Pharmacokinetic studies of six major 2-(2-phenylethyl) chromones in rat plasma using ultra high performance liquid chromatography with tandem mass spectrometry after oral administration of agarwood ethanol extract.

In this study, a simple, quick, sensitive and reliable method utilizing ultra-high performance liquid chromatography with tandem mass spectrometry method was validated for simultaneous quantification of six main 2-(2-phenylethyl) chromones, including agarotetrol, isoagarotetrol, (5S,6R,7R,8S)-5,6,7,8-tetrahydroxy-(4-methoxyphenethyl)-5,6,7,8-tetrahydro-4H-chromen-4-one, 8-chloro-2-(2-phenyl ethyl)-5,6,7-trihydroxy-5,6,7,8-tetrahydrochromone, 6,7-dimethoxy-2-(2-phenylethyl) chromone, and 2-(2-phenylethyl) chromone in rat plasma after oral administration of agarwood ethanol extract. Separation was performed on a Waters ACQUITY UPLC BEH C18 column (2.1 × 100 mm, 1.7 µm) using gradient elution with mobile phase of 0.2% formic acid-water and acetonitrile. The tandem mass was performed in the multiple reaction monitoring mode with positive ionization. The calibration curves indicated good linearity (r2  > 0.99) over the corresponding concentration range. The precision and accuracy were within the acceptable range. Mean absolute recoveries of all analytes were between 73.31% and 94.76%, and the relative standard deviations of matrix effects were not higher than 15%. The six analytes were proven to be stable during sample storage and analysis procedures. The validated method was successfully applied to pharmacokinetic study of six 2-(2-phenylethyl) chromones in rat after oral administration of agarwood ethanol extract for the first time. This study could serve as a reference and provide theoretical guidance for further pharmacodynamic research and clinical applications of agarwood.

Molecular structure, NBO analysis of the hydrogen-bonded interactions, spectroscopic (FT-IR, FT-Raman), drug likeness and molecular docking of the novel anti COVID-2 molecule (2E)-N-methyl-2-[(4-oxo-4H-chromen-3-yl)methylidene]-hydrazinecarbothioamide (Dimer) - quantum chemical approach.

Prospective antiviral molecule (2E)-N-methyl-2-[(4-oxo-4H-chromen-3-yl)methylidene]-hydrazinecarbothioamide has been probed using Fourier transform infrared (FTIR), FT-Raman and quantum chemical computations. The geometry equilibrium and natural bond orbital analysis have been carried out with density functional theory employing Becke, 3-parameter, Lee-Yang-Parr method with the 6-311G++(d,p) basis set. The vibrational assignments pertaining to different modes of vibrations have been augmented by normal coordinate analysis, force constant and potential energy distributions. Drug likeness and oral activity have been carried out based on Lipinski's rule of five. The inhibiting potency of 2(2E)-methyl-2-[(4-oxo-4H-chromen-3-yl)methylidene]-hydrazinecarbothioamide has been investigated by docking simulation against SARS-CoV-2 protein. The optimized geometry shows a planar structure between the chromone and the side chain. Differences in the geometries due to the substitution of the electronegative atom and intermolecular contacts due to the chromone and hydrazinecarbothioamide were analyzed. NBO analysis confirms the presence of two strong stable hydrogen bonded NH⋯O intermolecular interactions and two weak hydrogen bonded CH⋯O interactions. The red shift in NH stretching frequency exposed from IR substantiates the formation of NH⋯O intermolecular hydrogen bond and the blue shift in CH stretching frequency substantiates the formation of CH⋯O intermolecular hydrogen bond. Drug likeness, absorption, distribution, metabolism, excretion and toxicity property gives an idea about the pharmacokinetic properties of the title molecule. The binding energy of the nonbonding interaction with Histidine 41 and Cysteine 145, present a clear view that 2(2E)-methyl-2-[(4-oxo-4H-chromen-3-yl)methylidene]-hydrazinecarbothioamide can irreversibly interact with SARS-CoV-2 protease.

Glabrescione B delivery by self-assembling micelles efficiently inhibits tumor growth in preclinical models of Hedgehog-dependent medulloblastoma.

Aberrant activation of the Hedgehog (Hh) pathway leads to the development of several tumors, including medulloblastoma (MB), the most common pediatric brain malignancy. Hh inhibitors acting on GLI1, the final effector of Hh signaling, offer a valuable opportunity to overcome the pitfalls of the existing therapies to treat Hh-driven cancers. In this study, the toxicity, delivery, biodistribution, and anticancer efficacy of Glabrescione B (GlaB), a selective GLI1 inhibitor, were investigated in preclinical models of Hh-dependent MB. To overcome its poor water solubility, GlaB was formulated with a self-assembling amphiphilic polymer forming micelles, called mPEG5kDa-cholane. mPEG5kDa-cholane/GlaB showed high drug loading and stability, low cytotoxicity, and long permanence in the bloodstream. We found that mPEG5kDa-cholane efficiently enhanced the solubility of GlaB, thus avoiding the use of organic solvents. mPEG5kDa-cholane/GlaB possesses favorable pharmacokinetics and negligible toxicity. Remarkably, GlaB encapsulated in mPEG5kDa-cholane micelles was delivered through the blood-brain barrier and drastically inhibited tumor growth in both allograft and orthotopic models of Hh-dependent MB. Our findings reveal that mPEG5kDa-cholane/GlaB is a good candidate for the treatment of Hh-driven tumors and provide relevant implications for the translation of GlaB into clinical practice.

Evaluation of rohitukine-enriched fraction of Dysoxylum binectariferum Hook.f. (leaves) as anti-arthritic phytopharmaceutical candidate: Chemical standardization, in-vivo validation, formulation development and oral pharmacokinetics.

ETHNOPHARMACOLOGICAL RELEVANCE: Rheumatoid arthritis is a chronic inflammatory disease of joints. Dysoxylum binectariferum Hook.f (Family: Meliaceae) is a Indian medicinal plant which is traditionally being used to heal inflammation of joints. AIM OF THE STUDY: This work was aimed to carry out chemical standardization, in-vitro/in-vivo validation, oral pharmacokinetics and formulation development of anti-arthritic botanical lead, the rohitukine-enriched fraction of D. binectariferum. MATERIALS AND METHODS: The rohitukine-enriched fraction of D. binectariferum was standardized using four chemical markers and was checked for microbial load, heavy metal content, aflatoxins and pesticides. Its in-vitro inhibitory effect on the lipopolysaccharide (LPS) induced production of pro-inflammatory cytokines TNF-α and IL-6 was studied in THP-1 cells. The in-vivo anti-arthritic activity was investigated in collagen-induced arthritis model in DBA/1J mice. The sustained release capsule formulation was developed and characterized for physicochemical and pharmacokinetic properties. RESULTS: Rohitukine and schumaniofioside A were found to be major chemical constituents of the botanical lead. The rohitukine-enriched fraction of D. binectariferum significantly reduced the production of both pro-inflammatory cytokines TNF-α and IL-6 (>50% inhibition at 3.12 µg/mL) in THP-1 cells. In LPS-treated wild-type mice model, the rohitukine-enriched fraction at 200 mg/kg (PO, QD) completely reduced serum TNF-α levels. In transgenic mice model (collagen-induced arthritis in DBA/1J mice), rohitukine-enriched fraction at 100 mg/kg (PO, QD) dose has resulted in >75% reduction of TNF-α/IL-6 serum levels, 68% reduction in anti-mouse type II collagen IgG1 antibody levels, decreased joint proteoglycan loss and reduced paw edema in DBA/1J mice. The sustained release capsule formulation of rohitukine-enriched fraction showed sustained-release of rohitukine over the period of 24 h, and resulted in an improved plasma-exposure of rohitukine in SD rats. CONCLUSIONS: The data presented herein demonstrated anti-arthritic potential of rohitukine-enriched fraction of D. binectariferum and this study will serve as the benchmark for further research on this botanical lead and developed sustained release capsule formulation.

