Mechanism of Taohong Siwutang Alleviating Myocardial Ischemia Reperfusion Injury in Ovariectomized Mice by Up-regulating Nrf2/HO-1 Signaling Pathway / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo investigate the effect and mechanism of Taohong Siwutang （TSD） on myocardial ischemia reperfusion injury （MIRI） in ovariectomized （OVX） female mice. MethodAfter the OVX model of female mice was established， the estradiol （E2） level was detected by enzyme-linked immunosorbent assay （ELISA） to verify the model. Sixty OVX mice were randomly divided into six groups： Sham operation group， model group， low， medium， and high dose groups （9， 18， 36 g·kg-1） of TSD， and nuclear factor E2-related factor 2 （Nrf2） inhibitor group， with 10 mice in each group. The MIRI model was verified by a laser speckle flowmeter. The pathological changes in myocardial tissue were detected by 2，3， 5-triphenyltetrazolium chloride （TTC） and hematoxylin-eosin （HE） staining. Serum creatine kinase isoenzyme （CK-MB）， cardiac troponin Ⅰ （CTnⅠ）， malondialdehyde （MDA）， superoxide dismutase （SOD）， interleukin-6 （IL-6）， and interleukin-10 （IL-10） levels were detected by ELISA. The expression of Nrf2 and heme oxygenase-1 （HO-1） were observed by immunofluorescence staining. The expressions of Nrf2， HO-1， apoptotic B-cell lymphomato-2 （Bcl-2）， Bcl-2 associated X protein （Bax）， inflammatory cytokines interleukin-18 （IL-18）， and interleukin-1β （IL-1β） were detected by Western blot. ResultCompared with the sham operation group， the serum levels of CK-MB， CTnⅠ， MDA， and IL-6 in the model group were increased （P<0.01）， and the levels of SOD and IL-10 were decreased （P<0.01）. The damage scores of TTC and HE staining in myocardial tissue were increased （P<0.01）. The expressions of Nrf2 and HO-1 in myocardial tissue by immunofluorescence were decreased （P<0.01）， and the protein expressions of Nrf2， HO-1， and Bcl-2 in myocardial tissue were decreased. The protein expressions of Bax， IL-18， and IL-1β were increased （P<0.01）. Compared with the model group， serum levels of CK-MB， CTnⅠ， MDA， and IL-6 of TSD groups were significantly decreased （P<0.05， P<0.01）， and SOD and IL-10 were significantly increased （P<0.05， P<0.01）. TTC staining and HE staining damage scores of myocardial tissue were significantly decreased （P<0.01）. The expressions of Nrf2 and HO-1 in myocardial tissue by immunofluorescence were increased （P<0.01）. The protein expressions of Nrf2， HO-1， and Bcl-2 were significantly increased （P<0.05， P<0.01）， and those of Bax， IL-18， and IL-1β were significantly decreased （P<0.05， P<0.01）. The effect of the high dose group of TSD was the most significant. The serum levels of CK-MB， CTnⅠ， MDA， and IL-6 in the Nrf2 inhibitor group were significantly increased （P<0.05， P<0.01）， and the levels of SOD and IL-10 were significantly decreased （P<0.05， P<0.01）. The damage scores of TTC and HE staining in myocardial tissue were significantly increased （P<0.01）. The expressions of Nrf2 and HO-1 in myocardial tissue by immunofluorescence were significantly decreased （P<0.01）. The protein expressions of Nrf2， HO-1， and Bcl-2 in myocardial tissue were significantly decreased， and those of Bax， IL-18， and IL-1β were significantly increased （P<0.01）. ConclusionTSD can alleviate MIRI in OVX mice， reduce oxidative stress response and the release of inflammatory factors， and inhibit apoptosis， playing a protective role in OVX mice with MIRI， which may be related to the activation of Nrf2/HO-1 signaling pathway.