Quercetin In Plasma Research Articles

Impact of calcium-reinforcement on stability, bioavailability, and bioactivity of quercetin-loaded zein/alginate-pectin nanoparticles.

Cationic calcium ions can crosslink anionic alginate and pectin molecules. It was hypothesized that calcium crosslinking would improve the stability and functionality of biopolymer nanoparticles consisting of zein cores coated by alginate-pectin shells. The effects of calcium ion addition on the structural, physicochemical, and gastrointestinal properties of quercetin-loaded zein/alginate-pectin nanoparticles were therefore investigated. The nanoparticles remained stable to aggregation at calcium ion concentrations of 9 mmol/L or less but aggregated and sedimented at higher concentrations. Calcium ion reinforcement increased the particle dispersion stability even at NaCl concentrations up to 1.4 molL-1. The presence of the calcium ions also reduced quercetin release during the early stages of simulated gastrointestinal digestion but increased its release during the later stages. The relatively high release (56.1%) of quercetin from the calcium-reinforced nanoparticles after digestion resulted in higher intracellular antioxidant activities. The pharmacokinetics of the encapsulated quercetin was measured after its oral administration to rats. The maximal concentration (Cmax) of quercetin in rat plasma for calcium-reinforced nanoparticles was 6.1% higher than non-reinforced nanoparticles; the half-life (t1/2) increased by 17.5%, and the mean retention time (MRT) was 10.0% higher (P < 0.05). These results suggest that calcium ion addition improved the performance and bioavailability of nutraceutical-loaded biopolymer nanoparticles. This might find application in the food and beverage industry. © 2024 Society of Chemical Industry.

Method Development and Validation for Quantification of Quercetin in Blood Plasma of Wistar Rats Using LC-MS/MS

Background: Quercetin is a flavanol that has demonstrated pharmaceutical properties such as anti-inflammatory, antioxidant, and anti-carcinogenic properties. However, parenteral formulations of quercetin are currently not in widespread use due to its poor aqueous solubility, fast metabolism, and low bioavailability. Objective: This study aimed to develop a quick, simple, and accurate method for the quantification of quercetin using ultra-fast liquid chromatography-tandem mass spectrometry (LC-MS/MS). Methods: A rapid and sensitive LC-MS/MS method was developed and fully validated for the quantification of quercetin in rat plasma after intravenous administration. Quercetin reference standard was used for the method development as well as in-vivo validation. ACQUITY UPLC BEH C18 Column (2.1 x 50 mm, 1.7 μm) was used for the chromatographic separation. The mobile phase consisted of solution A (water with 0.1% formic acid) and solution B (methanol: acetonitrile with 0.1% formic acid in the ratio of 1:1) with a flow rate of 0.350 μL/min. Further, the method was applied to quantify and pharmacokineticly profile quercetin in the blood plasma of outbred male and female Wistar rats. Results: The accuracy of the method was calculated for intraday and inter-day, which came out as ≤ 85.23% and 84.87%, respectively. The precision of the method calculated for intraday was ≤3.02%, and for inter-day was ≤2.75%. The percentage recovery was found to be ≤85.23% for intraday and ≤84.87% for inter-day. The Relative Standard Deviation was 0.04 for intraday and 1.10 for inter day, respectively. Conclusion: The developed method has an advantage over other reported methods because of its short run time of 6 minutes as well as its short time of data registration of approximately 2.5 minutes. This method can be used for the routine analysis of quercetin in vivo animal studies.

Origanum majorana L. polyphenols: in vivo antiepileptic effect, in silico evaluation of their bioavailability, and interaction with the NMDA receptor.

Introduction: Epilepsy is a chronic brain disease characterized by repeated seizures and caused by excessive glutamate receptor activation. Many plants are traditionally used in the treatment of this disease. This study aimed to evaluate the bioavailability of a polyphenolic extract obtained from Origanum majorana L. (OMP) leaves, as well as its antiepileptic activity and its potential mechanism of action. Methods: We have developed and validated a simple, rapid, and accurate stability-indicating reversed-phase liquid chromatographic method for the simultaneous determination of caffeine and quercetin in rat plasma. The OMP antiepileptic effect was evaluated with pilocarpine-induced seizures, and a docking method was used to determine the possible interaction between caffeic acid and quercetin with the N-methyl-D-aspartate (NMDA) receptor. Results and Discussion: Both compounds tested showed low bioavailability in unchanged form. However, the tested extract showed an anticonvulsant effect due to the considerably delayed onset of seizures in the pilocarpine model at a dose of 100mg/kg. The molecular docking proved a high-affinity interaction between the caffeic acid and quercetin with the NMDA receptor. Taken together, OLP polyphenols demonstrated good antiepileptic activity, probably due to the interaction of quercetin, caffeic acid, or their metabolites with the NMDA receptor.