In Situ Forming Injectable Hydrogel For Encapsulation Of Nanoiguratimod And Sustained Release Of Therapeutics.

BACKGROUND: Iguratimod (IGUR) is a novel disease-modifying antirheumatic drug used for treating rheumatoid arthritis (RA). To improve its bioavailability and to alleviate gastrointestinal side effects, we changed the formulation into nanoiguratimod-loaded hydrogel (NanoIGUR-loaded hydrogel) composites for sustained release of therapeutics. METHODS: IGUR was first encapsulated in biodegradable polyvinyl alcohol micelle by liquid antisolvent precipitation (LAP) technology, and then loaded into an in situ injectable hyaluronic acid hydrogel, which was cross-linked by PEG (Thiol)2 (HS-PEG-SH) through Michael addition reaction. In vitro, the biological effects (proliferation, migration, and invasion) of NanoIGUR-loaded hydrogel on fibroblast-like synoviocytes (RA-FLS) from RA patients were evaluated. In vivo, the pharmacokinetics of NanoIGUR-loaded hydrogel was assessed and the efficacy of NanoIGUR-loaded hydrogel in treating collagen-induced arthritis (CIA) rats was evaluated. RESULTS: By the LAP technique, we acquired the amorphous form nanoiguratimod, with an average size of 458 nm, which had higher dissolution rates and higher stability. The release of IGUR from hydrogel composite in PBS was gradual and sustained for up to 72 hrs compared with nanoiguratimod. Different concentrations of NanoIGUR-loaded hydrogel inhibited the proliferation, migration, and invasion of RA-FLS. The pharmacokinetic parameters showed better bioavailability and longer half-life time with NanoIGUR-loaded hydrogel by subcutaneous administration than oral raw iguratimod. Animal experiments confirmed that subcutaneous injection of NanoIGUR-loaded hydrogel (10 mg/kg every 3 days) and oral raw iguratimod (10mg/kg daily) showed similar efficacy in decreasing arthritis index score, pathological score, and expression of inflammatory cytokines. CONCLUSION: Overall, we demonstrate that NanoIGUR-loaded hydrogel provides a new route of administration and extends the administration interval. It could be a promising drug-delivery approach in the management of RA.

Simultaneous bioanalysis and pharmacokinetic interaction study of acebrophylline, levocetirizine and pranlukast in Sprague-Dawley rats.

The combination of acebrophylline (ABP), levocetirizine (LCZ) and pranlukast (PRN) is used to treat allergic rhinitis, asthma, hay-fever and other conditions where patients experience difficulty in breathing. This study was carried out with the aim of developing and validating a reverse-phase high-performance liquid chromatographic bioanalytical method to simultaneously quantitate ABP, LCZ and PRN in rat plasma. The objective also includes determination of the pharmacokinetic interaction of these three drugs after administration via the oral route after individual and combination treatment in rat. Optimum resolution between the analytes was observed with a C18 Kinetex column (250 mm × 4.6 mm × 5 µm). The chromatography was performed in a gradient elution mode with a 1 mL/min flow rate. The calibration curves were linear over the concentration range of 100-1600 ng/mL. The intra- and inter-day precision and accuracy were found to be within acceptable limits as specified in US Food and Drug Administration guideline for bioanalytical method validation. The analytes were stable on the bench-top (8 h), after three freeze-thaw cycles, in the autosampler (8 h) and as a dry extract (-80°C for 48 h). The statistical results of the pharmacokinetic study in Sprague-Dawley rats showed a significant change in pharmacokinetic parameters for PRN upon co-administration of the three drugs.

A simple blending with α-glycosylated naringin produces enhanced solubility and absorption of pranlukast hemihydrate.

The possibility of newly developed α-glycosylated naringin (Naringin-G) as a solubilizing agent was investigated against pranlukast hemihydrate (PLH), a model drug with extremely low water solubility. The physical mixtures (PMs) of PLH/Naringin-G increased the solubility of PLH compared with PLH crystals and PMs with other additives, such as α-glycosylated rutin (Rutin-G) and sodium dodecyl sulfate (SDS). Naringin-G did not decrease the surface tension, whereas SDS showed a surface-active property and critical micelle concentration. The apparent solubility of PLH increased in proportion to the concentration of Naringin-G, and similarly for SDS, indicating that constant amounts of Naringin-G molecules interacted with PLH molecules. There was no change in the Caco-2 cell viability following contact with a high concentration of Naringin-G solution (10% (w/v)). The oral absorption of PLH in a rat animal model was improved when administrated with Naringin-G. The value for the area under plasma concentration-time curve from PMs of PLH/Naringin-G was 2.2 times higher than that from PLH crystals alone. Together, these results suggested that newly synthesized Naringin-G would be a promising solubilizing agent as an alternative to surfactants.

PLGA nanoparticle-based docetaxel/LY294002 drug delivery system enhances antitumor activities against gastric cancer.

Docetaxel (TXT) is acknowledged as one of the most important chemotherapy agents for gastric cancer (GC). PI3K/AKT signaling is frequently activated in GC, and its inhibitor LY294002 exerts potent antitumor effects. However, the hydrophobicity of TXT and the poor solubility and low bioavailability of LY294002 limit their clinical application. To overcome these shortcomings, we developed poly(lactic acid/glycolic) (PLGA) nanoparticles loaded with TXT and LY294002. PLGA facilitated the accumulation of TXT and LY294002 at the tumor sites. The in vitro functional results showed that PLGA(TXT+LY294002) exhibited controlled-release and resulted in a markedly reduced proliferative capacity and an elevated apoptosis rate. An in vivo orthotopic GC mouse model and xenograft mouse model confirmed the anticancer superiority and tumor-targeting feature of PLGA(TXT+LY294002). Histological analysis indicated that PLGA(TXT+LY294002) was biocompatible and had no toxicity to major organs. Characterized by the combined slow release of TXT and LY294002, this novel PLGA-based TXT/LY294002 drug delivery system provides controlled release and tumor targeting and is safe, shedding light on the future of targeted therapy against GC.

Multi-target-directed ligands for Alzheimer's disease: Discovery of chromone-based monoamine oxidase/cholinesterase inhibitors.

There has been a substantial research effort to design multi-target ligands for the treatment of Alzheimer's disease (AD), an approach that is moved by the knowledge that AD is a complex and multifactorial disease affecting many linked to pathological pathways. Accordingly, we have devoted efforts to develop multi-target ligands based on the chromone scaffold. As a result, a small library of chromone derivatives was synthesized and screened towards human cholinesterases and monoamine oxidases. Compounds 2-(dimethylamino)ethyl (E)-3-(4-oxo-2-(p-methylphenlcarbamoyl)-4H-chromen-6-yl)acrylate (9a) and 2-(dimethylamino)ethyl (E)-3-(4-oxo-3-(phenylcarbamoyl)-4H-chromen-6-yl)acrylate (23a) were identified as the most promising multi-target inhibitors of the series. Compound 9a acted as a potent, selective and bifunctional AChEI (IC50 = 0.21 µM, Ki = 0.19 µM) and displayed dual hMAO inhibitory activity (hMAO-A IC50 = 0.94 µM, Ki = 0.057 µM and hMAO-B IC50 = 3.81 µM, Ki = 0.48 µM). Compound 23a acted as a selective IMAO-B (IC50 = 0.63 µM, Ki = 0.34 µM) while still displaying hChE inhibitory and bifunctional activity in the low micromolar range. Overall, these two compounds stand out as reversible multi-target inhibitors with favourable permeability, toxicological and drug-like profiles, thus being valid candidates for subsequent optimization and pre-clinical studies.

