PMID:
Circ J. 2019 Jul 25 ;83(8):1726-1736. Epub 2019 Jun 20. PMID: 31217391
Abstract Title:
Withaferin A Prevents Myocardial Ischemia/Reperfusion Injury by Upregulating AMP-Activated Protein Kinase-Dependent B-Cell Lymphoma2 Signaling.
Abstract:
BACKGROUND: Withaferin A (WFA), an anticancer constituent of the plant Withania somnifera, inhibits tumor growth in association with apoptosis induction. However, the potential role of WFA in the cardiovascular system is little-studied and controversial.Methods and Results:Two different doses of WFA were tested to determine their cardioprotective effects in myocardial ischemia/reperfusion (MI/R) injury through evaluation of cardiofunction in wild-type and AMP-activated protein kinase domain negative (AMPK-DN) gentransgenic mice. Surprisingly, cardioprotective effects (improved cardiac function and reduced infarct size) were observed with low-dose WFA (1 mg/kg) delivery but not high-dose (5 mg/kg). Mechanistically, low-dose WFA attenuated myocardial apoptosis. It decreased MI/R-induced activation of caspase 9, the indicator of the intrinsic mitochondrial pathway, but not caspase 8. It also upregulated the level of AMP-activated protein kinase (AMPK) phosphorylation and increased the MI/R inhibited ratio of Bcl2/Bax. In AMPK-deficient mice, WFA did not ameliorate MI/R-induced cardiac dysfunction, attenuate infarct size, or restore the Bcl2/Bax (B-cell lymphoma2/Mcl-2-like protein 4) ratio.CONCLUSIONS: These results demonstrated for the first time that low-dose WFA is cardioprotective via upregulation of the anti-apoptotic mitochondrial pathway in an AMPK-dependent manner.
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