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Evidence-Based Complementary and Alternative Medicine
Volume 2018, Article ID 6139372, 13 pages
https://doi.org/10.1155/2018/6139372
Research Article

The Protective Effect of Total Flavones from Rhododendron simsii Planch. on Myocardial Ischemia/Reperfusion Injury and Its Underlying Mechanism

1Department of Pharmacology, Anhui Medical University, Hefei, Anhui 230032, China
2Anhui Academy of Medical Sciences, Hefei, Anhui 230061, China
3Department of Pharmacy, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230032, China

Correspondence should be addressed to Gong Peng; moc.361@ko.8002gnepgnog and Zhi-Wu Chen; moc.361@wzmrahphc

Received 28 August 2017; Accepted 25 October 2017; Published 9 January 2018

Academic Editor: Christian Lehmann

Copyright © 2018 Sheng-Yong Luo 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

Objectives. Total flavones from Rhododendron simsii Planch. (TFR) are the effective part extracted from the flowers of Rhododendron simsii Planch. and have obvious protective effects against cerebral ischemic or myocardial injuries in rabbits and rats. However, their mechanism of cardioprotection is still unrevealed. Therefore, the present study was designed to investigate the effect of TFR on myocardial I/R injury and the underlying mechanism. Methods. TFR groups were treated by gavage once a day for 3 days at a dose of 20, 40, and 80 mg/kg, respectively, and then the model of myocardial I/R injury was established. Myocardial infarction, ST-segment elevation, and the expression of UTR, ROCK1, ROCK2, and p-MLC protein in rat myocardium were determined at 90 min after reperfusion. UTR siRNA in vivo transfection and competition binding assay method were used to study the relationship between the protective effect of TFR and UTR. Results. The expression of UTR protein markedly decreased in myocardium of UTR siRNA transfection group rats. TFR could significantly reduce the infarct size and inhibit the increase of RhoA activity and ROCK1, ROCK2, and p-MLC protein expressions both in WT and UTR knockdown rats. The reducing rate of TFR in myocardial infarction area, RhoA activity, and ROCK1, ROCK2, and p-MLC protein expressions in UTR knockdown rats decreased markedly compared with that in WT rats. In addition, TFR had no obvious effect on the increase of ΣST in UTR knockdown rats in comparison with that in model group. In particular, TFR could significantly inhibit the combination of []-hu-II and UTR, and IC50 was 0.854 mg/l. Conclusions. The results indicate that the protective effect of TFR on I/R injury may be correlated with its blocking UTR and the subsequent inhibition of RhoA/ROCK signaling pathway.