OBJECTIVES: We have investigated whether endoplasmic reticulum stress and Bcl-2 proteins were linked to the protective effect exerted by flavonoids on ischaemia/reperfusion-induced cardiac damage. METHODS: Cell viability and immunoblotting were performed. KEY FINDINGS: H9c2 cardiac muscle cells were exposed to flavonoids such as biochanin A, daidzein, genistein, luteolin, quercetin and rutin, followed by ischaemia 12 h/reperfusion 4 h. The flavonoids protected against cell death induced by ischaemia/reperfusion. Flavonoid treatment significantly increased the expression level of the anti-apoptotic protein, Bcl-2, but decreased that of the proapoptotic protein, Bax. The flavonoids down-regulated the expression levels of endoplasmic reticulum stress proteins, glucose-regulated protein-78, activating transcription factor 6alpha, X-box binding protein 1, inositol-requiring protein-1, phosphor-eukaryotic initiation factor 2alpha, and C/EBP-homologous protein. CONCLUSIONS: This study suggested that the protective mechanisms of flavonoids included regulation of Bcl-2/Bax proteins as well as the endoplasmic reticulum stress proteins.
OBJECTIVES: We have investigated whether endoplasmic reticulum stress and Bcl-2 proteins were linked to the protective effect exerted by flavonoids on ischaemia/reperfusion-induced cardiac damage. METHODS: Cell viability and immunoblotting were performed. KEY FINDINGS: H9c2 cardiac muscle cells were exposed to flavonoids such as biochanin A, daidzein, genistein, luteolin, quercetin and rutin, followed by ischaemia 12 h/reperfusion 4 h. The flavonoids protected against cell death induced by ischaemia/reperfusion. Flavonoid treatment significantly increased the expression level of the anti-apoptotic protein, Bcl-2, but decreased that of the proapoptotic protein, Bax. The flavonoids down-regulated the expression levels of endoplasmic reticulum stress proteins, glucose-regulated protein-78, activating transcription factor 6alpha, X-box binding protein 1, inositol-requiring protein-1, phosphor-eukaryotic initiation factor 2alpha, and C/EBP-homologous protein. CONCLUSIONS: This study suggested that the protective mechanisms of flavonoids included regulation of Bcl-2/Bax proteins as well as the endoplasmic reticulum stress proteins.