DiOHF Protects Against And Reverses Doxorubicin-induced Cardiotoxicity By The ERK1/2 Signaling Pathway

Background Doxorubicin(DOX)is an anthracycline antibiotic with antitumor activity,which is used as a first-line drug in numerous types of cancer.Similar to any other chemotherapeutic agents,DOX presents several adverse effects that limit its clinical use,including cardiotoxicity,reversible alopecia,hyperpigmentation of nailbeds and so on.3',4'-dihydroxyflavonol(DiOHF)is a recently developed potent synthetic flavonoid which has been reported to protect against myocardial ischemiareperfusion injury.However,whether DiOHF has an effect on DOX-induced cardiotoxicity remains unknown.Objective To explore the effects of DiOHF on DOX-induced cardiotoxicity and the underlying mechanisms.Methods H9C2 cells were divided into the following groups(i)control group;(ii)DOX(1 ?M)treatment group,(iii)DiOHF(10 ?M)treatment group,(iv)DiOHF + DOX group(the cells were pretreated with DiOHF for 2 h before co-incubating with DiOHF and DOX for 24 h),and(v)DOX + DiOHF group(the cells were treated with DOX for 2 h before co-incubating with DiOHF and DOX for 22 h).Cell viability,level of ROS,mitochondrial membrane potential(MMP),apoptosis and related protein(cleaved-caspase3,bid,bcl-2)were detected.The protein level of ERK1/2 and pERK1/2 were also detected by Western Blotting.Tansfected with Scr-si RNA/ERK1-si RNA/ERK2-si RNA,H9C2 cells were divided into the following groups(i)control group,(ii)DOX treatment group,(iii)DiOHF group,and(iv)DiOHF+DOX group.Cell viability,MMP,apoptosis and related protein were detected.Female balb/c mice were randomly divided into four groups(i)control group,(ii)DOX treatment group,(iii)DiOHF group,and(iv)DiOHF+DOX group.DOX(20 mg/kg)were administered by intraperitoneal injection in balb/c mice to establish DOX-induced cardiotoxicity models.The mortality and the body weight of mice was recorded;serum CK-MB,ALT and urea levels were tested by ELISA.Transthoracic echocardiography was conducted to assess the cardiac function.Then,mice were sacrified and masson-trichrome stain was performed to observe the fibrosis of the heart.Results(1)Compared with the control,DOX treatment significantly increased the ROS level,apoptosis rate and decreased the cell viability,MMP(p<0.05).DiOHF pre/post-treatment could alleviate and reverse these changes(p<0.05).(2)Western blotting showed that the protective effect of DiOHF was accompanied by increased ERK1/2 activation and abolished by the silence of ERK1,rather than ERK2.(3)Compared with the control,mice received DOX treatment manifested weakness,lethargy,lost weight and even died.The serum levels of CK-MB were also increased after DOX treatment.Besides,DOX administration impaired cardiac function significantly and masson staining showed an apparently increase of fibrosis.These changes were diminished by DiOHF administration.(4)DiOHF treatment did not affect the serum ALT and urea levels when compared with the control mice.Conclusion DiOHF suppresses and reverses the DOX-induced cardiotoxicity through activation of the ERK1/2 signaling.