scholarly journals Dried Leaf Artemisia Annua Improves Bioavailability of Artemisinin via Cytochrome P450 Inhibition and Enhances Artemisinin Efficacy Downstream

Biomolecules ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 254 ◽  
Author(s):  
Matthew R. Desrosiers ◽  
Alexis Mittleman ◽  
Pamela J. Weathers
Keyword(s):  
Tissue Distribution ◽  
Artemisia Annua ◽  
Liver Microsomes ◽  
Hepatic Metabolism ◽  
Oral Consumption ◽  
Tnf Α ◽  
Ic50 Values ◽  
Distribution Studies ◽  
Pass Metabolism

Artemisia annua L. and artemisinin, have been used for millennia to treat malaria. We used human liver microsomes (HLM) and rats to compare hepatic metabolism, tissue distribution, and inflammation attenuation by dried leaves of A. annua (DLA) and pure artemisinin. For HLM assays, extracts, teas, and phytochemicals from DLA were tested and IC50 values for CYP2B6 and CYP3A4 were measured. For tissue distribution studies, artemisinin or DLA was orally delivered to rats, tissues harvested at 1 h, and blood, urine and feces over 8 h; all were analyzed for artemisinin and deoxyartemisinin by GC-MS. For inflammation, rats received an intraperitoneal injection of water or lipopolysaccharide (LPS) and 70 mg/kg oral artemisinin as pure drug or DLA. Serum was collected over 8 h and analyzed by ELISA for TNF-α, IL-6, and IL-10. DLA-delivered artemisinin distributed to tissues in higher concentrations in vivo, but elimination remained mostly unchanged. This seemed to be due to inhibition of first-pass metabolism by DLA phytochemicals, as demonstrated by HLM assays of DLA extracts, teas and phytochemicals. DLA was more effective than artemisinin in males at attenuating proinflammatory cytokine production; the data were less conclusive in females. These results suggest that the oral consumption of artemisinin as DLA enhances the bioavailability and anti-inflammatory potency of artemisinin.

scholarly journals Tetrasaccharide iteration synthesis of a heparin-like dodecasaccharide and radiolabelling for in vivo tissue distribution studies

2013 ◽  
Vol 4 (1) ◽  
Author(s):  
Steen U. Hansen ◽  
Gavin J. Miller ◽  
Claire Cole ◽  
Graham Rushton ◽  
Egle Avizienyte ◽  
...  
Keyword(s):  
Tissue Distribution ◽  
Distribution Studies

scholarly journals Predicting Intestinal and Hepatic First-Pass Metabolism of Orally Administered Testosterone Undecanoate

2020 ◽  
Vol 10 (20) ◽  
pp. 7283 ◽  
Author(s):  
Atheer Zgair ◽  
Yousaf Dawood ◽  
Suhaib M. Ibrahem ◽  
Hyun-moon Back ◽  
Leonid Kagan ◽  
...  
Keyword(s):  
Liver Microsomes ◽  
Hepatic Metabolism ◽  
Hydrolysis Time ◽  
Testosterone Undecanoate ◽  
Main Site ◽  
Cell Homogenate ◽  
First Pass Metabolism ◽  
First Pass ◽  
Pass Metabolism

The bioavailability of orally administered drugs could be impacted by intestinal and hepatic first-pass metabolism. Testosterone undecanoate (TU), an orally administered ester prodrug of testosterone, is significantly subjected to first-pass metabolism. However, the individual contribution of intestinal and hepatic first-pass metabolism is not well determined. Therefore, the aim of the current study was to predict the metabolic contribution of each site. The hydrolysis–time profiles of TU incubation in human liver microsomes and Caco-2 cell homogenate were used to predict hepatic and intestinal first-pass metabolism, respectively. The in vitro half-life (t1/2 inv) for the hydrolysis of TU in microsomal mixtures was 28.31 ± 3.51 min. By applying the “well-stirred” model, the fraction of TU that could escape hepatic first-pass metabolism (FH) was predicted as 0.915 ± 0.009. The incubation of TU in Caco-2 cell homogenate yielded t1/2 inv of 109.28 ± 21.42 min, which was applied in a “Q gut” model to estimate the fraction of TU that would escape intestinal first-pass metabolism (FG) as 0.114 ± 0.02. Accordingly, only 11% of the absorbed fraction of TU could escape intestinal metabolism, while 91% can pass through hepatic metabolism. Hence, compared to the liver, the intestinal wall is the main site where TU is significantly metabolised during first-pass effect.

