Small molecules modified mesoporous silica nanoparticles orally deliver indomethacin with synergistic effect.

Molecularly functional drug delivery systems possessed huge potentials to realize novel drug administration. To explore small molecules modified drug delivery, a series of small molecules modified mesoporous silica nanoparticles (L-Mal-MSNs, D-Mal-MSNs) were established by grafting small molecules. Poorly water-soluble indomethacin (IMC) was chosen to load into these small molecules modified carriers as well as corresponding control carrier, and further to study characteristics and delivery effects of drug loaded carriers. The results indicated that all these small molecules modified carriers formed hydrogen bonds with drugs and can successfully convert drug crystal phase to amorphous state so as to enhance drug dissolution compared to raw drug. In vivo rat intestinal perfusion demonstrated that IMC loaded L-Mal-MSNs performed the fastest drug absorption while analgesic and anti-inflammatory effects of IMC loaded D-Mal-MSNs turned out to be the best, giving hints that D-malic acid exhibited best synergic functions for IMC. The herein small molecules modified delivery system is an effective solution strategy for the current application of analgesia and anti-inflammatory drugs with outstanding significance.

Comprehensive Stereoselectivity Assessment of Toxicokinetics, Tissue Distribution, Cytotoxicity, and Environmental Fate of Chiral Pesticide Propiconazole.

Propiconazole (PRO) has been widely used in the treatment of fungal infection in fruits, vegetables, cereals, and seeds. In this study, a newly established chiral liquid chromatography tandem mass spectrometry method was applied to the systemic stereoselectivity evaluation of PRO enantiomers, including toxicokinetics, tissue distributions, cytotoxicity, accumulation, and degradation. Our results showed that both trans (+)-2S,4S-PRO and cis (-)-2S,4R-PRO had lower Cmax and AUC0-∞ and higher CLz/F values in plasma and lower accumulation concentrations in the liver, heart, and brain. In cytotoxic assays, cis (-)-2S,4R-PRO exhibited the lowest cytotoxicity in PC12 neuronal, N9 microglia, SH-SY5Y neuroblastoma, and MRC5 lung fibroblast cell lines. Moreover, the Eisenia fetida incubation experiment revealed that the accumulations of both trans (+)-2S,4S-PRO and cis (-)-2S,4R-PRO were higher than those of their antipodes in E. fetida. In summary, our findings first suggested that the application of cis (-)-2S,4R-PRO for agriculture would hugely reduce the environmental risk.

Cerebral iron deficiency may induce depression through downregulation of the hippocampal glucocorticoid-glucocorticoid receptor signaling pathway.

BACKGROUND: Iron is a trace essential element to sustain the normal neurological function of human. Many researches had reported the involvement of iron deficiency (ID) in neural development and cognitive functions. However, the role of ID in pathogenesis of depression and its underlying mechanism are still unclear. METHODS: In this study, we first used chronic unpredicted mild stress (CUMS) and iron deprivation mouse models to clarify the pathogenesis role of cerebral ID in depression. Then the role of hippocampal glucocorticoid (GC)-glucocorticoid receptor (GR) pathway in cerebral ID induced depression were elucidated in iron deprivation mice and iron deficiency anemia patients. RESULTS: Our results revealed that both CUMS and iron deprivation could induce cerebral ID in mice, and combination of iron deprivation and CUMS could accelerate the onset and aggravate the symptoms of depression in mice. In hippocampus, ID led to neuronal injury and neurogenesis decrease, which might be related to downregulation of GC-GR signaling pathway caused GR dysfunction, thereby inhibiting the negative feedback regulation function of hippocampus on hypothalamic-pituitary-adrenal (HPA) axis. Moreover, the overactivity of HPA axis in iron deprivation mice and iron deficiency anemia patients also confirmed GR dysfunction. LIMITATIONS: Iron deprivation led to food and water intake decrease of mice, which may affect the behavioral test. In addition, we mainly evaluated the role of hippocampal ID in depression, and the number of iron deficiency anemia patients was limited. CONCLUSIONS: Our results identified that cerebral iron homeostasis was a key factor for maintaining mental stability.

