It plays a key role in adipocyte differentiation, lipid accumulation, and insulin sensitivity ( Spiegelman, 1998 Francis et al., 2003), and is involved in whole-body glucose homeostasis ( Barroso et al., 1999). PPAR γ is expressed abundantly in adipocytes, particularly in WAT, as well as in the gastrointestinal tract and macrophages ( Thompson, 2007). The activation of PPAR α is an effective therapy for hyperglyceridemia. It mainly mediates the uptake and β-oxidation of fatty acids in the liver and heart ( Bishop-Bailey, 2000 Puddu, Puddu & Muscari, 2003). PPAR α is present in the liver ( Jia et al., 2003), heart ( Barger & Kelly, 2000 Gilde & Bilsen, 2003), skeletal muscle, BAT and kidneys. PPARs bind to the retinoid X receptors to form heterodimers, which regulate downstream gene expression by interacting with PPAR response elements in these genes ( Wahli, Braissant & Desvergne, 1995). PPARs are crucial regulators of lipid, glucose and tissue metabolism as well as cell differentiation and proliferation, apoptosis, and host immunity ( Desvergne & Wahli, 1999). PPAR α, PPAR β, and PPAR γ are their three isoforms.
Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear receptor family ( Francis et al., 2003). UCP1, UCP2, and UCP3 are related to energy metabolism in particular UCP1 plays a critical role in releasing electrons rather than storing them, resulting in heat release ( Kim & Plutzky, 2016). Moreover, white adipose tissue (WAT) can be used as an index of energy metabolism for it browning. When activated, BAT can express uncoupling protein1(UCP1) to release energy in the form of heat by uncoupling the protons generated by substrate oxidation during adenosine triphosphate (ATP) production ( Izzi-Engbeaya et al., 2015). Thus, although difficult, novel therapeutics to prevent and treat obesity are urgently required ( Apovian et al., 2015).īrown adipose tissue (BAT) is essential for thermogenesis and body temperature maintenance ( Harms & Seale, 2013). Recent relevant experimental and clinical research results can be summarized as follows: (1) develop practical methods to address the main causes of MS, and (2) identify a direct method to eliminate adverse factors, such as insulin resistance, hyperlipidemia, obesity, and hypertension ( Ginsberg, 2003). Excessive calorie intake and lack of exercise are the two main reasons leading to MS.
It is characterized by obesity, insulin resistance, hyperlipidemia, type 2 diabetes mellitus, hypertension, and atherosclerotic cardiovascular disease ( Morikawa et al., 2004 Eckel et al., 2010). Metabolic syndrome (MS) is prevalent world-wide, particularly in Western countries. Radix Stellariae extract prevents high-fat-diet-induced obesity in C57BL/6 mice by accelerating energy metabolism. Cite this article Li Y, Liu X, Fan Y, Yang B, Huang C.
For attribution, the original author(s), title, publication source (PeerJ) and either DOI or URL of the article must be cited. Licence This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, China DOI 10.7717/peerj.3305 Published Accepted Received Academic Editor Dunxian Tan Subject Areas Molecular Biology, Diabetes and Endocrinology, Global Health, Pharmacology, Metabolic Sciences Keywords Radix stellariae, Metabolic syndrome, High-fat diet, UCPs, PPARs Copyright © 2017 Li et al.