Effect of total glucosides of paeony and Tripterygium wilfordii polyglycosides on erythrocyte methotrexate polyglutamates in rats, analysed using ultra-high-performance liquid chromatography-tandem mass spectrometry.

OBJECTIVES: The aim of the study was to explore the effect of total glucosides of paeony (TGP) and Tripterygium wilfordii polyglycosides (TWP) on erythrocyte methotrexate polyglutamates (MTXPGs), the metabolites of methotrexate (MTX). METHODS: An ultra-high-performance liquid chromatography (UPLC)-tandem mass spectrometry (MS/MS) method was developed to determine MTXPGs. The effects of MTXPGs were analysed using 24 male Sprague-Dawley rats that were randomly divided into the MTX alone, MTX-TGP combined, and MTX-TWP combined groups. Rats were administered MTX at a dose of 0.9 mg/kg once a week, TGP at 0.054 g/kg and TWP at 1.8 mg/kg three times a day. Venous blood (1.0 ml) was collected at weeks 2, 4, 6, 9, 12 and 15 and then analysed using the developed UPLC-MS/MS method. KEY FINDINGS: Specificity, linear range, inter-and intra-day precision, recovery, matrix effect and stability of MTXPGs met the standard regulations. This method was successfully used for the detection of MTXPGs. After administration of MTX alone, erythrocyte MTXPGs increased and accumulated in a time- and dose-dependent manner. Compared to MTX alone, the combination with TGP significantly decreased the content of total MTXPGs and short-chain MTXPGs (Methotrexate [MTX/MTXPG1] and 4-amino-10-methylpteroyldiglutamic acid [MTXPG2], P < 0.05), but had no significant effect on long-chain MTXPGs (4-amino-10-methylpteroyltriglutamic acid [MTXPG3], P > 0.05) and very long-chain MTXPGs (4-amino-10-methylpteroyltetraglutamic acid [MTXPG4] and 4-amino-10-methylpteroylpentaglutamic acid [MTXPG5], P > 0.05) at week 15. The combination of MTX with TWP had no significant effect on the content of total MTXPGs, short-chain MTXPGs and long-chain MTXPGs (P > 0.05), but it significantly decreased the content of very long-chain MTXPGs (P < 0.05) at week 15. CONCLUSIONS: The UPLC-MS/MS method was successfully used to determine MTXPGs in rat erythrocytes. TGP and TWP in combination with MTX affected the production of MTXPGs of different chain lengths in erythrocytes.

Hyaluronate-functionalized hydroxyapatite nanoparticles laden with methotrexate and teriflunomide for the treatment of rheumatoid arthritis.

Rheumatoid arthritis (RA), an autoimmune inflammatory disorder is currently incurable. Methotrexate and Teriflunomide are routinely prescribed drugs but their uses are limited due to severe hepatotoxicity. Hyaluronic acid (HYA) is a targeting ligand for CD44 receptors overexpressed on inflamed macrophages. The present investigation aimed at design and fabrication of HYA coated hydroxyapatite nanoparticles (HA-NPs) loaded with Methotrexate (MTX) and Teriflunomide (TEF) (HAMT-NPs) to form HYA-HAMT-NPs for the treatment of RA. HYA-HAMT-NPs showed the nanoscale size of 274.9 ± 64 nm along with a zeta potential value of -26.80 ± 6.08 mV. FTIR spectra of HYA and HYA-HAMT-NPs proved the coating of HYA on HYA-HAMT-NPs. HYA-HAMT-NPs showed less cell viability compared to drugs on RAW 264.7 macrophage cells. A biodistribution study by gamma scintigraphy imaging further strengthened the results by revealing significantly higher (p<0.05) percentage radioactivity (76.76%) of HYA-HAMT-NPs in the synovial region. The results obtained by pharmacodynamic studies ensured the better efficacy of HYA-HAMT-NPs in preventing disease progression and promoting articular regeneration. Under hepatotoxicity evaluation, liver histopathology and liver enzyme assay revealed ~29% hepatotoxicity was reduced by HYA-HAMT-NPs when compared to conventional FOLITRAX-10 and AUBAGIO oral treatments. Overall, the results suggest that HYA-HAMT-NP is a promising delivery system to avoid drug-induced hepatotoxicity in RA.

