Cytoprotective effect of atmospheric pressure helium plasma on oxygen and glucose deprivation-induced cell death in H9C2 cardiac myoblasts and primary neonatal rat cardiomyocytes

Atmospheric pressure plasma jet (APPJ) has shown excellent potential prospects in biomedical applications, based on the production of reactive oxygen species and reactive nitrogen species (RNS) from APPJ emissions. The current research focused on the protective effect of APPJ on oxygen and glucose deprivation (OGD)-induced cell death in both the H9C2 cardiac myoblast cell line, a frequently used cardiac cell line in cardioprotective studies, and primary neonatal rat cardiomyocytes (NRCMs). Cells were treated with APPJ for different durations, cultured for 6 h and then subjected to OGD for 18 h before their use in assays. We found that APPJ treatment could maintain H9C2 cell viability and reduce cell apoptosis in a dose-dependent manner in cells subjected to the OGD conditions. To confirm the cardioprotective effect of APPJ on primary NRCM, we first identified the 'safe dose' of APPJ treatment by evaluating the cytotoxicity of APPJ on primary NRCMs in normal culture conditions. Under the 'safe dose' of APPJ treatment, we also found that the APPJ treatment could maintain NRCM viability under OGD conditions and reduce CK-MB and cTnI release from cardiomyocytes. Further studies revealed that the cytoprotective effect of APPJ may be related to NO production induced by APPJ treatment. Our results gave the first evidence of the cardiotoxicity and cytoprotective effect of APPJ on cardiomyocytes against OGD injury, and furthermore, contributed to new insights into the potential medical applications of plasma in cardiovascular diseases.