Protective effects of API0134 on myocardial ischemia and reperfusion injury.

Previous studies have demonstrated that a crude extract from Chinese medicinal herb Andrographis Paniculata Nees (APN) could prevent myocardial ischemia and reperfusion injury. A refined extract API0134 was studied further. LAD was ligated for 90 min in 20 dogs and then reperfused for 120 min. The animals were randomly divided into 2 groups, API0134 treated group (n = 10), 45 min after ischemia receiving a slow i.v. bolus of 1 mg/kg and then an infusion of 80 micrograms.kg-1/min for 60 min and control group (n = 10) which was given only 5% glucose in saline. Result showed that the hemodynamics in API0134 treated group showed better effects of preventing the increase of the LVEDP and maintaining relatively normal CO as compared with control group. Ischemic ECGs were significantly milder. Malignant arrhythmia did not appear in API0134 treated group. After reperfusion, the infarct size was smaller (5.06 +/- 2.67% vs 10.45 +/- 3.11%, P < 0.01), the damages found in myocardial ultrastructure were significantly milder. It is concluded that API0134 may protect the myocardium from ischemic reperfusion injury.