Xanthones from Securidaca inappendiculata antagonized the antirheumatic effects of methotrexate in vivo by promoting its secretion into urine.

BACKGROUND: This study was designed to characterize the interaction between Securidaca inappendiculata Hassk. derived xanthones and methotrexate (MTX). METHODS: Collagen-induced arthritis (CIA) was induced in rats, which were treated with MTX, a xanthone-rich fraction (XRF), or MTX+XRF by gavage for 30 days. Clinical efficacy was assessed based on arthritis scores, serological analysis, and histological examination. Protein expression was investigated by either immunohistochemical or immunoblotting methods. MTX concentrations were determined by HPLC or LC-MS methods. Obtained results were further validated by in vitro assays using 1,7-dihydroxy-3,4-dimethoxyxanthone and HEK 293 T cells. RESULTS: XRF antagonized the antirheumatic effects of MTX in vivo, suggested by higher levels of proinflammatory cytokines, and severer swelling and deformation of joints in CIA rats in the MTX+XRF group compared with MTX monotherapy. XRF reduced MTX concentration in plasma and promoted its excretion into urine. As a result, XRF attenuated MTX-induced edema of the proximal tubule. Furthermore, XRF restored the decreased expression of organic anion transporter three (OAT3), which accounts for MTX secretion in the kidney. Consistently, 1,7-dihydroxy-3,4-dimethoxyxanthone promoted the cellular intake of MTX by increasing OTA3 expression. CONCLUSION: It is suggested that the combined use of S. inappendulata with MTX should be optimized to avoid the antagonistic effects and improve the safety of the MTX regimen.

Co-encapsulating CoFe2O4 and MTX for hyperthermia.

Magnetic manotheranostics can be a fascinating charm to diagnose a tumour with MRI, and treatment through hyperthermia. This study aims to synthesise and characterise magnetically responsive polymer colloids (MRPCs). Healthy tissue damage done by chemotherapy session could be minimised by MRPCs. For the colloidal formulation of MRPCs, the oil in water emulsion technique was employed with the aid of sonication and stirring. The organic phase of emulsion contained methotrexate (MTX) drug, Eudragit E100 and CoFe2O4 (synthesised by co-precipitation) in ethanol, and the aqueous phase contained tween 80 in deionised water. The emulsion was optimised by studying/adjusting two different parameters, i.e. the concentration of constituents and sonication cycles. Multiple formulations were produced at sonication amplitude of 60% at 20 kHz, followed by centrifugation and lyophilisation. Characterisation of MRPCs was done for morphology, size measurement (23-25 nm), surface charge (∼15.12), coercivity (∼1549.6 G), magnetisation (2.6 emu) and retentivity (1.34 emu). Drug release in simulating physiological environment (pH = 7.4), was observed for up to 48 h, and, to determine the best release kinetic mechanism results were compared with kinetic models. Magnetic hyperthermia studies showed that MRPCs achieved an acceptable temperature of 42°C, for hyperthermia treatments in cancer patients.

Metabolomic Profiling to Identify Molecular Biomarkers of Cellular Response to Methotrexate In Vitro.

