Pretreatment with Total Flavonoid Extract from Dracocephalum Moldavica L. Attenuates Ischemia Reperfusion-induced Apoptosis

Cheng Zeng,Jianguo Xing,Wen Wang,Wen Jiang,Chenghui He,Xiaoyi Yang

doi:10.1038/s41598-018-35726-4

Abstract

We previously demonstrated the cardio-protection mediated by the total flavonoid extracted from Dracocephalum moldavica L. (TFDM) following myocardial ischemia reperfusion injury (MIRI). The present study assessed the presence and mechanism of TFDM-related cardio-protection on MIRI-induced apoptosis in vivo. Male Sprague-Dawley rats experienced 45-min ischemia with 12 h of reperfusion. Rats pretreated with TFDM (3, 10 or 30 mg/kg/day) were compared with Sham (no MIRI and no TFDM), MIRI (no TFDM), and Positive (trapidil tablets, 13.5 mg/kg/day) groups. In MIRI-treated rats, high dose-TFDM (H-TFDM) pre-treatment with apparently reduced release of LDH, CK-MB and MDA, enhanced the concentration of SOD in plasma, and greatly reduced the infarct size, apoptotic index and mitochondrial injury. H-TFDM pretreatment markedly promoted the phosphorylation of PI3K, Akt, GSK-3β and ERK1/2 in comparison with the MIRI model group. Western blot analysis after reperfusion also showed that H-TFDM decreased release of Bax, cleaved caspase-3, caspase-7 and caspase-9, and increased expression of Bcl-2 as evident by the higher Bcl-2/Bax ratio. TFDM cardio-protection was influenced by LY294002 (PI3K inhibitor) and PD98059 (ERK1/2 inhibitor). Taken together, these results provide convincing evidence of the benefit of TFDM pretreatment due to inhibited myocardial apoptosis as mediated by the PI3K/Akt/GSK-3β and ERK1/2 signaling pathways.

Highlights

Cardiomyocyte death is a common characteristic of myocardial ischemia reperfusion injury (MIRI)
We have previously demonstrated the utility of total flavonoid extract from Dracocephalum moldavica L. (TFDM) to protect cardiomyocytes and have shown its’ anti-oxidant activity[29,30]
When compared with the MIRI group, the activities of LDH and CK-MB, and MDA level were significantly decreased in high dose-TFDM (H-TFDM) and trapidil tablets groups

Summary

Introduction

Cardiomyocyte death is a common characteristic of MIRI. Apoptosis is the principal cellular pathway which results in cardiomyocyte death[10]. The other pathway is the phosphatidylinositol-3-kinase (PI3K)/Akt pathway Activation of this pathway reduces myocardial apoptosis, which is important in maintaining mitochondrial integrity by the phosphorylation of proteins including glycogen synthase kinase 3β (GSK-3β)[16,17]. We reported the five main chemical constituents of TFDM24, which include luteolin-7-O-β-D-glucuronide[31], apigenin -7-O-β-D-glucuronide[32], diosmetin-7-O-β-D-glucuronide[33], acacetin-7-O-β-D-glucuronide[34] and tilianin[35] These compounds (Fig. 1) all display significant myocardial protective effects. While TFDM can activate the PI3K/Akt signaling pathway to reduce apoptosis, whether TFDM inhibits apoptosis during MIRI via GSK3β-dependent cell-survival and the ERK1/2 signaling pathway is unknown. The third is to elucidate the mechanisms of TFDM on cardiomyocyte apoptotic pathways (PI3K/Akt/GSK3β and ERK1/2 signaling pathway) in the MIRI.

Methods

Results

Conclusion