Synthesis and evaluation of mesoporous carbon/lipid bilayer nanocomposites for improved oral delivery of the poorly water-soluble drug, nimodipine.

PURPOSE: A novel mesoporous carbon/lipid bilayer nanocomposite (MCLN) with a core-shell structure was synthesized and characterized as an oral drug delivery system for poorly water-soluble drugs. The objective of this study was to investigate the potential of MCLN-based formulation to modulate the in vitro release and in vivo absorption of a model drug, nimodipine (NIM). METHODS: NIM-loaded MCLN was prepared by a procedure involving a combination of thin-film hydration and lyophilization. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), specific surface area analysis, differential scanning calorimetry (DSC) and X-ray diffraction (XRD) were employed to characterize the NIM-loaded MCLN formulation. The effect of MCLN on cell viability was assessed using the MTT assay. In addition, the oral bioavailability of NIM-loaded MCLN in beagle dogs was compared with that of the immediate-release formulation, Nimotop®. RESULTS: Our results demonstrate that the NIM-loaded MCLN formulation exhibited a typical sustained release pattern. The NIM-loaded MCLN formulation achieved a greater degree of absorption and longer lasting plasma drug levels compared with the commercial formulation. The relative bioavailability of NIM for NIM-loaded MCLN was 214%. MCLN exhibited negligible toxicity. CONCLUSION: The data reported herein suggest that the MCLN matrix is a promising carrier for controlling the drug release rate and improving the oral absorption of poorly water-soluble drugs.

Detection of early pulmonary emphysema by multi-contrast x-ray Talbot-Lau interferometer.

BACKGROUND: Pulmonary emphysema is a part of chronic obstructive pulmonary disease, which is an irreversible chronic respiratory disease. In order to avoid further damage to lung tissue, early diagnosis and treatment of pulmonary emphysema is essential. PURPOSE: Early pulmonary emphysema diagnosis is difficult with conventional radiographic imaging. Recently, x-ray phase contrast imaging has proved to be an effective and promising imaging strategy for soft tissue, due to its high sensitivity and multi-contrast. The aim of this study is to diagnose pulmonary emphysema early utilizing an x-ray Talbot-Lau interferometer (TLI). METHODS: We successfully established the mouse model of emphysema by porcine pancreatic elastase treatment, and then used the established x-ray TLI to perform imaging experiments on the mice with different treatment time. The traditional absorption CT and phase contrast CT were obtained simultaneously through TLI. The CT results and histopathology of mice lung in different treatment time were quantitatively analyzed. RESULTS: By imaging mice lungs, it can be found that phase contrast has higher sensitivity than absorption contrast in early pulmonary emphysema. The results show that the phase contrast signal could distinguish the pulmonary emphysema earlier than the conventional attenuation signal, which can be consistent with histological images. Through the quantitative analysis of pathological section and phase contrast CT, it can be found that there is a strong linear correlation. CONCLUSIONS: In this study, we quantitatively analyze mean linear intercept of histological sections and CT values of mice. The results show that the phase contrast signal has higher imaging sensitivity than the attenuation signal. X-ray TLI multi-contrast imaging is proved as a potential diagnostic method for early pulmonary emphysema in mice.

Engineering a potent and long-acting GLP-1/Y2 receptor dual agonist as a multi-agonist therapy for diabetes and obesity.

Novel dual agonists for the glucagon-like peptide-1 (GLP-1) and Y2 receptor hold the potential for enhanced efficacy over GLP-1 receptor (GLP-1R) agonists in treating obesity and diabetes. In this study, we aimed to improve the stability and increase the drug development success rate of our previously identified GLP-1/Y2 receptor dual agonist, 6q. To achieve this, we first optimized the structure of the linker within 6q. Additionally, we explored various fatty acid albumin binders to further enhance the stability of 6q. These binders were mainly selected from approved or clinically developed GLP-1R agonists or GLP-1-based multi-agonists. Through this process, we were able to identify a lead peptide, xGLP/PYY-6, that exhibited comparable in vitro potency toward the GLP-1 and Y2 receptors as 6q but with significantly improved stability compared to 6q. In Kunming and DIO mice, xGLP/PYY-6 showed a comparable hypoglycemic effect to semaglutide, and a significantly better effect on inhibiting food intake than semaglutide. In a chronic study in DIO mice, xGLP/PYY-6 exhibited significant metabolic benefits, as reflected by regulation of lipid levels, improved glucose tolerance, weight loss, decreased hepatocellular vacuolation, and the reversal of steatosis effects caused by xGLP/PYY-6. These results indicate the potential of developing xGLP/PYY-6 as an antiobesity, lipid regulation, antisteatotic, and antidiabetic agent.

Naphthofuran Derivative BF4, a New Potent SIRT1 Activator, Regulates Lipid Metabolism in 3T3-L1 Adipocytes via the SIRT1-AMPK Pathway.

AIM: Our previously reported naphthofuran derivative BF4, identified as a potent silent information regulator 1 (SIRT1) activator, could alleviate high glucose stimulating apoptosis and inflammation response in human renal tubular epithelial (HK-2) cells. INTRODUCTION: In this study, the underlying effects of BF4 on lipid metabolism in 3T3-L1 adipocytes were investigated. METHODS: The effects of BF4 on pre-adipocyte differentiation and adipocyte lipolysis were studied using oil red O staining and quantitative glycerol and triglyceride content assay kits. Moreover, the molecular mechanism of BF4 on adipogenesis and lipid metabolism in 3T3-L1 adipocytes was investigated by real-time quantitative PCR and Western blotting analysis. RESULTS: We found that compound BF4 significantly decreased adipogenesis and lipid accumulation and inhibited the differentiation of 3T3-L1 pre-adipocytes into adipocytes. Moreover, compound BF4 decreased the expressions of several key regulators in adipocyte differentiation, including C/EBPß and PPARγ, and their downstream lipogenesis targets via the activation of the SIRT1/ AMPK pathway. CONCLUSION: Our results demonstrated that the novel SIRT1 activator BF4 might be a potent candidate for regulating lipid metabolism.

High energy x-ray Talbot-Lau interferometer employing a microarray anode-structured target source to extend the field of view.

Objective. High energy and large field of view (FOV) phase contrast imaging is crucial for biological and even medical applications. Although some works have devoted to achieving a large FOV at high energy through bending gratings and so on, which would be extremely challenging in medical high energy imaging.Approach.We analyze the angular shadowing effect of planar gratings in high-energy x-ray Talbot-Lau interferometer (XTLI). Then we design and develop an inverse XTLI coupled with a microarray anode-structured target source to extend the FOV at high energy.Main results.Our experimental results demonstrate the benefit of the source in the inverse XTLI and a large FOV of 106.6 mm in the horizontal direction is achieved at 40 keV. Based on this system, experiments of a mouse demonstrate the potential advantage of phase contrast mode in imaging lung tissue.Significance.We extend the FOV in a compact XTLI using a microarray anode-structured target source coupled with an inverse geometry, which eliminates grating G0 and relaxes the fabrication difficulty of G2. We believe the established design idea and imaging system would facilitate the wide applications of XTLI in high energy phase contrast imaging.

Polyene Phosphatidylcholine Ameliorates High Fat Diet-Induced Non-alcoholic Fatty Liver Disease via Remodeling Metabolism and Inflammation.

Recent years have witnessed a rise in the morbidity of non-alcoholic fatty liver disease (NAFLD), in line with the global outbreak of obesity. However, effective intervention strategy against NAFLD is still unavailable. The present study sought to investigate the effect and mechanism of polyene phosphatidylcholine (PPC), a classic hepatoprotective drug, on NAFLD induced by high fat diet (HFD). We found that PPC intervention reduced the mass of liver, subcutaneous, epididymal, and brown fats in HFD mice. Furthermore, PPC supplementation significantly mitigated liver steatosis and improved glucose tolerance and insulin sensitivity in HFD mice, which was accompanied by declined levels of hepatic triglyceride, serum triglyceride, low density lipoprotein, aspartate aminotransferase, and alanine aminotransferase. Using transcriptome analysis, there were 1,789 differentially expressed genes (| fold change | ≥ 2, P < 0.05) including 893 upregulated genes and 896 downregulated genes in the HFD group compared to LC group. A total of 1,114 upregulated genes and 1,337 downregulated genes in HFD + PPC group were identified in comparison to HFD group. With the help of Gene Ontology (GO) analysis, these differentially expressed genes between HFD+PPC and HFD group were discovered related to "lipid metabolic process (GO: 0006629)," "lipid modification (GO: 0030258)," and "lipid homeostasis (GO: 0055088)". Though Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, we found pathways associated with hepatic homeostasis of metabolism and inflammation. Notably, the pathway "Non-alcoholic fatty liver disease (mmu04932)" (P-value = 0.00698) was authenticated in the study, which may inspire the potential mechanism of PPC to ameliorate NAFLD. The study also found that lipolysis, fatty acid oxidation, and lipid export associated genes were upregulated, while the genes in uptake of lipids and cholesterol synthesis were downregulated in the liver of HFD mice after PPC supplementation. Interestingly, PPC attenuated the metabolic inflammation via inhibiting pro-inflammatory macrophage in the livers of mice fed by HFD. In summary, this study demonstrates that PPC can ameliorate HFD-induced liver steatosis via reprogramming metabolic and inflammatory processes, which inspire clues for further clarifying the intervention mechanism of PPC against NAFLD.

