Modifications to microplastics by potassium ferrate(VI): impacts on sorption and sinking capability in water treatment.

Pre-treatment (oxidation) may induce potential modifications to microplastics (MPs), further affecting their behaviors and removal efficiency in drinking water treatment plants. Herein, potassium ferrate(VI) oxidation was tested as a pre-treatment for MPs with four polymer types and three sizes each. Surface oxidation occurred with morphology destruction and oxidized bond generation, which were prosperous under low acid conditions (pH 3). As pH increased, the generation and attachment of nascent state ferric oxides (FexOx) gradually became dominant, making MP-FexOx complexes. These FexOx were identified as Fe(III) compounds, including Fe2O3 and FeOOH, firmly attaching to the MP surface. Using ciprofloxacin as the targeted organic contaminant, the presence of FexOx enhanced MP sorption dramatically, e.g., the kinetic constant Kf of ciprofloxacin raised from 0.206 (6.5 µm polystyrene) to 1.062 L g-1 (polystyrene-FexOx) after oxidation at pH 6. The sinking performance of MPs was enhanced, especially for small MPs (< 10 µm), which could be attributed to the increasing density and hydrophilicity. For instance, the sinking ratio of 6.5 µm polystyrene increased by 70% after pH 6 oxidation. In general, ferrate pre-oxidation possesses multiple enhanced removals of MPs and organic contaminants through adsorption and sinking, reducing the potential risk of MPs.

The Mechanism of Quercetin in the Treatment of Lung Squamous Cell Carcinoma Based on a Protein-Protein Interaction Network.

Background: Lung squamous cell carcinoma (LUSC) is characterized by poor prognosis and obvious limitations of therapeutic methods. The molecular target and mechanism of quercetin (QR), a natural anticancer product with extensive pharmacological activities, on lung squamous cell carcinoma is still unclear. Method: The effects of QR on LUSC were examined using cell proliferation, migration, and invasion tests. Key target genes were screened using The Cancer Genome Atlas (TCGA) database, Gene Ontology (GO)/Kyoto Encyclopedia of Genes and Genomes (KEGG) database, STRING website, topology, and prognosis analysis, molecular docking, and other bioinformatics methods for further analysis. Finally, the effects of QR on the expression of key targets in LUSC cells were detected using a cell cycle assay and western blotting. Results: Our study demonstrates that QR not only inhibits the proliferation of LUSC but also affects the invasion and metastasis of LUSC. After downloading and analyzing the TCGA database, 2150 differentially expressed genes were identified. PLK1, CDC20, and BUB1B were identified using enrichment analysis, topological network analysis, cluster analysis, and molecular docking screening. Subsequent experiments showed that QR could interfere with the cell cycle and downregulate the expression of the target gene PLK1 at the protein level. Conclusions: We found that QR not only inhibits the proliferation, migration, and invasion but also blocks the cell cycle progression of LUSC. QR downregulated the expression of the LUSC target gene PLK1 at the protein level.

Transcriptome sequencing and metabolome analysis reveal the mechanism of Shuanghua Baihe Tablet in the treatment of oral mucositis.

Oral mucositis (OM) caused by cancer therapy is the most common adverse reaction in the radiotherapy of head and neck tumors. In severe cases, it can lead to the interruption of treatment, which affects the control of the disease and the quality of life. Shuanghua Baihe Tablet (SBT) is a traditional Chinese medicine (TCM) formula, which is administerd to treat OM in China. It has been clinically effective for more than 30 years, but the underlying mechanism is not completely understood. With the development of multiple omics, it is possible to explore the mechanism of Chinese herbal compound prescriptions. Based on transcriptomics and metabolomics, we explored the underlying mechanism of SBT in the treatment of OM. An OM model of rats was established by 5-FU induction, and SBT was orally administered at dosages of 0.75 and 3 g·kg-1·d-1. In order to search for SBT targets and related metabolites, the dysregulated genes and metabolites were detected by transcriptomics and metabolomics. Immune related indicators such as interleukin-17 (IL-17) and tumor necrosis factor-α (TNF-α) were detected by ELISA. Treg cell disorders was analyzed by flow cytometry. Our results showed that SBT significantly alleviated the symptoms of OM rats and the inflammatory infiltration of ulcer tissues. After SBT administration, inflammatory related metabolic pathways including linoleic acid metabolism, valine, leucine and isoleucine biosynthesis were significantly altered. Furthermore, the production of proinflammatory factors like IL-17 and TNF-α, were also dramatically reduced after SBT administration. Besides, the infiltration degree of Treg cells in the spleen of OM modeling rats was significantly improved by SBT administration, thus maintaining the immune balance of the body. The current study demonstrates that SBT regulates inoleic acid metabolism, glycerophospholipid metabolism and amino acid metabolism, and inhibits IL-17/TNF signal transduction to restore Treg and Th17 cell homeostasis in OM rats, thereby alleviating chemotherapy-induced OM.

