Abstract:

Objective To discuss the effect of curcumin on ameliorating doxorubicin （DOX）-induced cytotoxicity in the H9c2 cardiomyocytes， and to clarify its mechanism. Methods The H9c2 cardiomyocytes were treated with DOX to establish the cardiotoxicity model. The H9c2 cells were divided into normal group， DOX group， DOX+curcumin group， and DOX+curcumin+silent information regulator 3 （SIRT3） inhibitor-3 （3-TYP） group. After 24 h， the morphology of the cells in various groups were observed； CCK-8 method was used to detect the viabilities of the cells in various groups； TUNEL staining was used to detect the apoptotic rates of the cells in various groups； enzyme-linked immunosorbent assay （ELISA） method was used to detect the activities of catalase （CAT） and superoxide dismutase （SOD） and the levels of malondialdehyde （MDA） in the cells in various groups； 2，7-dichlorofluorescein diacetate（DCFH-DA） staining was used to detect the levels of reactive oxygen species （ROS） in the cells in various groups； Western blotting method was used to detect the expression levels of B-cell lymphoma 2 （Bcl-2）， Bcl-2-associated X protein （Bax）， nicotinamide adenine dinucleotide phosphate（NADPH） oxidase 2 （NOX2）， NADPH oxidase 4 （NOX4）， SIRT3， acetylated superoxide dismutase 2 （Ac-SOD2）， and superoxide dismutase 2 （SOD2） proteins in the cells in various groups. Results Compared with normal group， the H9c2 cells in DOX group exhibited swelling， the activity of the cells was decreased （P<0.05）， the CAT and SOD activities were decreased （P<0.05）， the MDA and ROS levels were increased （P<0.05）， the expression levels of NOX2， and NOX4 proteins were increased （P<0.05）， the ratio of Bcl-2/Bax and the expression level of SIRT3 protein were decreased （P<0.05）， and the expression levels of SOD2 and Ac-SOD2 proteins were increased （P<0.05）. Compared with DOX group， the H9c2 cells in DOX+curcumin group showed improved morphology， the activity of the cells was increased （P<0.05），the CAT and SOD activities were increased （P<0.05）， the MDA and ROS levels were decreased （P<0.05）， the expression levels of NOX2， and NOX4 proteins were decreased （P<0.05）， the ratio of Bcl-2/Bax and the expression level of SIRT3 protein were increased （P<0.05）， and the expression levels of SOD2 and Ac-SOD2 proteins were decreased （P<0.05）. Compared with DOX+curcumin group， the cells in DOX+curcumin+3-TYP group exhibited swelling， the activity of the cells was decreased （P<0.05）， the apoptotic rate of the cells was significantly increased （P<0.05）， the CAT and SOD activities were decreased （P<0.05）， the MDA and ROS levels were significantly increased （P<0.05）， the expression levels of NOX2 and NOX4 proteins were increased （P<0.05）， the ratio of Bcl-2/Bax and the expression level of SIRT3 protein were decreased （P<0.05）， and the expression levels of SOD2 and Ac-SOD2 proteins were increased （P<0.05）. Conclusion Curcumin suppresses the oxidative stress and apoptosis by activating the SIRT3/SOD2 signaling pathway， improving the cell activity and alleviating the DOX-induced cytotoxicity in the H9c2 cells.

Key words: Curcumin, Doxorubicin, Silent information regulator 3, Oxidative stress, Cardiotoxicity