The Effects Of The Combination Of Aspirin And Warfain On CYP3A Enzyme

The pathogenesis of cardiovascular disease is complex and often accompanied by a variety of thrombosis and complications, blood clots can induce cerebral thrombosis or embolism complications such as vascular embolization and finally led to death. Therefore, the prevention and treatment of thrombosis becomes are the key to reduce the rate of mortality and disability. However, the blood clot situation in clinic is complex, such as arterial thrombosis often merges vein thrombosis or intracardiac thrombus, so the combination therapy is commom in clinic. Anticoagulant and antithrombotic drugs are widely used in various kinds of vascular embolization and atherosclerotic disease, because these two kinds of drugs effect on blood coagulation system and platelet aggregation, respectively.Their mechanisms may be complementary, so the combination of these two drugs may be beneficial. Warfarin is a classic drug of coumarin anticoagulant, aspirin is commonly used as antiplatelet aggregation drugs in clinic. The combination therapy is commonly used in foreign countries, for exemple more than 1 million patients accept the treatment of aspirin and warfarin at the same time in North America.Due to the diversity and complexity of clinical symptoms, and the safety of drugs, there are significant controversy about the curative effect of combined use and safety evaluation in clinic and academic field. Because of the significantly high risk of bleeding of combination therapy, the doctors often confused about whether the combination therapy should be used, and under what circumstances to use. Our group has studied the pharmacokinetic and pharmacodynamic interactions of aspirin with warfarin in beagle dogs, the results have illustrated the combination therapy can change the pharmacokinetic and pharmacodynamic parameters of warfarin(AUC and Cmax).Cytochrome P450 enzyme system (CYP450) participate in the bioconversion of a variety of endogenous and exogenous substances in the human body. CYP450 enzyme is the most important drug metabolic enzymes, including CYP2E1 and CYP3A4 involved in about 90% of drugs metabolism. Many foreign substances can induce or inhibit the activity of CYP450 enzyme, thus cause drug interaction, then leads to the change of drug pharmacology and toxicology. So the study of effects of exogenous substances on cytochrome P450 enzyme system is an effective evaluation method to evaluate the interaction of two drugs. This research studies the influence of combination therapy on CYP3A enzyme activity and protein expression level and mRNA expression level, elucidating the interaction between warfarin and aspirin.The main research content is divided to four sections, as follows:1.Effects of the combination of aspirin and warfarin on CYP3A enzyme activity in rats According to randomized controlled principle,32 male SD rats were divided into four groups. A group was the control group, CMC-Na (0.1 mol/L) solution was given by intragastric administration every day for seven consecutive days; Aspirin group was intragastric administrated with aspirin (10 mg/Kg) for seven consecutive days; Warfarin group was intragastric administrated with warfarin (0.8 mg/Kg) for seven consecutive days; the combination therapy group was given with aspirin and warfarin solution for seven days by gastric perfusion. After the last treatment, all rats stopped feeding for 24h, then prepared liver microsomal. Determination of liver microsomal protein content was after incubation reaction. With 6β-hydroxy testosterone as probe substrates, the HPLC analysis method was established to observe the differences of activity of rat liver microsomal in deferent groups. The result showed that the aspirin-warfarin combination therapy can inhibit the activity of liver microsomal (P< 0.01).2. Used in combination with aspirin and warfarin for the influence of CYP3A enzyme protein expression in ratsUsing western blot method to detect four groups of liver microsomal CYP3A protein expression. Compared with the normal group, aspirin group, aspirin and warfarin group rats CYP3A significantly lower the amount of protein expression, and statistically significant (P< 0.01); Compared with warfarin group, aspirin and warfarin group rats decreased CYP3A protein expression, statistically significant (P< 0.05). The expression of CYP3A protein between aspirin group and normal group, aspirin group and warfarin group had no significant statistical difference.3. Used in combination with aspirin and warfarin for the influence of CYP3A mRNA expression in ratsQRT-PCR were used to detect each group rats of C YP3 A enzyme mRNA expression is decreased, the results showed that only the aspirin and warfarin were decreased mRNA expression of CYP3A enzyme.4. The immunohistochemical methodSP method,4% formaldehyde fixed liver tissue paraffin section. Result showed that aspirin and warfarin were markedly reduced enzyme expression quantity.Conclusion:The combination of aspirin and warfarin can inhibit the mRNA expression of CYP3A enzyme, and then reduce the protein expression of CYP3A enzyme, thus the activity of CYP3A enzyme decrease.