Improvement of Oral Bioavailability and Anti-Tumor Effect of Zingerone Self-Microemulsion Drug Delivery System.

This study sought to prepare a self-microemulsion drug delivery system containing zingerone (Z-SMEDDS) to improve the low oral bioavailability of zingerone and anti-tumor effect. Z-SMEDDS was characterized by particle size, zeta potential and encapsulation efficiency, while its pharmacokinetics and anti-tumor effects were also evaluated. Z-SMEDDS had stable physicochemical properties, including average particle size of 17.29 ± 0.07 nm, the zeta potential of -22.81 ± 0.29 mV, and the encapsulation efficiency of 97.96% ± 0.02%. In vitro release studies have shown the release of zingerone released by Z-SMEDDS was significantly higher than free zingerone in different release media. The relative oral bioavailability of Z-SMEDDS was 7.63 times compared with free drug. Meanwhile, the half inhibitory concentration （IC50）of Z-SMEDDS and free zingerone was 8.45 µg/mL and 13.30 µg/mL, respectively on HepG2. This study may provide a preliminary basis for further clinical research and application of Z-SMEDDS.

[6]-Shogaol/ß-CDs inclusion complex: preparation, characterisation, in vivo pharmacokinetics, and in situ intestinal perfusion study.

Aims: The aim was to improve the absorption and bioavailability of [6]-shogaol with ß-cyclodextrin (ß-CD) prior to in vitro and in vivo evaluation. Methods: [6]-Shogaol/ß-CDs inclusion complexes (6-S-ß-CDs) were developed using saturated aqueous solution method and characterised with appropriate techniques. The absorption and bioavailability potential of [6]-shogaol was evaluated via in vivo pharmacokinetics and in situ intestinal perfusion. Results: The results of characterisation showed that 6-S-ß-CDs (drug loading, 7.15%) were successfully formulated. In vitro release study indicated significantly improved [6]-shogaol release. Pharmacokinetic parameters such as Cmax, AUC0-36 h, and oral relative bioavailability (about 685.36%) were substantially enhanced. The in situ intestinal perfusion study revealed that [6]-shogaol was markedly absorbed via passive diffusion in the intestinal segments, and duodenum followed by ileum and jejunum. Conclusions: Cyclodextrin inclusion technology could enhance the intestinal absorption and oral bioavailability of hydrophobic drugs like [6]-shogaol.

[Application of affinity chromatography and its mathematical model in study of active components of traditional Chinese medicine].

Affinity chromatography is characterized by its high specificity,high recovery rate and sensitivity,and it has been widely used in the selection of active ingredients of traditional Chinese medicine,separation and enrichment of low molecular weight sugars and protein peptides,research on mechanism of action and discovery of targets.This paper reviewed the application of affinity chromatography and its adsorption isotherm model,kinetic model and adsorption thermodynamic mechanism in the field of traditional Chinese medicine.This summarizes and provides thinking for comprehensive applications of affinity chromatography theory in the field of active ingredient screening,purification and medicine interaction.

Preparation and evaluation of isoliquiritigenin-loaded F127/P123 polymeric micelles.

Isoliquiritigenin (ISL) possesses a variety of pharmacological activities amid poor solubility in water which has restricted its clinical application. In this study, isoliquiritigenin-loaded F127/P123 polymeric micelles (ISL-FPM) were successfully prepared and evaluated in vitro and in vivo. The particle size, polydispersity index, and zeta potential of the selected formulation were 20.12 ± 0.72 nm, 0.183 ± 0.046, and -38.31 ± 0.33 mV, respectively, coupled with high encapsulation efficiency of 93.76 ± 0.31%. Drug-loading test showed the solubility of ISL after formulating into micelles was 232 times higher than its intrinsic solubility. Moreover, critical micelle concentration (CMC) was tested with fluorescence probe method and turned out to be quite low, which implied high stability of ISL-FPM. Release profile in HCl (pH 1.2), double distilled water, and PBS (pH 7.4) of ISL-FPM reached over 80%, while free ISL was around 40%. Pharmacokinetic research revealed that formulated ISL-FPM significantly increased bioavailability by nearly 2.23-fold compared to free ISL. According to the results of in vitro antioxidant activity, scavenging DPPH activity of ISL was significantly strengthened when it was loaded into polymeric micelles. Altogether, ISL-FPM can act as a promising approach to improve solubility as well as enhance bioavailability and antioxidant activity of ISL.

