cardioprotective effects of methanolic extract of scrophularia frigida on ischemia-reperfusion-induced injuries in isolated rat heart

myocardial infarction is a common presentation of coronary artery disease and the leading cause of death worldwide. the present study was investigated potential resistance to ischemia-reperfusion (i/r) injuries following administration of methanolic (meoh) extract of scrophularia frigida (s. frigida) in isolated rat heart. male wistar rat hearts (n= 8-10) were isolated and allowed to equilibrate for 20 min, and then subjected to 30 min regional ischemia followed by 120 min reperfusion. in the control group, krebs-henseleit (k/h) solution was perfused, however in the treatment groups; k/h solution containing 1, 5, and 10 µg/ml of extract was infused. in addition, total phenol, total flavonoid content and antioxidant property were evaluated and extract was subjected to phytochemical analysis. administration of extract improved the flow rate, developed pressure and max and min left ventricular dp/dt. number and duration of vt significantly were reduced by all extract concentrations in ischemic phase. in reperfusion phase, significant decreases in single and total arrhythmias were seen. furthermore, 5 and 10 µg/ml of the extract remarkably decreased the infarct size. an appropriate concentration of s. frigida extract exhibited a protective effect against i/r-induced injures, which might be due to the antioxidant activity of the iridoids and phenolics.