Variation in methotrexate (MTX) efficacy represents a significant barrier to early and effective disease control in the treatment of autoimmune arthritis. We hypothesize that the utilization of metabolomic techniques will allow for an improved understanding of the biochemical basis for the pharmacological activity of MTX, and can promote the identification and evaluation of novel molecular biomarkers of MTX response. In this work, erythroblastoid cells were exposed to MTX at the physiologic concentration of 1,000 nM and analyzed using three metabolomic platforms to give a broad spectrum of cellular metabolites. MTX pharmacological activity, defined as cellular growth inhibition, was associated with an altered cellular metabolomic profile based on the analysis of 724 identified metabolites. By discriminant analysis, MTX treatment was associated with increases in ketoisovaleric acid, fructose, galactose, and 2-deoxycytidine, and corresponding reductions in 2-deoxyuridine, phosphatidylinositol 32:0, orotic acid, and inosine monophosphate. Inclusion of data from analysis of folate metabolism in combination with chemometric and metabolic network analysis demonstrated that MTX treatment is associated with dysregulated folate metabolism and nucleotide biosynthesis, which is in line with its known mechanism of action. However, MTX treatment was also associated with alterations in a diversity of metabolites, including intermediates of amino acid, carbohydrate, and lipid metabolism. Collectively, these findings support a robust metabolic response following exposure to physiologic concentrations of MTX. They also identify various metabolic intermediates that are associated with the pharmacological activity of MTX, and are, therefore, potential molecular biomarker candidates in future preclinical and clinical studies of MTX efficacy in autoimmune arthritis.

Magnesium oil enriched transdermal nanogel of methotrexate for improved arthritic joint mobility, repair, and reduced inflammation.

Aim: Methotrexate (Mtx) is prescribed to reduce pain and inflammation in arthritis patients; however, improved repair and mobility of joints still are the major concerns. Magnesium oil (MO) improves joint mobility and repair; therefore, MO-assisted transdermal delivery of Mtx was aimed.Methods: MO integrated Mtx nanoemulsion (Mtx-MONE) was prepared with uniform size (175 ± 35.4 nm), pH (6.15 ± 0.3) near to skin pH, and high entrapment efficiency (65 ± 8.6%). Mtx-MONE was transformed to nanogel (Mtx-MONEG) with semisolid consistency (43,408 ± 77.72 cP) and good spreadability (3.63 ± 0.033 mJ).Results: Mtx-MONEG showed significant reduction in oedema, arthritic scores, level of inflammatory cytokines, and improved walking as compared to diseased control. MO offered additional improvements in joints, mobility, and repair.Conclusion: Transdermal delivery of Mtx has been successfully achieved by Mtx-MONEG. Tremendous recovery from inflammation, improved joints mobility and repair, and reduced pain strongly support the use of MO as an adjutant of Mtx for improved transdermal application.

The role of therapeutic drug monitoring in the management of safety of anticancer agents: a focus on 3 cytotoxics.

Introduction: Therapeutic drug monitoring in oncology is used to prevent major toxicities of selected anticancer agents due to overexposure by individualizing the dose based on a pharmacokinetic target. Areas covered: Numerous studies relating a relation between pharmacokinetic variability and toxicity have been reported since the eighties but very few have been implemented in clinical practice due to a lack of validation and harmonization, logistical constraints and reluctance from oncologists. Following recent recommendations, this paper highlights the current-validated applications of pharmacokinetic monitoring in oncology focusing on the safety of anticancer therapies. Expert opinion: Paradoxically given the oldness of the agents, guidelines of dose adjustment have been recently available for intravenous busulfan, 5-fluorouracil, and high-dose methotrexate. Interestingly, besides the enhancement of tolerability, it applies to potential curative clinical situations. In an era of personalized oncology that integrates complex molecular factors in the treatment of cancer, education is needed for oncologists to show the benefits of this valuable (even old) resource for the safety of patients. Therapeutic drug monitoring for busulfan, 5-fluorouracil and methotrexate will still hold in the future unless more active agents are available in the concerned indications.

NIR- and thermo-responsive semi-interpenetrated polypyrrole nanogels for imaging guided combinational photothermal and chemotherapy.

