With recognition of biological functions of brown adipose tissue (BAT) in adults, it has become a hot topic in medical research. In the present study, the effects of (-)-Epigallocatechin-3-gallate(EGCG) on the metabolism of BAT are investigated through animal experiments, histopathologicaland immunohistochemical methods. The results show that there are disparities in morphology of interscapular BAT among different species of mice. Vacuoles of fat droplets in adipocytes of C57BL/6 mice are the largest, and the cytoplasmic content is the least. Vacuoles in adipocytes of BALB/c mice are the smallest, and the cytoplasmic content is the most. Vacuoles and cytoplasmic content in Kunming mice lie between those in C57BL/6 and BALB/c mice. EGCG at 150 mg/kg decreases the increment rate of body weight and reduces the weights of epididymal white adipose tissue, but there is no statistical significance after different doses of EGCG are administered p.o. to Kunming mice. EGCG significantly decreases the content of fat (shown as vacuoles in the sections) in BAT and increases the cytoplasmic content (P<0.001). By immunohistochemical examination, EGCG increases the expression level of uncoupling protein 1, indicating the increase of energymetabolism in BAT. Therefore, there exist diversemorphological characteristics in different inbred lines of mice, which provides the basis for selection of mice in BAT studies. EGCG may regulate the metabolism of BAT in mice, which lays the foundation for further studies of its mechanism and provides new ideas for studies of the regulation of fat metabolism by tea.
SHANG Yue
,
LI Yi
,
CHEN Shuzhen
,
ZHEN Yongsu
. Effects of Tea Polyphenol EGCG on the Metabolism of Brown Adipose Tissue in Mice[J]. Science & Technology Review, 2014
, 32(11)
: 21
-25
.
DOI: 10.3981/j.issn.1000-7857.2014.11.002
[1] 陈淑珍, 甄永苏. 茶多酚的分子作用靶点及其在抗肿瘤药物实验治疗中的作用[J]. 药学学报, 2013, 48(1): 1-7. Chen Shuzhen, Zhen Yongsu. Molecular targets of tea polyphenols and its roles of anticancer drugs in experimental therapy[J]. Acta Pharmaceutica Sinica, 2013, 48(1): 1-7.
[2] 罗居东, 薛姣, 葛欣, 等. PPARα活化增加肿瘤细胞对EGCG的敏感性的机制[J]. 科技导报, 2013, 31(27): 21-26. Luo Judong, Xue Jiao, Ge Xin, et al. Mechanism of sensitizing effect of PPARα activation on epigallocatechin-3-gallate (EGCG) in cancer cells[J]. Science & Technology Reviews, 2013, 31(27): 21-26.
[3] Kim J, Kim H S, Quon M J. New insights into the mechanisms of polyphenols beyond antioxidant properties; lessons from the green tea polyphenol, epigallocatechin 3-gallate[J]. Redox Biology, 2014, 2: 187-195.
[4] Chan C Y, Wei L, Castro-Muozledo F, et al. (-)-Epigallocatechin-3-gallate blocks 3T3-L1 adipose conversion by inhibition of cell proliferation and suppression of adipose phenotype expression[J]. Life Sciences, 2011, 89(21): 779-785.
[5] Rosenwald M, Wolfrum C. The origin and definition of brite versus white and classical brown adipocytes[J]. Adipocyte, 2014, 3(1): 4-9.
[6] Seale P, Bjork B, Yang W, Kajimura S, et al. PRDM16 controls a brown fat/skeletal muscle switch[J]. Nature, 2008, 454(7207): 961-967.
[7] Truong M T, Erasmus J J, Munden R F, et al. Focal FDG uptake in mediastinal brown fat mimicking malignancy: A potential pitfall resolved on PET/CT[J]. American Journal of Roentgenology, 2004, 183(4): 1127- 1132.
[8] Silva F J, Holt D J, Vargas V, et al. Metabolically active human brown adipose tissue derived stem cells[J]. Stem Cells, 2014, 32(2): 572-581.
[9] Gilsanz V, Hu H H, Kajimura S. Relevance of brown adipose tissue in infancy and adolescence[J]. Pediatric Research, 2012, 73(1): 3-9.
[10] 黄海艳, 钱淑文, 汤其群. 诱导性产热脂肪的性质、诱导因素及潜在临床应用[J]. 中国细胞生物学学报, 2013, 35(9): 1259-1271. Huang Haiyan, Qian Shuwen, Tang Qiqun. Characterization of the inducible thermogenic adipose tissue and its potential application in treatment of obesity and related complications[J]. Chinese Journal of Cell Biology, 2013, 35(9): 1259-1271.
[11] Prats C, Gomez-Cabello A, Nordby P, et al. An optimized histochemical method to assess skeletal muscle glycogen and lipid stores reveals two metabolically distinct populations of type I muscle fibers[J]. Plos One, 2013, 8(10): e77774.
[12] Zhou J, Farah B L, Sinha RA, et al. Epigallocatechin- 3- gallate (EGCG), a green tea polyphenol, stimulates hepatic autophagy and lipid clearance[J]. PLoS One, 2014, 9(1): e87161.
[13] Byun J K, Yoon B Y, Jhun J Y, et al. Epigallocatechin-3-gallate ameliorates both obesity and autoinflammatory arthritis aggravated by obesity by altering the balance among CD4+ T-cell subsets[J]. Immunology Letters, 2014, 157(1): 51-59.
[14] Ohno H, Shinoda K, Ohyama K, et al. EHMT1 controls brown adipose cell fate and thermogenesis through the PRDM16 complex[J]. Nature, 2013, 504(7478): 163-167.
[15] Kajimura S, Seale P, Kubota K, et al. Initiation of myoblast to brown fat switch by a PRDM16-C/EBP-β transcriptional complex[J]. Nature, 2009, 460(7259): 1154-1158.
[16] Okamatsu-Ogura Y, Fukano K, Tsubota A, et al. Thermogenic ability of uncoupling protein 1 in beige adipocytes in mice[J]. Plos One, 2013, 8(12): e84229.
[17] Stier A, Bize P, Habold C, et al. Mitochondrial uncoupling prevents cold- induced oxidative stress: A case study using UCP1 knockout mice[J]. The Journal of Experimental Medicine, 2014, 217(4): 624- 630.
