LPO and myocardial infarction: In anaesthetized open-chest dogs treated with American ginseng leaf extract, the myocardial infarct size, activity of serum creatine kinase (CK), lactate dehydrogenase (LDH), the contents of serum free fatty acid (FFA) and lactoperoxidase (LPO) significantly decreased, whereas the activity of serum superoxide dismutase (SOD) and Gtutathione peroxidase (GSH-Px) significantly increased.