Systemic Stereoselectivity Study of Fenobucarb: Environmental Behaviors in Greenhouse Vegetables, Fruits, Earthworms, and Soils and Its Cytotoxicity.

Fenobucarb (2-sec-butylphenyl methylcarbamate, BPMC) is a potent carbamate pesticide with high insecticidal activity. In this study, the enantioselective accumulation of BPMC in earthworms (Eisenia foetida) and dissipation in cabbage, Chinese cabbage, strawberry, and soils were investigated. The samples were prepared using the QuEChERS method and analyzed using fast and sensitive chiral high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) analysis. The stereoselective accumulation of BPMC enantiomers revealed that S-(+)-BPMC was preferentially accumulated in earthworms rather than its antipode. However, the dissipation studies showed that S-(+)-BPMC degraded faster than the R-(-)-isomer in cabbage, Chinese cabbage, strawberry, and soils. Furthermore, the cytotoxic effect of BPMC enantiomers toward PC12 and N9 neuronal, A549 lung cancer, and MRC5 lung fibroblast cell lines was evaluated using an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Compared with R-(-)- and rac-isomers, S-(+)-BPMC exhibited lower cytotoxicity in neuronal cells and a weaker proliferating effect on lung cancer and lung fibroblast cells. Altogether, the findings suggest the use of the pure S-(+)-enantiomer in agricultural management rather than the use of the racemate or the R-(-)-isomer, which might reduce the environmental risk.

Seed oil of Brucea javanica induces apoptosis through the PI3K/Akt signaling pathway in acute lymphocytic leukemia Jurkat cells.

Brucea javanica oil emulsion (BJOE) has been used to treat tumor in China for more than 40 years. However, its components and effectiveness in the treatment of acute lymphocytic leukemia (ALL) and its mechanism of anti-cancer activity remain unknown. In the current study, high-performance liquid chromatography-evaporative light scattering detector (HPLC-ELSD) was used to analyze the components of BJOE. Then, the anti-leukemia effects of BJOE were examined both in vitro and in vivo using ALL Jurkat cells and the p388 mouse leukemia transplant model, respectively. The primary ALL leukemia cells were also used to confirm the anti-leukemia effects of BJOE. The apoptotic-related results indicated that BJOE induced apoptosis in Jurkat cells and were suggestive of intrinsic apoptotic induction. Moreover, BJOE inhibited Akt (protein kinase B) activation and upregulated its downstream targets p53 and FoxO1 (forkhead box gene, group O-1) to initiate apoptosis. The activation of GSK3ß was also involved. Our findings demonstrate that BJOE has anti-leukemia effects on ALL cells and can induce apoptosis in Jurkat cells through the phosphoinositide3-kinase (PI3K) /Akt signaling pathway.

Design, synthesis and biological evaluation of 2-arylaminopyrimidine derivatives bearing 1,3,8-triazaspiro[4,5]decan-4-one or piperidine-3-carboxamide moiety as novel Type-I1/2 ALK inhibitors.

Aiming to develop novel Type-I1/2 inhibitors of ALK to overcome extensive resistance mutations, especially the L1196M mutation surrounding the ATP pocket, two series of 2-arylaminopyrimidine derivatives (11a-f and 22a-t) were designed based on scaffold hopping. The extensive structural elaboration discovered compound 22o which possessed excellent IC50 values of 0.06 and 0.23 µM against ALK-positive Karpas299 and H2228 cell lines, respectively. Meanwhile, 22o displayed encouraging inhibitory potency in the ALKWT (2.5 nM) and ALKL1196M (6.5 nM) enzymatic assays. Furthermore, the AO/EB and Hoechst 33258 assays illustrated 22o could induce cell apoptosis in a dose-dependent manner. Eventually, the molecular docking of 22o with ALK clearly presented the vital interactions within the active site, which was in accordance with Type-I1/2 inhibitor binding mode.

Antioxidative and Anti-Apoptotic Roles of Silibinin in Reversing Learning and Memory Deficits in APP/PS1 Mice.

