demethyleneberberine and berberrubine

Protoberberine alkaloids, including berberine, palmatine, and berberrubine, are produced by medicinal plants and are known to have various pharmacological effects. We isolated two berberine-utilizing bacteria, Sphingobium sp. strain BD3100 and Rhodococcus sp. strain BD7100, from soil collected at a natural medicine factory. BD3100 had the unique ability to utilize berberine or palmatine as the sole carbon and energy source. BD3100 produced demethyleneberberine in berberine-supplemented medium. In a resting-cell incubation with berberine, BD3100 produced 11-hydroxyberberine; the structure of 11-hydroxyberberine was determined by detailed analysis of NMR and MS spectroscopic data. α-Naphthoflavone, miconazole, and ketoconazole, which are known inhibitors of cytochrome P450, interfered with BD3100 metabolism of berberine in resting cells. Inhibition by miconazole led to the production of a new compound, 11-hydroxydemethyleneberberine. In a resting-cell incubation with palmatine, BD3100 generated 11-hydroxypalmatine. This work represents the first report of the isolation and characterization of novel berberine-utilizing aerobic bacteria for the production of 11-hydroxylation derivatives of berberine and palmatine.

Topics: Benzoflavones; Berberine; Berberine Alkaloids; Cytochrome P-450 Enzyme Inhibitors; Hydroxylation; Japan; Microbial Sensitivity Tests; Molecular Sequence Data; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Plants, Medicinal; Sphingomonadaceae

Berberine (BBR) is an isoquinoline alkaloid isolated from several Chinese herbal medicines, such as Coptis chinensis, Berberis aristata, and Coptis japonica. It exhibits a lipid-lowering effect by up-regulating the hepatic low density lipoprotein receptor (LDLR) expression. However, the plasma concentration of BBR is very low after oral administration for the reason that BBR is poorly absorbed and rapidly metabolized. Therefore, it is hard to explain the pharmacological effects of BBR in vivo. Here, RT-PCR, Western blotting and Oil Red O staining were used to investigate the effects of four BBR metabolites on LDLR expression and lipid accumulation in human hepatoma Hep G2 cells. Our results suggested that BBR increased the LDLR mRNA and protein levels in a time- and dose-dependent manner. Four metabolites of BBR, jatrorrhizine, columbamine, berberrubine and demethyleneberberine, were found to be able to up-regulate LDLR mRNA and protein expression. Moreover, almost all the metabolites had potent effects on inhibiting cellular lipid accumulation. These results suggest that both BBR and its metabolites exhibit lipid-lowering effects by up-regulating LDLR expression, and BBR and its metabolites might be the in vivo active forms of BBR produced after oral administration. This study provides information to help us understand the mechanisms underlying the hypolipidemic effects of BBR in vivo.

Topics: Berberine; Berberine Alkaloids; Berberis; Carcinoma, Hepatocellular; Coptis; Dose-Response Relationship, Drug; Hep G2 Cells; Humans; Hypolipidemic Agents; Lipid Metabolism; Lipoproteins, LDL; Liver Neoplasms; Plant Extracts; Receptors, LDL; RNA, Messenger; Up-Regulation

Berberine (BBR) is a drug with multiple effects on cellular energy metabolism. The present study explored answers to the question of which CYP450 (Cytochrome P450) isoenzymes execute the phase-I transformation for BBR, and what are the bioactivities of its metabolites on energy pathways.. BBR metabolites were detected using LC-MS/MS. Computer-assistant docking technology as well as bioassays with recombinant CYP450s were employed to identify CYP450 isoenzymes responsible for BBR phase-I transformation. Bioactivities of BBR metabolites in liver cells were examined with real time RT-PCR and kinase phosphorylation assay.. In rat experiments, 4 major metabolites of BBR, berberrubine (M1), thalifendine (M2), demethyleneberberine (M3) and jatrorrhizine (M4) were identified in rat's livers using LC-MS/MS (liquid chromatography-tandem mass spectrometry). In the cell-free transformation reactions, M2 and M3 were detectable after incubating BBR with rCYP450s or human liver microsomes; however, M1 and M4 were below detective level. CYP2D6 and CYP1A2 played a major role in transforming BBR into M2; CYP2D6, CYP1A2 and CYP3A4 were for M3 production. The hepatocyte culture showed that BBR was active in enhancing the expression of insulin receptor (InsR) and low-density-lipoprotein receptor (LDLR) mRNA, as well as in activating AMP-activated protein kinase (AMPK). BBR's metabolites, M1-M4, remained to be active in up-regulating InsR expression with a potency reduced by 50-70%; LDLR mRNA was increased only by M1 or M2 (but not M3 and M4) with an activity level 35% or 26% of that of BBR, respectively. Similarly, AMPK-α phosphorylation was enhanced by M1 and M2 only, with a degree less than that of BBR.. Four major BBR metabolites (M1-M4) were identified after phase-I transformation in rat liver. Cell-free reactions showed that CYP2D6, CYP1A2 and CYP3A4 seemed to be the dominant CYP450 isoenzymes transforming BBR into its metabolites M2 and M3. BBR's metabolites remained to be active on BBR's targets (InsR, LDLR, and AMPK) but with reduced potency.

Topics: AMP-Activated Protein Kinases; Animals; Berberine; Biotransformation; Cytochrome P-450 Enzyme System; Hep G2 Cells; Humans; Isoenzymes; Liver; Male; Metabolic Detoxication, Phase I; Rats; Rats, Wistar; Receptor, Insulin; Receptors, LDL

Berberine (Ber) and its main metabolites were identified and quantified using liquid chromatography/electrospray ionization/ion trap mass spectrometry. Rat plasma contained the main metabolites, berberrubine, thalifendine, demethyleneberberine, and jatrorrhizine, as free and glucuronide conjugates after p.o. Ber administration. Moreover, the original drug, the four main metabolites, and their glucuronide conjugates were all detected in liver tissues after 0.5 h and in bile samples 1 h after p.o. Ber administration. Therefore, the metabolic site seemed to be the liver, and the metabolites and conjugates were evidently excreted into the duodenum as bile. The pharmacokinetics of Ber and the four metabolites were determined in conventional and pseudo germ-free rats (treated with antibiotics) after p.o. administration with 40 mg/kg Ber. The AUC0-limt and mean transit time values of the metabolites significantly differed between conventional and pseudo germ-free rats. The amounts of metabolites were remarkably reduced in the pseudo germ-free rats, whereas levels of Ber did not obviously differ between the two groups. The intestinal flora did not exert significant metabolic activity against Ber and its metabolites, but it played a significant role in the enterohepatic circulation of metabolites. In this sense, the liver and intestinal bacteria participate in the metabolism and disposition of Ber in vivo.

Topics: Animals; Bacteria; Berberine; Bile; Chromatography, Liquid; Germ-Free Life; Intestinal Absorption; Intestine, Small; Liver; Male; Rats; Rats, Wistar; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry