracts could improve hyperglycemia that had been confirmed. However the reported TSL compounds are from high to mid-high polar extracts. Therefore, we use supercritical-CO2 fluid extraction to obtain the non-polar constituents of the T. sinensis leave extract (TS-SCF) and we want to know whether the TS-SCF could improve insulin resistance and inhibit unilocular lipid droplet formation in adipocytes. And we investigate whether the TS-SCF could transdifferentiate the white adipocyte to brite adipocyte. We treated differentiated 3T3-L1 with the TSL extracts. Then, we used 6-NBDG fluorescence to observe glucose uptake in 3T3-L1. And we used microscope and oil red stain to observe morphology of adipocyte and lipid droplets. The gene expression was analyzed by DNA microarray and confirmed by real-time PCR and western blotting. In animal model, hematoxylin and eosin stain was used to observe adipocyte size in subcutaneous and visceral fat tissue. We measured blood glucose level by OGTT and used ELISA to measured RBP4 and insulin concentration in serum. Then, we observed brown adipocyte differentiated factors PRDM16, PGC-1α, thermogenesis protein UCP-1 expression and adrenergic signaling ADRβ3 expression. Our results demonstrated that TSL treatment increased glucose uptake and improve insulin sensitivity in the adipocytes. TSL treatment significantly prevented the formation of large unilocular LD by inhibiting FSP27 and Plin1 expression. In our studies, TS-SCF maybe could induce transdifferentiation of white adipocytes into brite adipocytes by increasing adrenergic signaling ADRβ3 expression.