Neng Qiu

Synthesis and Biological Evaluation of Novel 5-Benzylidenethiazolidine-2,4-dione Derivatives for the Treatment of Inflammatory Diseases

Twenty-two compounds based on thiazolidine-2,4-dione moiety were synthesized and evaluated for the inhibitory potency on the production of nitric oxide (NO), inducible nitric oxide synthase (iNOS) activity, and the generation of prostaglandin E(2) (PEG(2)). (Z)-N-(3-chlorophenyl)-2-(4-((2,4-dioxothiazolidin-5-ylidene) methyl) phenoxy) acetamide (3I), superior to the commercial anti-inflammatory drug indomethacin, significantly inhibited iNOS activity (IC(50) = 8.66 μM), iNOS-mediated NO, and cyclooxygenase (COX)-2-derived PGE(2) production (IC(50) = 4.16 and 23.55 μM, respectively) on lipopolysaccharide (LPS)-induced RAW 264.7 cells. Docking study revealed that 3I was perfectly docking into the active site of murine iNOS and suppressed the expression of iNOS protein as evidenced by Western blot analysis. At the dose of 50 mg/kg, oral administration of 3I possessed protective properties in both carrageenan-induced paw edema and adjuvant-induced arthritis rat models.

Inclusion complex of barbigerone with hydroxypropyl-β-cyclodextrin: preparation and in vitro evaluation.

The aim of this study was to improve the water solubility of barbigerone by complexing it with hydroxypropyl-β-cyclodextrin (HP-β-CD). The inclusion complexation behavior, characterization and interactions of barbigerone with HP-β-CD were investigated in both solution and the solid state by means of UV/VIS, (1)H NMR, FT-IR, PXRD, SEM. All the characterization information demonstrated the formation of barbigerone-HP-β-CD (bar-HP-β-CD) inclusion complex, and the bar-HP-β-CD inclusion compounds exhibited different spectroscopic features and properties from barbigerone. The results demonstrated that the water solubility of barbigerone was notably increased in the presence of HP-β-CD. Furthermore, preliminary in vitro cytotoxicity assay showed that bar-HP-β-CD still maintain the anticancer activity of barbigerone. These results suggest that HP-β-CD will be potentially useful in the delivery of water-insoluble anticancer agents such as barbigerone.

Peptide ligand and PEG-mediated long-circulating liposome targeted to FGFR overexpressing tumor in vivo.

Background and methods Paclitaxel, a widely used antitumor agent, has limited clinical application due to its hydrophobicity and systemic toxicity. To achieve sustained and targeted delivery of paclitaxel to tumor sites, liposomes composed of egg phosphatidylcholine, cholesterol, and distearolyphosphatidyl ethanolamine-N-poly(ethylene glycol) (PEG2000) were prepared by a lipid film method. In addition, the liposomes also contained truncated fibroblast growth factor fragment-PEG-cholesterol as a ligand targeting the tumor marker fibroblast growth factor receptor. Physicochemical characteristics, such as particle size, zeta potential, entrapment efficiency, and release profiles were investigated. Pharmacokinetics and biodistribution were evaluated in C57BL/6 J mice bearing B16 melanoma after intravenous injection of paclitaxel formulated in Cremophor EL (free paclitaxel), conventional liposomes (CL-PTX), or in targeted PEGylated liposomes (TL-PTX). Results Compared with CL-PTX and free paclitaxel, TL-PTX prolonged the half-life of paclitaxel by 2.01-fold and 3.40-fold, respectively, in plasma and improved the AUC0→t values of paclitaxel by 1.56-fold and 2.31-fold, respectively, in blood. Biodistribution studies showed high accumulation of TL-PTX in tumor tissue and organs containing the mononuclear phagocyte system (liver and spleen), but a considerable decrease in other organs (heart, lung, and kidney) compared with CL-PTX and free paclitaxel. Conclusion The truncated fibroblast growth factor fragment-conjugated PEGylated liposome has promising potential as a long-circulating and tumor-targeting carrier system.

Design, synthesis, and structure-activity relationship studies of novel millepachine derivatives as potent antiproliferative agents.