A Single Dose of Baicalin Has No Clinically Significant Effect on the Pharmacokinetics of Cyclosporine A in Healthy Chinese Volunteers.

Despite its narrow therapeutic window and large interindividual variability, cyclosporine A (CsA) is the first-line therapy following organ transplantation. Metabolized mainly by CYP3A and being a substrate of P-glycoprotein (P-gp), CsA is susceptible to drug-drug interactions. Baicalin (BG) is a drug used for adjuvant therapy of hepatitis in traditional Chinese medicine. Since its aglycone baicalein (B) inhibits CYP3A and P-gP, co-administration might affect CsA pharmacokinetics. This study investigated the effect of BG on CsA pharmacokinetics. In a two-period study, 16 healthy volunteers received a single 200 mg oral CsA dose alone (reference period) or in combination with 500 mg BG (test period). Pharmacokinetic evaluation of CsA was carried out using non-compartmental analysis (NCA) and population pharmacokinetics (popPK). Treatments were compared using the standard bioequivalence method. Based on NCA, 90% CIs of AUC and C max test-to-reference ratios were within bioequivalence boundaries. In the popPK analysis, a two-compartment model (clearance/F 62.8 L/h, central and peripheral volume of distribution/F 254 L and 388 L) with transit compartments for absorption appropriately described CsA concentrations. No clinically relevant effect of 500 mg BG co-administration on CsA pharmacokinetics was identified and both treatments were well tolerated.

Metabolism and Bioactivation of Corynoline With Characterization of the Glutathione/Cysteine Conjugate and Evaluation of Its Hepatotoxicity in Mice.

Corynoline (CRL), an isoquinoline alkaloid, is the major constituent derived from Corydalis bungeana Herba, which is a well-known Chinese herbal medicine widely used in many prescriptions. The purpose of this study was to comprehensively investigate the metabolism and bioactivation of CRL, and identify the CYP450 isoforms involved in reactive ortho-benzoquinone metabolites formation and evaluate its hepatotoxicity in mice. Here, high resolution and triple quadrupole mass spectrometry were used for studying the metabolism of CRL. Three metabolites (M1-M3) and four glutathione conjugates (M4-M7) of CRL ortho-benzoquinone reactive metabolite were found in vitro using rat and human liver microsomes supplemented with NADPH and glutathione. Four cysteine conjugates (M8-M11) were trapped in mice besides M1-M7. Using human recombinant CYP450 enzymes and chemical inhibitor method, we found that CYP3A4, CYP2C19, CYP2C9, and CYP2D6 were mainly involved in the bioactivation of CRL. Furthermore, CRL had no obvious hepatotoxicity and did not induce acute liver injuries in the experimental dosage (125-500 mg/kg) used in this study. However, phenomena of abnormal behaviors and low body temperature appeared in mice after drug administration, and three of them were dead. Tissue distribution study of CRL in mice showed that the main target organ of CRL was liver, then kidney, heart, and brain. CRL could traverse the blood-brain barrier, and have relative high concentration in brain. So, we surmise that toxicity effect of CRL on other organs may have occurred, and more attention should be paid on the traditional Chinese medicine contained CRL in clinic.

Xanthatin Promotes Apoptosis via Inhibiting Thioredoxin Reductase and Eliciting Oxidative Stress.

Xanthatin (XT), a naturally occurring sesquiterpene lactone presented in cocklebur ( Xanthium strumarium L.), is under development as a potential anticancer agent. Despite the promising anticancer effect of XT, the molecular mechanism underlying its cellular action has not been well elucidated. The mammalian thioredoxin reductase (TrxR) enzymes, the essential seleno-flavoproteins containing a penultimate selenocysteine (Sec) residue at the C-terminus, represent a promising target for cancer chemotherapeutic agents. In this study, XT inhibits both the purified TrxR and the enzyme in cells. The possible binding mode of XT with the TrxR protein is predicted by the covalent docking method. Mechanism studies reveal that XT targets the Sec residue of TrxR and inhibits the enzyme activity irreversibly. Simultaneously, the inhibition of TrxR by XT promotes the oxidative stress-mediated apoptosis of HeLa cells. Importantly, the knockdown of the enzyme sensitizes the cells to XT treatment. Targeting TrxR thus discloses a novel molecular mechanism in accounting for the cellular action of XT and provides insights into the development of XT as an anticancer agent.