Discovery and Preclinical Development of IIIM-290, an Orally Active Potent Cyclin-Dependent Kinase Inhibitor.

Rohitukine (1), a chromone alkaloid isolated from Indian medicinal plant Dysoxylum binectariferum, has inspired the discovery of flavopiridol and riviciclib, both of which are bioavailable only via intravenous route. With the objective to address the oral bioavailability issue of this scaffold, four series of rohitukine derivatives were prepared and screened for Cdk inhibition and cellular antiproliferative activity. The 2,6-dichloro-styryl derivative IIIM-290 (11d) showed strong inhibition of Cdk-9/T1 (IC50 1.9 nM) kinase and Molt-4/MIAPaCa-2 cell growth (GI50 < 1.0 µM) and was found to be highly selective for cancer cells over normal fibroblast cells. It inhibited the cell growth of MIAPaCa-2 cells via caspase-dependent apoptosis. It achieved 71% oral bioavailability with in vivo efficacy in pancreatic, colon, and leukemia xenografts at 50 mg/kg, po. It did not have CYP/efflux-pump liability, was not mutagenic/genotoxic or cardiotoxic, and was metabolically stable. The preclinical data presented herein indicates the potential of 11d for advancement in clinical studies.

Discovery and Optimization of Chromeno[2,3-c]pyrrol-9(2H)-ones as Novel Selective and Orally Bioavailable Phosphodiesterase 5 Inhibitors for the Treatment of Pulmonary Arterial Hypertension.

Phosphodiesterase 5 (PDE5) inhibitors have been used as clinical agents to treat erectile dysfunction and pulmonary arterial hypertension (PAH). Herein, we detail the discovery of a novel series of chromeno[2,3-c]pyrrol-9(2H)-one derivatives as selective and orally bioavailable inhibitors against phosphodiesterase 5. Medicinal chemistry optimization resulted in 2, which exhibits a desirable inhibitory potency of 5.6 nM with remarkable selectivity as well as excellent pharmacokinetic properties and an oral bioavailability of 63.4%. In addition, oral administration of 2 at a dose of 5.0 mg/kg caused better pharmacodynamics effects on both mPAP (mean pulmonary artery pressure) and RVHI (index of right ventricle hypertrophy) than sildenafil citrate at a dose of 10.0 mg/kg. These activities along with its reasonable druglike properties, such as human liver microsomal stability, cytochrome inhibition, hERG inhibition, and pharmacological safety, indicate that 2 is a potential candidate for the treatment of PAH.

Development and validation of a sensitive UHPLC-MS/MS method for quantitative analysis of farrerol in rat plasma: Application to pharmacokinetic and bioavailability studies.

Farrerol is a 2,3-dihydro-flavonoid isolated from rhododendron. In this study, a sensitive and selective ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed for the determination of farrerol in rat plasma. Liquid-liquid extraction by ethyl ether was used for sample preparation. Chromatographic separation was achieved on an Agilent UHPLC XDB-C18 column (2.1 × 100 mm, 1.8 µm) with water and methanol (30:70, v/v) as the mobile phase. An electrospray source was applied and operated in negative ion mode; selection reaction monitoring was used for quantification using target fragment ions m/z 299 → 179 for farrerol and m/z 267 → 252 for internal standard. Calibration plots were linear in the range of 2.88-1440 ng/mL for farrerol in rat plasma. Intra- and inter-day precisions were <11.6%, and the accuracy ranged from -13.9 to 11.9%. The UHPLC-MS/MS method was successfully applied in pharmacokinetics and bioavailability studies of farrerol in rats.

Polymeric glabrescione B nanocapsules for passive targeting of Hedgehog-dependent tumor therapy in vitro.

