Differential cardioprotective effects of salvianolic acid and tanshinone on acute myocardial infarction are mediated by unique signaling pathways.

Salvianolic acid (SAL) and tanshinone (TAN) are major hydrophilic and lipophilic compounds, respectively, from one herbal medicine, Danshen, which has been widely and successfully used for treating cardiovascular diseases in Asian countries. Because few studies have reported different molecular mechanisms between the different compounds in same herb, we investigate if separate molecular pathways are involved in cardioprotective effect by different active components of Danshen. We used an acute myocardial infarction (MI) model to compare the cardioprotective effects of SAL and TAN in rats. Both infarct size and echocardiographic response were evaluated at 3, 7, 14 and 28 days after surgery. Genes involved in ischemic injury and in responses to SAL or TAN treatment in ischemic hearts were identified by microarray analysis and verified by quantitative real-time RT-PCR. Results showed that both SAL and TAN delay the development of ischemia by decreasing infarct size and improving systolic function post MI. Gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated different kinetics and gene expression profiles by SAL and TAN. SAL acts in a later period after ischemia, and its effect is probably mediated by downregulation of genes involved in oxidative stress, certain G-protein coupled receptor activities and apoptosis. On the other hand, TAN acts relatively early after ischemic injury and its effect is at least in part mediated by inhibition of intracellular calcium, cell adhesion and alternative complement pathway. Strikingly, we found that TAN, a recently identified member of selective estrogen receptor modifier (SERM), indeed regulates genes known to be involved in estrogen metabolism post MI. Although both SAL and TAN contribute to the cardioprotective effect of Danshen, there are significant mechanistic and temporal differences between the two: TAN acts at an early stage after ischemic injury mainly by inhibition of intracellular calcium and cell adhesion pathways whereas SAL acts mainly by down-regulating apoptosis.

Wang X ，Wang Y ，Jiang M ，Zhu Y ，Hu L ，Fan G ，Wang Y ，Li X ，Gao X ... -  《-》

Salvianolic acid B and tanshinone IIA attenuate myocardial ischemia injury in mice by NO production through multiple pathways.

Pan C ，Lou L ，Huo Y ，Singh G ，Chen M ，Zhang D ，Wu A ，Zhao M ，Wang S ，Li J ... -  《-》

Tanshinone II A attenuates inflammatory responses of rats with myocardial infarction by reducing MCP-1 expression.

The root of Salvia miltiorrhiza Bunge, a well-known traditional Chinese medicine, has been used effectively for the treatment of cardiovascular diseases for a long time. The mechanisms underlying this therapeutic effect are not, however, fully understood. Tanshinone IIA (Tan IIA) is one of the major active components of this Chinese medicine. Therefore, the present study was performed to investigate whether Tan IIA, which has shown a cardio-protective capacity in myocardial ischemia, has an inhibitory effect on the inflammatory responses following myocardial infarction (MI) and its potential mechanisms. In an in vivo study, rat MI model was induced by permanent left anterior descending coronary artery (LAD) ligation. After the operation rats were divided into three groups (sham, MI and Tan IIA). Tan IIA was administered intragastrically at a dose of 60mg/kg body wt./day. One week later, rats were sacrificed and the hemodynamic, pathological and molecular biological indices were examined. In an in vitro study, the inflammatory model was established by TNF-alpha stimuli on cardiacmyocyte and cardiac fibroblasts. Tan IIA attenuates the MI pathological changes and improves heart function, and reduces expression of MCP-1, TGF-beta(1) and macrophage infiltration. Furthermore, Tan IIA could also decrease the expression of TNF-alpha and activation of nuclear transcription factor-kappa B (NF-kappaB). In vitro, Tan IIA could reduce MCP-1 and TGF-beta(1)secretion of cardiac fibroblasts. The present study demonstrated that the cardioprotective effects of Tan IIA might be attributed to its capacity for inhibiting inflammatory responses.

Ren ZH ，Tong YH ，Xu W ，Ma J ，Chen Y ... -  《-》

Tanshinone IIA reduces apoptosis induced by hydrogen peroxide in the human endothelium-derived EA.hy926 cells.

Salvia Miltiorrhiza Bunge (also known as herb Danshen in Chinese) is a widely used Chinese herbal medicine. Tanshinone IIA (TSN IIA) is considered to be the most important bioactive ingredient in Danshen and exhibits an anti-atherosclerotic activity. To evaluate the protective effect of TSN IIA on the human endothelial EA.hy926 cells injured by hydrogen peroxide in vitro and its possible mechanism. The EA.hy926 cells were incubated for 24h with different concentrations of TSN IIA (5, 10 and 20 μg/μL ) or DMEM. Subsequently, cells were treated with 300 μmol/L H(2)O(2) for another 4h. Then, the percentage of cell viability was evaluated by 3-(4, 5-di-methylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay. The apoptosis of EA.hy926 cells was detected by flow cytometry with AnnexinV-FITC/PI double staining and laser scanning spectral confocal technique. The generation of intracellular reactive oxygen species (ROS) generation was analyzed by flow cytometry. The mRNA expressions of caspase-3, Bcl-2 and Bax were tested by real time-reverse transcription polymerase chain reaction (real time RT-PCR). The protein expression of Bcl-2 and Bax was determined by Western blotting. MDA levels, NO production, LDH leakage, and SOD as well as caspase-3 activities were also measured using standard methods. Loss of cell viability and excessive cell apoptosis were observed in EA.hy926 cells after 4h of challenge with H(2)O(2) (300 μmol/L). However, cell apoptosis was attenuated in different concentrations of TSN IIA (5, 10 and 20 μg/μL) pretreated cells. Furthermore, TSN IIA markedly inhibited the elevation of ROS evoked by H(2)O(2). Real time RT-PCR and Western blotting analysis showed that TSN IIA significantly decreased the expressions of pro-apoptotic proteins (Bax and caspase-3) while significantly increased the expression of anti-apoptotic protein Bcl-2, and resulted in obvious reduction of Bax/Bcl-2 ratio in EA.hy926 cells induced by H(2)O(2). These observations provide preliminary evidence that TSN IIA protects EA.hy926 cells against H(2)O(2) damage, which is mainly associated with the ROS generation, followed by the imbalance of the Bax/Bcl-2 ratio, and caspase-3 activation leading to apoptosis.

Jia LQ ，Yang GL ，Ren L ，Chen WN ，Feng JY ，Cao Y ，Zhang L ，Li XT ，Lei P ... -  《-》

Salvianolic acid A demonstrates cardioprotective effects in rat hearts and cardiomyocytes after ischemia/reperfusion injury.

Pan H ，Li D ，Fang F ，Chen D ，Qi L ，Zhang R ，Xu T ，Sun H ... -  《-》