In this paper, 38 millepachine derivatives have been designed, synthesized and evaluated for their in vitro and in vivo antiproliferative activity. Among these novel derivatives, 15 displayed more potent antiproliferative activity than millepachine against HepG2, K562, SK-OV-3, HCT116, HT29, and SW620 tumor cells (mean IC(50) = 0.64 vs. 2.86 μM, respectively). Furthermore, 15 could effectively inhibit tubulin polymerization in HepG2 cells, and induce the HepG2 cell cycle arrest at the G2/M phase in a concentration-dependant manner. Further studies confirmed that 15 significantly suppressed the growth of tumor volume and exerted more potent anticancer potency than millepachine and anticancer drug cisplatin in A549 lung xenograft tumor model.

A novel truncated basic fibroblast growth factor fragment-conjugated poly (ethylene glycol)-cholesterol amphiphilic polymeric drug delivery system for targeting to the FGFR-overexpressing tumor cells

Targeted uptake of therapeutic nanoparticles in tumor cells-specific manner represents a potentially powerful technology in cancer therapy. In present study, we proposed a drug delivery system formulated with biocompatible and biodegradable cholesterol-block-poly (ethylene glycol) (Chol-PEG(2000)-COOH) polymer. And the surface of the polymer was chemically linked with truncated bFGF fragments (tbFGF). The tbFGF could recognize fibroblast growth factor receptors (FGFR) that are highly expressed by a variety of human cancer cells. The micelles had a size distribution of about 10-50 nm and significantly enhanced the cytotoxicity of paclitaxel to LL/2 cells as demonstrated by MTT test (IC₅₀=0.21 μg/mL for tbFGF conjugated Chol-PEG(2000)-COOH micelles (tbFGF-M-PTX) versus 26.43 μg/mL for free paclitaxel, respectively). Flow cytometry revealed the cellular uptake of rhodamine B encapsulated in the tbFGF-conjugated micelles was increased by 6.6-fold for HepG2, 6.2-fold for A549, 2.9-fold for C26 and 2.7-fold for LL/2 tumor cells, respectively, compared with micelles without tbFGF. The fluorescence spectroscopy images further demonstrated that the tbFGF conjugated micelles could specifically bind to the tumor cells that over-expressed FGFRs and then release rhodamine B into the cytoplasm. Our results suggest the tbFGF conjugated Chol-PEG(2000)-COOH micelles have great potential application for tumor targeting therapy.

Identification of metabolites of honokiol in rat urine using 13C stable isotope labeling and liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry.

A general approach based on stable isotope labeling and UPLC/Q-TOF-MS analysis of in vivo novel metabolites of honokiol has been developed in our study. In this method, urine samples were collected after intravenous administration of mixture of regular and [(13)C6]-labeled honokiol at 1:1 ratio to healthy rats. The metabolites could be easily recognized by the determination of a chromatographically co-eluted pair of isotopomers (MS doublet peaks) with similar peak intensities and mass difference corresponding to that between isotope-labeled and non-isotope-labeled honokiol. A total of 51 metabolites were detected, 37 of which were tentatively identified based on mass accuracy (<5 ppm). Among them, 33 of honokiol metabolites were first reported with 5 metabolites belonging to phase I and other 32 metabolites belonging to phase II metabolites. Our results highlighted that the main phase I metabolic pathways of honokiol in rats were oxidation, and the phase II metabolic pathways were sulfation, glucuronidation, acetylation as well as amino acids conjugation. This was the first research focused on the biotransformation of honokiol in rats, and the identification of these metabolites might provide us essential information for further pharmacological and clinical studies of honokiol.

Characterization of metabolic profile of honokiol in rat feces using liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry and 13C stable isotope labeling

As fecal excretion is one of important routes of elimination of drugs and their metabolites, it is indispensable to investigate the metabolites in feces for more comprehensive information on biotransformation in vivo. In this study, a sensitive and reliable approach based on ultra-performance liquid chromatography/quadrupole-time-of-flight-mass spectrometry (UHPLC-Q-TOF-MS) was applied to characterize the metabolic profile of honokiol in rat feces after the administration of an equimolar mixture of honokiol and [(13)C6]-labeled honokiol. Totally 42 metabolites were discovered and tentatively identified in rat feces samples, 26 metabolites were first reported, including two novel classes of metabolites, methylated and dimeric metabolites of honokiol. Moreover, this study provided basic comparative data on the metabolites in rat plasma, feces and urine, which gave better understanding of the metabolic fate of honokiol in vivo.