Glutathione-sensitive PEGylated curcumin prodrug nanomicelles: Preparation, characterization, cellular uptake and bioavailability evaluation.

The anti-tumor efficacy of curcumin can be markedly improved by nano-drug self-delivery systems with high drug loading capacity and smart stimulus-triggered drug release in tumor cells. Herein, a type of novel, glutathione (GSH)-responsive, PEGylated prodrug nano-micelles (PPNMs) was prepared by self-assembly of curcumin-s-s-vitamin E/mPEG2k-DSPE mixture. The PPNMs (entrapment efficiency: 96.7%) was acceptably stable in water with a mean particle size of 29.84 nm. Compared with curcumin-loaded mPEG2k-DSPE nano-micelles (CUR-NMs), PPNMs showed a higher drug loading (1.68% vs 27.3%) and remarkably improved the chemical stability of curcumin in phosphate buffer saline (PBS) (pH = 7.4), 10% FBS culture medium, and rat plasma. In vitro release study showed that PPNMs could redox responsively control the release of curcumin from the prodrug. Moreover, PPNMs showed a cytotoxicity in HepG2 cells similar to that of the free curcumin; however, when the HepG2 cells were pretreated with 1 mM GSH, PPNMs displayed a markedly enhanced cytotoxicity and cellular uptake than the free curcumin. After intravenous injection, PPNMs showed an increased half-life in blood circulation (10.6-fold) and bioavailability (107-fold) compared with the free curcumin injection. Altogether, the prodrug nano-micelles represent a promising preparation for sustained and controlled delivery of curcumin with enhanced antitumor activity.

[Study on mechanism and structure-activity relationship of hypolipidemic polysaccharides: a review].

Hypolipidemic polysaccharides have notable activity and safety with a range of diverse sources. In this paper, the classification of hypolipidemic polysaccharides was carried out into polysaccharide sulfate, glycosaminoglycan, homopolysaccharide and heteropolysaccharide. The hypolipidemic activity mechanism and structure-activity relationship hypothesis of those polysaccharides in recent years were briefly reviewed therefore to provide references for the study and product development of polysaccharides.

Octreotide-periplocymarin conjugate prodrug for improving targetability and anti-tumor efficiency: synthesis, in vitro and in vivo evaluation.

Cardiac glycosides could increase intracellular Ca2+ ion by inhibiting the Na+/K+ATPase to induce apoptosis in many tumor cells. However, narrow therapeutic index, poor tumor selectivity and severe cardiovascular toxicity hinder their applications in cancer treatment. To improve the safety profile and tumor targetablility of cardiac glycosides, we designed octreotide conjugated periplocymarin, a cardiac glycoside isolated from Cortex periplocae. The conjugate showed higher cytotoxicity on MCF-7 cells and HepG2 tumor cells (SSTRs overexpression) but much less toxicity in L-02 normal cells. Tissue distribution studies of the conjugate using H22 tumor model in mice showed higher accumulation in tumor and lower distribution in heart and liver than periplocymarin. Furthermore, in vivo anticancer effects of the conjugate on mice bearing H22 cancer xenografts confirmed enhanced anti-tumor efficacy and decreased systemic toxicity. Altogether, octreotide-conjugated periplocymarin demonstrated tumor selectivity and may be useful as a targeting agent to improve the safety profile of cardiac glycosides for cancer therapy.

Ergosterol-loaded poly(lactide-co-glycolide) nanoparticles with enhanced in vitro antitumor activity and oral bioavailability.