Targeting thioredoxin reductase by plumbagin contributes to inducing apoptosis of HL-60 cells.

Plumbagin (PLB), a natural naphthoquinone from the traditional folk medicines Plumbago zeylanica, Dionaea muscipula, or Nepenthes gracilis, has been documented possessing a wide variety of pharmacological activities. Although PLB demonstrates anticancer activity in multiple types of malignant cells, the cellular targets of PLB have not been well defined and remained only partially understood. We reported here that PLB selectively inhibits TrxR and elicits reactive oxygen species in human promyelocytic leukemia HL-60 cells, which leads to elevation of GSSG/GSH ratio and decrease of cellular thiol pool. As a consequence, PLB disturbs the cellular redox homeostasis, induces oxidative stress-mediated apoptosis and eventually selectively kills HL-60 cells. Inhibition of TrxR by PLB thus discloses an unprecedented mechanism underlying the anticancer efficacy of PLB, and sheds light in considering the usage of PLB as a promising cancer therapeutic agent.

Simultaneous quantification of chlorogenic acid and taurocholic acid in human plasma by LC-MS/MS and its application to a pharmacokinetic study after oral administration of Shuanghua Baihe tablets.

An LC-MS/MS method was developed and validated for the simultaneous quantification of chlorogenic acid (CGA) and taurocholic acid (TCA) in human plasma using hydrochlorothiazide as the internal standard. The chromatographic separation was achieved on a Hedera ODS-2 column with a gradient elution using 10 mmol·L(-1) of ammonium acetate buffer solution containing 0.5% of formic acid - acetonitrile as mobile phase at a flow rate of 300 µL·min(-1). The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring in negative ESI mode. The method was fully validated over the concentration ranges of 0.1-10 ng·mL(-1) for CGA and 2-150 ng·mL(-1) for TCA. It was successfully applied to a pharmacokinetic study of CGA and TCA in healthy Chinese volunteers after oral administration of Shuanghua Baihe tablets (SBTs). In the single-dose study, the maximum plasma concentration (Cmax), time to reach Cmax (Tmax) and elimination half-life (t1/2) of CGA were (0.763 8 ± 0.542 0) ng·mL(-1), (1.0 ± 0.5) h, and (1.3 ± 0.6) h, respectively. In the multiple-dose study, the Cmax, Tmax and t1/2 of CGA were (0.663 7 ± 0.583 3) ng·mL(-1), (1.1 ± 0.5) h, and (1.4 ± 0.7) h, respectively. For TCA, no significant characteristic increasing plasma TCA concentration-time curve was found in the volunteers after oral administration of SBTs, indicating its complicated process in vivo as an endogenous ingredient.

Simultaneous determination of corynoline and acetylcorynoline in human urine by LC-MS/MS and its application to a urinary excretion study.

Corynoline and acetycorynoline, the major active components derived from Corydalis bungeana Herba, showed multiple pharmacological activities. However, quantification of the two compounds in human urine has not been reported. A simple liquid chromatography with tandem mass spectrometry method for the simultaneous determination of corynoline and acetycorynoline in human urine has been developed and fully validated. The analytes were extracted from urine samples by simple liquid-liquid extraction. Chromatographic separation was achieved on a Hedera ODS-2C18 column with the mobile phase of water (containing 0.5% formic acid) and acetonitrile (28:72, v/v) at a flow rate of 0.4mL/min. A tandem mass spectrometric detection was conducted using multiple reaction monitoring via an electrospray ionization source in positive mode. The monitored ion transitions were m/z 368.1→289.1 for corynoline, m/z 410.2→289.2 for acetycorynoline and m/z 380.2→243.2 for donepezil (internal standard), respectively. The calibration curves were linear (correlation coefficients>0.9970) over the concentration ranges of 3.0-3000pg/mL for corynoline and 3.0-1000pg/mL for acetycorynoline. The established method was highly sensitive with the lower limit of quantification (LLOQ) of 3.0pg/mL for both analytes. The intra- and inter-day precision was lower than 10% in terms of relative standard deviation for the low, medium, and high quality control samples, and lower than 16% for the LLOQ samples of the analytes. The accuracy was within ±10% in terms of relative error for both analytes. The method was successfully applied to a urinary excretion study after oral administration of the Chinese medicine formula Shuanghua Baihe tablets in healthy volunteers. The urinary excretion profiles of corynoline and acetycorynoline in human were first reported. The results of this study suggest that renal excretion was not the main excretion pathway of corynoline and acetycorynoline in humans.