Versatile, multifunctional nanomaterials for theranostic approaches in cancer treatment are highly on demand in order to increase therapeutic outcomes. Here, we developed thermo-responsive nanogels equipped with the efficient near-infrared (NIR) transducing polymer polypyrrole (PPY) for combinational photothermal and chemotherapeutic therapy along with photoacoustic imaging ability. Long-term stability and water-dispersibility of PPY was achieved using semi-interpenetration method for in situ polymerization of PPY into hydrophilic thermo-responsive nanogels. The semi-interpenetrated nanogels of spherical shape and with hydrodynamic sizes of around 200 nm retained the temperature response behaviour and exhibit excellent photothermal transducing abilities in the NIR region. The PPY nanogels served as photoacoustic contrast agents, which allowed determination of biodistribution profiles ex vivo. In addition, we developed a new method for biodistribution determination based on the photothermal response of the nanogels with an accuracy down to 12.5 µg/mL. We examined the ability of the nanogels as photothermal agents and drug delivery systems in vitro and in vivo. We showed that they efficiently inhibit tumor growth with combinational effects of chemotherapeutics and photothermal treatment. Our work encourages further exploration of nanogels as functional stabilizing matrix for photothermal transducers and their application as drug delivery devices in combination with photothermal therapy and imaging.

Self-microemulsifying drug delivery system (SMEDDS) for improved oral delivery and photostability of methotrexate.

Purpose: The objective of this study was to exploit a novel methotrexate (MTX)-loaded solid self-microemulsifying drug delivery system (SMEDDS) with enhanced bioavailability and photostability. Materials and methods: The optimized liquid SMEDDS was composed of castor oil, Tween® 80, and Plurol® diisostearique at a voluminous ratio of 27:63:10. The solid SMEDDS was formulated by spray drying liquid SMEDDS with the solid carrier (calcium silicate). Particle size analyzer, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and Fourier transform infrared (FTIR) spectroscopy experiments characterized the physiochemical properties of the MTX-loaded solid SMEDDS. These properties include a z-average diameter of emulsion around 127 nm and the amorphous form of the solid SMEDDS. Furthermore, their solubility, dissolution, and pharmacokinetics in Sprague-Dawley rats were analyzed in comparison with the MTX powder. Results: The final dissolution rate and required time for complete release of solid SMEDDS were 1.9-fold higher and 10 min shorter, respectively, than those of MTX powder. Pharmacokinetic analysis demonstrated 2.04- and 3.41-fold increments in AUC and Cmax, respectively in comparison to MTX powder. The AUC and Cmax were significantly increased in solid SMEDDS. Finally, the photostability studies revealed the substantially enhanced photostability of the MTX-loaded SMEDDS under the forced degradation and confirmatory conditions. Conclusion: This solid SMEDDS formulation could be an outstanding candidate for improving the oral bioavailability and photostability of MTX.

Folate Conjugated Double Liposomes Bearing Prednisolone and Methotrexate for Targeting Rheumatoid Arthritis.

PURPOSE: This investigation was aimed to explore the targeting potential of folate conjugated double liposomes (fDLs) bearing combination of synergistic drugs (Prednisolone and Methotrexate) for effective management of the rheumatoid arthritis (RA). METHODS: To overcome the drawbacks of monotherapy, a combination of prednisolone (PRD) (an anti-inflammatory agent) and methotrexate (MTX) (a disease modifying anti-rheumatoid agent, DMARDs) was chosen for dual targeting approach. fDLs were prepared in two steps i.e. development of inner liposomes (ILs) using thin film casting method followed by encapsulation of ILs within folate conjugated outer liposomes (double liposomes; fDLs). Developed liposomes were characterized for various physicochemical parameters and in vivo performance. RESULTS: fDLs were prepared using FA-PEG-4000-NH-DSPE conjugate. These double liposomes were having 429.3 ± 3.6 nm in size with 0.109 PDI, 8.01 ± 0.3 mV zeta potential (ζ) and 66.7 ± 3.9% and 45.3 ± 1.7% entrapments of PRD and MTX, respectively. After 24 h, the concentrations of PRD in blood were observed to be 8.66 ± 3.11 (ILs) and 15.13 ± 0.81% (DLs) while concentration of MTX were found to be 10.89 ± 0.69 and 2.34 ± 3.15% when given as ILs and fDLs, respectively. The concentration of both drugs in inflamed joint was observed to be higher than that in the non-inflamed joints. CONCLUSIONS: The folate conjugated double liposomes possess superior targeting efficiency than conjugated and unconjugated single liposomes.

Design and development of bioinspired calcium phosphate nanoparticles of MTX: pharmacodynamic and pharmacokinetic evaluation.

