Cyp450 In Vitro Metabolic System Of Three Kinds Of Phenolic Acids Metabolism Of Borneol Ester Compounds

In vitro CYP450metabolic system with liver microsomes or recombinant human CYP450isoforms which expressed by yeast is an important kind of drug metabolism model for research. The advantages of these models are simple, rapid, and efficient as used to determine drug metabolic product generating pathways and enzymatic kinetic parameters. In addition, in vitro metabolic system can also be used to study the relationship between drug and CYP450. To detect the CYP450isoforms which metabolize the drug and which is inhibited by the drug, these data can be evaluated the drug-drug interaction, also can speculate the drug safety and give clinical treatment a guide. In those respects mentioned above, in vitro CYP450metabolic system plays an important role.In this paper, in vitro CYP450metabolism were applied to study the metabolism of three new compounds:gallate borneol ester (GBE), syringate acid borneol ester (SBE) and protocatechuate borneol ester (PBE), the study of the relationship between these compounds and CYP450were also conducted. Then I optimized the method of liver microsomes preparation and the size of the in vitro system, as well as sample extracted from in vitro metabolic system.In the metabolic experiments, the metabolites of these compounds in human, rat, dog and monkey liver microsomes metabolic system were compared. The results showed that metabolites of each drug in every microsomes are the same type, except the SBE, it have a unique product in rat liver microsomes, these results provided useful guides for chose the experimental animals in the animal experiments and for the experimental analysis of the results. Compared the kinetic parameters of drug metabolism in human and rat liver microsomes, by means of CLint, we can found the clearance of drugs in the rat liver was several times bigger than that in human liver. The results of mass spectrometry deduced that the major generating route of drug metabolites by liver microsomes is monooxygenase reaction, but2of SBE products may have the reaction of demethylation in addition to monooxygenase reaction.To understand the relationship between drugs and CYP450have a profound meaning. To decide the CYP isoform which involved in the metabolism of the three compounds by adding different CYP isoform-specific enzyme inhibitors. Statistical analysis showed that the system after adding CYP2C8inhibitors(quercetin), the formation of each products of the three compounds have been reduced, due to the similar structure of three drug candidates. It could be determined CYP2C8were involved in the metabolism of these compounds. The compounds should be avoided use together with the drug which inhibited the activity of CYP2C8. Then studied the six major CYP450isoforms which was mainly inhibited by the3compounds, with the method of fluorescent probe substrates and fluorescent scanning technology. The results indicated that GBE strongly inhibited the activity of CYP3A4and CYP2C9. SBE and PBE, respectively inhibited2C19and2C9. If the corresponding CYP isoforms involved in the metabolism of drugs which might be taken together with the compounds, it would be possible to produce drug-drug interactions, as a result the clearance of the drug is affected.This study successfully used the in vitro CYP450metabolism system for researching the metabolism of three compounds, the results can help to further understand the mechanism of the three compounds formation and would give a guide for follow-up to the screening process, could also speed up drug candidates for drug development and provide important support on drug safety guidance.