AIM: With the purpose of delivering high doses of glabrescione B (GlaB) to solid tumors after systemic administration, long-circulating GlaB-loaded oil-cored polymeric nanocapsules (NC-GlaB) were formulated. MATERIALS & METHODS: Synthesis of GlaB and its encapsulation in nanocapsules (NCs) was performed. Empty and GlaB-loaded NCs were assessed for their physico-chemical properties, in vitro cytotoxicity and in vivo biodistribution. RESULTS: GlaB was efficiently loaded into NCs (∽90%), which were small (∽160 nm), homogeneous and stable upon storage. Further, GlaB and NC-GlaB demonstrated specific activities against the cancer stem cells. Preliminary studies in tumor-bearing mice supported the ability of NC to accumulate in pancreatic tumors. CONCLUSION: This study provides early evidence that NC-GlaB has the potential to be utilized in a preclinical setting and justifies the need to perform therapeutic experiments in mice.

Pharmacokinetic interactions in mice between irinotecan and MBL-II-141, an ABCG2 inhibitor.

PURPOSE: The chromone derivative MBL-II-141, specifically designed to inhibit ABCG2, was previously demonstrated to combine strong inhibition potency, low toxicity and good efficiency in reversing resistance to irinotecan in a xenografted mouse model. Here, the pharmacokinetic interactions in mice between irinotecan, its active metabolite SN-38 and MBL-II-141 were characterized quantitatively in the blood and in the brain. METHODS: Compartmental models were used to fit the data. Goodness-of-fit was assessed by simulation-based diagnostic tools. RESULTS: Irinotecan increased the MBL-II-141 apparent clearance and Vss 1.5-fold, probably by increasing the MBL-II-141 unbound fraction. MBL-II-141 decreased the total apparent clearance of irinotecan by 23%, by decreasing its biliary clearance. MBL-II-141 increased 3-fold the brain accumulation of irinotecan, as a result of the rise of systemic exposure combined with the inhibition of ABCG2-mediated efflux at the blood-brain barrier. Finally, SN-38 exposure was increased by 1.16-fold under treatment with MBL-II-141, owing to the higher irinotecan exposure with increased metabolism towards the formation of SN-38. CONCLUSIONS: These results may help to anticipate the pharmacokinetic interactions between MBL-II-141 and other ABCG2 substrates. The irinotecan-MBL-II-141 interaction is also expected to occur in humans. Copyright © 2017 John Wiley & Sons, Ltd.

Kinetic modelling of in vitro data of PI3K, mTOR1, PTEN enzymes and on-target inhibitors Rapamycin, BEZ235, and LY294002.

The phosphatidylinositide 3-kinases (PI3K) and mammalian target of rapamycin-1 (mTOR1) are two key targets for anti-cancer therapy. Predicting the response of the PI3K/AKT/mTOR1 signalling pathway to targeted therapy is made difficult because of network complexities. Systems biology models can help explore those complexities but the value of such models is dependent on accurate parameterisation. Motivated by a need to increase accuracy in kinetic parameter estimation, and therefore the predictive power of the model, we present a framework to integrate kinetic data from enzyme assays into a unified enzyme kinetic model. We present exemplar kinetic models of PI3K and mTOR1, calibrated on in vitro enzyme data and founded on Michaelis-Menten (MM) approximation. We describe the effects of an allosteric mTOR1 inhibitor (Rapamycin) and ATP-competitive inhibitors (BEZ235 and LY294002) that show dual inhibition of mTOR1 and PI3K. We also model the kinetics of phosphatase and tensin homolog (PTEN), which modulates sensitivity of the PI3K/AKT/mTOR1 pathway to these drugs. Model validation with independent data sets allows investigation of enzyme function and drug dose dependencies in a wide range of experimental conditions. Modelling of the mTOR1 kinetics showed that Rapamycin has an IC50 independent of ATP concentration and that it is a selective inhibitor of mTOR1 substrates S6K1 and 4EBP1: it retains 40% of mTOR1 activity relative to 4EBP1 phosphorylation and inhibits completely S6K1 activity. For the dual ATP-competitive inhibitors of mTOR1 and PI3K, LY294002 and BEZ235, we derived the dependence of the IC50 on ATP concentration that allows prediction of the IC50 at different ATP concentrations in enzyme and cellular assays. Comparison of drug effectiveness in enzyme and cellular assays showed that some features of these drugs arise from signalling modulation beyond the on-target action and MM approximation and require a systems-level consideration of the whole PI3K/PTEN/AKT/mTOR1 network in order to understand mechanisms of drug sensitivity and resistance in different cancer cell lines. We suggest that using these models in a systems biology investigation of the PI3K/AKT/mTOR1 signalling in cancer cells can bridge the gap between direct drug target action and the therapeutic response to these drugs and their combinations.