Simultaneous Determination of Three Flavonoids in Rat Plasma of Masson Pinus Needles (Pinus massoniana L.) Extracts by UHPLC-MS/MS and Application to Pharmacokinetics Studies after Oral and Transdermal Administration.

Pinus massoniana needles, a traditional herb, were applied to prevent hair loss in China. Studies available mainly focused on pine needle flavonoids with various biological activities. However, there has been no pharmacokinetics study of the flavonoids from Pinus needles extract. A selective and sensitive ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed to simultaneously quantify taxifolin, quercetin and catechin in rat plasma. To separate the three constituents, an Agilent Extend-C18 column (2.1mm × 100mm, 1.8μm) was used with a mobile phrase of (A) 0.1% formic acid and (B) acetonitrile. The analytes were measured by multiple reaction monitoring in the negative ionization mode. There was good linearity in the established UHPLC-MS/MS method, with a coefficient of determination (r2) of >0.99. The accuracy, intra-day and inter-day precision and recovery were all satisfactory and these 3 compounds were stable under the tested conditions. The validated method in this study was successfully applied to pharmacokinetic study in healthy rats after oral and transdermal administration of Pinus needles extract. The results could provide further research foundation for pine needle extract as external preparations.

Liquid Chromatography-Electrospray Ionization Tandem Mass Spectrometry Estimation of Quercetin-Loaded Nanoemulsion in Rabbit Plasma: In Vivo-In Silico Pharmacokinetic Analysis Using GastroPlus.

In the present study, we developed and validated a rapid, specific, sensitive, and reproducible liquid chromatography-electrospray ionization tandem mass spectrometry method for quantifying quercetin (QT) in rabbit plasma using hydrochlorothiazide as the internal standard. Animals were orally administered with optimized QT-loaded nanoemulsion (QTNE) and QT suspension (QTS), equivalent to 30 mg/kg, to the test and control group, respectively. The blood samples were collected at pre-determined time points up to 48 h. The linearity range was from 5 to 5000 ng mL-1 with R 2 = 0.995. Further, we analyzed the various pharmacokinetic parameters and established the in vitro-in vivo correlation (IVIVC) of QTNE using GastroPlus software. The method was successfully developed and validated, and when applied for the determination of QT in rabbit plasma, it exhibited an increase in C max from 122.56 ng mL-1 (QTS) to 286.51 ng mL-1 (QTNE) (2.34-fold) and AUC0-48 from 976 ng h mL-1 (QTS) to 4249 ng h mL-1 (QTNE) (4.35-fold), indicating improved oral bioavailability QT when administered as QTNE. Statistical analysis revealed that the Loo-Riegelman method (two-compartmental method) best fitted the deconvolution approach (R 2 = 0.998, SEP = 4.537, MAE = 2.759, and AIC = 42.38) for establishing the IVIVC. In conclusion, the established bioanalytical method and IVIVC studies revealed that QTNE is a potential carrier for the effective delivery of QT with enhanced oral bioavailability.

Regional distributions of curcumin and tetrahydrocurcumin in the liver and small intestine of rats when orally co-administered with quercetin and paeoniflorin.

Curcumin (CUR), derived from the dietary spice turmeric, is a polyphenolic compound with various biological and pharmacological activities. Tetrahydrocurcumin (THC) is one of the major reductive metabolites of curcumin. A pharmacokinetic study using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) for the simultaneous determination of curcumin, THC, quercetin (QR), and paeoniflorin (PF) in rat plasma had been performed. In this study, the regional distributions of curcumin and tetrahydrocurcumin in the liver and the three segments of small intestine (duodenum, jejunum, and ileum) of rats when orally co-administered with quercetin and paeoniflorin were carried out. Drug concentrations were determined using UHPLC-MS/MS. The results showed that curcumin was well distributed in the small intestine, while the distributions of tetrahydrocurcumin in the liver, duodenum, jejunum were similar, but much more abundant in the ileum. When orally co-administered with quercetin and paeoniflorin, the tissue to plasma concentration ratios (Kp values) of curcumin in the three segments of the small intestine were increased, indicating that the presence of quercetin and paeoniflorin increases the distribution of curcumin in these regions. Moreover, the half-life (t1/2 ) of THC in the liver was significantly prolonged, and the Kp value of THC in the liver was increased and the Kp values in the small intestine were decreased, suggesting that the combination of quercetin and paeoniflorin might suppress the metabolism of curcumin in the small intestine. In brief, the combination had an effect on the distributions of curcumin and tetrahydrocurcumin in the liver and small intestine of rats.