Silibinin has been widely used to treat liver diseases due to its antioxidant activity. However, the effects of silibinin on the central nervous system have not been thoroughly investigated. The pathological hallmarks of Alzheimer's disease are the accumulation of amyloid ß protein, development of neurofibrillary tangles and increased oxidative stress, which ultimately lead to irreversible neuronal loss and cognitive impairment. Our findings show that silibinin ameliorated memory impairments in APP/PS1 mice in the Morris water maze via suppression of oxidative stress and inhibition of apoptosis. Treatment with silibinin reduced malondialdehyde content level and increased glutathione and superoxide dismutase activity in APP/PS1 mice. A terminal deoxynucleotidyl transferase dUTP nick end labeling assay revealed an anti-apoptotic effect of silibinin. Silibinin suppressed the activation of caspase-3 by inhibiting Jun N-terminal kinase phosphorylation and the downstream hippocampal Bax/Bcl-2 ratio. Silibinin treatment significantly increased levels of synaptophysin and PSD95 in APP/PS1 transgenic mice. These results suggest that silibinin could be a potential therapeutic agent for the treatment of Alzheimer's disease.

Silibinin rescues learning and memory deficits by attenuating microglia activation and preventing neuroinflammatory reactions in SAMP8 mice.

Silibinin was reported to be effective in reversing the learning and memory deficits of several AD animal models. These improvements are thought to be regulated by various factors, including antioxidative stress, inhibition of acetylcholinesterase activity and Aß aggregation. However, there are still no reports that demonstrate the effect of silibinin on microglia activation in vivo. Thus, in this study, we used the senescence-accelerated mouse (SAMP8) strain to test the effects of silibinin on behavioral impairments and microglia activation-induced neuroinflammation. Silibinin treatment significantly rescued memory deficits in novel object recognition test and Morris water maze test. Silibinin treatment significantly attenuated microglial activation; down-regulated the level of the proinflammatory cytokine IL-6, anti-inflammatory cytokine IL-4, and inflammation-associated proteins, iNOS and COX-2; and further modulated MAPK to protect neural cells. These results suggest that silibinin could be a potential candidate for the therapy of neurodegenerative disorders.

Simultaneous determination of 1-ß-d-Arabinofuranosylcytosine and two metabolites, 1-ß-d-Arabinofuranosyluracil and 1-ß-d-Arabinofuranosylcytosine triphosphate in leukemic cell by HPLC-MS/MS and the application to cell pharmacokinetics.

A specific and reliable HPLC-MS/MS method was developed and validated for the simultaneous determination of 1-ß-d-Arabinofuranosylcytosine (ara-C), 1-ß-d-Arabinofuranosyluracil (ara-U) and 1-ß-d-Arabinofuranosylcytosine triphosphate (ara-CTP) in the leukemic cells for the first time. The analytes were separated on a C18 column (100mm×2.1mm, 1.8µm) and a triple-quadrupole mass spectrometry equipped with an electrospray ionization (ESI) source was used for detection. The ion-pairing reagent, NFPA, was added to the mobile phase to retain the analytes in the column. The cell homogenates sample was prepared by the simple protein precipitation. The calibration curves were linear over a concentration range of 3.45-3450.0ng/mL for ara-C, 1.12-1120.0ng/mL for ara-U and 4.13-4130.0ng/mL for ara-CTP. The intra-day and inter-day precision was less than 15% and the relative error (RE) were all within ±15%. The validated method was successfully applied to assess the disposition characteristics of ara-C and support cell pharmacokinetics after the patients with leukemia were intravenously infused with SDAC and HiDAC. The result of the present study would provide the valuable information for the ara-C therapy.

A HPLC-MS/MS method for the simultaneous quantitation of six alkaloids of Rhizoma Corydalis Decumbentis in rat plasma and its application to a pharmacokinetic study.

