Low concentration of rutin treatment might alleviate the cardiotoxicity effect of pirarubicin on cardiomyocytes via activation of PI3K/AKT/mTOR signaling pathway

Cancer is the leading cause of deaths around the world, especially in low- and middle- income countries. Pirarubicin (THP) is an effective drug for treatment of cancer, however, there still exists cardiotoxic effects of THP. Rutin is a kind of antioxidative compound extracted from plants, and might be a protective compound for cardiomyocytes. Phosphatidylinositol 3-hydroxy kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway is critical for cellular survival, proliferation and metabolism, and thus we speculated rutin might perform a protective role in cardiomyocytes via PI3K/AKT/mTOR signaling pathway. And in this experiment, we first established a cardiotoxicity model of THP in mice model and cell models, and then found that rutin treatment could increase the proliferation of cells at low concentration. Then we explored the possible mechanism of the protective effect of rutin using Western blotting, quantitative polymerase chain reaction (qPCR) and ELISA methods, and found that the activation of PI3K/AKT/mTOR/nuclear factor-κB (NF-κB) signaling pathway was increased, and expression of downstream molecules involved in antioxidative stress were also increased. We further noticed that concentration of angiogenesis promoting factors were also increased in medium of cultured cells. Thus, we speculated that rutin could increase the activation of PI3K/AKT/mTOR signaling pathway, further decrease the oxidative stress level via increasing the expression of antioxidative stress enzymes with the increasing concentration of angiogenesis promoting factors, resulting in the protective role in cardiomyocytes and cardiac function.