The aim of this investigation is the management of rheumatoid arthritis (RA) by developing methotrexate-loaded calcium phosphate nanoparticles (MTX-CAP-NP) and to evaluate pharmacokinetic and pharmacodynamic behavior in adjuvant induced arthritis model. The nanoparticles were synthesized by wet precipitation method and optimized by Box-Behnken experimental design. MTX-CAP-NPs were characterized by TEM, FTIR, DSC and XRD studies. The particle size, zeta potential and entrapment efficiency of the optimized nanoparticles were found to be 204.90 ± 64 nm, -11.58 ± 4.80 mV, and 88.33 ± 3.74%, respectively. TEM, FTIR, DSC and XRD studies revealed that the developed nanoparticles were nearly spherical in shape and the crystalline structure of CAP-NP was not changed after MTX loading. The pharmacokinetic studies revealed that MTX-CAP-NP enhanced bioavailability of MTX by 2.6-fold when compared to marketed formulation (FOLITRAX-10). Under pharmacodynamic evaluation, arthritic assessment, radiography and histopathology studies revealed that CAP has ability to regenerate cartilage and bone therefore, together with MTX, MTX-CAP-NPs have shown significant reduction in disease progression. The overall work demonstrated that the developed nanodelivery system was well tolerated and more effective than the marketed formulation.

Calcium Channel Blockers Possibly Delay the Elimination of Plasma Methotrexate in Patients Receiving High-Dose Methotrexate Therapy.

Delayed elimination of plasma methotrexate (MTX), which leads to elevated toxicity, is often observed in patients receiving high-dose methotrexate (HD-MTX) therapy, despite of the preventive measures. In this study, we investigated the factors that delay elimination of plasma MTX in patients on HD-MTX therapy. Fifteen patients who received HD-MTX therapy (21 cycles) were classified into two groups: delayed elimination of plasma MTX (38.1%, 8/21) and normal elimination of plasma MTX (61.9%, 13/21). Patient characteristics, plasma MTX concentrations, laboratory values, and adverse reactions were compared between the two groups using Fisher's exact test. Univariate analysis showed that co-administration of calcium channel blockers was significantly associated with delayed elimination of plasma MTX (p = 0.042). This is the first report demonstrating that co-administration of calcium channel blockers may be a predictive factor of delayed elimination of plasma MTX in patients receiving HD-MTX therapy.

Effects of Red Ginseng Extract on the Pharmacokinetics and Elimination of Methotrexate via Mrp2 Regulation.

We aimed to investigate the effects of red ginseng extract (RGE) on the expression of efflux transporters and to study the pharmacokinetics of representative substrate. For this, rats received single or repeated administration of RGE (1.5 g/kg/day) for 1 and 2 weeks via oral gavage. mRNA and protein levels of multidrug resistance-associated protein2 (Mrp2), bile salt export pump (Bsep), and P-glycoprotein (P-gp) in the rat liver were measured via real-time polymerase chain reaction and Western blot analysis. Ginsenosides concentrations from the rat plasma were also monitored using a liquid chromatography⁻tandem mass spectrometry (LC⁻MS/MS) system. Plasma concentrations of ginsenoside Rb1, Rb2, Rc, and Rd following repeated administration of RGE for 1 and 2 weeks were comparable but significantly higher than those after single administration of RGE. These dosing regimens did not induce significant biochemical abnormalities in the liver, kidneys, and lipid homeostasis. In the RGE repeated oral administration groups, the mRNA and protein levels of Mrp2 significantly decreased. Accordingly, we investigated the changes in the pharmacokinetics of methotrexate, a probe substrate for Mrp2, following intravenous administration of 3 mg/kg methotrexate to rats in the RGE 1-week repeated oral administration group, compared to that in the control group. Biliary excretion, but not urinary excretion, of methotrexate decreased in the RGE repeated administration group, compared to that in the control group. Consequently, the plasma concentrations of methotrexate slightly increased in the RGE repeated administration group. In conclusion, repeated administration of RGE for 1 week resulted in a decrease in Mrp2 expression without inducing significant liver or kidney damage. Pharmacokinetic herb⁻drug interaction between RGE and methotrexate might occur owing to the decrease in the mRNA and protein levels of Mrp2.