Pharmacokinetic and Pharmacodynamic Analyses of Drug-Drug Interactions between Iguratimod and Warfarin.

Iguratimod (IGU), a disease-modifying antirheumatic drug launched in September 2012, has been reported to carry a risk of severe hemorrhages through a suspected interaction with warfarin (WF) in the all-case surveillance and early postmarketing-phase vigilance. To elucidate possible mechanisms of adverse interaction between IGU and WF, we analyzed the effects of IGU on the pharmacodynamics and pharmacokinetics of WF in rats. IGU was orally administered to male Wistar rats once daily for 5 d at 10 or 30 mg/kg in combination with WF at an oral dose of 0.25 mg/kg. Coadministration of IGU 30 mg/kg enhanced the anticoagulant activity of WF; prolonged blood coagulation time (prothrombin time and activated partial thromboplastin time) and decreased levels of vitamin K (VK)-dependent blood coagulation factors (II, VII, IX, and X) were observed. On the other hand, the pharmacokinetic parameters of WF including maximum plasma concentration (Cmax) and area under the plasma concentration-time curve from 0 to 24 h (AUC0-24 h) were not affected by the combination with IGU. IGU alone did not change blood coagulation time at doses up to 100 mg/kg, while VK-dependent blood coagulation factors decreased slightly at 30 and 100 mg/kg. These results suggest that the pharmacodynamic effect of IGU on VK-dependent blood coagulation factors is involved in the mechanism of drug-drug interaction of IGU with WF.

[B7-H4-mediated immunoresistance is supressed by PI3K/Akt/mTOR pathway inhibitors].

B7-H4 plays an important role in tumor immune evasion. In previous studies we have found that B7-H4 can translocate to the nucleus, and the exposure to PI3K inhibitor Ly294002 affects B7-H4 subcellular distribution. In this study we report the role of PI3K/Akt pathway in the B7-H4 subcellular distribution and the effect of PI3K/Akt inhibitors on B7-H4-mediated immunoresistance. The involvement of PI3K/Akt pathway in B7-H4 subcellular distribution was evident in experiments with wortmannin, while MDM2 inhibitor nutlin-3 and the mTOR inhibitor rapamycin were used to dissect the signaling downstream of Akt. Wortmannin and rapamycin demonstrated similar effects on B7-H4 subcellular distribution. Exposure to any of these inhibitors decreased levels of membrane B7-H4 while at the same time inducing its nuclear accumulation, while exposure to nutlin-3 had no effect on B7-H4 subcellular distribution. In the T cell proliferation assay, both wortmannin and rapamycin effectively inhibited B7-H4 WT/293 cells-mediated T cell proliferation while exerting no effect on Mock/293 cells. PI3K/Akt/mTOR plays a role in B7-H4 subcellular distribution, while MDM2 does not take part in it. Moreover, we show that wortmannin and rapamycin inhibit B7-H4-mediated tumor immunoresistance through regulating B7-H4 subcellular distribution. Taken together, these results suggest that PI3K/Akt/mTOR inhibitors might be used for adjuvant therapy aimed at inhibition of immune evasion.

Enhancement of Solubility, Transport Across Madin-Darby Canine Kidney Monolayers and Oral Absorption of Pranlukast Through Preparation of a Pranlukast-Phospholipid Complex.

