Effects Of Ginkgo Biloba Extract In Combination With Anti-platelet Drugs On Platelet Aggregation------meta-analysis And The Mechanism Of The Combination Inhibiting ROS Generation In Human Coronary Artery Endothelial Cells Induced By Activated Platelets

EGb’s main components is flavonoids and terpene lactones.It has effects of anti-oxidant, anti-free radical, anti-inflammatory, anti-allergy, dilating blood vessel and protecting the cardiovascular.It has been widely used in the prevention and treatment of cardiovascular and cerebrovascular disease.ASP is the most widely used anti-inflammatory drugs. ASP can inhibit the platelet release reaction and platelet aggregation, which was also used for preventing cardiovascular and cerebrovascular diseases in clinical settings. Chinese doctors often used EGb combined with ASP to treat cardiovascular disease in clinical work, but there is no consistent conclusion whether the combination has the synergistic effect.This study is divided into two sections:Effects of anti-platelet drugs in combination with Ginkgo biloba extract on platelet aggregation------Meta-analysis and Effects of Ginkgo biloba Extract and Aspirin on the production of ROS and the expressions of NADPH oxidase4 and RhoA in human coronary artery endothelial cells induced by activated plateletsSection 1:Effects of Anti-platelet Drugs in Combination with Ginkgo Biloba Extract on Platelet Aggregation-----Meta-analysisAim:To study the effects of anti-platelet drugs in combination with EGb on platelet aggregation in order to provide reference proof for rational use of them.Methods:Randomized controlled trails(RCT) were searched from PubMed^ Spring Ling、Biosis Previews、Cochrane and CNKI、VIP、CBM. A meta-analysis was performed by RevMan 5.0.Results:Seven randomized controlled trails are included in my analysis. The combination of EGb and anti-platelet drugs has significant inhibitory effect on ADP-induced platelet aggregation [MD=-6.41.95% CI (-0.95.-3.78). P<0.00001], but no inhibitory effect on collagen-induced platelet aggregation [MD=-0.56.95% CI (-3.91, 2.80), P=0.74]. No significant difference of prolonged bleeding time between the combination and anti-platelet drugs alone was seen in the pooled trials [MD=0.39,95% CI (-0.09,0.86), P=0.11].Conclusion:Compared with anti-platelet drugs used alone, the effect of the combination of EGb with anti-platelet drugs on platelet aggregation rate is uncertain, and it is also no significant effect on bleeding time.Section2:Effects of Ginkgo biloba Extract and Aspirin on the Production of ROS and the Expressions of NADPH oxidase4 and RhoA in Human Coronary Artery Endothelial Cells Induced by Activated PlateletsAim:In the present study, we established the model of oxidative stress in ex vivo via activated-platelets inducing HCAECs to explore whether the different dosages of EGb and ASP, especially in combination, might synergistically suppress ROS produced in HCAECs through regulating the expression of N0X4 and RhoA in HCAECs.Methods:HCAECs stressed with activated platelets 2×108/ml, were divided the cells into 4 groups:activated platelets. Aspirin, Extract of Ginkgo biloba and their combination. In addition, HCAECs were set to control group. ASP (1,2 or 5 mmol/L), EGb (4.40 or 400 μg/ml) and combinational (ASP 1 mmol/L and EGb 40 μg/ml) treated for 12 hours. ROS in HCAECs was measured with DCFH-DA probe and observed by fluorescence microscopy. The expression of NOX4 and RhoA were examined by Western Blot.Results:The results observed by fluorescence microscopy showed that in HCAECs, after stimulation of activated platelets, intracellular ROS was markedly increased (p<0.05 vs. HCAECs control). Both ASP and EGb inhibited ROS in HCAECs in a dosage dependent manner (p<0.05 vs. activated platelets group) and the combination of ASP and EGb showed synergistic effect (p<0.05 vs. ASP or EGb alone). By Western blot analysis, in HCAECs stressed by activated platelets, we were able to show that the expression of NOX4 and RhoA were markedly enhanced (p<0.05 vs. control). Both ASP and EGb alone reduced the expression of NOX4 in a dosage dependent manner (p<0.05 vs. activated platelets), but RhoA in a dosage independent manner. As expected, Combinational administration of ASP and EGb caused the effect of synergistic inhibition not only the expression of NOX4 but also RhoA. (p<0.05 vs. ASP or EGb alone)Conclusions:Both EGb and ASP attenuate the expression of ROS, NOX4 and RhoA in HCAECs induced by activated platelets ex vivo, furthermore, the combination of ASP and EGb have synergistic effects to inhibit of ROS, NOX4 and RhoA, from which, we conclude that the mechanism of the combination of ASP and EGb in the treatment of coronary atherosclerotic heart disease may correlate with the inhibition of ROS production through supressing NOX4 and RhoA expression.