The Protective Effect Of BN52021in Doxorubicin Induced Carditoxicity And Its Related Mechanisms

Doxrubicin is a well-established and highly effetive agent in cancer treatment.It is used to treat several different type of cancers, however adverse events will alsobe caused by doxorubicin, cardiotoxicity is one of the most severe condition, whichlead to the restriction use of doxorubicin. During the past few years, progresses havebeen made on doxorubicin induced cardiotoxicity, however, the mechanism has notyet full elucidated. Moreover, there is no effective therapy on cardiotoxicity has beenproposed. BN52021is active constitute extracted from the Ginkgo biloba leavies.Previous studies have been shown that BN52021exerted an effect on the activity ofplatelet activator factor and possesses protective role in multiple disease. However,whether it is effective in cardiotoxicity has not been explored yet. Here, wehypothesized that BN52021exerted a protective role in cardiotoxicity. Therefore, weexamined the protective effect of BN52021by using the in vivo mouse model and invitro cell model and explored the related mechanisms.Objective:To explore and establish a mouse model of cardiotoxicity with high efficacy.Toexplore the protective effect of BN52021in above established mouse model ofcardiotoxicity. To explore the mechanism onf protective effect of BN52021in an invitro cardiomyocyte model.Methods:Doxorubicin (15mg/kg) was adminstrated by intraperitoneal injection to inducethe cardiotoxicity model. BN52021was delivered by gavage for5day and once perday. The weight and survival of mice were recorded. The pathological section wasmade to analyze the hisological change. The serum level of lactate (LDH) andcreatine kinase (CK) were measured and the GSH and MDA level in cardiomyocytes were also detected by biochemical method. Doxorubicin with different concentrationwas used to treat the mouse cardiomyocytes H9c2. MTT was employed to evaluatethe cell viability; TUNEL staining was used to analyze the cell apoptosis; JC-1fluroresence staining was used to detect themitochondrial membrane potential(MMP); DCFH-DA fluroresence probe was employed to detect reactive oxygenspices (ROS); Western-blot was used to analyze the apoptotic protein (Caspase-3,Cytochrome c) level; Fluo-3AMfluroresence probe was used to detect the calciumlevel in cardiomyocytes. Western-blot was also employed to analyze the effect ofMAPK signaling pathway protein p38phosphorylation in the doxorubicin inducedcardiomyocytes toxicity. p38inhibitor SB203580and calcium antagonistBATPA/AM were employed to verify the effect of p38signaling and calciumsignaling in the carditotoxicity.Results:Compared to control mice, significant decreased on mice weight was observedin doxorubicin treated mice while no significant change was found in cardiac index.We also observed a decreased survival rate in doxorubicin-induced mice. Seven dayafter doxorubicin treatment, a significant increased level of LDH and CK was foundin the mice serum. Moreover, we also detected a significant increased level of GSHand MDA in doxorubicin treated mice. Compared to doxorubicin treated mice,increased mice weight and cardiac index were observed, but no significant changewas found. We also observed a increased survival rate in BN52021treated mice thandoxorubicin treated mice. Seven day after doxorubicin treatment, a significantdecreased level of LDH and CK was found in the mice treated by BN52021.Moreover, we also detected a significant decreased level of GSH and MDA inBN52021treated mice. Reduced phosphorylation was found after the treatment ofBN52021and the use of the p38inhibitor SB203580and calcium antagonistBATPA/AM showed a similar effect as BN52021pretreatment.Conclusion:Intraperitoneal injection adminstration of doxorubicin at a dose of15mg/kgwas enough to induce cardiotoxicity in mice. BN52021treatment increase thesurvival rate of cardiotoxicity mice, indicating it exerted a protective effect on cardiotoxicity. BN52021treatment could protect cardiomytes from cardiotxocitythrough increasing cell viability, decreasing cell apoptosis, increasing MMPs,decreasing ROS, apoptotic protein level and inhibition of calcium level elevation incardiomyocytes.