Ginsenoside Rb1 protects cardiomyocytes against CoCl2-induced apoptosis in neonatal rats by inhibiting mitochondria permeability transition pore opening

Abstract

Aim: To investigate whether mitochondria permeability transition pore (mPTP) opening was involved in ginsenoside Rb1 (Gs-Rb1) induced anti-hypoxia effects in neonatal rat cardiomyocytes ex vivo. Methods: Cardiomyocytes were randomly divided into 7 groups: control group, hypoxia group (500 µmol/L CoCl 2 ), Gs-Rb1 200 µmol/L group (CoCl 2 intervention+Gs-Rb1), wortmannin (PI3K inhibitor) 0.5 µmol/L group, wortmannin+Gs-Rb1 group, adenine 9-β-Darabinofuranoside (Ara A, AMPK inhibitor) 500 µmol/L group, and Ara A and Gs-Rb1 group. Apoptosis rate was determined by using flow cytometry. The opening of the transient mPTP was assessed by using co-loading with calcein AM and CoCl 2 in high conductance mode. Expression of GSK-3β, cytochrome c, caspase-3 and poly (ADP-ribose) polymerase (PARP) was measured by using Western blotting. ΔGSK-3β was defined as the ratio of p-Ser9-GSK-3β to total GSK-3β. Results: CoCl 2 significantly stimulated mPTP opening and up-regulated the level of ΔGSK-3β. There was a statistically significant positive correlation between apoptosis rate and mPTP opening, between apoptosis rate and ΔGSK-3β, and between mPTP opening and ΔGSK-3β. Gs-Rb1 significantly inhibited mPTP opening induced by hypoxia (41.3%±2.0%, P<0.001) . Gs-Rb1 caused a 77.3%±3.2% reduction in the expression of GSK-3β protein (P<0.001) and a significant increase of 1.182±0.007-fold (P=0.0001) in p-Ser9-GSK-3β compared with control group. Wortmannin and Ara A significantly inhibited the effect of Gs-Rb1 on mPTP opening and ΔGSK-3β. Gs-Rb1 significantly decreased expression of cytochrome c (66.1%±1.7%, P=0.001), caspase-3 (56.5%±2.7%, P=0.001) and cleaved poly ADP-ribose polymerase (PARP) (57.9%±1.4%, P=0.001). Conclusion: Gs-Rb1 exerted anti-hypoxia effect on neonatal rat cardiomyocytes by inhibiting GSK-3β-mediated mPTP opening.

Ginsenoside Rb1 Attenuates Agonist-Induced Contractile Response via Inhibition of Store-Operated Calcium Entry in Pulmonary Arteries of Normal and Pulmonary Hypertensive Rats

“…Ginsenoside Rb1 has been shown to attenuate cellular hypertrophy, apoptosis and oxidative injury of cardiomyocytes [16,17,18,19,20]; and protect against ischemic-reperfusion injury [21,22], dilated cardiomyopathy [23] and right heart hypertrophy [24]. It exerts these cardioprotective effects through different mechanisms, for example by reducing [Ca 2+ ] i , enhancing the expression of eNOS and increasing nitric oxide production, attenuating reactive oxygen species and inhibiting the Ca 2+ -calcineurin signal transduction pathway in cardiac myocytes [17,20,21,24,39].…”

“…Previous studies have demonstrated that ginsenoside Rb1 promotes endothelial nitric oxide production [10], suppresses intimal hyperplasia after vascular injury [11,12,13], protects against endothelial dysfunction [14] and inhibits inflammatory responses in vascular smooth muscle cells [15]. It also suppresses apoptosis and oxidative injury of cardiomyocytes [16,17,18,19,20]; and protect against ischemic-reperfusion injury [21,22], dilated cardiomyopathy [23] and cardiac hypertrophy [24]. A previous study showed that ginsenoside Rb1 can suppress and reverse the development of right heart hypertrophy in monocrotaline (MCT)-treated rats, and the finding was explained by an inhibitory effect of ginsengoside Rb1 on the calcineurin-NFAT signaling pathway in cardiomyocytes [24].…”

Plants and Their Bioactive Compounds with the Potential to Enhance Mechanisms of Inherited Cardiac Regeneration

“…Consistent with these findings, it was reported that Rg1 could reduce apoptosis of cultured H9c2 cardiomyocytes [64] and dose-dependently increase cell viability in a cardiomyocyte hypoxia/reoxygenation model [65]. Rb1, another major ginsenoside isolated from ginseng, also showed a protective effect of cardiomyocytes from apoptosis [66][67][68]. Some studies indicated that the PKA signaling pathway and caspase-9 pathway might be involved in an Rb1-mediated antiapoptotic effect [69].…”

Compound K, a metabolite of ginsenosides, induces cardiac protection mediated nitric oxide via Akt/PI3K pathway

“…They suggested that the apoptotic effect of ginsenoside Rb1 might occur by improving glucose uptake. In addition, their recent report showed that the inhibition of PI3K and glycogen synthase kinase 3 beta (GSK-3β) mediated mPTP opening plays a role for the anti-hypoxia effect of ginsenoside Rb1 on neonatal rat cardiomyocytes (Kong et al, 2010). However, no previous studies have described a role for the major metabolite of ginsenosides, C-K, in cardiac protection.…”

“…Mitochondria play a central role in molecular events, leading to tissue damage after pathological situations such as ischemia. The mPTP is a complex found at the contact sites between the inner and outer mitochondrial membranes (Kong et al, 2010;Morin et al, 2009). Under conditions like oxidative stress, high Ca 2+ and low ATP, a number of proteins including BAX and Bad are recruited that enable pore formation at its high conductance state Reed and Kroemer, 2000).…”