Hindawi Publishing Corporation Evidence-Based Complementary and Alternative Medicine Volume 2013, Article ID 364519, 16 pages http://dx.doi.org/10.1155/2013/364519 Research Article Cardioprotective Effects of Quercetin in Cardiomyocyte under Ischemia/Reperfusion Injury Yi-Wen Chen, 1 Hsiu-Chuan Chou, 2 Szu-Ting Lin, 1 You-Hsuan Chen, 1 Yu-Jung Chang, 3 Linyi Chen, 3 and Hong-Lin Chan 1 1 Institute of Bioinformatics and Structural Biology and Department of Medical Sciences, National Tsing Hua University, 101 Kuang-Fu Road, Section 2, Hsinchu 30013, Taiwan 2 Department of Applied Science, National Hsinchu University of Education, Hsinchu 30013, Taiwan 3 Institute of Molecular Medicine and Department of Medical Science, National Tsing Hua University, Hsinchu 30013, Taiwan Correspondence should be addressed to Hong-Lin Chan; hlchan@mx.nthu.edu.tw Received 10 August 2012; Revised 22 November 2012; Accepted 7 February 2013 Academic Editor: Peng Nam Yeoh Copyright © 2013 Yi-Wen Chen et al. his 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. Quercetin, a polyphenolic compound existing in many vegetables, fruits, has antiinlammatory, antiproliferation, and antioxidant efect on mammalian cells. Quercetin was evaluated for protecting cardiomyocytes from ischemia/reperfusion injury, but its protective mechanism remains unclear in the current study. he cardioprotective efects of quercetin are achieved by reducing the activity of Src kinase, signal transducer and activator of transcription 3 (STAT3), caspase 9, Bax, intracellular reactive oxygen species production, and inlammatory factor and inducible MnSOD expression. Fluorescence two-dimensional diferential gel electrophoresis (2D-DIGE) and matrix-assisted laser desorption ionization time-of-light mass spectrometry (MALDI-TOF MS) can reveal the diferentially expressed proteins of H9C2 cells treated with H 2 O 2 or quercetin. Although 17 identiied proteins were altered in H 2 O 2 -induced cells, these proteins such as alpha-soluble NSF attachment protein (-SNAP), Ena/VASP-like protein (Evl), and isopentenyl-diphosphate delta-isomerase 1 (Idi-1) were reverted by pretreatment with quercetin, which correlates with kinase activation, DNA repair, lipid, and protein metabolism. Quercetin dephosphorylates Src kinase in H 2 O 2 -induced H9C2 cells and likely blocks the H 2 O 2 -induced inlammatory response through STAT3 kinase modulation. his probably contributes to prevent ischemia/reperfusion injury in cardiomyocytes. 1. Introduction Because of their high incidence and mortality rate, cardiovas- cular diseases have recently become a primary health concern worldwide. Myocardial ischemia/reperfusion injury, which causes excess reactive oxygen species (ROS) production that can lead to cardiac hypertrophy or dysfunction, is the most acute cardiovascular disease [1, 2]. In 2010, Chou et al. showed that ROS may afect intercellular connections and cytoskele- ton resulting in cell detachment, morphology change, or death. Src kinase also plays a key role in ROS-induced phosphorylation and cell damage in cardiomyocytes [2]. he ROS in this study includes hydrogen peroxide (H 2 O 2 ), singlet oxygen (O ∙ ), superoxide (O 2− ), and the hydroxyl radical (OH ∙ ). Among these ROS species, H 2 O 2 is the most stable and the most abundant in human cells. Although the optimal amount of ROS plays an important role in signal transduction, excess ROS causes cell damage [3]. H 2 O 2 regulates signal transduction-related proteins by phosphorylating or modifying the active sites of proteins but also inhibits phosphatase activity [4]. Quercetin, a type of polyphenolic compound, has anti- inlammatory, antiproliferation, anti-histamine, and antioxi- dant efects. Quercetin exists in many types of vegetables and fruits. Several reports have shown that quercetin has protec- tive efects on diferent types of cells, including myocytes, testis, renal cells, and liver cells in ischemia/reperfusion injury [5]. A study conducted in 1992 showed that quercetin