scholarly journals In Vitro Liver Metabolism of Six Flavonoid C-Glycosides

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6632
Author(s):  
Martina Tremmel ◽  
Christian Paetz ◽  
Jörg Heilmann
Keyword(s):  
Phase I ◽  
Human Liver ◽  
Solid Phase ◽  
Liver Microsomes ◽  
Liver Metabolism ◽  
Metabolite Profiles ◽  
Medical Plants ◽  
Passiflora Incarnata ◽  
Phase I And Ii

Several medical plants belonging to the genera Passiflora, Viola, and Crataegus accumulate flavonoid C-glycosides, which likely contribute to their efficacy. Information regarding their phase I and II metabolism in the liver are lacking. Thus, in vitro liver metabolism of orientin, isoorientin, schaftoside, isoschaftoside, vitexin, and isovitexin, all of which accumulated in Passiflora incarnata L., was investigated by incubation in subcellular systems with human liver microsomes and human liver S9 fraction. All metabolite profiles were comprehensively characterized using HPLC-DAD and UHPLC–MS/MS analysis. Mono-glycosylic flavones of the luteolin-type orientin and isoorientin showed a broad range of mono-glucuronidated and mono-sulfated metabolites, whereas for mono-glycosylic flavones of the apigenin-type vitexin and isovitexin, only mono-glucuronidates could be detected. For di-glycosylic flavones of the apigenin-type schaftosid and isoschaftosid, no phase I or II metabolites were identified. The main metabolite of isoorientin was isolated using solid-phase extraction and prep. HPLC-DAD and identified as isoorientin-3′-O-α-glucuronide by NMR analysis. A second isolated glucuronide was assigned as isoorientin 4′-O-α-glucuronide. These findings indicate that vitexin and isovitexin are metabolized preferentially by uridine 5′-diphospho glucuronosyltransferases (UGTs) in the liver. As only orientin and isoorientin showed mono-sulfated and mono-glucuronidated metabolites, the dihydroxy group in 3′,4′-position may be essential for additional sulfation by sulfotransferases (SULTs) in the liver. The diglycosylic flavones schaftoside and isoschaftoside are likely not accepted as substrates of the used liver enzymes under the chosen conditions.

scholarly journals In Vitro Metabolism of Six C-Glycosidic Flavonoids from Passiflora incarnata L.

2021 ◽  
Vol 22 (12) ◽  
pp. 6566
Author(s):  
Martina Tremmel ◽  
Josef Kiermaier ◽  
Jörg Heilmann
Keyword(s):  
Phase I ◽  
Cell Line ◽  
In Vitro Metabolism ◽  
Cleavage Reaction ◽  
Compound Libraries ◽  
Medical Plants ◽  
Passiflora Incarnata ◽  
Metabolism Model ◽  
Phase I And Ii

Several medical plants, such as Passiflora incarnata L., contain C-glycosylated flavonoids, which may contribute to their efficacy. Information regarding the bioavailability and metabolism of these compounds is essential, but not sufficiently available. Therefore, the metabolism of the C-glycosylated flavones orientin, isoorientin, schaftoside, isoschaftoside, vitexin, and isovitexin was investigated using the Caco-2 cell line as an in vitro intestinal and epithelial metabolism model. Isovitexin, orientin, and isoorientin showed broad ranges of phase I and II metabolites containing hydroxylated, methoxylated, and sulfated compounds, whereas schaftoside, isoschaftoside, and vitexin underwent poor metabolism. All metabolites were identified via UHPLC-MS or UHPLC-MS/MS using compound libraries containing all conceivable metabolites. Some structures were confirmed via UHPLC-MS experiments with reference compounds after a cleavage reaction using glucuronidase and sulfatase. Of particular interest is the observed cleavage of the C–C bonds between sugar and aglycone residues in isovitexin, orientin, and isoorientin, resulting in unexpected glucuronidated or sulfated luteolin and apigenin derivatives. These findings indicate that C-glycosidic flavones can be highly metabolized in the intestine. In particular, flavonoids with ortho-dihydroxy groups showed sulfated metabolites. The identified glucuronidated or sulfated aglycones demonstrate that enzymes expressed by Caco-2 cells are able to potentially cleave C–C bonds in vitro.

scholarly journals Development and validation of UPLC-MS/MS method for in vitro quantitative analysis of pyrazinamide in lipid core-shell nanoarchitectonics for improved metabolic stability

2021 ◽  
Author(s):  
Maharshi Thalla ◽  
Aishwarya Jala ◽  
Roshan M. Borkar ◽  
Subham Banerjee
Keyword(s):  
Quantitative Analysis ◽  
Human Liver ◽  
Liver Microsomes ◽  
Entrapment Efficiency ◽  
Liver Metabolism ◽  
Human Liver Microsomes ◽  
Metabolic Stability ◽  
Core Shell ◽  
Lipid Core

AbstractPyrazinamide (PZA), a medication for tuberculosis, has high aqueous solubility and low permeability, undergoes extensive liver metabolism, and exhibits liver toxicity through its metabolites. To avoid this, PZA in lipid core-shell nanoarchitectonics has been formulated to target lymphatic uptake and provide metabolic stability to the incorporated drug. The UPLC-MS/MS method for reliable in vitro quantitative analysis of pyrazinamide (PZA) in lipid core-shell nanoarchitectonics as per ICH guidance was developed and validated using the HILIC column. The developed UPLC-MS/MS method is a simple, precise, accurate, reproducible, and sensitive method for the estimation of PZA in PZA-loaded lipid core-shell nanoarchitectonics for the in vitro determination of % entrapment efficiency, % loading of pyrazinamide, and microsomal stability of lipid core-shell nanoarchitectonics in human liver microsomes. The % entrapment efficiency was found to be 42.72% (±12.60). Lipid nanoarchitectonics was found to be stable in human liver microsomes, where %QH was found to be 6.20%, that is, low clearance. Thus, this formulation is suitable for preventing PZA-mediated extensive liver metabolism. These findings are relevant for the development of other lipid-mediated, suitable, stable nanoformulations containing PZA through various in vitro methods.

