Objective: To investigate the effect of panax notogin seng (PNS) on the expression of miRNA-466b and its apoptosis related proteins in myocardial cells of acute myocardial infarction (AMI) animal model

and to explore the post transcriptional molecular mechanism of the anti-apoptosis effect of PNS. Method: The 36 male wistar rats were randomly divided into 3 groups:sham operation group

model group

and PNS group. Coronary ligation of left anterior descending branch was done to establish acute myocardial infarction (AMI) models. PNS group rats were intramuscularly injected with PNS (1.429 mg·g-1) respectively on 4 h before AMI

1 day and 2 days after AMI. TUNEL

RT-PCR and Western blot methods were used to observe the apoptosis of myocardial tissue in rats

and detect the expression of miRNA-466b

Caspase-3

Caspase-9 and Bcl2L13 genes and proteins. Result: Compared with model group

PNS treatment group could significantly reduce infarction area and apoptosis of myocardial cells (P<0.05)

and there was no difference in miRNA-466b expression level between model group and sham operation group

while miRNA-466b in PNS group was significantly up-regulated

with significant difference with model group (P<0.01). Compared with sham operation group

the expression of Caspase-3 mRNA and protein in model group was significantly increased (P<0.05)

and PNS can significantly down-regulate it (P<0.05

P<0.01)

and changes in expression of Bcl2L13 and Caspase-9 mRNA and protein were not evident in model group

while PNS can significantly down-regulate the expression of these two indicators (P<0.05

P<0.01). Conclusion: PNS plays a key role in the protection of myocardial cells in rats with AMI

probably by up-regulating miRNA-466b

down-regulating Bcl2L13

Caspase-3 and Caspase-9 protein expression to inhibit cell apoptosis.