AIM: Ergosterol is a plant sterol with anti-tumor and anti-angiogenic activities, but is poorly soluble. In this study, we attempted to enhance its anti-tumor action and oral bioavailability via poly(lactide-co-glycolide) (PLGA) nanoparticle encapsulation. METHODS: Ergosterol-loaded PLGA nanoparticles (NPs/Erg) were prepared using the emulsion/solvent evaporation technique. Their physicochemical properties were characterized, and their cytotoxicity against human cancer cell lines was evaluated with MTT assay. The pharmacokinetics and tissue distribution of NPs/Erg were investigated in rats and mice, respectively. RESULTS: NPs/Erg were spherical in shape with a particle size of 156.9±4.8 nm and a Zeta potential of -19.27±1.13 mV, and had acceptable encapsulation efficiency and loading capacity. NPs/Erg exerted much stronger cytotoxicity against human cancer cells than the free ergosterol, and showed significantly reduced IC50 values (14.69±0.48 µg/mL in glioma U251 cells; 9.43±0.52 µg/mL in breast cancer MCF-7 cells; 4.70±0.41 µg/mL in hepatoma HepG2 cells). After oral administration of a single dose in rats, NPs/Erg displayed a prolonged plasma circulation with a 4.9-fold increase of oral bioavailability compared with the free ergosterol. After mice received NPs/Erg, the ergosterol in NPs/Erg was rapidly distributed in stomach, kidneys, liver, brain, spleen, and virtually non-existent in heart and lungs. The presence of NPs/Erg in brain was particularly improved compared with the free ergosterol. CONCLUSION: The PLGA nanoparticles serve as a promising carrier for the poorly soluble ergosterol and significantly improve its bioavailability, biodistribution and in vitro anti-tumor activities.

Tumor targeted delivery of octreotide-periplogenin conjugate: Synthesis, in vitro and in vivo evaluation.

Periplogenin (PPG), a cardiac glycoside prepared from Cortex periplocae, with similar structure to bufalin, has been found to induce apoptosis in many tumor cells. However, lots of cardiac glycosides possessing strong antitumor activity in vitro have still not passed phase I clinical trials, mostly due to poor tumor selectivity and systemic toxicity. To overcome this drawback, we designed octreotide-periplogenin (OCT-PPG) conjugate by coupling PPG-succinate to the amino-terminal end of octreotide. In comparison with free PPG, the conjugate exhibited significantly stronger cytotoxicity on HepG2 cells (SSTRs overexpression) but much less toxicity in L-02 cells. After intravenous injection of OCT-PPG conjugate into H22 tumor-bearing mice, its total accumulation in tumor was 2.3 fold higher than that of free PPG, but was 0.71- and 0.84-fold lower in heart and liver, respectively, suggesting somatostatin-mediated target delivery of PPG into the tumor tissue and reduced distribution in heart and liver. In vivo studies using H22 tumor model in mice confirmed the remarkable therapeutic effect of this conjugate. These results suggested that OCT-PPG conjugate could provide a new approach for clinical application of cardiac glycosides and as a targeting agent for cancer therapy.

[Progresses in screening active compounds from herbal medicine by affinity chromatography].

Affinity chromatography is a chromatographic method for separating molecules using the binding characteristics of the stationary phase with potential drug molecules. This method can be performed as a high throughput screening method and a chromatographic separation method to screen a variety of active drugs. This paper summarizes the history of affinity chromatography, screening technology of affinity chromatography, and application of affinity chromatography in screening bio-active compounds in herbal medicines, and then discusses its application prospects, in order to broaden applications of the affinity chromatography in drug screening.

[Advances in novel carrier systems of chemical constituents from spice volatile oils].