Bioanalytical Method Development and Validation for Determination of Rifampicin and Quercetin in Rat Plasma by UHPLC-MS/MS: Applications to Pharmacokinetic Study

UHPLC-MS/MS was utilised to quantitatively analyse Rifampicin and Quercetin-loaded Liquisolid compact in rat plasma. The UPLC Acquity C18 (1.7 μm, 2.1 × 15 mm) column and 0.5 ml/min were used to separate the analyte. In a low-pressure gradient mode, A: In water 0.1 % formic acid and B: In acetonitrile 0.1 % formic acid as the mobile phase. Sample pre-treatment was performed by protein precipitation technique with methanol and acetonitrile (1:1) from rat plasma. As an internal standard (IS), the analyte was found by tracking precursor-to-product ion transformations of 823 → 791.3 m/z for rifampicin, 303 → 257 m/z for quercetin, and 138 → 121 m/z for isoniazid in MRM mode. The proposed technique was validated for precisions (Intraday and Interday) accuracy, linearity, quantification at lower limits, and analyte recovery. The findings showed that the plasma samples inter and intra-day precision and consistency values were determined to be within the acceptable range. After orally administering Liquid solid compact and pure drug solution, which showed a substantial difference in the pace and extent of absorption, the method’s suitability for determining the pharmacokinetic profile of each drug was tested.

Deciphering the Active Compounds and Mechanisms of HSBDF for Treating ALI via Integrating Chemical Bioinformatics Analysis.

The Huashi Baidu Formula (HSBDF), a key Chinese medical drug, has a remarkable clinical efficacy in treating acute lung injury (ALI), and it has been officially approved by the National Medical Products Administration of China for drug clinical trials. Nevertheless, the regulated mechanisms of HSBDF and its active compounds in plasma against ALI were rarely studied. Based on these considerations, the key anti-inflammatory compounds of HSBDF were screened by molecular docking and binding free energy. The key compounds were further identified in plasma by LC/MS. Network pharmacology was employed to identify the potential regulatory mechanism of the key compounds in plasma. Next, the network pharmacological prediction was validated by a series of experimental assays, including CCK-8, EdU staining, test of TNF-α, IL-6, MDA, and T-SOD, and flow cytometry, to identify active compounds. Molecular dynamic simulation and binding interaction patterns were used to evaluate the stability and affinity between active compounds and target. Finally, the active compounds were subjected to predict pharmacokinetic properties. Molecular docking revealed that HSBDF had potential effects of inhibiting inflammation by acting on IL-6R and TNF-α. Piceatannol, emodin, aloe-emodin, rhein, physcion, luteolin, and quercetin were key compounds that may ameliorate ALI, and among which, there were five compounds (emodin, aloe-emodin, rhein, luteolin, and quercetin) in plasma. Network pharmacology results suggested that five key compounds in plasma likely inhibited ALI by regulating inflammation and oxidative damage. Test performed in vitro suggested that HSBDF (0.03125 mg/ml), quercetin (1.5625 μM), emodin (3.125 μM), and rhein (1.5625 μM) have anti-inflammatory function against oxidative damage and decrease apoptosis in an inflammatory environment by LPS-stimulation. In addition, active compounds (quercetin, emodin, and rhein) had good development prospects, fine affinity, and stable conformations with the target protein. In summary, this study suggested that HSBDF and its key active components in plasma (quercetin, emodin, and rhein) can decrease levels of pro-inflammatory factors (IL-6 and TNF-α), decrease expression of MDA, increase expression of T-SOD, and decrease cell apoptosis in an inflammatory environment. These data suggest that HSBDF has significant effect on anti-inflammation and anti-oxidative stress and also can decrease cell apoptosis in treating ALI. These findings provided an important strategy for developing new agents and facilitated clinical use of HSBDF against ALI.

A sensitive UPLC/ESI/MS/MS method for concomitant quantification of active plant constituent combinations in rat plasma after single oral administration.