Gambogic acid exhibits anti-psoriatic efficacy through inhibition of angiogenesis and inflammation

BACKGROUND Psoriasis is a chronic T cell-mediated inflammatory skin disease. Studies have shown that angiogenesis plays an important role in the pathogenesis of psoriasis. Studies have also indicated that Gambogic acid (GA) inhibits angiogenesis and may be a viable drug candidate in anti-angiogenesis therapies. OBJECTIVE The aim of this study was to investigate the anti-psoriatic effect of GA and the possible mechanisms. METHODS MTT test on HaCaT cells and immunofluorescence on HUVEC cells were processed. An O/W cream of GA was prepared and topically applied to the ears of K14-VEGF transgenic mice and psoriasis-like guinea-pigs, and the tail skin of Balb/C mice independently. Furthermore, hematoxylin-eosin staining of tissues from three models and immunohistochemistry staining of ear samples from K14-VEGF mice were performed. RESULTS In vitro, GA inhibited proliferation of HaCaTs and TNF-α-induced activation of NF-κB in HUVECs. In vivo, animals treated with GA showed significant morphological and histological improvements. Immunohistochemical analysis of K14-VEGF transgenic mice revealed that hyperplastic and inflamed vessels were suppressed with GA treatment. The expression of adhesion molecules such as ICAM-1 and E-selectin was significantly decreased. GA inhibited angiogenesis and the expression of VEGFR2 and p-VEGFR2. T lymphocyte infiltration and the expression of IL-17 and IL-22 were also reduced by GA treatment. CONCLUSION Our results suggest that GA has anti-psoriatic efficacy through inhibition of angiogenesis and inflammation. Therefore, GA is attractive and offers future potential for application in patients with psoriasis.

Identification of honokiol metabolites in rats by the method of stable isotope cluster technique and ultra-high performance liquid chromatography/quadrupole-time-of-flight mass spectrometry.

Honokiol, a natural molecule isolated from Magnolia officinalis Rehd. et Wils., is widely known as an antitumor agent. In present work, an analysis of in vivo biotransformation and metabolites of honokiol has been performed by a combined method based on stable isotope cluster technique with honokiol-[(13)C6]-labeled and ultra-high performance liquid chromatography/quadrupole-time-of-flight-mass spectrometry (UHPLC/Q-TOF-MS). The metabolites could be easily identified by the determination of a chromatographically co-eluted pair of isotopomers (MS doublet peaks) with similar peak intensities and mass difference corresponding to that between isotope-labeled and non-isotope-labeled honokiol. A total of eighteen metabolites were detected and tentatively identified, fourteen of which were reported for the first time. The results indicated that the main metabolic pathways of honokiol in rats were hydroxylation, methylation, sulfation and glucuronidation. This study provided the first essential information on biotransformation and metabolites of honokiol in rats, which was very useful for further pharmacological and clinical studies of honokiol as a potent drug candidate.

Improving aqueous solubility and antitumor effects by nanosized gambogic acid-mPEG2000 micelles

The clinical application of gambogic acid, a natural component with promising antitumor activity, is limited due to its extremely poor aqueous solubility, short half-life in blood, and severe systemic toxicity. To solve these problems, an amphiphilic polymer-drug conjugate was prepared by attachment of low molecular weight (ie, 2 kDa) methoxy poly(ethylene glycol) methyl ether (mPEG) to gambogic acid (GA-mPEG2000) through an ester linkage and characterized by 1H nuclear magnetic resonance. The GA-mPEG2000 conjugates self-assembled to form nanosized micelles, with mean diameters of less than 50 nm, and a very narrow particle size distribution. The properties of the GA-mPEG2000 micelles, including morphology, stability, molecular modeling, and drug release profile, were evaluated. MTT (3-(4,5-dimethylthiazo l-2-yl)-2,5 diphenyl tetrazolium bromide) tests demonstrated that the GA-mPEG2000 micelle formulation had obvious cytotoxicity to tumor cells and human umbilical vein endothelial cells. Further, GA-mPEG2000 micelles were effective in inhibiting tumor growth and prolonged survival in subcutaneous B16-F10 and C26 tumor models. Our findings suggest that GA-mPEG2000 micelles may have promising applications in tumor therapy.