ABSTRACT
Xiaoshuan Tongluo formula is effective in treating mental retardation and speech astringency caused by cerebral thrombosis, but its mechanism remains unclear. In this investigation, by collecting the chemical constituents from Xiaoshuan Tongluo formula and the targets related to stroke, we obtained 1 251 constituents from the formula and 10 drug targets related with stroke. We established 18 prediction models of compound-target interaction for 10 stroke-related targets, using molecular docking method and machine learning methods includes Naive Bayesian and recursive partitioning based on the input of molecular fingerprints and molecular descriptors. Using these models, we predicted the active chemical constituents from Xiaoshuan Tongluo formula and their drug targets, 153 potential active constituents were discovered, 22 among them could interact with at least two drug targets related with stroke. On this basis, the chemical constituent-target network was constructed using network construction software, and then the important metabolic pathways of the targets were identified by using Gene-Ontology (GO) enrichment analysis, such as blood coagulation, positive regulation of angiogenesis, positive regulation of ion transport and so on. On this basis, a target-pathway network was constructed. In conclusion, using machine learning, molecular docking, virtual screening, data mining and network construction, this study explored and partially revealed the active chemical constituents and chemical constituent-target-pathway network action mechanism of Xiaoshuan Tongluo formula against stroke, which will provide important information for its further study.
ABSTRACT
Hemorrhagic transformation (HT) is a frequent complication of ischemic stroke, especially after thrombolytic therapy. This event is associated with increased morbidity and mortality. Tissue plasminogen activator (t-PA), the only FDA proved drug for breaking blood clots, is underutilized in ischemic stroke, because of its limited therapeutic window and hemorrhagic complications. Due to the lack of clear understanding of the pathological mechanism, there are no effective drugs to decrease the incidence of HT. Pinocembrin is a natural flavonoid compound and has neuroprotective effects in animal ischemic stroke models. In this study, we investigated the role of pinocembrin in t-PA thrombolysis-induced HT in rat thromboembolic stroke model. t-PA was administrated 6 h after ischemia and pinocembrin (5, 10 and 20 mg·kg-1) was given 5 min before t-PA administration. Infarct volume, neurological score and hemoglobin content were evaluated at 24 h after ischemia. Evans blue leakage was used to detect blood-brain barrier (BBB) permeability. All procedures were approved by the Institutional Animal Care and Use Committee of the Peking Union Medical College. The results showed that treatment with t-PA at 6 h after ischemia aggravated brain injury and increased the risk of HT, with infarct volume and brain water content reached 39% and 83.4%, respectively. Pretreatment with pinocembrin decreased the infarct volume and brain water content to 28.5% and 80.3%, and improved neurological function. In addition, the combined application of pinocembrin with t-PA reduced hemoglobin content and Evans blue content in brain tissue by 50% and 40%, indicating that pinocembrin could protect the BBB permeability and reduce the occurrence of HT. Among these doses, 10 mg·kg-1 is most effective. In conclusion, our results demonstrate that the combination of pinocembrin with t-PA protects against cerebral ischemia, reduces the occurrence of HT induced by t-PA thrombolysis. Thus, pinocembrin may be a potential therapeutic drug for t-PA induced HT.
ABSTRACT
This study was designed to compare the antithrombotic effects of salvianolic acid A and aspirin. The anti-platelet aggregation and anticoagulant effects of salvianolic acid A and aspirin in vitro and in vivo were investigated in normal rats. The anti-cerebral ischemia and anti-platelet aggregation effects of salvianolic acid A and aspirin were also investigated in rats with thrombotic cerebral ischemia. All animal care and experimental procedures were reviewed and approved by the Animal Ethics Committee of Chinese Academy of Medical Sciences. The results of antiplatelet aggregation in vitro and in vivo showed that salvianolic acid A could mildly inhibit adenosine diphosphate (ADP), arachidonic acid (AA) and thrombin (THR)-induced antiplatelet aggregation in a dose-dependent manner, while aspirin played a strong inhibitory effect on AA-induced platelet aggregation in vivo. The effects of salvianolic acid A and aspirin on the coagulation system were similar. At the same time, the results of maximum platelet aggregation rate (MAR) in the rat cerebral ischemia model [MARADP= (41.67±4.55)%, MARAA= (53.22±2.83)%, MARTHR= (73.33±5.04)%] indicated that salvianolic acid A could mildly inhibit ADP and AA-induced antiplatelet aggregation [MARADP= (26.13±4.60)%, MARAA= (35.53±13.73)%, P<0.01], while aspirin played a strong inhibitory effect on AA-induced platelet aggregation [MARAA= (8.13±2.99)%]. Salvianolic acid A (10 mg·kg-1) significantly improved the neurological function, cerebral infarction volume [(10.77±7.80)%] and brain edema [(79.72±0.83)%] compared with the model group [(43.50±12.69)%, (82.25±0.89)%] (P<0.01), while the effect of aspirin (100 mg·kg-1) was not obvious. The above results suggest that compared with aspirin, salvianolic acid A provided a mild inhibitory effect on platelet aggregation and protected against cerebral ischemia induced by thrombus. Therefore, salvianolic acid A has a good application prospect in the prevention and treatment of thrombotic diseases.
ABSTRACT
Hemorrhagic transformation (HT) is a common complication of ischemic stroke, especially after thrombolytic therapy, which is associated with increased morbidity and mortality. Thrombolysis with tissue plasminogen activator (t-PA) increases the rate of HT by as much as 10-fold, and the mortality by about 60%. The patients who are eligible for t-PA treatment are still between 3.4% and 5.2% of all patients with acute ischemic stroke because of the narrow therapeutic time window. Due to the unknown mechanism and therapeutic target of HT, there are no effective drugs to decrease the incidence of HT. The main mechanism of HT is disruption of the blood-brain barrier (BBB) integrity and neurovascular homeostasis, involving a variety of molecular signaling pathways. In animal and clinical studies, combining therapeutic agents with t-PA, which may help to minimize BBB perturbations, reduces the incidence of HT and increases the safety of thrombolytic therapy. This article is prepared to review the mechanisms, targets and therapeutic drugs of t-PA induced HT in recent years to provide a reference to the basic research and drug development of HT.
ABSTRACT
In the present study, the specifically knockdown models of P-gp or MRP2 were constructed by using a series of chemically synthesized small interfering RNA (siRNA) in vitro. The expression of P-gp and MRP2 was measured by real-time PCR and Western blot, and the function was evaluated by applying P-gp and MRP2 substrate, rhodamine and methotrexate. The results showed that MRP2 siRNA-3 or P-gp siRNA-2 significantly decreased the mRNA expression of MRP2 or P-gp, the inhibition ratio was 68% or 84%; MRP2 siRNA-3 or P-gp siRNA-2 at a dose of 80 nmol x L(-1) significantly reduced the protein expression of MRP2 or P-gp at 48 h after treatment, the inhibition ratio was 62% or 70%. Meanwhile, other transporters were not influenced by siRNA. When pretreatment with MRP2 siRNA-3 or P-gp siRNA-2, the efflux of methotrexate or rhodamine decreased significantly and the intra-cellular concentration increased. The results suggested that chemically synthesized siRNA could significantly inhibit the expression and function of MRP2 and P-gp, and the model of RNAi in vitro could be used to evaluate the role of efflux transporters in transportation of drugs.