The Inhibition And Metabolic Evaluation Of Andrographolide Derivatives Towards UDP-glucuronosyl Transferase

Acanthaceae Andrographis is aboveground dry part, one-terpene lactones andrographolide is isolated from Andrographis, which have anti-inflammatory, antiviral,immunomodulatory, liver and gallbladder, anti-diabetic, anti-fertility effects, anti-tumor activity in recent years, research scholars is a hot topic andrographolide. Oleanolic acid is pentacyclic triterpenoids, widely distributed, cloves, jujube, ginseng and other plants are present. After the initial discovery and isolation of oleanolic acid in the British scientists,people began oleanolic acid in-depth research in recent years, researchers have found that oleanolic acid has the ability to reduce radiation damage and anticancer change, so that people oleanolic AHA study into a new field.The use of natural herbal active ingredients developed drugs, sometimes because patients during the treatment of many diseases, had combined with two or more drugs cause side effects to a certain extent, and produce the drug- drug interactions(DDIs), for the health of patients affected. UDP glucuronosyl transferase(UGT)is the catalytic conversion of human endogenous compounds and phase II drug metabolizing enzymes in vitro and discharged, can effectively enhance hydrophilic drug molecules, thereby contributing to the body of some drugs and endogenous metabolites.In this paper, the use of a single recombinant UGT enzymes in the study andrographolides and oleanolic acid compound derivative class of medicine antitumor activity of UGT enzyme inhibition of metabolic activity, measured pharmacokinetics of these two compounds in vitro experimental model parameters to determine the type of inhibition, which discuss the possible DDIs, provide the basis for further drug research and rational drug use.In 4-methyl umbelliferone(4-MU)as a substrate, more than two classes of compounds screened for UGT enzyme inhibition model.With Ultra-fast liquid instrument( UFLC),detecting enzymatic product, 4-methylumbelliferyl-β-D glucuronides(4-MUG)yield changes in screening compounds with a strong ability to suppress, and the compound for further kinetic analysis.Different compounds of UGT isoforms inhibition: In andrographolides compound,zfx-45-7 for UGT2B7 has a strong inhibitory effect. Oleanolic acid and lupine ketone have strongly inhibit to UGT1A3, oleanolic acid derivative compounds LLH-3-one and lupine ketone are also strong inhibitory effect to UGT2B7.The inhibition and kinetics analysis of andrographolide and oleanolic acid: According to experimental data chart the Lineweaver-Burk and Dixon, analysis these detrvatives to UGT inhibition type and using inhibition kinetics equation determines the inhibition constant(Ki)values. Andrographolide derivatives zfx-45-7 can competitively inhibits UGT2B7, its Ki value 0.15μM. Oleanolic acid and its derivatives lupine ketone is a competitive inhibitor of UGT1A3, their Ki values were 0.4μM and 0.0016μM; oleanolic acid derivatives LLH-3and lupine ketone can be non-competitive inhibition UGT2B7, its Ki values were 7.7μM and 10.3μM.