A specific and reliable HPLC-MS/MS method was developed and validated for the simultaneous determination of six alkaloids in rat plasma, jatrorrhizine, berberine, tetrahydropalmatine, protopine, bicuculline and palmatine. The analytes were separated on a C18 column (50mm×2.1mm, 1.8µm) and a triple-quadrupole mass spectrometry equipped with an electrospray ionization (ESI) source was used for detection. The plasma sample was prepared by the simple protein precipitation and the recovery for the six analytes was over 80%. The calibration curves were linear over a concentration range of 0.38-1900.0ng/mL for jatrorrhizine, 0.57-2850.0ng/mL for berberine, 0.32-1600.0ng/mL for tetrahydropalmatine, 0.21-1050.0ng/mL for protopine, 0.34-1700.0ng/mL for bicuculline and 0.22-1100ng/mL for palmatine. The intra-day and inter-day precision was less than 15% and the relative error (RE) was all within ±15%. The validated method was successfully applied to a pharmacokinetics study in rats after oral administration of the extracts of Rhizoma Corydalis Decumbentis (a famous Chinese herb).

Novel nanostructured lipid-dextran sulfate hybrid carriers overcome tumor multidrug resistance of mitoxantrone hydrochloride.

Novel nanostructured lipid-dextran sulfate hybrid carriers (NLDCs) were successfully developed for sustained delivery of water-soluble cationic mitoxantrone hydrochloride (MTO) and overcoming multidrug resistance. The introduction of negative polymer of dextran sulfate sodium significantly improved the encapsulation efficiency (97.4%) and sustained the release of MTO (86.9% at 72 hours). In vivo pharmacokinetics in rats after intravenous administration demonstrated that MTO-loaded NLDCs (MTO-NLDCs) had higher area under the curve and longer half-life than MTO solution (MTO-Sol). In the biodistribution study, NLDCs significantly improved the MTO levels in plasma, spleen, and brain, and decreased the distribution of MTO in heart and kidney. In comparison with MTO-Sol, MTO-NLDCs efficiently enhanced cytotoxicity through the higher accumulation of MTO in breast cancer resistance protein (BCRP)-overexpressing MCF-7/MX cells. MTO-NLDCs entered into the resistant cancer cells by the clathrin-mediated endocytosis pathway, which escaped the efflux induced by BCRP transporter and thereby overcame the multidrug resistance of MCF-7/MX cells. FROM THE CLINICAL EDITOR: In this study, novel nanostructured lipid-dextran sulfate hybrid carriers were synthesized and utilized for sustained delivery of mitoxantrone hydrochloride. The utilized methods successfully addressed multidrug resistance to this chemotherapy agent.

Bcl-xL is a dominant antiapoptotic protein that inhibits homoharringtonine-induced apoptosis in leukemia cells.

Homoharringtonine (HHT) has been reported to be effective in a portion of patients with acute myeloid leukemia (AML) or chronic myeloid leukemia (CML). To investigate its mechanism of action, cell growth inhibition and cytotoxicity of HHT were investigated in three AML cell lines, HL-60, NB4, and U937, and in three CML cell lines, K562, KU812, and KCL22. AML cells were more sensitive than CML cells to HHT-induced cytotoxicity. Using HL-60 cells, it was revealed that HHT decreased the levels of myeloid cell leukemia 1 (Mcl-1), X-linked inhibitor of apoptosis protein (XIAP), survivin, and B-cell lymphoma 2 (Bcl-2)-homology domain 3 (BH3)-only proteins as well as the mitochondrial membrane potential. The levels of Bcl-2, Bcl-2-associated X protein (Bax), and Bcl-2 homologous antagonist/killer (Bak) proteins in HL-60 cells were not changed after HHT treatment. U937, K562, KU812, and KCL22 cells expressed B-cell lymphoma-extra large (Bcl-xL) and were less responsive to HHT-induced apoptosis than HL-60 cells. Silencing Mcl-1 or Bcl-xL, but not XIAP or survivin, enhanced HHT-induced apoptosis in U937 cells. The levels of HHT-induced apoptosis in K562, KCL22, and KU812 cells were inversely correlated with the levels of Bcl-xL but not those of Bcl-2 or Mcl-1. K562 cells expressing high levels of Bcl-xL but no Bcl-2 were less responsive to HHT-induced apoptosis than KCL22 cells that expressed lower levels of Bcl-xL and higher levels of Bcl-2 protein. In K562 cells, knockdown of Bcl-xL, but not of Mcl-1, enhanced HHT-induced apoptosis. Transfection of Bcl-xL into KCL22 cells attenuated HHT-induced apoptosis. These data suggest that Bcl-xL plays a more important role than Bcl-2 and Mcl-1 in protecting against HHT-induced apoptosis.

