OBJECTIVE Our study aimed to investigate the effects of alprostadil and Salvia miltiorrhiza extract on myocardial ischemia-reperfusion injury (IRI) and related underlying molecular mechanisms. METHODS A myocardial IRI model was established in Wistar rats via surgical ligation of the left anterior descending coronary artery followed by loosening of the occlusion. The rats were divided into four groups: saline, sham, alprostadil, and S. miltiorrhiza. Rats in the saline and sham groups were injected with normal saline by tail vein once daily for 10 consecutive days. Rats in the S. miltiorrhiza and alprostadil groups were injected with S. miltiorrhiza extract (20 μg/kg) or alprostadil. Histological differences in myocardial tissues between rats in the sham group and in the myocardial IRI model were observed by hematoxylin and eosin staining. India ink perfusion was used to quantify the number of capillary microvessels. Real-time quantitative reverse transcription polymerase chain reaction was used to determine serum expression levels of soluble intercellular adhesion molecule (sICAM), soluble vascular adhesion molecule (sVCAM), CD11b and CD18. RESULTS The alprostadil and S. miltiorrhiza groups had significantly higher numbers of microvessels than the saline group. Serum sICAM and sVCAM expression was significantly reduced in the alprostadil and S. miltiorrhiza groups. Meanwhile, sICAM and sVCAM in the alprostadil group were markedly lower than in the S. miltiorrhiza group. Moreover, the alprostadil group had markedly lower mRNA expression of CD11b and CD18, which were clearly lower than in the S. miltiorrhiza group. CONCLUSIONS Alprostadil may have cardioprotective effects for myocardial IRI, with down-regulated expression of sICAM, sVCAM, CD11b, and CD18.