In vitro phase I metabolism of vinclozolin by human liver microsomes

Xenobiotica ◽  
2018 ◽  
Vol 49 (8) ◽  
pp. 895-904
Author(s):  
Marycarmen Cruz-Hurtado ◽  
Ma de Lourdes López-González ◽  
Victor Mondragón ◽  
Adolfo Sierra-Santoyo
Keyword(s):  
Phase I ◽  
Human Liver ◽  
Liver Microsomes ◽  
Human Liver Microsomes ◽  
Phase I Metabolism

Phase I Clinical and Pharmacologic Study of 13-cis-Retinoic Acid, Interferon Alfa, and Paclitaxel in Patients With Prostate Cancer and Other Advanced Malignancies

1999 ◽  
Vol 17 (7) ◽  
pp. 2213-2213 ◽  
Author(s):  
R. S. DiPaola ◽  
M. M. Rafi ◽  
V. Vyas ◽  
D. Toppmeyer ◽  
E. Rubin ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Retinoic Acid ◽  
Phase I ◽  
Human Liver ◽  
Liver Microsomes ◽  
Interferon Alfa ◽  
Time Curve ◽  
Concentration Time ◽  
Advanced Malignancies

PURPOSE: Recent studies demonstrate that retinoids decrease expression of the anti-apoptotic protein bcl-2, enhance the effect of chemotherapy, and act synergistically with interferon alfa (IFNα) to inhibit tumor cell growth in vitro. A phase I trial of 13-cis-retinoic acid (CRA), IFNα, and paclitaxel (TAX) was conducted to determine the toxicity and recommended phase II dose of this combination. Pharmacodynamic studies were performed to determine whether CRA and IFNα could modulate bcl-2 expression in vitro and in patients. PATIENTS AND METHODS: Twenty-two patients with prostate cancer or other advanced malignancies were treated with CRA/IFNα and escalating doses of TAX. The effect of CRA/IFNα on TAX pharmacokinetics was analyzed in both patients and human liver microsomes. The effect of CRA/IFNα on bcl-2 expression was assessed in vitro and in peripheral-blood mononuclear cells (PBMCs) by immunoblotting. RESULTS: CRA 1 mg/kg on days 1 to 4, IFNα 6 MU/m2 subcutaneously on days 1 to 4, and TAX 175 mg/m2 onday 3 was well tolerated. Pharmacokinetic studies demonstrated that CRA/IFNα caused a 33% decrease in TAX clearance and a 23% decrease in the area under the concentration-time curve values of the TAX metabolite 6-alfa-hydroxytaxol (6-HT). CRA alone reduced conversion of TAX to 6-HT by 41% in human liver microsomes. CRA/IFNα decreased bcl-2 expression in vitro and in PBMCs. CONCLUSION: CRA/IFNα and TAX is a well-tolerated regimen. CRA/IFNα increases TAX area under the concentration-time curve through an inhibitory effect of CRA on the metabolism of TAX to 6-HT. CRA/IFNα can modulate bcl-2 expression in vitro and demonstrates similar biologic activity in patients. Further studies will determine the activity of CRA/IFNα/TAX and validate the assessment of bcl-2 in PBMCs as a marker of tumor response.

scholarly journals In vitro biotransformation of pyrrolizidine alkaloids in different species: part II—identification and quantitative assessment of the metabolite profile of six structurally different pyrrolizidine alkaloids

2020 ◽  
Vol 94 (11) ◽  
pp. 3759-3774
Author(s):  
Ina Geburek ◽  
Dieter Schrenk ◽  
Anja These
Keyword(s):  
Human Liver ◽  
Pyrrolizidine Alkaloids ◽  
High Resolution Mass Spectrometry ◽  
Liver Microsomes ◽  
Metabolite Profile ◽  
Human Liver Microsomes ◽  
Rat Liver Microsomes ◽  
Metabolite Profiles ◽  
Fragmentation Patterns

Abstract Pyrrolizidine alkaloids (PA) exert their toxic effects only after bioactivation. Although their toxicity has already been studied and metabolic pathways including important metabolites were described, the quantification of the latter revealed a large unknown portion of the metabolized PA. In this study, the qualitative and quantitative metabolite profiles of structurally different PAs in rat and human liver microsomes were investigated. Between five metabolites for europine and up to 48 metabolites for lasiocarpine were detected. Proposals for the chemical structure of each metabolite were derived based on fragmentation patterns using high-resolution mass spectrometry. The metabolite profiles of the diester PAs showed a relatively good agreement between both species. The metabolic reactions were summarized into three groups: dehydrogenation, oxygenation, and shortening of necic acid(s). While dehydrogenation of the necine base is considered as bioactivation, both other routes are considered as detoxification steps. The most abundant changes found for open chained diesters were dealkylations, while the major metabolic pathway for cyclic diesters was oxygenation especially at the nitrogen atom. In addition, all diester PAs formed several dehydrogenation products, via the insertion of a second double bond in the necine base, including the formation of glutathione conjugates. In rat liver microsomes, all investigated PAs formed dehydropyrrolizidine metabolites with the highest amount formed by lasiocarpine, whereas in human liver microsomes, these metabolites could only be detected for diesters. Our findings demonstrate that an extensive analysis of PA metabolism can provide the basis for a better understanding of PA toxicity and support future risk assessment.

Sign in / Sign up

Export Citation Format

Share Document