Magnetic Fe3O4-graphene composites as targeted drug nanocarriers for pH-activated release.

A novel nanocarrier of magnetic Fe(3)O(4)-graphene nanocomposites (MGNs) was proposed as an effective drug delivery system for cancer treatment. The nanocarrier was synthesized by covalently attaching modified Fe(3)O(4) nanoparticles onto water-soluble graphene sheets via the formation of an amide bond with the aid of 1-ethyl-3-(3-dimethyaminopropyl) carbodiimide. The obtained MGNs exhibited excellent dispersibility and stability in aqueous solution and they also exhibited superparamagnetic properties with a saturation magnetization of 23.096 emu g(-1). An efficient loading of 5-fluorouracil (5-FU) on MGNs as high as 0.35 mg mg(-1) was obtained. Furthermore, the in vitro drug release of 5-FU was examined in pH 6.9 and pH 4.0 buffers at 37 °C, and showed strong pH dependence. Transmission electron microscope observations revealed that MGNs can be internalized efficiently by HepG2 cells. More importantly, the cytotoxicity evaluation shows that the resulting MGNs exhibit excellent biocompatibility. The as-prepared nanocarrier system combined the advantages of the superparamagnetic iron oxide nanoparticles and water-soluble graphene sheets, which will find many potential applications in biomedicine and biomaterials.

Metabolomics coupled with proteomics advancing drug discovery toward more agile development of targeted combination therapies.

To enhance the therapeutic efficacy and reduce the adverse effects of traditional Chinese medicine, practitioners often prescribe combinations of plant species and/or minerals, called formulae. Unfortunately, the working mechanisms of most of these compounds are difficult to determine and thus remain unknown. In an attempt to address the benefits of formulae based on current biomedical approaches, we analyzed the components of Yinchenhao Tang, a classical formula that has been shown to be clinically effective for treating hepatic injury syndrome. The three principal components of Yinchenhao Tang are Artemisia annua L., Gardenia jasminoids Ellis, and Rheum Palmatum L., whose major active ingredients are 6,7-dimethylesculetin (D), geniposide (G), and rhein (R), respectively. To determine the mechanisms underlying the efficacy of this formula, we conducted a systematic analysis of the therapeutic effects of the DGR compound using immunohistochemistry, biochemistry, metabolomics, and proteomics. Here, we report that the DGR combination exerts a more robust therapeutic effect than any one or two of the three individual compounds by hitting multiple targets in a rat model of hepatic injury. Thus, DGR synergistically causes intensified dynamic changes in metabolic biomarkers, regulates molecular networks through target proteins, has a synergistic/additive effect, and activates both intrinsic and extrinsic pathways.

The preparation and drug delivery of a graphene-carbon nanotube-Fe3O4 nanoparticle hybrid.

We report a green and facile procedure of synthesizing a graphene nanosheet-carbon nanotube-iron oxide nanoparticle hybrid (GN-CNT-Fe3O4) as a promising platform for the loading and delivery of anticancer drugs. The obtained GN-CNT-Fe3O4 hybrid exhibited superparamagnetic properties with the saturation magnetization of 19.824 emu g-1. This hybrid nanostructure possesses a superior capability of binding the anticancer drug 5-fluorouracil (5-FU) with a high loading capacity of up to 0.27 mg mg-1 with a 5-FU concentration of 0.5 mg mL-1, and also possesses a pH-activated release profile. Moreover, cellular uptake studies show that the resulting GN-CNT-Fe3O4 hybrid can be internalized efficiently by HepG2 cells. In vitro cytotoxicity tests suggest that the obtained GN-CNT-Fe3O4 hybrid is nontoxic for Chang liver cells, even at the high concentration of 80 µg mL-1, however, the 5-FU-loaded GN-CNT-Fe3O4 hybrid showed significant cytotoxic effects in HepG2 cells. The results show that this novel 3D hybrid is a promising candidate for anti-cancer drug delivery systems.

Simultaneous in vivo RP-HPLC-DAD quantification of multiple-component and drug-drug interaction by pharmacokinetics, using 6,7-dimethylesculetin, geniposide and rhein as examples.