Ultra-performance liquid chromatography electrospray ionization tandem mass spectrometry (UPLC/ESI/MS/MS) for the concomitant quantification of active plant constituents, namely quercetin and piperine, in rat plasma was developed and validated to assess pharmacokinetics after a single oral administration. Liquid-liquid extraction technique with ethyl acetate and n-hexane (1 : 1) was used, and fisetin was added as an internal standard (IS). Effective chromatographic separation of quercetin, piperine and IS was executed on a Waters Acquity BEH C18 column (50.0 mm × 2.1 mm, 1.7 μm) using formic acid both (0.1% w/v) in water (A) and acetonitrile (B) as the mobile phase in gradient mode. For detection purposes, positive electrospray ionization (ESI) mode was used with multiple reaction monitoring (MRM) mode for estimation using [M + H]+ fragment ions m/z 303.04 → 152.9 for quercetin, 286.12 → 201.04 for piperine and 287.01 → 136.93 for IS. The method was linear over the calibration range of 0.1-200 ng mL-1. The lower limit of quantification (LLOQ) of quercetin and piperine was obtained as 0.1 ng mL-1 in rat plasma, along with negligible matrix effect and acceptable stability. Furthermore, the bioanalytical method was successfully implemented to determine the pharmacokinetic profiles of quercetin-and piperine-enriched nanostructured lipid carriers (NLCs) in rat plasma after oral administration. The enhancement in the oral bioavailability of quercetin and piperine was 20.72 and 4.67 fold, respectively, compared to their native pristine dispersions. Future exploration of the concentrations of these active constituents in human plasma and organs is feasible using this sensitive, validated UPLC/ESI/MS/MS method.

Development and validation of RP-HPLC based bioanalytical method for simultaneous estimation of curcumin and quercetin in rat's plasma

Curcumin (CUR) and quercetin (QUE) are the two important flavonoids that possess very good anti-inflammatory, anti-oxidant, antidiabetic, analgesic and anti-cancer activities. Reverse phase high performance liquid chromatography (RP-HPLC) was used to develop a bioanalytical method for simultaneous estimation of both the drugs in the rat's plasma. The method was further validated as per ICH M10 guidelines using C-18 reverse phase column. Fisetin was used as an internal standard. Gradient elution was carried out at a flow rate of 1 mL/min in acetonitrile (ACN) and 2% glacial acetic acid (GAA). The chromatograms of all three phytoconstituents were recorded at detection wavelength of 392 nm. The drugs were extracted from the plasma samples by using protein precipitation method. The retention times (Rts) of fisetin, QUE and CUR were found to be 4.2, 5.5 and 12.1 min respectively. The developed method was found to be linear in the range of 2–10 µg/mL with regression coefficient (r2) of 0.9998 and 0.9993 for QUE and CUR respectively. The percentage recovery of drug more than 95% and percentage relative standard deviation less than 2% among the replicate studies indicated that the method was accurate and precise. Limit of detection (LOD) and limit of quantification (LOQ) in plasma samples were found to be 0.18 and 0.54 µg/mL for QUE and 0.35 and 1 µg/mL for CUR respectively. Further, the stability studies were also carried out at freeze-thaw cycles, short term stability at room temperature. The developed method was found to be robust and passed all the parameters of validation and therefore can be used effectively for estimation of CUR and QUE in the rat plasma.

Активність ферментів антиоксидантного захисту і вміст глутатіону у плазмі крові щурів за дії кверцетину та гістаміну в дослідах in vitro