LC-MS/MS determination and urinary excretion study of seven alkaloids in healthy Chinese volunteers after oral administration of Shuanghua Baihe tablets.

An LC-MS/MS method was developed and validated for the simultaneous determination of magnoflorine, berberrubine, jatrorrhizine, coptisine, epiberberine, palmatine and berberine in human urine. The sample preparation procedure involved the four-fold dilution of the urine samples with acetonitrile/water (1:3, v/v). The chromatographic separation was achieved on a Hedera ODS-2 column under gradient elution at a flow rate of 0.4 mL/min with acetonitrile and water containing 0.5% formic acid as the mobile phase. The mass detection was performed in the positive mode. Calibration curves of the seven alkaloids showed good linearity (correlation coefficients>0.9973) over their concentration ranges. To meet the requirements of urinary excretion study for each alkaloid in human, the lower limit of quantification was set at different values from 0.05063 ng/mL to 2.034 ng/mL for the seven alkaloids, respectively. The intra- and inter-batch precision and accuracy were all within ± 15%. No matrix effect was observed for the analytes. The validated method was applied to the excretion study for the seven alkaloids in healthy Chinese volunteers after oral administration of Shuanghua Baihe tablets. The average 72 h cumulative urinary excretion of magnoflorine, berberrubine, jatrorrhizine, coptisine, epiberberine, palmatine and berberine accounted for 1.81%, 0.27%, 0.29%, 0.046%, 0.027%, 0.010% and 0.021% of the respective administered dose.

Study on the pharmacokinetic profiles of corynoline and its potential interaction in traditional Chinese medicine formula Shuanghua Baihe tablets in rats by LC-MS/MS.

Corynoline, the major isoquinoline alkaloid component derived from Corydalis bungeana Herba, has greatly impressed many scientists due to its various pharmacological effects. However, there is little information on its pharmacokinetics. In this study, a sensitive and rapid liquid chromatography with tandem mass spectrometry method has been developed and validated for the determination of corynoline in rat plasma. The calibration curve showed good linearity within the concentration range of 0.01-20 ng/mL. The method was fully validated and successfully applied in a pharmacokinetic study of corynoline in rats, in which the rats were treated with corynoline, corynoline combined with berberine and the traditional Chinese medicine formula Shuanghua Baihe tablets (SBT, containing corynoline, berberine and other ingredients), respectively. Corynoline showed low bioavailability and a high elimination rate. The terminal elimination half-life was prolonged about 3-fold, and the maximum plasma concentration (C(max)), area under the plasma concentration-time curve (AUC(0-12)) of corynoline were increased by 46.5% and 34.2%, respectively, when the same dosage of corynoline was administered in SBT. Furthermore, compared with the corynoline group, the C(max) and AUC(0-12) were increased by 11.1-fold and 5.0-fold respectively, in the rats treated with corynoline combined with berberine. The results suggested that oral administration of the SBT prolonged the elimination half-life of corynoline and increased its bioavailability. Berberine played an important role in the pharmacokinetic drug-drug interaction of corynoline and ingredients in SBT, and the influence of other co-existing compounds in SBT on the pharmacokinetic profiles of corynoline could not be ignored.

Highly sensitive method for simultaneous determination of nine alkaloids of Shuanghua Baihe tablets in human plasma by LC-MS/MS and its application.

