Protective effects of Andrographis paniculata Nees on post-infarction myocardium in experimental dogs

Summary

One hour after the development of myocardial infarction by formation of thrombus, watery extract of Andrographis paniculata Nees (APN) was injected intravenously to 7 dogs for observing the protective effect of this drug on ischemic myocardium. 6 dogs served as control group. In the treated group PGI₂ increased remarkably, synthesis of TXA₂ was inhibited, cAMP in platelets was elevated, CK-MB peak was lowered and appeared earlier, ELT was shortened, release of platelet ß-GT was decreased, platelet maximum aggregation rate was inhibited, the size of ischemie area recorded by epicardial ECG was reduced, the amplitude of ST segment elevation was lower than that in the control group, Q wave appeared in only one dog. Pathologically, the myocardial structure surrounding the initially appearing ischemie area, i.e., the reversiblely damaged area, became relatively normal, while the degree of myocardial degeneration and necrosis in the central part of the ischemie area was mild. These data suggest that APN may limit the expansion of ischemie focus, exert marked protective effect on reversibly ischemie myocardium and demonstrate a weak fibrinolytic action.