Recent years, chemical constituents from spice volatile oils have gained worldwide concern owing to its multiple pharmacological effects and safety for using as the natural antibacterial agents. However, their poor dissolution, strong volatility, serious irritation, weak stability, easy oxidation and low bioavailability characteristics are the major obstacle in the preparation of effective oral formulation and practical application. Therefore, there is an urgent need to select a novel carrier system that can delivery the chemical constituents from spice volatile oils more efficiently with improving their stability as well as alleviating the irritation, and develop the functional food, health products and even medicine for exerting their pharmacological effects, which also is the focus and nodus of the research on their application. This review presents recent systematic studies on their novel carrier systems, including cyclodextrin inclusion complex, liposomes, nanoemulsions, nanoparticles, solid dispersion and so on, and summarizes the characteristics, application range and problems of each novel carrier systems, in order to provide some beneficial thoughts in further developing new products of chemical constituents from spice volatile oils.

[Advances in research of pharmacological effects and formulation studies of linalool].

Linalool, as a major volatile compound, is widely distributed in natural plant essential oil. In addition, it can also be artificially synthesized. Linalool is used frequently as an important ingredient of perfumes and household detergents. It is still employed in food flavor and industries. Besides, linalool has some positive effect on healthcare. Many studies have showed that linalool exhibited a variety of pharmacological activities, including analgesic, anxiolytic, sedative, anti-inflammatory, anti-tumor and anti-bacterial effects. Therefore, linalool will be a promising agent for clinical application. This article reviews the pharmacological effects and formulation studies of linalool so as to provide a theoretical basis for its further development and utilization.

Oral delivery of capsaicin using MPEG-PCL nanoparticles.

AIM: To prepare a biodegradable polymeric carrier for oral delivery of a water-insoluble drug capsaicin (CAP) and evaluate its quality. METHODS: CAP-loaded methoxy poly (ethylene glycol)-poly(ε-caprolactone) nanoparticles (CAP/NPs) were prepared using a modified emulsification solvent diffusion technique. The quality of CAP/NPs were evaluated using transmission electron microscopy, powder X-ray diffraction, differential scanning calorimetry and Fourier transform infrared techniques. A dialysis method was used to analyze the in vitro release profile of CAP from the CAP/NPs. Adult male rats were orally administered CAP/NPs (35 mg/kg), and the plasma concentrations of CAP were measured with a validated HPLC method. The morphology of rat gastric mucosa was studied with HE staining. RESULTS: CAP/NPs had an average diameter of 82.54 ± 0.51 nm, high drug-loading capacity of 14.0% ± 0.13% and high stability. CAP/NPs showed a biphasic release profile in vitro: the burst release was less than 25% of the loaded drug within 12 h followed by a more sustained release for 60 h. The pharmacokinetics study showed that the mean maximum plasma concentration was observed 4 h after oral administered of CAP/NPs, and approximately 90 ng/mL of CAP was detected in serum after 36 h. The area under the curve for the CAP/NPs group was approximately 6-fold higher than that for raw CAP suspension. Histological studies showed that CAP/NPs markedly reduced CAP-caused gastric mucosa irritation. CONCLUSION: CAP/NPs significantly enhance the bioavailability of CAP and markedly reduce gastric mucosa irritation in rats.

[Advanced in solubilization methods of water-insoluble natural drugs].

With the development of natural products, the research activities on the solubilization methods of water-insoluble natural products have been carried out worldwide. Big molecular weight and poor solubility of most natural active ingredients lead to a very poor oral absorption and low bioavailability, which has extremely limited their development in pharmaceutical fields and clinical application. As a result, it is necessary to find out a suitable technique to improve the solubility and enhance the oral bioavailability of insoluble natural drugs. Based on the related references published in these years, this review introduced some new techniques to improve the solubility and bioavailability of natural drugs, including prodrugs, inclusion complex, solid dispersion, cocrystals, osmotic pump, liquisolid compacts, micronization, self-microemulsifying, nanosuspensions, lipsomes, polymeric micelles and so on, and summarized the theory, characteristics, application range, application examples, problems and development direction of each technique.

[Advances in research of chemical constituents and pharmacological activities of common used spices].