Shuanghua Baihe tablets (SBT) is a traditional Chinese medicinal formula which has been used to treat recurrent aphthous stomatitis for many years. To study the pharmacokinetic profiles of berberine, epiberberine, coptisine, palmatine, jatrorrhizine, magnoflorine, berberrubine, corynoline and acetylcorynoline in human after administration of SBT, a sensitive liquid chromatography-tandem mass spectrometry method was developed and fully validated for the simultaneous quantification of these nine alkaloids in human plasma. After protein precipitation, the nine alkaloids in human plasma sample was separated on a Hanbon C18 (150mm×2.1mm, 5µm) column with gradient elution using methanol and 0.5% formic acid water solution, and detected by a triple quadrupole mass spectrometer with an electrospray ionization source. It is a challenge to design different calibration ranges for different analytes in a bioanalytical method for simultaneous determination of multi-analytes in bio-samples. To ensure that each alkaloid in the plasma was determined accurately by the simultaneous quantitation method, the upper limits of quantification for the nine alkaloids were designed at 100, 300, 800, 1800 and 5000pg/mL, respectively, according to the maximum plasma concentration value of each alkaloid obtained from the pilot pharmacokinetic study. The lower limit of quantification was 15pg/mL for berberine, epiberberine, coptisine, magnoflorine, berberrubine, corynoline and acetylcorynoline, while for palmatine and jatrorrhizine it was 1.5pg/mL. This method was successfully applied to investigate the pharmacokinetic profiles of the nine alkaloids in healthy Chinese volunteers after a single oral administration of SBT.

The Arabidopsis kinesin gene AtKin-1 plays a role in the nuclear division process during megagametogenesis.

KEY MESSAGE: Atkin - 1 , the only Kinesin-1 member of Arabidopsis thaliana , plays a role during female gametogenesis through regulation of nuclear division cycles. Kinesins are microtubule-dependent motor proteins found in eukaryotic organisms. They constitute a superfamily that can be further classified into at least 14 families. In the Kinesin-1 family, members from animal and fungi play roles in long-distance transport of organelles and vesicles. Although Kinesin-1-like sequences have been identified in higher plants, little is known about their function in plant cells, other than in a recently identified Kinesin-1-like protein in a rice pollen semi-sterile mutant. In this study, the gene encoding the only Kinesin-1 member in Arabidopsis, AtKin-1 was found to be specifically expressed in ovules and anthers. AtKin-1 loss-of-function mutants showed substantially aborted ovules in siliques, and this finding was supported by complementation testing. Reciprocal crossing between mutant and wild-type plants indicated that a defect in AtKin-1 results in partially aborted megagametophytes, with no observable effects on pollen fertility. Further observation of ovule development in the mutant pistils indicated that the enlargement of the megaspore was blocked and nuclear division arrested at the one-nucleate stage during embryo sac formation. Our data suggest that AtKin-1 plays a role in the nuclear division cycles during megagametogenesis.

[Study on pharmacokinetics of asperosaponin VI and its active metabolite in rats].

To study the pharmacokinetics, excretion characteristics and plasma protein binding rate of asperosaponin VI (A-VI) and its active metabolite hederagenin (M1). A-VI and M1 concentrations in plasma, bile, urine and feces were determined by established LC-MS/MS to calculate the pharmacokinetic parameters. The plasma protein binding rate of A-VI was determined by equilibrium dialysis method. the double peaks was observed in the A-VI plasma concentration-time curve, after rats were orally administered with low, medium and high doses of A-VI (0.03, 0.09, 0.27 g x kg(-1)). The Cmax1 and Cmax2 of A-VI were (28.88 +/- 49.78) and (4.480 +/- 1.872) microg x L(-1), (35.19 +/- 23.53) and (22.11 +/- 16.15) microg x L(-1), (73.37 +/- 37.28) and (132.2 +/- 160.7) microg x L(-1), respectively. The AUC0-t, of A-VI were (43.21 +/- 37.32), (133.9 +/- 102.5) and (779.6 +/- 876.9) microg x h x L(-1), respectively. The t1/2 of A-VI were (3.3 +/- 0.8), (3.2 +/- 2.3) and (4.5 +/- 1.2) h, respectively. The Cmax of M1 were (16.03 +/- 9.336), (26.41 +/- 11.95) and (28.71 +/- 5.874) microg x L(-1), respectively. The AUC0-t, of M1 were (105.6 +/- 73.60), (260.0 +/-153.9) and (323.1 +/- 107.9) microg x h x L(-1), respectively. The t1/2 of M1 were (4.1 +/- 3.4), (4.4 +/- 2.3), (3.9 +/- 0.9) h, respectively. No significant gender difference was found in the in vivo pharmacokinetics of A-VI and M1. There was no accumulation of A-VI and M1 after multiple administrations of A-VI (0.09 g x kg(-1)). After oral administration of A-VI, the double peaks were also observed in biliary and urinary excretion rate-time curves for A-VI. M1 was detected in the feces samples at 6 h after oral administration. The average plasma protein binding rate of A-VI was 92. 9% in rats.