Increasing evidence has demonstrated that multidrug combinations could amplify the therapeutic efficacies of each agent. Interestingly, the pharmacological effect of traditional Chinese medicine (TCM) is usually attributed to the drug-interaction property (synergism) of multiple active constituents. Pharmacokinetics is a useful means of evaluating the drug interactions of major active compounds in TCM. A simple, sensitive and reliable RP-HPLC-DAD method has been developed to simultaneously quantify 6,7-dimethylesculetin (D), geniposide (G) and rhein (R), which are the active ingredients in Yin-Chen-Hao-Tang (YCHT), performing drug-interaction pharmacokinetics studies in vivo. Plasma samples were prepared using methanolic precipitation, a filtration step, and then injection of the methanolic extract onto a Nova-Pak C18 Guard-Pak™ guard column with a gradient mobile phase. Triple-wavelength diode array detection was set at λ(max) values of 343 nm for D, 241 nm for the G, and 259 nm for R. Our results successfully demonstrate that this method has excellent and satisfactory selectivity, sensitivity, linearity, precision, accuracy and recovery. In healthy rats, the estimated pharmacokinetic parameters (i.e. C(max) , AUC and Cl) of D, G and R, when administered with COC (a combination of D, G and R), were C(max) 16.05 mg/L, AUC 108.96 mg h/L and Cl 0.36 L/h for D; C(max) 9.35 mg/L, AUC 64.71 mg h/L and Cl 0.88 L/h for G; and C(max) 14.18 mg/L, AUC 57.98 mg h/L and Cl 1.77 L/h for R. Here, we report that the COC combination could significantly increase the plasma level and slow the elimination rate compared with any one or two of the three individual compounds, which may indicate a drug-drug interaction.

Pharmacokinetics screening for multi-components absorbed in the rat plasma after oral administration traditional Chinese medicine formula Yin-Chen-Hao-Tang by ultra performance liquid chromatography-electrospray ionization/quadrupole-time-of-flight mass spectrometry combined with pattern recognition methods.

Traditional Chinese medicine (TCM) has been widely used in many oriental countries for thousands of years and played an indispensable role in the prevention and treatment of diseases, especially the complicated and chronic ones. It is a very complex mixture containing hundreds or thousands of different components. Pharmacokinetic study on active constituents in TCM preparations is a good way for us to explain and predict a variety of events related to the efficacy and toxicity of TCM. A selective and sensitive method of ultra performance liquid chromatography coupled with electrospray ionization/quadrupole-time-of-flight mass spectrometry (UPLC-ESI-Q-TOF-MS/MS) was first developed to screen the potentially bioactive components in vivo, using the semi-quantitative determination of multicomponents in the rat plasma after a single oral administration of Yin-Chen-Hao-Tang (YCHT), a famous TCM formula for liver disorders. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) were built to evaluate the differences of pharmacokinetic behaviors (time-course) of the absorbed components of YCHT. Here, we report that the developed method was successfully applied to monitoring the pharmacokinetic time-course of 21 compounds in rat plasma, and were grouped in 3 separate clusters using pattern recognition approaches (both HCA and PCA). Comparing the body dynamics of each composition, the initial choice of the following 9 compounds as the candidate components was: 7-methoxycoumarin-6-hydroxyl sulfate, genipingentiobioside, geniposide, 6,7-dimethylesculetin, peak 16, chimaphylin, 6-dementhoxycapillarisin, capillarisin, rhein. Pharmacokinetics based-UPLC-ESI-Q-TOF-MS/MS combined with HCA and PCA approaches can provide a reliable and suitable means of identifying and screening potentially bioactive components contributing to pharmacological effects of TCM, further prospecting natural products in the search for new leads in drug discovery.

An in vivo analysis of the therapeutic and synergistic properties of Chinese medicinal formula Yin-Chen-Hao-Tang based on its active constituents.

6,7-Dimethylesculetin (D), geniposide (G) and rhein (R) are the three major active ingredients of Yin-Chen-Hao-Tang (YCHT), a famous Chinese herbal formula, which has been shown to be clinically effective for treating hepatic injury (HI) syndrome. The present study was conducted to investigate the therapeutic and synergistic effects of COC (combination of D, G and R) on HI rats by combining pharmacokinetic with biochemical analysis strategy. Plasma was analyzed by using reversed-phase high performance liquid chromatography (RP-HPLC). Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) models were built to evaluate the therapeutic and synergistic effects of COC at the biochemical level. Here, we report that the COC combination could increase the plasma level, slow elimination rate, exert a more robust therapeutic effect than any one or two of the three individual compounds by hitting multiple targets in a rat model of HI. Overall, this beneficially accounts for the popular view that traditional Chinese medicine (TCM) formula usually takes multi-component to exert their therapeutic effects. We suggest that dissecting the mode of action of clinically effective formula to be capable of producing a sufficient effect at low doses.