The effect of histamine and quercetin, as well as their combined effect on the activity of superoxide dismutase, catalase and the content of reduced glutathione in the blood plasma of rats was studied. It was found that the addition to the blood of quercetin at a concentration of 0.1; 0.3; 0.5; 1.0; 5.0 mM causes an increase in superoxide dismutase activity. It was found that histamine at concentrations of .01 and 0.1 μm leads to a decrease in superoxide dismutase activity by 31 and 17 %, respectively. Whereas the biogenic amine in the lowest and highest concentrations does not change the activity of superoxide dismutase in plasma. At simultaneous introduction into blood of histamine in the maximum concentration (10.0 μm) and quercetin in concentration of 0,1; 0.5; 3.0 mM normalizes the activity of superoxide dismutase. And only the combined action of histamine of this concentration and quercetin at a concentration of 5.0 mM reduces the activity of the enzyme by 21 %. Histamine at a concentration of 0.01 μm and the simultaneous action of quercetin at a concentration of 0.1; 0.5; 3.0; 5.0 mM increases the activity of superoxide dismutase, which indicates the generation of reactive oxygen species, in particular the superoxide anion radical. It was found that the addition of whole concentrations of quercetin to whole blood causes a decrease in plasma catalase activity. The combined action of quercetin and histamine causes a decrease in catalase activity. It was found that the addition to the blood of quercetin at a concentration of 0.1; 0.3; 0.5; 1.0 mM causes a decrease in the content of reduced glutathione. Quercetin at a concentration of 3.0 and 5.0 mM causes an increase in reduced glutathione by 27 and 14 %, respectively, compared to the reference plasma. Histamine at concentrations of 10.0, 1.0 and 0.01 μm leads to an increase in the amount of reduced glutathione by 24, 26 and 19 %, respectively. And at a concentration of 0.1 μm, the biogenic amine reduces the GSH content by 39 %. With simultaneous introduction into the blood of histamine at a concentration of 10.0 μm and quercetin at a concentration of 0.1; 0.5; 3.0 mM there is an increase in the content of reduced glutathione. And only at a concentration of 5.0 mM quercetin on the background of the action of histamine (10.0 μm), the content of reduced glutathione is slightly reduced. However, with the combined action of histamine at a minimum concentration (0.01 μM) and quercetin at a concentration of 0.1; 0.5; 3.0 and 5.0 mM there is a decrease in the content of reduced glutathione. After performing a dispersion analysis, it was found that the state of the antioxidant system, both enzymatic and non-enzymatic, is significantly affected by histamine. The smallest, but significant share of the effect is on the action of quercetin in the blood plasma of rats. The indirect and significant effect of the simultaneous action of histamine and quercetin on the antioxidant system of rat plasma was revealed.

Effect of Lipopolysaccharide-Induced Inflammatory Challenge on β-Glucuronidase Activity and the Concentration of Quercetin and Its Metabolites in the Choroid Plexus, Blood Plasma and Cerebrospinal Fluid

Quercetin-3-glucuronide (Q3GA), the main phase II metabolite of quercetin (Q) in human plasma, is considered to be a more stable form of Q for transport with the bloodstream to tissues, where it can be potentially deconjugated by β-glucuronidase (β-Gluc) to Q aglycone, which easily enters the brain. This study evaluates the effect of lipopolysaccharide (LPS)-induced acute inflammation on β-Gluc gene expression in the choroid plexus (ChP) and its activity in blood plasma, ChP and cerebrospinal fluid (CSF), and the concentration of Q and its phase II metabolites in blood plasma and CSF. Studies were performed on saline- and LPS-treated adult ewes (n = 40) receiving Q3GA intravenously (n = 16) and on primary rat ChP epithelial cells and human ChP epithelial papilloma cells. We observed that acute inflammation stimulated β-Gluc activity in the ChP and blood plasma, but not in ChP epithelial cells and CSF, and did not affect Q and its phase II metabolite concentrations in plasma and CSF, except Q3GA, for which the plasma concentration was higher 30 min after administration (p < 0.05) in LPS- compared to saline-treated ewes. The lack of Q3GA deconjugation in the ChP observed under physiological and acute inflammatory conditions, however, does not exclude its possible role in the course of neurodegenerative diseases.

Inhibitory effects of quercetin and its major metabolite quercetin-3-O-β-D-glucoside on human UDP-glucuronosyltransferase 1A isoforms by liquid chromatography-tandem mass spectrometry.

Quercetin is a flavonoid that is widely present in plant-derived food. Quercetin-3-O-β-D-glucoside (Q3GA) is a predominant metabolite of quercetin in animal and human plasma. The inhibitory effects of the UDP-glucuronosyl transferases (UGTs) caused by herbal components may be a key factor for the clinical assessment of herb-drug interactions (HDIs). The present study aimed to investigate the inhibitory profile of quercetin and Q3GA on recombinant UGT1A isoforms in vitro. The metabolism of the nonspecific substrate 4-methylumbelliferone (4-MU) by the UGT1A isoforms was assessed by liquid chromatography-tandem mass spectrometry. Preliminary screening experiments indicated that quercetin exhibited stronger inhibitory effects on UGT1A1, UGT1A3, UGT1A6 and UGT1A9 enzymes than Q3GA. Kinetic experiments were performed to characterize the type of inhibition caused by quercetin and Q3GA towards these UGT isoforms. Quercetin exerted non-competitive inhibition on UGT1A1 and UGT1A6, with half maximal inhibitory concentration (IC50) values of 7.47 and 7.07 µM and inhibition kinetic parameter (Ki) values of 2.18 and 28.87 µM, respectively. Quercetin also exhibited competitive inhibition on UGT1A3 and UGT1A9, with IC50 values of 10.58 and 2.81 µM and Ki values of 1.60 and 0.51 µM, respectively. However, Q3GA displayed weak inhibition on UGT1A1, UGT1A3 and UGT1A6 enzymes with IC50 values of 45.21, 106.5 and 51.37 µM, respectively. In the present study, quercetin was a moderate inhibitor of UGT1A1 and UGT1A3, a weak inhibitor of UGT1A6, and a strong inhibitor on UGT1A9. The results of the present study suggested potential HDIs that may occur following quercetin co-administration with drugs that are mainly metabolized by UGT1A1, UGT1A3 and UGT1A9 enzymes.

