ABSTRACT
To investigate the effects of saponins extracted from Panax japonicus(SPJ) on cardiomyocyte apoptosis in natural aging rats and explore its underlying mechanisms. SD male rats were randomly divided into four groups: young control group, natural aging group, SPJ low dose group and SPJ high dose group, with 10 rats in each group. The rats in natural aging group, SPJ low and high dose groups were respectively treated with normal saline, SPJ 10 and 60 mg•kg-1•d-1 from the beginning of 18 month-old, 6 days per week for 6 months till 24 month-old. Then the animals were sacrificed. Their myocardial morphology changes were observed by using haematoxylin-eoin(HE) staining; cardiomyocyte apoptosis was tested by using Tunel assays; and the protein expression levels of Bcl-2, Bax, IL-1β, TNF-α, AMPK, p-AMPK, Sirt1, and Ac-NF-κB p65 in myocardial tissues of rats were detected by Western blot. The results showed that SPJ could effectively improve the arrangement disorder of myocardial fibers, reduce the infiltration of inflammatory cells and inhibit cardiomyocyte apoptosis in natural aging rats. At the same time, SPJ could significantly inhibit the protein expression of Bax, IL-1β, TNF-α and Ac-NF-κB p65, and increase the expression of Bcl-2, Bcl-2/Bax, p-AMPK/AMPK and Sirt1 in the heart tissues of natural aging rats. SPJ can effectively inhibit cardiomyocyte apoptosis in natural aging rats, and its mechanisms may be related with the regulation of inflammatory reaction by AMPK/Sirt1/NF-κB signaling pathway.