Abstract: Objective To explore the efficacy and mechanism of exogenous reduced glutathione(GSH)on cardiotoxicity induced by epirubicin(EPI).Methods 60 postoperative patients with breast cancer were randomly divided into the treatment group and control group with 30 cases in each group.The treatment group received 6 cycles of chemotherapy with CEF regimen plus the reduced GSH.The control group also received 6 cycles of chemotherapy only with CEF alone.The cardiotoxicity of all patients were estimated by the ECG,myocardial enzymes,troponin Ⅰ(cTnⅠ),ultrasoundcardiogram and tissue Doppler technique before hemotherapy and after 3 cycles and 6 cycles of chemotherapy.Results After 3 cycles of chemotherapy,there were no significant differences in ECG,cTnⅠ,left ventricle ejection fraction(EF),fraction shortening(FS),E/A,decline time(DT)and myocardial creatine kinase(CK),isoenzyme of creatine kinase containing M and B subunits(CK-MB),lactate dehydrogenase(LDH)between two groups(P>0.05);While,there was a significant difference in Em/Am between two groups(P<0.01).After 6 cycles of chemotherapy,there were also no significant differences in EF,FS,myocardial CK,CK-MB,LDH between two groups(P>0.05);there were significant differences in ECG,cTnI,E/A,DT and Em/Am between two groups(P<0.01).Conclusion The reduced GSH can prevent the cardiotoxicicy induced by EPI,which may be related with the ability of GSH against the oxidant injury and inhibiting calcium overload.

Key words: reduced glutathione, epirubicin, cardiotoxicity, prophylactic effect