scholarly journals Investigation on the metabolic characteristics of isobavachin in Psoralea corylifolia L. (Bu-gu-zhi) and its potential inhibition against human cytochrome P450s and UDP-glucuronosyltransferases

2020 ◽  
Author(s):  
Han Xing ◽  
Jing Yang ◽  
Kaidi Ren ◽  
Zifei Qin ◽  
Peile Wang ◽  
...  
Keyword(s):  
Correlation Analysis ◽  
Kinetic Modelling ◽  
Liver Microsomes ◽  
Hepatic Metabolism ◽  
Relative Activity ◽  
Metabolic Characteristics ◽  
Activity Factor ◽  
Human Cytochrome

Abstract Objectives Isobavachin is a phenolic with anti-osteoporosis activity. This study aimed to explore its metabolic fates in vivo and in vitro, and to investigate the potential drug–drug interactions involving CYPs and UGTs. Methods Metabolites of isobavachin in mice were first identified and characterized. Oxidation and glucuronidation study were performed using liver and intestine microsomes. Reaction phenotyping, activity correlation analysis and relative activity factor approaches were employed to identify the main CYPs and UGTs involved in isobavachin metabolism. Through kinetic modelling, inhibition mechanisms towards CYPs and UGTs were also explored. Key findings Two glucuronides (G1 - G2) and three oxidated metabolites (M1 - M3) were identified in mice. Additionally, isobavachin underwent efficient oxidation and glucuronidation by human liver microsomes and HIM with CLint values from 5.53 to 148.79 μl/min per mg. CYP1A2, 2C19 contributed 11.3% and 17.1% to hepatic metabolism of isobavachin, respectively, with CLint values from 8.75 to 77.33 μl/min per mg. UGT1As displayed CLint values from 10.73 to 202.62 μl/min per mg for glucuronidation. Besides, significant correlation analysis also proved that CYP1A2, 2C19 and UGT1A1, 1A9 were main contributors for the metabolism of isobavachin. Furthermore, mice may be the appropriate animal model for predicting its metabolism in human. Moreover, isobavachin exhibited broad inhibition against CYP2B6, 2C9, 2C19, UGT1A1, 1A9, 2B7 with Ki values from 0.05 to 3.05 μm. Conclusions CYP1A2, 2C19 and UGT1As play an important role in isobavachin metabolism. Isobavachin demonstrated broad-spectrum inhibition of CYPs and UGTs.

Assessment of Inhibition of Bovine Hepatic Cytochrome P450 by 43 Commercial Bovine Medicines Using a Combination of In Vitro Assays and Pharmacokinetic Data from the Literature

2020 ◽  
Vol 13 (2) ◽  
pp. 123-131
Author(s):  
Steven X. Hu ◽  
Chase A. Mazur ◽  
Kenneth L. Feenstra
Keyword(s):  
Liver Microsomes ◽  
In Vitro Assay ◽  
In Vitro Assays ◽  
Pharmacokinetic Studies ◽  
Pharmacokinetic Data ◽  
Vitro Assay ◽  
Administration Routes ◽  
Ic50 Values

Background: There has been a lack of information about the inhibition of bovine medicines on bovine hepatic CYP450 at their commercial doses and dosing routes. Objective: The aim of this work was to assess the inhibition of 43 bovine medicines on bovine hepatic CYP450 using a combination of in vitro assay and Cmax values from pharmacokinetic studies with their commercial doses and dosing routes in the literature. Methods: Those drugs were first evaluated through a single point inhibitory assay at 3 μM in bovine liver microsomes for six specific CYP450 metabolisms, phenacetin o-deethylation, coumarin 7- hydroxylation, tolbutamide 4-hydroxylation, bufuralol 1-hydroxylation, chlorzoxazone 6-hydroxylation and midazolam 1’-hydroxylation. When the inhibition was greater than 20% in the assay, IC50 values were then determined. The potential in vivo bovine hepatic CYP450 inhibition by those drugs was assessed using a combination of the IC50 values and in vivo Cmax values from pharmacokinetic studies at their commercial doses and administration routes in the literature. Results: Fifteen bovine medicines or metabolites showed in vitro inhibition on one or more bovine hepatic CYP450 metabolisms with different IC50 values. Desfuroylceftiour (active metabolite of ceftiofur), nitroxinil and flunixin have the potential to inhibit one of the bovine hepatic CYP450 isoforms in vivo at their commercial doses and administration routes. The rest of the bovine medicines had low risks of in vivo bovine hepatic CYP450 inhibition. Conclusion: This combination of in vitro assay and in vivo Cmax data provides a good approach to assess the inhibition of bovine medicines on bovine hepatic CYP450.

