Original ArticleCytoprotection of Baicalein Against Oxidative Stress-induced Cardiomyocytes Injury Through the Nrf2/Keap1 PathwayCui, Guozhen PhD*,†; Chui Wah Luk, Sharon PhD*; Li, Ronald Adolphus PhD‡; Chan, Ken Kwok Keung PhD‡; Lei, Si Wan MSc*; Wang, Liang MSc*; Shen, Huifang PhD†; Leung, George Pak Heng PhD§; Lee, Simon Ming Yuen PhD*Author Information *State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China; †Department of Bioengineering, Zhuhai Campus of Zunyi Medical University, Zhuhai, China; ‡Stem Cell and Regenerative Medicine Consortium, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, China; and §Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, China. Reprints: George Pak Heng Leung, PhD, Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, 999077 China (e-mail: email@example.com), or and Simon Ming Yuen Lee, PhD, State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Macao, 999078 China (e-mail: firstname.lastname@example.org). Supported by the Science and Technology Development Fund of Macao SAR (Ref. No. 014/2011/A1), Overseas and Hong Kong, Macau Young Scholars Collaborative Research Fund by the Natural National Science Foundation of China (Ref. No. 81328025), Research Committee, University of Macau, the Research Grant Council of HKSAR (TBRS, T13-706/11), SCRMC, and Faculty Cores of the University of Hong Kong. The authors report no conflicts of interest. Received May 01, 2014 Accepted August 05, 2014 Journal of Cardiovascular Pharmacology: January 2015 - Volume 65 - Issue 1 - p 39-46 doi: 10.1097/FJC.0000000000000161 Buy Metrics Abstract Abstract: Baicalein is one of the major flavonoids found in the root of Scutellaria baicalensis Georgi. Previous studies suggest that baicalein displays protective effect on experimental cardiac models in vitro and in vivo. However, the mode of action remains unclear. Here, we showed that baicalein conferred cardioprotective effect against oxidative stress-induced cell injury in H9c2 cells and human embryonic stem cells-derived cardiomyocytes. Immunoprecipitation with anti-NF-E2–related factor 2 (Nrf2) antibody in baicalein-treated cells demonstrated that baicalein effectively disrupted the association between Nrf2 and Kelch-like epichlorohydrin-associated protein 1 (Keap1). In addition, the unbounded Nrf2 translocated from cytoplasm to nucleus and increased Nrf2/heme oxygenase-1 (HO-1) content in a time-dependent manner. Moreover, antioxidant response element transcriptional activity was enhanced by baicalein treatment, and the Nrf2 siRNA transfection could block the cytoprotective effect of baicalein. Taken together, these results demonstrate that baicalein protected cardiomyocytes against oxidative stress-induced cell injury through the Nrf2/Keap1 pathway. © 2015 by Lippincott Williams & Wilkins.