Quercetin and Isorhamnetin Attenuate Benzo[a]pyrene-Induced Toxicity by Modulating Detoxification Enzymes through the AhR and NRF2 Signaling Pathways.

Benzo[a]pyrene, classified as a Group 1 carcinogen, is metabolized to B[a]P-7,8-dihydrodiol-9,10-epoxide (BPDE), causing DNA mutations and eventually cancer. Quercetin is a dietary flavonoid abundant in fruits and vegetables. After quercetin intake, quercetin’s metabolites isorhamnetin and miquelianin are more highly concentrated than quercetin in the human plasma. In this study, we investigated the molecular mechanisms associated with the cytoprotective effect of quercetin and its metabolites against benzo[a]pyrene from a detoxification perspective. Quercetin and its metabolite isorhamnetin reduced benzo[a]pyrene-induced cytotoxicity, whereas the metabolite miquelianin did not mitigate benzo[a]pyrene-induced cytotoxicity. Moreover, quercetin and isorhamnetin reduced intracellular levels of BPDE-DNA adducts. The formation and elimination of BPDE is mediated by the xenobiotic detoxification process. Quercetin and isorhamnetin increased the gene and protein expression levels of phase I, II, and III enzymes involved in xenobiotic detoxification. Furthermore, quercetin and isorhamnetin induced the translocation of aryl hydrocarbon receptor (AhR) and nuclear factor erythroid 2-related factor 2 (NRF2), which regulate the expression level of phase enzymes. Our results suggest that quercetin and isorhamnetin promote the metabolism, detoxification, and elimination of B[a]P, thereby increasing anti-genotoxic effects and protecting against B[a]P-induced cytotoxicity.

Enhancement of oral bioavailability of quercetin by metabolic inhibitory nanosuspensions compared to conventional nanosuspensions

Quercetin-loaded nanosuspensions (Que-NSps) added metabolic inhibitors were evaluated as drug delivery system to promote the oral bioavailability of quercetin. Que-NSps were prepared respectively using d-alpha tocopherol acid polyethylene glycol succinate (TPGS) or Soybean Lecithin (SPC) as stabilizer. On the basis, Piperine (Pip) or sodium oleate (SO) was, respectively, encapsulated in Que-NSps as phase II metabolic inhibitors. The resulting Que-NSps all displayed a mean particle size of about 200 nm and drug loading content was in the range of 22.3–27.8%. The release of quercetin from Que-NSps was slow and sustained. After oral administration of 50 mg/kg different Que-NSps, the levels of free quercetin in plasma were significantly promoted, the concentration of quercetin metabolites (isorhamnetin and quercetin 3-O-β-d-Glucuronide) were decreased. The absolute bioavailability was, respectively 15.55%, 6.93%, 12.38%, and 23.58% for TPGS-Que-NSps, TPGS-SO-Que-NSps, SPC-Que-NSps, and SPC-Pip-Que-NSps, and 3.61% for quercetin water suspension. SPC-Pip-Que-NSps turned out to an ideal nanocarrier combined nano drug delivery system together with metabolic inhibitor to promote oral absorption of quercetin.