scholarly journals HPLC-MS/MS-Mediated Analysis of the Pharmacokinetics, Bioavailability, and Tissue Distribution of Schisandrol B in Rats

2021 ◽  
Vol 2021 ◽  
pp. 1-12 ◽  
Author(s):  
Dahu Liang ◽  
Zijing Wu ◽  
Yanhao Liu ◽  
Chao Li ◽  
Xianghong Li ◽  
...  
Keyword(s):  
Tissue Distribution ◽  
Oral Bioavailability ◽  
Internal Standard ◽  
Rat Plasma ◽  
Absolute Bioavailability ◽  
Sprague Dawley ◽  
Linear Calibration ◽  
Tissue Homogenates ◽  
Distribution Studies

Schisandrol B, a lignan isolated from dried Schisandra chinensis fruits, has been shown to exhibit hepatoprotective, cardioprotective, renoprotective, and memory-enhancing properties. This study sought to design a sensitive and efficient HPLC-MS/MS approach to measuring Schisandrol B levels in rat plasma and tissues in order to assess the pharmacokinetics, oral bioavailability, and tissue distributions of this compound in vivo. For this analysis, bifendate was chosen as an internal standard (IS). A liquid-liquid extraction (LLE) approach was employed for the preparation of samples that were subsequently separated with an Agilent ZORBAX Eclipse XDB-C18 (4.6 × 150 mm, 5 μm) column with an isocratic mobile phase consisting of methanol and water containing 5 mM ammonium acetate and 0.1% formic acid (90 : 10, v/v). A linear calibration curve was obtained over the 5–2000 ng/mL and 1–1000 ng/mL ranges for plasma samples and tissue homogenates, respectively. This established method was then successfully applied to investigate the pharmacokinetics, oral bioavailability, and tissue distributions of Schisandrol B in Sprague-Dawley (SD) rats that were intravenously administered 2 mg/kg of Schisandrol B monomer, intragastrically administered Schisandrol B monomer (10 mg/kg), or intragastrically administered 6 mL/kg SCE (equivalent to 15 mg/kg Schisandrol B monomer). The oral absolute bioavailability of Schisandrol B following intragastric Schisandrol B monomer and SCE administration was approximately 18.73% and 68.12%, respectively. Tissue distribution studies revealed that Schisandrol B was distributed throughout several tested tissues, with particular accumulation in the liver and kidneys. Our data represent a valuable foundation for future studies of the pharmacologic and biological characteristics of Schisandrol B.

A comparative study on pharmacokinetics and tissue distribution of 5-hydroxy-4-methoxycanthin-6-one and its metabolite in normal and dextran sodium sulfate-induced colitis rats by HPLC-MS/MS

2020 ◽  
Author(s):  
Fangle Liu ◽  
Qiuyu Zhang ◽  
Chaozhan Lin ◽  
Yufeng Yao ◽  
Meiqi Wang ◽  
...  
Keyword(s):  
Tissue Distribution ◽  
Sodium Sulfate ◽  
Intestinal Tract ◽  
Dextran Sodium Sulfate ◽  
Main Metabolite ◽  
Pathological Conditions ◽  
Significant Difference ◽  
Distribution Studies ◽  
Existing Form

Abstract Objectives This study aimed to investigate the existing form of 5-hydroxy-4-methoxycanthin-6-one (PQ-A) in vivo after oral administration and the effects on its pharmacokinetics and tissue distribution by colitis. Methods A rapid HPLC-MS/MS method was established to simultaneously determine PQ-A and its main metabolite, 1-methoxicabony-β-carboline (PQ-B), in biological samples acquired from normal and dextran sodium sulfate (DSS)-induced colitic rats administered orally with PQ-A. Then, the pharmacokinetics of both PQ-A and PQ-B, and tissue distribution of PQ-A in the above two states were analysed. Key findings The pharmacokinetic results showed that the prototype of PQ-A was the main existing form in both physiological and pathological conditions. And significant difference between the above two status in pharmacokinetics of PQ-A was observed, such as higher exposure and longer elimination in colitis than that in normal rats. It suggested that the pharmacokinetics of medications for colitis was affected by enteritis. The tissue distribution studies displayed that PQ-A mainly accumulated in intestinal tract. Especially, the distribution of PQ-A in intestinal tract was increased obviously in colitic rats. Conclusions These results contributed to further illuminate the ADME process of PQ-A in different status and were prospected to be the reference to the clinical application of similar medicines in pathological states.

