Ononin alleviates Doxorubicin-induced cardiotoxicity by inhibiting ER stress through activation of SIRT3

Abstract Introduction Doxorubicin (DOX) is a powerful anthracycline antineoplastic drug, but the clinical application of DOX is seriously limited by its dose-dependent cardiotoxicity. Ononin is a natural isoflavone glycoside and plays a key role in modulating apoptosis related signaling pathways. The aim of this study was to assess the possible cardioprotective effects of Ononin in DOX-induced cardiotoxicity and the underlying molecular mechanisms. Materials and methods Wistar rats were treated with normal saline, DOX with or without Ononin. After the last administration, cardiac function was evaluated by echocardiography. Rats were then sacrificed for histological and TUNEL analyses, with immunological detection for β-actinin, Bax, Bcl-2, GRP78, CHOP and SIRT3. An enzyme-linked immunosorbent assay was performed to assess the myocardial injury markers. H9C2 cells were treated with vehicle, DOX with or without Ononin. Then, 3-TYP was used to find out the relationship between ER stress and SIRT3. Results Ononin treatment ameliorated DOX-induced myocardial injury as demonstrated by echocardiography. Ononin partially restored DOX-induced cardiac dysfunction, both LVEF and LVFS were increased under the cotreatment of Ononin. Ononin also inhibited DOX-induced ER stress and apoptosis in rat cardiomyocytes and H9C2 cells. DOX group had a higher Bax/Bcl-2 ratio, GRP78 and CHOP expression then control group, but Ononin treatment improved these results. This effect was associated with SIRT3 activity, moreover, selective inhibition of SIRT3 blocked the protective effects of Ononin. Conclusion In the present study, we tested the hypothesis that Ononin may protect against DOX-induced cardiomyopathy through ER stress both in vitro and in vivo. Ononin is able to protect against DOX-induced cardiotoxicity by inhibiting ER stress and apoptosis, this effect may via stimulation of the SIRT3 pathway.