Bifunctional peptidomimetic prodrugs of didanosine for improved intestinal permeability and enhanced acidic stability: synthesis, transepithelial transport, chemical stability and pharmacokinetics.

Five peptidomimetic prodrugs of didanosine (DDI) were synthesized and designed to improve bioavailability of DDI following oral administration via targeting intestinal oligopeptide transporter (PepT1) and enhancing chemical stability. The permeability of prodrugs was screened in Caco-2 cells grown on permeable supports. 5'-O-L-valyl ester prodrug of DDI (compound 4a) demonstrated the highest membrane permeability and was selected as the optimal target prodrug for further studies. The uptake of glycylsarcosine (Gly-Sar, a typical substrate of PepT1) by Caco-2 cells could be inhibited by compound 4a in a concentration-dependent manner. The Caco-2 cells were treated with 0.2 nM leptin for enhanced PepT1 expression. The uptake of compound 4a was markedly increased in the leptin-treated Caco-2 cells compared with the control Caco-2 cells, both of which were obviously inhibited by 20 mM Gly-Sar. The K(m) and V(max) values of kinetic study of compound 4a transported by PepT1 in Caco-2 cells were 0.91 mM and 11.94 nmol/mg of protein/10 min, respectively. The chemical stability studies were performed in simulated gastric fluid (SGF), phosphate buffers under various pH conditions, rat tissue homogenates and plasma at 37 °C. The concentrations of DDI could not be detected in the two minutes in SGF. But compound 4a could significantly increase DDI acidic stability, and its t(½) was extended to as long as 36 min in SGF. Compound 4a was stable in pH 6.0 phosphate buffer but could be quickly transformed into DDI in plasma and tissue homogenates. The oral absolute bioavailability of DDI was 47.2% and 7.9% after compound 4a and DDI were orally administered to rats at a dose of 15 mg/kg, respectively. The coadministration with antiacid agent could also suggest that compound 4a was more stable under harsh acidic conditions compared with DDI. Compound 4a bioavailability in rats was reduced to 33.9% when orally co-administered with Gly-Sar (100 mg/kg). The In Vivo bioactivation mechanism of compound 4a was investigated by comparing the levels of DDI and compound 4a in the jugular and portal veins in rats. The plasma concentration of intact compound 4a was very low in portal veins and could hardly be detected in the jugular vein. In conclusion, compound 4a could significantly improve the oral bioavailability of DDI in rats through PepT1-mediated absorption and enhanced acidic stability, followed by rapid and mostly intracellular bioactivation, the majority in the intestinal cells but the minority in the liver. Additionally, the prodrug strategy targeted to intestinal PepT1 could offer a promising strategy to improve oral bioavailability of poorly absorbed didanosine.

Triterpenoids from Calophyllum inophyllum and their growth inhibitory effects on human leukemia HL-60 cells.

A new friedelane-type triterpene (1), along with seven known triterpenoids, was isolated from the stems and leaves of Calophyllum inophyllum Linn. Their structures were established as 3beta, 23-epoxy-friedelan-28-oic acid (1), friedelin (2), epifriedelanol (3), canophyllal (4), canophyllol (5), canophyllic acid (6), 3-oxo-friedelan-28-oic acid (7), and oleanolic acid (8) by spectroscopic methods (NMR, EI-MS). The growth inhibitory effects of these triterpenoids on human leukemia HL-60 cells were determined.

Design and synthesis of novel 2-phenylaminopyrimidine (PAP) derivatives and their antiproliferative effects in human chronic myeloid leukemia cells.

A series of novel 2-phenylaminopyrimidine (PAP) derivatives structurally related to STI-571 were designed and synthesized. The abilities of these compounds to inhibit proliferation were tested in human chronic myeloid leukemia K562 cells. (E)-3-(2-bromophenyl)-N-[4-methyl-3-(4-pyridin-3-yl-pyrimidin-2-ylamino)phenyl]acrylamide(12d) was the most effective cell growth inhibitor and was 3-fold more potent than STI-571.

Rapid and sensitive hydrophilic interaction chromatography/tandem mass spectrometry method for the determination of glycyl-sarcosine in cell homogenates.

