Studies On Interactions And Metabolic Mechanism Of Berberine And Liver Enzyme

Purpose:Firstly,To identify CYP isozymes responsible for berberine metabolism and its contribution, and to determine the structures of metabolism. Sceond,To investigate the effect of CYP450enzyme inhibition of berberine in pooled human liver microsomes.Fianlly,To investigate the effect of CYP450enzyme induction of berberine in HepG2cell.Method:①Pooled human liver microsomes were incubated with berberine (20,100,200,400,600,800, and1200ng/mL).The Michaelis-Menten parameters (Km), maximum velocity (Vmax), and clearance (Clint) of pooled liver microsomes were initially estimated by analyzing Lineweave-Brurk plot.②Various selective CYP inhibitors were used to investigate their inhibitory effects on the metabolism of berberine and the certain concentration of berberine was incubated with recombinant human CYP isozymes (CYP3A4, CYP1A2, CYP2D6, and CYP2C9).The P450isozymes were ranked with the method of total normalized rate (TNR).㏄ooled human liver microsomes were incubated with berberine and the related metabolites were identified by LC-MS/MS@the effect of CYP450enzyme inhibition and induction of berberine by in pooled human liver microsomes and HepG2cell by cocktail probe drugs.Result:The Vmax, Km, and Clint of berberine in pooled human liver microsomes were1.5lnmoL·mg-1(protein)·h-1,2.69nmoL·mL-1, and0.56mL·mg-1(protein)·h-1, respectively.Quinidine (the specific inhibitor of CYP2D6)and Furafylline (the specific inhibitor of CYP1A2) could significantly inhibit the berberine metabolism, and the other CYP inhibitors had no significant effect on the metabolism of berberine. CYP2D6and CYP1A2were responsible for75.2539%and d23.3236%of the berberine metabolite M1(demethyleneberberine), and responsible for46.8938%and8.6795%of M2(thalifendine or berberrubine).The pharmacokinetics of chlorzoxazone and dextromethorphan was significantly decreased in pooled human liver microsomes,The pharmacokinetics of midazolam and phenacetin were significantly increased in HepG2cell. ConclusionrBererine is metabolized by CYP2D6and CYP1A2in human liver, the metabolites of berberine are demethyleneberberine and thalifendine or berberrubine.Berberine can inhibit the activity of CYP2E1and CYP2D6,can induce the activity of CYP3A4and CYP1A2.