scholarly journals The synthesis of [14C]streptozotocin and its distribution and excretion in the rat

1974 ◽  
Vol 142 (3) ◽  
pp. 673-683 ◽  
Author(s):  
Eric H. Karunanayake ◽  
David J. Hearse ◽  
Graham Mellows
Keyword(s):  
Biological Activity ◽  
Tissue Distribution ◽  
Renal Clearance ◽  
Dose Response ◽  
Whole Body ◽  
Response Curves ◽  
Intestinal Excretion ◽  
Metabolic Transformation ◽  
Distribution Studies

[14C]Streptozotocin was synthesized specifically labelled at three positions in the molecule. The biological activity of synthetic streptozotocin was characterised by studies in vivo of its diabetogenic activity and its dose–response curves. After this characterization the excretion pattern of all three labelled forms of streptozotocin was studied. With [1-14C]streptozotocin and [2′-14C]streptozotocin the injected radioactivity was excreted (approx. 70% and 80% respectively) mainly in the urine, the greater part of the excretion occurring in the first 6h period; small amounts (approx. 9% and 8% respectively) were found in the faeces. In contrast, with [3′-methyl-14C]streptozotocin a much smaller proportion (approx. 42%) of the injected radioactivity was excreted in the urine, the major proportion appearing in the first 6h, whereas approx. 53% of the injected radioactivity was retained in the carcasses. In whole-body radioautographic studies very rapid renal clearance and hepatic accumulation of the injected radioactivity was observed with all three labelled forms of the drug. There was some evidence for biliary and intestinal excretion. Major differences were apparent in the tissue-distribution studies, with each of the three labelled forms, particularly with [3′-methyl-14C]streptozotocin. There was no accumulation of [1-14C]streptozotocin in the pancreas for the 6h period after administration. However, with [3′-methyl-14C]streptozotocin (and also [2′-14C]streptozotocin) there was evidence of some pancreatic accumulation after 2h. The results indicate that streptozotocin is subjected to considerable metabolic transformation and to rapid renal clearance. The implication of these suggestions is evaluated with particular reference to the diabetogenic action of streptozotocin.

scholarly journals Metabolite identification, tissue distribution, excretion and preclinical pharmacokinetic studies of ET-26-HCl, a new analogue of etomidate

2020 ◽  
Vol 7 (2) ◽  
pp. 191666
Author(s):  
Lu Yu ◽  
Xu Chen ◽  
Wen Sheng Zhang ◽  
Liang Zheng ◽  
Wen Wen Xu ◽  
...  
Keyword(s):  
Tissue Distribution ◽  
Intravenous Administration ◽  
High Performance ◽  
Anaesthetic Agent ◽  
Parent Compound ◽  
Liver Microsomes ◽  
Metabolite Identification ◽  
Pharmacokinetic Studies

ET-26-HCl, a novel anaesthetic agent with promising pharmacological properties, lacks extensive studies on pharmacokinetics and disposition in vitro and in vivo . In this study, we investigated the metabolic stability, metabolite production and plasma protein binding (PPB) of ET-26-HCl along with its tissue distribution, excretion and pharmacokinetics in animals after intravenous administration. Ultra-high performance liquid chromatography–tandem quadrupole time-of-flight mass spectrometry identified a total of eight new metabolites after ET-26-HCl biotransformation in liver microsomes from different species. A hypothetical cytochrome P450-metabolic pathway including dehydrogenation, hydroxylation and demethylation was proposed. The PPB rate was highest in mouse and lowest in human. After intravenous administration, ET-26-HCl distributed rapidly to all tissues in rats and beagle dogs, with the highest concentrations in fat and liver. High concentrations of ET-26-acid, a major hydroxylation metabolite of ET-26-HCl, were found in liver, plasma and kidney. Almost complete clearance of ET-26-HCl from plasma occurred within 4 h after administration. Only a small fraction of the parent compound and its acid form were excreted via the urine and faeces. Taken together, the results added to a better understanding of the metabolic and pharmacokinetic properties of ET-26-HCl, which may contribute to the further development of this drug.

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