Spices have enjoyed a long history and a worldwide application. Of particular interest is the pharmaceutical value of spices in addition to its basic seasoning function in cooking. Concretely, equipped with complex chemical compositions, spices are of significant importance in pharmacologic actions, like antioxidant, antibacterial, antitumor, as well as therapeutical effects in gastrointestinal disorders and cardiovascular disease. Although increasing evidences in support of its distinct role in the medical field has recently reported, little information is available for substantive, thorough and sophisticated researches on its chemical constituents and pharmacological activities, especially mechanism of these actions. Therefore, in popular wave of studies directed at a single spice, this review presents systematic studies on the chemical constituents and pharmacological activities associated with common used spices, together with current typical individual studies on functional mechanism, in order to pave the way for the exploitation and development of new medicines derived from the chemical compounds of spice (such as, piperine, curcumin, geniposide, cinnamaldehyde, cinnamic acid, linalool, estragole, perillaldehyde, syringic acid, crocin).

Preparation of Pluronic/Bile salt/Phospholipid Mixed Micelles as Drug Solubility Enhancer and Study the Effect of the PPO Block Size on the Solubility of Pyrene.

Pluronic/bile salt/phospholipid mixed micelles (Pluronic/BS/PS-MM) drug carrier system for solubilization hydrophobic drugs was developed. A typical hydrophobic compound, pyrene, was selected as a representative hydrophobic compound to model the hydrophobic drugs. Five Pluronics, F68, F88, F98, F108, and F127 with different PPO chain length were studied. CMC data and solubilization capacities were obtained from a pyrene solubilization method. A closed association model was used to obtain the thermodynamic parameters: Gibbs free energy (ΔG°), enthalpy, (ΔH°) and entropy (ΔS°) of micellization. The results obtained from these experiments suggest that the mixed micelles was more stable and solubilize more pyrene than single one; and the solubilization of pyrene was strong effected by the PPO block size, thus accentuating synergistic interaction mechanism in Pluronic/BS/PS-MM. The study generated an important dataset so as to compare the effect of different Pluronics on solubility capacity of Pluronic/BS/PS-MM.

[Advance in studies on anti-tumor mechanism of matrine].

Matrine is one of the main active components extracted from Sophora flavescens, S. subprostrata and S. alopecuroides. In recent years, its anti-tumor activity has attracted wide attention. According to studies, matrine shows the anti-tumor effect through multiple channels such as inducing apoptosis and autophagy of cancer cells, arresting cell cycle, inhibiting tumor cell migration, angiogenesis and NF-kappaB, as well as the synergistic effect with chemotherapeutics. Along with the further studies on matrine's anti-tumor mechanism, it has a broad prospect for development and application in tumor clinical treatment.

In vitro release and in vitro-in vivo correlation for silybin meglumine incorporated into hollow-type mesoporous silica nanoparticles.

BACKGROUND: The purpose of this study was to develop a sustained drug-release model for water-soluble drugs using silica nanoparticles. METHODS: Hollow-type mesoporous silica nanoparticles (HMSNs) were prepared using Na(2)CO(3) solution as the dissolution medium for the first time. The water-soluble compound, silybin meglumine, was used as the model drug. The Wagner-Nelson method was used to calculate the in vivo absorption fraction. RESULTS: The results of transmission electron microscopy and nitrogen adsorption revealed that the empty HMSNs had uniformly distributed particles of size 50-100 nm, a spherical appearance, a large specific surface area (385.89 ± 1.12 m(2)/g), and ultralow mean pore size (2.74 nm). The highly porous structure allowed a large drug-loading rate (58.91% ± 0.39%). In 0.08 M Na(2)CO(3) solution, silybin meglumine-loaded HMSNs could achieve highly efficacious and long-term sustained release for 72 hours in vitro. The results of in vitro-in vivo correlation revealed that HMSNs in 0.08 M Na(2)CO(3) solution had a correlation coefficient R(2) value of 0.9931, while those of artificial gastric juice and artificial intestinal juice were only 0.9287 and 0.7689, respectively. CONCLUSION: The findings of in vitro-in vivo correlation indicate that HMSNs together with Na(2)CO(3) solution could achieve an excellent linear relationship between in vitro dissolution and in vivo absorption for 72 hours, leading to a promising model for sustained release of water-soluble drugs.

