Objective

2

To explore the possible mechanism of

Huanglian Ejiao Decoction

（黄连阿胶汤， HED） for heart failure.

Methods

2

Seventy-eight SD rats were randomly divided into a blank group （n=13） and modeling group （n=65）. The rats in the modeling group were intraperitoneally injected with adriamycin to establish the heart failure model. The 56 successfully modeled rats were randomly divided into a model group， a positive drug group and a HED high dose and a medium dose groups， with 14 rats in each group. Rats in the HED high dose and medium dose groups were treated with 1.96 and 3.92 g/（kg·d） of HED granule by gavage， respectively； the rats in the positive drug group were treated with 2.25 mg/（kg·d） of metoprolol tartrate tablets and 1.80 mg/（kg·d） of enalapril maleate tablets by gavage， while those in the blank group and model group were given 10 ml/（kg·d） of distilled water by gavage. After three weeks of intragastric administration， Doppler echocardiography was performed to detect the cardiac function indicators including left ventricular ejection fraction （LVEF）， left ventricular fractional shortening （LVFS）， left ventricular internal diameter in systole （LVIDs）， left ventricular internal diameter in diastole （LVIDd）， left ventricular volume in diastole （LVVOLd）， left ventricular volume in systole （LVVOLs）， left ventricular posterior wall thickness in diastole （LVPWd）， and left ventricular posterior wall thickness in systole （LVPWs）. The concentration of norepinephrine （NE）， epinephrine （E）， isoproterenol （ISO）， and angiotensin Ⅱ （AngⅡ） in the blood were assessed； the content of reactive oxygen species （ROS） in myocardial tissue and the concentration of Ca

2+

in cardiomyocytes， as well as the expression of calmodulin-dependent protein kinase Ⅱ （CaMKⅡ），oxidized CaMKⅡ （ox-CaMKⅡ） and phosphorylated CaMKⅡ （p-CaMKⅡ） in the myocardial tissue were detected. Hematoxylin eosin （HE） staining was used to observe the myocardial tissue and cell morphology.

Results

2

Compared to those in the blank group，the cardiac function indicators including LVIDd， LVVOLd， LVEF， LVFS and LVPWs as well as the blood concentration of NE， E and ISO in the model group were significantly lowered； the blood AngⅡ concentration， the ROS content in myocardial tissue and the Ca

2+

concentration in myocardial cells significantly increased （

P

＜0.05 or

P

＜0.01）.Compared to those in the model group， the LVIDs and LVVOLs in the HED high dose group significantly decreased， while the LVPWs， LVEF and LVFS increased； the LVIDs in the HED medium dose group significantly decreased； the blood NE， E and ISO concentration in the both HED high and medium dose groups significantly increased， while the AngⅡ concentration， the content of ROS in myocardial tissue and the concentration of Ca

2+

in myocardial cells were significantly reduced （

P

＜0.05 or

P

＜0.01）. There were no significant differences in the cardiac function indicators

the ROS content in myocardial tissue and the Ca

2+

concentration in myocardial cells between the positive drug group and HED high dose group (

P

＞0.05); compared to those in the positive drug group

the LVIDS and LVVOLs levels

and blood AngⅡ concentration in the HED medium dose group increased

while the LVPWs and LVFS levels decreased (

P

＜0.05). Compared to those in the HED high dose group

the LVIDS and LVVOLs levels

the ROS content in myocardial tissue and the Ca

2+

concentration in myocardial cells in the medium dose group increased

and the LVPWd

LVPWs

LVEF

and LVFS levels significantly decreased (

P

＜0.05 or

P

＜0.01). There were no significant differences between groups in the protein expression of CaMKⅡ， ox-CaMKⅡ and p-CaMKⅡ in myocardial tissue （

P

＞0.05）. HE staining results showed that in the model group， the myocardium arrangement was disordered； stripes disappeared； the cytoplasm of cardiomyocytes were uneven and extensively swelling with cavitation seen. In the HED high and medium dose groups， the cardiomyocytes damage was reduced； the cytoplasmic uniformity and swelling were improved； and the cavitation was reduced.

Conclusion

2

HED can improve cardiac function and reduce myocardial damage in adriamycin-induced heart failure rats. The mechanism may be related to reducing blood AngⅡ concentration and ROS production， promoting the release of NE， E and ISO， and reducing Ca

2+

concentration of cardiomyocytes， thereby reducing cardiac afterload， reducing myocardial oxidation， enhancing myocardial contractility and inhibiting calcium overload.