Co-Delivery of Teriflunomide and Methotrexate from Hydroxyapatite Nanoparticles for the Treatment of Rheumatoid Arthritis: In Vitro Characterization, Pharmacodynamic and Biochemical Investigations.

PURPOSE: The present investigation was aimed at developing Teriflunomide (TEF) and Methotrexate (MTX) loaded hydroxyapatite nanoparticles and increasing tolerability towards combination therapy against rheumatoid arthritis by reducing hepatotoxicity. METHODS: Drug-loaded HAp-NPs were synthesized by wet-chemical precipitation method and optimized by Box-Behnken experimental design. The developed NPs were subjected to in vitro and in vivo characterization. In-vivo pharmacodynamics and biochemical studies were performed on adjuvant- induced arthritis model treated with different formulations; MTX-TEF-SOL, TEF-HAp-NP, MTX-HAp-NP, TEF-MTX-HAp-NP, FOLITRAX-10 and AUBAGIO. RESULTS: The size of the optimized formulations, TEF-HAp-NP and MTX-HAp-NP, was found to be 224.3 ± 83.80 nm and 268.3 ± 73.86 nm with drug loading 53.11 ± 0.84% and 67.04 ± 1.12% respectively. In vitro release of TEF from TEF-HAp-NP (70.41 ± 1.22%) and MTX from MTX-HAp-NP (82.43 ± 1.31%) up to 24 h revealed sustained release pattern. Results of the arthritic assessment study showed a significant (P < 0.05) reduction in ankle diameter (61.30 ± 7.42) and arthritis score (2.35 ± 0.24) with a marked restoration of ankle joint micro-architecture in TEF-MTX-HAp-NP treated group. During Hepatotoxicity studies, liver histopathology revealed that the formulation MTX-TEF-HAp-NP was least hepatotoxic with less hepatocyte swelling and fibrous connective tissue proliferation while Folitrax-10 was found to be most hepatotoxic. Biochemical studies revealed that Folitrax-10 significantly (P < 0.05) increased the GOT (313.64 ± 16) and GPT level (334.46 ± 13) while insignificant (P > 0.05) change in GOT (263.68 ± 17) and GPT (229.38 ± 10) level was recorded with TEF-MTX-HAp-NP. CONCLUSIONS: We report that the subcutaneous delivery of TEF-MTX-HAp-NP was most effective as it successfully reduced the dosage by half for maximizing therapeutic efficacy and minimizing side effects. Graphical Abstract ᅟ.

Imaging and Methotrexate Response Monitoring of Systemic Inflammation in Arthritic Rats Employing the Macrophage PET Tracer [18F]Fluoro-PEG-Folate.

Background: In rheumatoid arthritis, articular inflammation is a hallmark of disease, while the involvement of extra-articular tissues is less well defined. Here, we examined the feasibility of PET imaging with the macrophage tracer [18F]fluoro-PEG-folate, targeting folate receptor ß (FRß), to monitor systemic inflammatory disease in liver and spleen of arthritic rats before and after methotrexate (MTX) treatment. Methods: [18F]Fluoro-PEG-folate PET scans (60 min) were acquired in saline- and MTX-treated (1 mg/kg, 4x) arthritic rats, followed by tissue resection and radiotracer distribution analysis. Liver and spleen tissues were stained for ED1/ED2-macrophage markers and FRß expression. Results: [18F]Fluoro-PEG-folate PET and ex vivo tissue distribution studies revealed a significant (p < 0.01) 2-fold lower tracer uptake in both liver and spleen of MTX-treated arthritic rats. Consistently, ED1- and ED2-positive macrophages were significantly (p < 0.01) decreased in liver (4-fold) and spleen (3-fold) of MTX-treated compared with saline-treated rats. Additionally, FRß-positive macrophages were also significantly reduced in liver (5-fold, p < 0.005) and spleen (3-fold, p < 0.01) of MTX- versus saline-treated rats. Conclusions: MTX treatment reduced activated macrophages in liver and spleen, as markers for systemic inflammation in these organs. Macrophage PET imaging with [18F]fluoro-PEG-folate holds promise for detection of systemic inflammation in RA as well as therapy (MTX) response monitoring.

