Objective To evaluate the effect of Guanxinping Tablets（Tablets for coronary heart disease） on vascular endothelial cell（VEC） apoptosis induced by hydrogen peroxide（H

2

O

2

） and its mechanism.Methods Fifteen New Zealand rabbits were randomized into normal group

Verapamil group

Guanxinping small-dose

medium-dose

and large-dose groups

with 3 in each.They were administered normal saline

Verapamil 0.02g/kg

Guanxinping 2.8g/kg

5.6g/kg

and 11.2g/kg respectively.The medicines were melted with distilled water and given through intragastric feeding

10ml/kg

once a day

for 3 days in succession.One hour after the last time feeding

the venous blood was obtained from the vein of ear of rabbits for preparing medicine-containing serum.The H

2

O

2

at 100μmol/L in concentration was incubated in VEC in logarithmic growth phase to make the models with cell apoptosis injury.Meanwhile

Guangxinping medicine-containing serum was administered in different doses for intervention.After treatment

the cells were collected.The apoptosis rate of VEC was detected by flow cytometry.The bax and bcl-2 protein expressions were detected by immunocytochemistry.The content ratio of bax/bcl-2mRNA was detected by RT-PCR.Results Compared with the model group

the apoptosis rate in the Guanxinping large-dose and medium-dose group and Verapamil group was significantly lowered（P

<

0.05 or P

<

0.01）

the faciodensity of bax and the averaged faciodensity of bax/bcl-2 in the Verapamil group

Guanxinping small-dose

medium-dose

and large-dose group were significantly lowered（P

<

0.05）

the faciodensity of bcl-2 was significantly increased（P

<

0.05 or P

<

0.01）

and the bax/bcl-2 in the Guanxinping medium-dose and large-dose groups was lowered（P

<

0.05 or P

<

0.01）.Conclusion Guanxinping medicine-containing serum can resist the VEC apoptosis induced by H

2

O

2

and its possible mechanism is related with the regulation of the expression of apoptosis genes

bax and bcl-2.