Інтенсивність вільнорадикальних процесів у плазмі крові щурів за впливу гістаміну і кверцетину

The content of products of lipoperoxidation and oxidative modification of proteins in rat blood plasma under the action of quercetin and histamine was investigated. Quercetin was used at concentrations of 0.1; 0.3; 0.5; 1; 3; 5 mm, and histoma - 0.01; 0.1; 1; 10 μm. It was found that quercetin in the blood plasma of rats causes a slight increase in the content of hydroperoxides and TBA-positive products, except the concentration of 0.5 mm, at which the content of secondary products is reduced and the content of primary remains within the control. Histamine at concentrations of 0.01; 0.1; 1; 10 µM leads to an increase in the content of hydroperoxides and a decrease in the number of TBK-positive products. The combined effect of histamine and quercetin causes a significant increase in primary lipoperoxidation products, whereas TBK-positive lipid peroxidation products decrease. Quercetin in the concentration range of 0.1÷1 mM intensifies the accumulation of carbonyl groups of proteins of basic and neutral nature, while flavonoid at concentrations of 3.5 mM – slows down. Histamine at all tested concentrations leads to an increase in the content of carbonyl groups of proteins, except the concentration of 0.1 μm. Against the background of high concentration histamine, quercetin reduces the intensity of oxidative modification of proteins. The simultaneous action of low concentration histamine and quercetin at a concentration of 0.5 and 5 mm leads to the accumulation of carbonyl groups of proteins of a neutral nature, as well as to the main only when exposed to quercetin at a concentration of 5 mm. According to the analysis of variance, it was found that quercetin has a maximum effect on the accumulation of TBA-positive products and carbonyl groups of proteins of basic character. Histamine is strongly influenced by the accumulation of lipid hydroperoxides. Quercetin at concentrations of 0.1; 0.3; 0.5; 1; 3 mm determines between the indices of free radical processes under study, in the blood plasma of rats, a strong interconnectedness, and a bioflavonoid at a concentration of 5 mm leads to the formation of interconnections of average strength. Histamine at concentrations of 10; 1; 0.1 µM causes a close correlation of the mean strength between the individual indices of free radical oxidation. Histamine at a concentration of 0.01 μm causes a significant increase in the correlation between the parameters of sex and oxidative modification of proteins. The combined effect of quercetin at a concentration of 0.1 mm and histamine at a concentration of 0.01 μm causes a change in the nature of the correlation dependence, which becomes strong between most of the studied parameters.

UPLC-MS/MS Method for the Simultaneous Quantification of Eight Compounds in Rat Plasma and Its Application to a Pharmacokinetic Study after Oral Administration of Veratrum (Veratrum nigrum L.) Extract.

Veratrum nigrum L. is a well-known traditional Chinese medicine with a lot of pharmacological activities including antihypertensive, anticancer, and antifungal effects. In the current experiment, a rapid and sensitive UPLC-MS/MS method that takes only 7 min run time has been established and validated for simultaneous determination of eight bioactive compounds including cyclopamine, jervine, veratramine, polydatin, quercetin, apigenin, resveratrol, and veratrosine in rat plasma. The chromatographic separation of analytes and internal standard was performed on a Phenyl-Hexyl column (2.1 × 100 mm, 1.7 μm) with the mobile phase consisting of water (0.1% formic acid) and acetonitrile at a flow rate of 0.3 mL/min. An electrospray ionization (ESI) source was used to detect the samples in both positive and negative ion modes. The intra- and interday precisions of the compounds were less than 9.5% and the accuracy ranged from -10.8% to 10.4%. The extraction recoveries of the compounds were in the range of 85.1 ± 1.5% to 102.6 ± 8.0%, and the matrix effect ranged from 91.2 ± 4.5% to 113.8 ± 1.5%. According to the results of the stability test, the eight compounds have good stability under various conditions and the relative standard deviation (RSD) less than 13.2%. The pharmacokinetic parameters of the eight compounds in rat plasma after oral administration of Veratrum nigrum L. extract were successfully determined by the established UPLC-MS/MS method.

In situ growth of zeolitic imidazolate framework-8 on woven cotton yarn for the thin film microextraction of quercetin in human plasma and food samples

This study explored the in-situ growth of zeolitic imidazolate framework-8 on woven cotton yarn for the first time. The applicability of highly flexible and natural cotton yarn-polypyrrole-layered double hydroxide-zeolitic imidazolate framework-8 composite (CY- PPy-LDH-ZIF8) was introduced for the extraction of quercetin in plasma and food samples. For increasing the contact area of the analyte and the prepared sorbent, the green substrate was woven and employed as the substrate for the construction of ZIF8. Extraction, separation, and determination of the analyte were performed by TFME-HPLC-UV. Due to the large surface area, the number of cages and unique porous structure of the zeolitic imidazolate framework-8 (ZIF8) as well as hydrogen bonding, ionic and π-π interactions between the analyte and the ZIF8, the prepared thin film showed a high affinity towards the target analyte. The affecting parameters on the extraction efficiency, including pH of the sample solution, extraction time, stirring rate, desorption time, and elution solvent volume were investigated and optimized through applying Box-Behnken Design (BBD). Under optimum conditions, calibration curves were found to be linear in the range of 0.2–200 μg L−1 with r2 > 0.9958. The limits of detection (based on S/N = 3), limits of quantification (based on S/N = 10), and intra-day, as well as inter-day RSDs, were lower than 0.21 μg L−1, 0.70 μg L−1 and 5.6%, respectively.

