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

• Published in: Acta pharmacologica Sinica no. 6; pp. 687 - 695
• Main Author: Hong-liang KONG Zhan-quan LI Ying-jun ZHAO Shu-mei ZHAO Li ZHU Tong LI Yao FU Hui-jun LI
• Format: Journal Article
• Language: English
• Published: 2010
• Subjects: PNS; 人参皂甙; 心肌细胞凋亡; 新生大鼠; 氯化钴; 线粒体; 通透性
• ISSN: 1671-4083; 1745-7254

Aim： To investigate whether mitochondria permeability transition pore （mPTP） opening was involved in ginsenoside Rbl （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 CoCl2）, Gs-Rbl 200 μmol/L group （CoCl2 intervention＋Gs-Rbl）, wortmannin （PI3K inhibitor） 0.5 μmol/L group, wortmannin＋Gs-Rbl group, adenine 9-β-D- arabinofuranoside （Ara A, AMPK inhibitor） 500 μmol/L group, and Ara A and Gs-Rbl 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 CoCl2 in high conductance mode. Expression of GSK-3β, cytochrome c, caspase-3 and poly （ADP-ribose） polymerase （PARP） was measured by using Western blotting. △GSK-3β was defined as the ratio of p-Ser9-GSK-3β to total GSK-3β. Results： CoCl2 significantly stimulated mPTP opening and up-regulated the level of AGSK-3β. There was a statistically significant positive correlation between apoptosis rate and mPTP opening, between apoptosis rate and AGSK-3β, and between mPTP opening and AGSK-3β. Gs-Rbl significantly inhibited mPTP opening induced by hypoxia （41.3%±2.0%, P〈0.001）. Gs-Rbl 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-Rbl on mPTP opening and AGSK-3β. Gs-Rbl 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-Rbl exerted anti-hypoxia effect on neonatal rat cardiomyocytes by inhibiting GSK-3β-mediated mPTP opening.