Proteomic study of serum proteins in a type 2 diabetes mellitus rat model by Chinese traditional medicine Tianqi Jiangtang Capsule administration.

Proteomics technology was for the first time applied to investigate the changes of serum proteins levels in type 2 diabetes mellitus (T2DM) rat model after treated by Chinese traditional medicine Tianqi Jiangtang Capsule (ten normal Wistar rats, ten with T2DM and ten with T2DM administrated by Tianqi Jiangtang Capsule). In addition to two-dimensional polyacrylamide gel electrophoresis (2-DE), serum protein profiling in the three groups was further performed using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF-TOF/MS). 11 visualized spots were differentially regulated and identified as diabetes-associated proteins. All the samples in three groups were then analyzed by ELISA and estimated the 7 proteins which were found to vary. The distinct effect of T2DM induction on the pattern of rat serum includes the down-regulation of Apolipoprotein E, Apolipoprotein A-I, Ig gamma-2A chain C region, and up-regulation of Transthyretin (TTR), Haptoglobin (Hp), Serum amyloid P-componen (SAP), Prothrombin. The majority of those protein levels were interestingly restored to those of healthy rats after Tianqi Jiangtang Capsule treatment.

Development and validation of a ultra performance LC-ESI/MS method for analysis of metabolic phenotypes of healthy men in day and night urine samples.

Ultra-performance LC coupled to quadrupole TOF/MS (UPLC-QTOF/MS) in positive and negative ESI was developed and validated to analyze metabolite profiles for urine from healthy men during the day and at night. Data analysis using principal components analysis (PCA) revealed differences between metabolic phenotypes of urine in healthy men during the day and at night. Positive ions with mass-to-charge ratio (m/z) 310.24 (5.35 min), 286.24 (4.74 min) and 310.24 (5.63 min) were elevated in the urine from healthy men at night compared to that during the day. Negative ions elevated in day urine samples of healthy men included m/z 167.02 (0.66 min), 263.12 (2.55 min) and 191.03 (0.73 min), whilst ions m/z 212.01 (4.77 min) were at a lower concentration in urine of healthy men during the day compared to that at night. The ions m/z 212.01 (4.77 min), 191.03 (0.73 min) and 310.24 (5.35 min) preliminarily correspond to indoxyl sulfate, citric acid and N-acetylneuraminic acid, providing further support for an involvement of phenotypic difference in urine of healthy men in day and night samples, which may be associated with notably different activities of gut microbiota, velocity of tricarboxylic acid cycle and activity of sialic acid biosynthesis in healthy men as regulated by circadian rhythm of the mammalian bioclock.

Simultaneous determination by UPLC-ESI-MS of scoparone, capillarisin, rhein, and emodin in rat urine after oral administration of Yin Chen Hao Tang preparation.

A simple, sensitive, and validated method was developed for simultaneous determination of scoparone, capillarisin, rhein, and emodin in rat urine by ultra-performance liquid chromatography/electrospray ionization quadruple time-of-flight mass spectrometry (UPLC-MS). The urinary samples were analyzed on an Acquity UPLC BEH C18 1.7 microm 2.1x50 mm column. Scoparone, capillarisin, rhein, and emodin in rat urine were simultaneously analyzed with good separation. The lower limits of detection were 6.0, 9.0, 7.0, and 3.0 ng/mL, and the lower limits of quantification were 20.0, 33.0, 24.0, and 12.0 ng/mL for scoparone, capillarisin, rhein, and emodin, respectively. The intra- and inter-day precisions (RSD) were less than 9%. The intra- and inter-accuracies were found to be in the range of 94.14-104.54% for scoparone, 101.72-107.34% for capillarisin, 95.24-103.59% for rhein, and 101.32-107.82% for emodin at three concentration levels. The absolute recoveries for scoparone, capillarisin, rhein, and emodin were not less than 77.0%. The developed method has been applied to determine scoparone, capillarisin, rhein, and emodin in rat urine after oral administration of Yin Chen Hao Tang preparation, a traditional Chinese medicine formulation widely used in China for treatment of jaundice and liver disorders.