Flavonoids from Chinese Viscum coloratum produce cytoprotective effects against ischemic myocardial injuries: inhibitory effect of flavonoids on PAF‐Induced Ca²⁺ overload

Abstract

Viscum coloratum has been used in the indigenous system of medicine for the treatment of various diseases such as myocardial ischemia and arrhythmia. Platelet-activating factor (PAF) is an important player in cardiovascular diseases. The aim of this study was to investigate the protective effects of Viscum coloratum flavonoids (VCF) against ischemic myocardial injuries in vivo and to further investigate its regulatory effect on PAF. Studies were performed in a rat model of myocardial infarction and in isolated myocytes. It was found that VCF relieved myocardial injuries during ischemia. PAF (10 −11 M) significantly increased the intracellular free Ca 2+ concentration ([Ca 2+ ] i ) and VCF inhibited the changes induced by PAF in single cardiac myocytes. The results suggest that VCF can improve cardiac function and that VCF reduces ischemic myocardial injuries via blocking the signaling pathway of PAF. Therefore, PAF blockers may be candidate drugs for preventing cardiac injuries during ischemia/reperfusion, and subsequently improving cardiac function.

PAF exerts a direct apoptotic effect on the rat H9c2 cardiomyocytes in Ca2+-dependent manner

“…Unfortunately, the effect of PAF on apoptosis in cardiac myocytes has not been elucidated yet. We also recently found that PAF could induce [Ca 2+ ] i overload in the cardiac myocytes of guinea pig [18,19]. These observations promoted us to investigate whether PAF could induce apoptosis of cardiac myocytes through a Ca 2+ -dependent mechanism.…”

Protective effects of steroids from Allium chinense against H2O2‐induced oxidative stress in rat cardiac H9C2 cells

“…•− through Fenton reactions, contributing to a series of pathological events characterized by reduction of the activities of antioxidant enzymes (Túnez et al, 2006;Valentão et al, 2004), lipid peroxidation (Jung et al, 2007;Palmer et al, 1988;Yang et al, 2007), induction of mitochondrial permeability transition (MPT) (Akao et al, 2003;Vercesi et al, 1997), Ca 2+ overload (Chu et al, 2008;Gen et al, 2001;Schomig et al, 1984), necrosis and apoptosis (Aikawa et al, 2002;Kuramochi et al, 2004).…”

Rosa rugosa flavonoids alleviate myocardial ischemia reperfusion injury in mice by suppressing JNK and p38 MAPK

“…Eighty mice were divided into four groups: sham + phosphate‐buffered saline (PBS) group, MIRI + PBS group, MIRI + CDDP (166 mg/kg, positive drug control), MIRI + RRF (600 mg/kg, determined according to the content of flavonoids). The mice received intragastric administration of PBS, CDDP, or RRF for 7 days ahead, and the MIRI surgery was then performed as described in the literature .…”

“…Signals were detected at a wavelength of 360 nm and with a flow rate of 0.8 mL/min. 14 ). The mice received intragastric administration of PBS, CDDP, or RRF for 7 days ahead, and the MIRI surgery was then performed as described in the literature.…”