Clinical significance of polyglutamylation in primary central nervous system lymphoma.

The therapeutic response to high-dose methotrexate (HD-MTX) therapy for primary central nervous system lymphoma (PCNSL) varies. Polyglutamylation is a reversible protein modification with a high occurrence rate in tumor cells. MTX incorporated into cells is polyglutamylated and strongly binds to dihydrofolate reductase without competitive inhibition by leucovorin (LV). Tumor cells with high polyglutamylation levels are selectively killed, whereas normal cells with lower polyglutamylation are rescued by LV. We hypothesized that the extent of polyglutamylation in tumor cells determines treatment resistance. Here, we investigated the therapeutic response of PCNSL to HD-MTX therapy with LV rescue based on polyglutamylation status. Among 113 consecutive PCNSL patients who underwent HD-MTX therapy in our department between 2001 and 2014, polyglutamylation was evaluated by immunostaining in 82 cases, with relationships between polyglutamylation and therapeutic response retrospectively examined. Human malignant lymphoma lines were used for in vitro experiments, and folpolyglutamate synthetase (FPGS), which induces polyglutamylation, was knocked down with short-hairpin RNA, and a stable cell line with a low rate of polyglutamylation was established. Cell viability after MTX treatment with LV rescue was evaluated using sodium butyrate (NaBu), a histone-deacetylase inhibitor that induces polyglutamylation by elevating FPGS expression. The complete response rate was significantly higher in the group with polyglutamylation than in the non-polyglutamylation group [58.1% (25/43) and 33.3% (13/39), respectively] (p < 0.05), and progression-free survival was also significantly increased in the group with polyglutamylation (p < 0.01). In vitro, the relief effect of LV after MTX administration was significantly enhanced after FPGS knockdown in al cell lines, whereas enhancement of FPGS expression by NaBu treatment significantly reduced this relief effect. These findings suggested that polyglutamylation could be a predictor of therapeutic response to HD-MTX therapy with LV rescue in PCNSL. Combination therapy with HD-MTX and polyglutamylation-inducing agents might represent a promising strategy for PCNSL treatment.

Smilax glabra Rhizoma affects the pharmacokinetics and tissue distribution of methotrexate by increasing the P­glycoprotein mRNA expression in rats after oral administration.

Methotrexate (MTX) is a widely used immunosuppressant and anticancer agent with high toxicity. Smilax glabra Rhizoma (SGR) has the effect of detoxification and immunoregulation, and has been used as both food and folk medicine in many countries. Co­administration of MTX and SGR occurs in several diseases. However, whether they work synergistically or are incompatible remains unknown. In the present study, MTX was administrated to rats alone or combined with SGR. Blood and tissue samples were collected at designated times. The concentrations of MTX were determined by high­performance liquid chromatography. Reverse transcription­quantitative polymerase chain reaction (RT­qPCR) was used to detected the gene expression. SGR decreased the AUC0­t and Cmax of MTX by 44.5 and 48.2%, but in a tissue­dependent manner. The total exposure of MTX was significantly decreased in the small intestine, stomach, plasma, and kidney by 61.6, 34.7, 63.3 and 46.1%, respectively, but was increased in the lung and spleen by 82.9 and 21.0%, respectively. RT­qPCR demonstrated that SGR increased the mean P­glycoprotein (gp) mRNA expression in the small intestine 2.54 times, but had a marginal effect on the expression of organic anion transporting polypeptide 2, and organic anion transporter (OAT)1 and OAT2. These results suggested that SGR affects the pharmacokinetics of MTX in a tissue­dependent manner by affecting P­gp, and the clinical effect of co­administration depended on the disease site.

Interaction between rhein acyl glucuronide and methotrexate based on human organic anion transporters.

