Cardioprotective effects and mechanism of Radix Salviae miltiorrhizae and Lignum Dalbergiae odoriferae on rat myocardial ischemia/reperfusion injury

Radix Salviae miltiorrhizae (SM) and Lignum Dalbergiae odoriferae (DO) are traditional Chinese medicinal herbs used to treat ischemic heart disease and other cardiovascular diseases; however, to the best of our knowledge, there are currently few studies regarding their effects. The present study aimed to investigate the cardioprotective effects of SM and DO during myocardial ischemia/reperfusion (MI/R) injury in rats, and explore the molecular mechanisms that underlie their actions. In the present study, Sprague-Dawley rats were pretreated with SM, the aqueous extract of DO (DOA) and the volatile oil of DO (DOO), either as a monotherapy or in combination for 7 days. Subsequently, the rats were subjected to 30 min of ischemia followed by 180 min of reperfusion. Traditional pharmacodynamic evaluation and metabonomics based on gas chromatography/time-of-flight mass spectrometry were used to identify the therapeutic effects of these traditional Chinese medicines. The results revealed that SM, DOA and DOO monotherapies ameliorated cardiac function, and this effect was strengthened further when used in combined therapies. Among the combined treatments, SM + DOO exhibited the greatest potential (P<0.05) to improve electrocardiogram results and heart rate, reduce the heart weight index and myocardial infarct size, and decrease the levels of creatine kinase-MB and lactate dehydrogenase. In addition, metabonomics-based findings, including the principal component analysis and partial least squares discriminant analysis score plot of the metabolic state in rat serum, provided confirmation for the aforementioned results, verifying that SM + DOO exerted synergistic therapeutic efficacies to exhibit a greater effect on rats with MI/R injury when compared with the other pretreatment groups. Furthermore, the most effective duration of SM + DOO treatment was 30 min and the least effective duration was 180 min. Treatment with SM + DOO also significantly (P<0.01) reduced the number of terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling-positive cells, tumor necrosis factor-α andinterleukin-6 expression, and malondialdehyde content, and increased the serum and tissue activity of superoxide dismutase. These results indicated that the combined effects of SM + DOO may be more effective compared with the single pretreatments against MI/R injury in rats. This effect may be achieved partly through anti-apoptotic, antioxidant and anti-inflammatory activities. Therefore, SM + DOO may be considered an effective and promising novel strategy for the prophylaxis and treatment of ischemic heart disease.