Antiapoptotic Mechanisms of Chinese Medicine Formula, Guan-Xin-Er-Hao, in the Rat Ischemic Heart

Abstract

Considerable evidence indicates that apoptosis plays a critical role in acute myocardial infarction. We have previously shown that Guan-Xin-Er-Hao (GXEH), a Chinese medicine formula, attenuates postischemia myocardial apoptosis. The present study was designed to determine the mechanisms by which GXEH exerts its antiapoptotic effect. Adult male Sprague-Dawley rats were randomized to receive vehicle or GXEH (5 or 15 g/kg) orally 30 min before ischemia and subjected to myocardial ischemia of 3 h (apoptosis peak) or 24 h (necrosis peak) for determination of infarct size. Compared with rats receiving vehicle, those rats treated with GXEH (15 g/kg) showed significantly reduced infarct size, the reduced myocardial apoptosis, as judged by the decreases in TUNEL-positive staining (22.40 ± 5.68% vs. 40.31 ± 10.58%, p < 0.01), and the decrease in the degree of caspase-3 activation (82.97 ± 10.54 vs. 159.95 ± 9.16 μ mol cleaved acetylAsp-Glu-Val-Asp-p-nitroanilide/mg protein, p < 0.01). Treatment with GXEH (15 g/kg) significantly reduced the release of mitochondrial cytochrome c, a primary mediator of apoptosis, the degree of caspase-9 activation, and the Bax/Bcl-2 ratio. Caspase-9 cleaves and activates caspase-3. Bax promotes apoptosis, while Bcl-2 inhibits apoptosis. Thus, the antiapoptotic mechanisms of GXEH may involve the mitochondrial cytochrome cmediated caspase-3 activation in cardiomyocytes after acute myocardial infarction. Taken together, GXEH tilted the balance between Bax and Bcl-2 toward an antiapoptotic state, decreased mitochondrial cytochrome c release, reduced caspase-9 activation, and attenuated subsequent caspase-3 activation and postischemic myocardial apoptosis in rats. GXEH may be used as a promising agent for future treatment of cardiovascular diseases. Traditional Chinese medicine; Guan-Xin-Er-Hao; Apoptosis; Mitochondrial pathway. Tohoku

Anti-Inflammatory Effect of Guan-Xin-Er-Hao via the Nuclear Factor-Kappa B Signaling Pathway in Rats with Acute Myocardial Infarction

“…GXEH reduced 24-h infarct size (Fig. 2), indicating that GXEH has a cardioprotective effect, a result consistent with our previous studies [24,36,37]. A recent study concluded that CRP is a specific inflammatory marker of CVD [1,3], and that the serum concentration of CRP is associated with coronary events, especially AMI [10,19].…”

“…Formula extracts were prepared as previously described [36,37]. All of the herbs were purchased from West China Hospital (Chengdu, China).…”

“…The determination of infarct size was performed as previously described [36,37]. At the end of the 24-h ischemic period, Evans blue dye was injected into the aortic root to stain the normally perfused region blue and outline the area at risk (Ar).…”

“…It has been demonstrated that some TCMs have anti-inflammatory effects in CVD treatment [18,29,35]. In our previous studies, GXEH reduced infarct size by mediating lots of endogenous materials via multiple pathways to act on myocardial cells during acute myocardial infarction (AMI) in rats [12,24,36,37]. Accordingly, we speculated that GXEH might have an anti-inflammatory effect and that the anti-inflammatory effect might be one of the cardioprotective mechanisms.…”

“…Recently, it has been demonstrated that GXEH protects the heart from ischemic injury by inhibiting myocardial apoptosis [7,8,12,28,36,37], increasing coronary flow velocity [34,37] and suppressing oxidative stress [24]. However, to the best of our knowledge, no research has reported on the antiinflammatory effect of GXEH during the acute phase of myocardial infarction.…”