Objective: To investigate the cardio-protective effects of Corocalm on acute myocardial ischemia in rats

and to explore its possible therapeutic mechanisms.Methods: The acute ischemic model was prepared by ligating the left anterior descending (LAD) coronary artery in rats. The animals were divided into 6 groups

8 in each group. The sham operated group underwent heart exposure without ligation and were treated with normal saline 3 ml/kg

while the other 5 groups

the model groups

consisted of acceptable acute ischemic model rats and were also treated with normal saline

with the Guanxin Capsule (GXC) group treated with refined GXC

600 mg/kg

the low and high dose Corocalm groups treated with 85 mg/kg and 340 mg/kg of Corocalm respectively

and the Diltiazem group

treated with Diltiazem 5 mg/kg

with all the tested drugs prepared with normal saline into equal volume (3 ml/kg) and administrated once via duodenum 10 min before ligation. Myocardial infarction area was determined by the quantitative histological assay with nitroblue tetrazolium (N-BT) stain. And the levels of creatine phosphokinase (CK)

lactate dehydrogenase (LDH)

malondialdehyde (MDA) content

and the activity of superoxide dismutase (SOD) in serum were measured by biochemical assay and spectrophotometry respectively. Besides

the blood viscosity in another 50 rats was determined

who received for 7 successive days oral administration with different concentration of Corocalm or aspirin.Results: It showed that low and high dose Corocalm could significantly reduce the infarction area

inhibit the increase of serum CK

LDH activity and MDA content

and enhance the SOD activity after ischemia/reperfusion. The whole blood viscosity at different shear rates in rats treated with high dose Corocalm was significantly lower than those treated with normal saline (P < 0.05).Conclusion: Corocalm has favourable protective effects on heart in ischemic condition

the effect of which might be through its actions in inhibiting CK and LDH activity

scavenging oxygen free radicals

and lowering blood viscosity.