A rapid, selective and sensitive hydrophilic interaction chromatography/tandem mass spectrometry (HILIC/MS/MS) was developed and validated for the determination of glycyl-sarcosine (Gly-Sar) in Caco-2 cell homogenates. After a simple protein precipitation with acetonitrile, the analyte was separated on a HILIC column and detected by a triple quadrupole mass spectrometry equipped with an electrospray ionization (ESI) source. The method was linear among the concentration range of 1-2000 ng/mL for Gly-Sar and the lower limit of quantification (LLOQ) was 1 ng/mL using as l ittle as 50 microL of cell homogenates. The intra-day and inter-day relative standard deviations (RSD) were less than 15% and the relative errors (RE) were all within +/-15%. The validated method was successfully employed in the study of Gly-Sar uptake inhibition in Caco-2 cells by valcytarabine, a potential substrate of the peptide transporter 1 (PEPT1).

Synthesis, transport and pharmacokinetics of 5'-amino acid ester prodrugs of 1-beta-D-arabinofuranosylcytosine.

Cytarabine (1-beta-d-arabinofuranosylcytosine, ara-C, 1) suffers from low oral bioavailability due to low intestinal membrane permeability and poor metabolic stability, and intravenous infusion is usually adopted as the clinical standard dosing administration. To develop an oral alternative for 1 and utilize the intestinal oligopeptide transporter 1 (PepT1), a series of 5'-amino acid ester derivatives of 1 was synthesized to clarify which modification was the most suitable to increase the oral bioavailability of 1. Their apical-to-basolateral permeability across Caco-2 cells and the antiproliferative activity with HL-60 cells were screened. 5'-Valyl prodrug 2 demonstrated the highest permeability and was selected for further study. Glycylsarcosine (gly-sar, a typical substrate of PepT1) uptake by Caco-2 cells can be inhibited by 2 in a concentration-dependent manner, and IC(50) for 2 was 2.18 +/- 0.12 mM. The uptake of 2 was markedly increased in the long-term leptin-treated Caco-2 cells compared with the control Caco-2 cells, and was significantly inhibited by the excess of gly-sar, but not by l-valine. A dose-proportional pharmacokinetics was observed in rats when 5, 15, 30 mg/kg doses of 2 (calculated as 1) were orally administered. The oral absolute bioavailability of 1 was 60.0% and 21.8% after 2 and 1 were orally administered to rats 30 mg/kg, respectively. Following oral administration of 15 mg/kg, the absorption and bioactivation of 2 were extensive and rapid, over 98% of prodrug hydrolysis occurring before appearance in the portal vein. The in vivo dispositions of 1-beta-D-arabinofuranosyluracil (ara-U), a deaminated product of 1, were investigated. Oral administration of 2 resulted in an increased 1/ara-U ratio (2.76) in the blood, much higher than that (1.25) after 1 orally taken. Overall, these results demonstrated that the PepT1-mediated absorption of 2 and the increased metabolic stability resulted in a dramatic increase in the oral bioavailability of 1 in rats and further corroborated the thought that prodrug design strategy targeting intestinal PepT1 was an important and promising strategy to improve oral bioavailability of poorly absorbed drugs.

Three novel sterols isolated from Selaginella tamariscina with antiproliferative activity in leukemia cells.

Three new sterols, 3beta,16alpha-dihydroxy-5alpha,17beta-cholestan-21-carboxylic acid (1), 3beta-acetoxy-16alpha-hydroxy-5alpha,17beta-cholestan-21-carboxylic acid (2) and 3beta-(3-hydroxybutyroxy)-16alpha-hydroxy-5alpha,17beta-cholestan-21-carboxylic acid (3) were isolated from Selaginella tamariscina (Beauv.) Spring (Selaginellaceae). Their structures were elucidated based on NMR analyses. The growth inhibitory effects and differentiation induction abilities of compounds 1 - 3 were determined in human leukemia HL-60 cells. Compound 1 was more effective than compounds 2 and 3 in inhibiting cell growth, but compound 3 was more effective than compounds 1 and 2 in enhancing induction of all- trans-retinoic acid differentiation.