Rhein, a major bioactive compound of many medicinal herbs and the prodrug of diacerein, is often used with low dose of methotrexate as drug combination to treat rheumatoid arthritis. In this study, potential drug-drug interaction between methotrexate and rhein was investigated based on organic anion transporters (OAT). Our study demonstrated that rhein acyl glucuronide (RAG), the major metabolite of rhein in the human blood circulation, significantly inhibited the uptake of p-aminohippurate in hOAT1 transfected cells with IC50 value of 691 nM and estrone sulfate uptake in hOAT3 transfected cells with IC50 value of 78.5 nM. As the substrate of both hOAT1 and hOAT3, the methotrexate transport was significantly inhibited by RAG in hOAT1 transfected cells at 50 µM and hOAT3 transfected cells at 1 µM by 69% and 87%, respectively. Further in vivo study showed that after co-administrated with RAG in rats the AUC0-24 values of methotrexate increased from 3109 to 5370 ng/mL*hr and the t1/2 was prolonged by 40.5% (from 7.4 to 10.4 h), demonstrating the inhibitory effect of RAG on methotrexate excretion. In conclusion, rhein acyl glucuronide could significantly decrease the transport of methotrexate by both hOAT1 and hOAT3. The combination use of rhein, diacerein or other rhein-containing herbs with methotrexate may cause obvious drug-drug interaction and require close monitoring for potential drug interaction in clinical practice.

Multifunctional nanospheres for co-delivery of methotrexate and mild hyperthermia to colon cancer cells.

A multifunctional nanomedicine platform was designed and evaluated for efficient colon cancer therapy by a combinatorial therapeutic approach based on a chemotherapeutic drug and mild hyperthermia. Advantage was taken from the dual role of methotrexate (MTX), as folate receptor-targeting, overexpressed in tumor cells, and as anticancer drug. Incorporation of superparamagnetic iron oxide nanoparticles (SPIONs) allows to heat cancer cells externally through an alternating magnetic field. The developed nanocarrier was based on polyethylene glycol-polylactic acid (PEG-PLA) nanospheres to improve biocompatibility, enhancing their targeting by prolonging blood circulation time. By an emulsion-evaporation method the nanospheres were produced and then characterized for size distribution, zeta-potential, in vitro drug release profile and cellular studies. The co-delivery of MTX and SPIONs on PEG-PLA nanospheres resulted in nanocarriers with a size of 160nm in diameter, a polydispersity index below 0.2 and a zeta potential of ca. -18mV. Multifunctional nanospheres were monodisperse and stable up to 3months. MTX was released preferentially under mild hyperthermia conditions. The multifunctional nanospheres were able to increase the cytotoxicity of MTX towards Caco-2 and SW-480 colon cancer cells, in comparison to free drug. Also, the nanospheres allowed the incorporated MTX to induce greater cell cycle arrest and apoptotic effects than the free MTX. This study provides evidences that MTX-SPIONs-PEG-PLA nanospheres are a promising solution to address colorectal cancer over-expressing folate receptors, by a combinatory approach.

Review of the bioanalytical methods for the determination of methotrexate and its metabolites in in vitro, preclinical and clinical studies: Case studies and perspectives.

Methotrexate is an old drug that has found use in several therapeutic areas, such as cancer to treat various malignancies, rheumatoid arthtritis and inflammatory bowel disease. Owing to its structural properties of possessing two carboxylic acid groups and having low native fluorescence, it has provided technical challenges for development of bioanalytical methods. Also, in vivo metabolism leading to circulatory metabolites such as 7-hydroxymethotrexate and 2,4-diamino N10 -methylpteroic acid, as well as the formation of polyglutamate metabolites intracellularly have added further complexity for the assays in terms of the analytes that need to be quantified in addition to methotrexate. The present review is aimed at providing a concise tabular summary of chromatographic assays with respect to method nuances including assay/chromatographic conditions, key validation parameters and applicable remarks. Several case studies are reviewed under various subheadings to provide the challenges involved in the method development for methotrexate and metabolites. Finally, a discussion section is devoted to overall perspectives obtained from this review.