Delivery of a transforming growth factor ß-1 plasmid to mesenchymal stem cells via cationized Pleurotus eryngii polysaccharide nanoparticles.

The objective of this study was to investigate the use of cationized Pleurotus eryngii polysaccharide (CPEPS) as a nonviral gene delivery vehicle to transfer plasmid DNA encoding transforming growth factor beta-1 (pTGF-ß1) into mesenchymal stem cells (MSCs) in vitro. Crude P. eryngii polysaccharide was purified, and then cationized by grafting spermine onto the backbone of the polysaccharide. Agarose gel electrophoresis, transmission electron microscopy, and a Nano Sense Zetasizer (Malvern Instruments, Malvern, UK) were used to characterize the CPEPS-pTGF-ß1 nanoparticles. The findings of cytotoxicity analysis showed that when the nanoparticles were formulated with a CPEPS/pTGF-ß1 weight ratio ≥ 10:1, a greater gel retardation effect was observed during agarose gel electrophoresis. The CPEPS-pTGF-ß1 nanoparticles with a weight ratio of 20:1, respectively, possessed an average particle size of 80.8 nm in diameter and a zeta potential of +17.4 ± 0.1 mV. Significantly, these CPEPS-pTGF-ß1 nanoparticles showed lower cytotoxicity and higher transfection efficiency than both polyethylenimine (25 kDa) (P = 0.006, Student's t-test) and Lipofectamine(TM) 2000 (P = 0.002, Student's t-test). Additionally, the messenger RNA expression level of TGF-ß1 in MSCs transfected with CPEPS-pTGF-ß1 nanoparticles was significantly higher than that of free plasmid DNA-transfected MSCs and slightly elevated compared with that of Lipofectamine 2000-transfected MSCs. Flow cytometry analysis demonstrated that 92.38% of MSCs were arrested in the G1 phase after being transfected with CPEPS-pTGF-ß1 nanoparticles, indicating a tendency toward differentiation. In summary, the findings of this study suggest that the CPEPS-pTGF-ß1 nanoparticles prepared in this work exhibited excellent transfection efficiency and low toxicity. Therefore, they could be developed into a promising nonviral vector for gene delivery in vitro.

Efficient gene delivery to mesenchymal stem cells by an ethylenediamine-modified polysaccharide from mulberry leaves.

This study investigates the use of a natural polysaccharide isolated from mulberry leaves as a nonviral gene vector. Ethylenediamine is chemically grafted to the backbone of a polysaccharide from mulberry leaves (MPS) to acquire nucleic acid binding affinity. A particle-size observation indicates that the cationic mulberry leaf polysaccharide (CMPS) can efficiently combine with plasmid transforming growth factor ß1 (TGF-ß1) to form nanoscaled particles. In addition, the electrophoresis assay indicates a retarded plasmid migration when the CMPS/pTGF-ß1 weight ratio is increased to 30:1. The in vitro cell transfection experiment is performed based on bone marrow mesenchymal stem cells (MSCs) derived from rat femurs and tibias, and the findings reveal that the complex with a CMPS/pTGF-ß1 weight ratio of 50:1 exhibits the highest cell transfection effect, which is significantly higher than that of branched poly(ethyleneimine) (PEI) (25 kDa; p = 0.001, Student's t-test) and slightly higher than Lipofectamine 2000. Moreover, the cytotoxicity assay also demonstrates that all of these tested complexes and the plasmid TGF-ß1 are nontoxic to mesenchymal stem cells (MSCs). The results of the living cell imaging confirm that more of the CMPS/plasmid TGF-ß1 nanoparticles can be taken up and at a faster rate by the MSCs than by the positive control Lipofectamine 2000; these data are consistent with the transfection efficiency data. Together, these results suggest that the CMPS/pTGF-ß1 nanoparticle can potentially be developed into a promising alternative for the transfer of therapeutic genes into cells.