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Evidence-Based Complementary and Alternative Medicine
Volume 2015 (2015), Article ID 142059, 12 pages
http://dx.doi.org/10.1155/2015/142059
Research Article

A Cistanches Herba Fraction/β-Sitosterol Causes a Redox-Sensitive Induction of Mitochondrial Uncoupling and Activation of Adenosine Monophosphate-Dependent Protein Kinase/Peroxisome Proliferator-Activated Receptor γ Coactivator-1 in C2C12 Myotubes: A Possible Mechanism Underlying the Weight Reduction Effect

Division of Life Science, Hong Kong University of Science and Technology, Kowloon, Hong Kong

Received 29 August 2014; Accepted 14 January 2015

Academic Editor: Man Li

Copyright © 2015 Hoi Shan Wong et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Previous studies have demonstrated that HCF1, a semipurified fraction of Cistanches Herba, causes weight reduction in normal diet- and high fat diet-fed mice. The weight reduction was associated with the induction of mitochondrial uncoupling and changes in metabolic enzyme activities in mouse skeletal muscle. To further investigate the biochemical mechanism underlying the HCF1-induced weight reduction, the effect of HCF1 and its active component, β-sitosterol (BSS), on C2C12 myotubes was examined. Incubation with HCF1/BSS caused a transient increase in mitochondrial membrane potential (MMP), possibly by fluidizing the mitochondrial inner membrane. The increase in MMP was paralleled to an increase in mitochondrial reactive oxygen species (ROS) production. Mitochondrial ROS, in turn, triggered a redox-sensitive induction of mitochondrial uncoupling by uncoupling protein 3 (UCP3). Biochemical analysis indicated that HCF1 was capable of activating an adenosine monophosphate-dependent protein kinase/peroxisome proliferator-activated receptor γ coactivator-1 pathway and thereby increased the expression of cytochrome c oxidase and UCP3. Animal studies using mitochondrial recoupler also confirmed the role of mitochondrial uncoupling in the HCF1-induced weight reduction. In conclusion, a HCF1/BSS causes the redox-sensitive induction of mitochondrial uncoupling and activation of AMPK/PGC-1 in C2C12 myotubes, with resultant reductions in body weight and adiposity by increased energy consumption.