Comparative pharmacokinetic study of five flavonoids in normal rats and rats with gastric ulcer following oral administration of Mongolian medicine, Shudage - 4 by UPLC – ESI – MS/MS

Purpose: To develop a simple, rapid and sensitive ultra-performance liquid chromatography - electrospray ionization-mass spectrometry (UPLC–ESI–MS/MS) method was developed and fully validated for the simultaneous determination of galangin, kaempferide, galangin-3-methylether, kaempferol and quercetin in rat plasma after oral administration of Mongolian Medicine, Shudage-4 extracts.&#x0D; Methods: The galangin, kaempferide, galangin-3-methylether, kaempferol and quercetin were separated on a C18 column using 0.1 % formic acid at a flow rate of 0.4 mL / min and detected by a mass spectrometer in negative-ion mode with selected reaction monitoring (SRM) mode. Plasma samples were processed with a simple deproteinization technique using ethyl acetate and acetonitrile. Following the protein precipitation, the plasma samples were evaporated under gentle stream of nitrogen and analyzed by above method. Naringin was used as an internal standard (IS). Method validation was performed according to the Chinese Food and Drug Administration guidelines.&#x0D; Results: A good linearity (r2 ≥ 0.9990) was showed by the UPLC – ESI – MS / MS method, the low limits of quantification for galangin, kaempferide, galangin-3-methylether, kaempferol and quercetin were 229.8, 78.8, 32.0, 123.7 and 137.8 ng / mL, respectively. The results of inter-day and intra-day precisions met the experimental requirement (&lt; 7.8 %). The matrix effect and recovery efficiency of the five analytes were more than 72.9 and 88.7 % respectively. The stability of the analytes were satisfactory. The UPLC – ESI – MS / MS method has been used for the five analytes’ pharmacokinetics study successfully after gastrointestinal route of the Mongolian Medicine Shudage-4. The pharmacokinetic parameters showed significant differences (P &lt; 0.05) between the normal and gastric ulcer groups. The metabolism and transport of the five analytes in gastric ulcer rates were faster than in normal rats after administration of Shudage - 4 extract. Double-peak phenomenon appeared in galangin, galangin – 3 - methylether and quercetin.&#x0D; Conclusion: The results suggest that the metabolism and transport of Mongolian Medicine Shudage-4 in gastric ulcer rats is faster than in normal rats and may be enriched and acted on at the lesion site.&#x0D; Keywords: UPLC – ESI – MS / MS; Mongolian medicine; Shudage - 4; pharmacokinetics; gastric ulcer

Development of a HPLC-MS/MS Method to Determine the 13 Elements of Semen Cuscutae and Application to a Pharmacokinetic Study in Rats

This study developed a method for simultaneous determination of 13 elements of Semen Cuscutae (quercitrin, quercetin, hyperoside, caffeic acid, chlorogenic acid, luteolin, apigenin, kaempferol, isoquercitrin, cryptochlorogenic acid, isorhamnetin-3-O-glucoside, astragalin, and rutin) in rat plasma using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) in the negative MRM mode. The analytes were analyzed with CORTECS®C18 column (4.6 × 150 mm, 2.7 μm) with mobile phases consisting of 0.1% formic acid in water (A) and acetonitrile (B). The intra- and interday precision of the target compounds were expressed as relative standard deviation (RSD) in the range of 0.5%–10.4%, and the accuracy of the target compounds was expressed as relative error (RE) not exceeding ±14.5% for all analytes. In the meantime, the extraction recovery of the target compounds in plasma samples ranged from 87.4% to 106.2% and matrix effect from 81.0% to 115.5%. The established method was successfully accomplished for the pharmacokinetic study of the analytes in rat plasma samples following oral administration of Semen Cuscutae extract, and the pharmacokinetic parameters of seven compounds were obtained.