This study aimed to enhance the solubility of a poorly water-soluble drug, pranlukast, as well as its transport across Madin-Darby canine kidney (MDCK) monolayers, thus increasing its oral bioavailability. To accomplish this aim, we prepared a pranlukast-phospholipid complex (PPC). The PPC was prepared by solvent-evaporation and characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), infrared (IR) spectroscopy, and solubilization studies. The solubility of pranlukast in the PPC was increased from 1.03 ± 0.32 µg/ml to 160.63 ± 2.72 µg/ml with a yield of 96.39 ± 1.20% when the PPC was prepared under optimal conditions. TEM images showed that the PPC particles had a spherical shape. XRD data indicated that pranlukast in the PPC was either in an amorphous form or in a dispersed molecular distribution. IR analysis confirmed the interaction between pranlukast and the phospholipids. The transport mechanism of the PPC and non-complexed pranlukast across MDCK cells was measured and was observed to be significantly greater for the former than for the latter. The in vivo bioavailability of the PPC in rats hastened the onset of pranlukast-induced therapeutic effects, with C(max) and AUC increases of 21.88- and 28.64-fold, respectively, compared with raw crystals. In addition, an in vivo imaging method was used to corroborate that the PPC exhibited rapid circulatory distribution and gastrointestinal tract accumulation. These results indicate that PPC appears to be a promising drug delivery system for pranlukast, improving drug absorption and decreasing side effects by reducing the required oral dose.

Improving dissolution and oral bioavailability of pranlukast hemihydrate by particle surface modification with surfactants and homogenization.

The present study was carried out to develop an oral formulation of pranlukast hemihydrate with improved dissolution and oral bioavailability using a surface-modified microparticle. Based on solubility measurements, surface-modified pranlukast hemihydrate microparticles were manufactured using the spray-drying method with hydroxypropylmethyl cellulose, sucrose laurate, and water and without the use of an organic solvent. The hydrophilicity of the surface-modified pranlukast hemihydrate microparticle increased, leading to enhanced dissolution and oral bioavailability of pranlukast hemihydrate without a change in crystallinity. The surface-modified microparticles with an hydroxypropylmethyl cellulose/sucrose laurate ratio of 1:2 showed rapid dissolution of up to 85% within 30 minutes in dissolution medium (pH 6.8) and oral bioavailability higher than that of the commercial product, with approximately 2.5-fold and 3.9-fold increases in area under the curve (AUC 0 → 12 h) and peak plasma concentration, respectively. Therefore, the surface-modified microparticle is an effective oral drug delivery system for the poorly water-soluble therapeutic pranlukast hemihydrate.

Pharmacokinetics, Tissue Distribution and Plasma Protein Binding Studies of Rohitukine: A Potent Anti-hyperlipidemic Agent.

Rohitukine (RH) is a chromone alkaloid considered as one of the major active component of Dysoxylum binectariferum, exhibiting diverse pharmacological activities such as anti-hyperlipidemic, anti-cancer, anti-inflammatory, immuno-modulatory, anti-leishmanial, anti ulcer and anti-fertility. There's still a lack of information of RH, inclusive of pharmacokinetics, tissue distribution and excretion, in vivo studies in experimental animals, such as hamster and rats. In this study, a selective and sensitive bioanalytical method was developed and validated using HPLC-UV system. The assay was applied to estimate pharmacokinetics, tissue distribution and excretion of RH in hamster at 50 mg/kg oral dose. It rapidly reached systemic circulation and distributed to various tissues, and highest concentration was observed in liver. The pharmacokinetic parameters such as clearance (CL/F) was 3.95±0.9 L/h/kg, volume of distribution (Vd/F) was 17.34±11.34 L/kg and elimination half-life was 2.62±1.34 h. RH shows moderate protein binding ~ 60% and found stable in gastro-intestinal fluid, a property that favors oral administration.