Design, Synthesis and Pharmacological Evaluation of Naphthofuran Derivatives as Potent SIRT1 Activators.

Diabetic nephropathy (DN) is one of the most important medical complications in diabetic patients, which is an essential cause of end-stage renal disease in diabetic patients and still lacks effective medicines. Silent information regulator 1 (SIRT1) is closely related to the occurrence and development of DN. Activation of SIRT1 could significantly improve the symptoms of DN, while the activities of SIRT1 activators need to be further improved. Based on the crystal structure of SIRT1, structure and ligand-based approaches were carried out, and a lead compound 4,456-0661 (renamed as M1) was identified. Moreover, seven M1 analogues (6a-6g) were designed using a structure-based drug design strategy followed by bioactivity evaluation with SRTR2104 used as positive drugs. Among the target molecules, compounds M1, 6b, and 6d were proved to be potent SIRT1 activators, the activities of which are comparable to SRT2104. More importantly, compounds M1, 6b, and 6d could resist high glucose-induced apoptosis of HK-2 cells by activating SIRT1 and deacetylation of p53. Apart from the beneficial effect on apoptosis of DN, these compounds also alleviated high glucose stimulating inflammation response in HK-2 cells through SIRT1/NF-κB (p65) pathway. Consequently, M1, 6b, and 6d could be promising drug candidates for SIRT1 related diseases.

TLR-2-mediated metabolic reprogramming participates in polyene phosphatidylcholine-mediated inhibition of M1 macrophage polarization.

This study aimed to investigate whether the classic hepatoprotective drug polyene phosphatidylcholine (PPC) regulates macrophage polarization and explores the potential role of TLR-2 in this process. In RAW264.7 macrophages and murine bone marrow-derived macrophages (BMDMs) stimulated by lipopolysaccharide (LPS), PPC significantly inhibited the production of IL-6, TNF-α, and the mRNA expression of M1-type macrophage markers. Consistently, PPC reduced the mRNA expression of several key enzymes in the pathways of glycolysis and lipid synthesis while increasing the expression of key enzymes associated with lipid oxidation. Moreover, blocking the glycolytic pathway using 2-deoxy-D-glucose (2-DG) significantly enhanced the anti-inflammatory effect of PPC. However, inhibition of lipid oxidation using GW9662 (an inhibitor of PPAR-γ) and GW6471 (an inhibitor of PPAR-α) abolished the anti-inflammatory effect of PPC. Interestingly, TLR-2 expression in macrophages was significantly downregulated after exposure to PPC. Moreover, pre-activation of TLR-2 hampered the anti-inflammatory effect of PPC. In addition, PPC did not inhibit the secretion of IL-6 and TNF-α in TLR-2-/- BMDMs that were activated by LPS. This was consistent with the increased expression of M1 markers and glycolytic and lipid synthesis enzymes but decreased lipid oxidation-related enzymes. These results showed that PPC inhibits the differentiation of M1-type macrophages, which was most likely related to TLR-2-mediated metabolic reprogramming.

The release of exosomes in the medial prefrontal cortex and nucleus accumbens brain regions of chronic constriction injury (CCI) model mice could elevate the pain sensation.

BACKGROUND: Brain function relies on the capacity of neurons to locally modulate each other at the level of synapses. Therefore, the exosomal pathway may constitute a well-designed mechanism for local and systemic interneuronal transfer of information within functional brain networks. Exosomes bind to and are endocytosed by neurons of different brain regions to play a definite role. The medial prefrontal cortex (mPFC) and nucleus accumbens (NAc) brain regions are known to involve in pain modulation. Our study observes the roles of exosomal activity in these two dominant regions of the pain-related pathway, and there influence on the analgesic effects in CCI mice. METHODS: We induced pain exosomes in the mPFC and NAc in the mice of chronic constriction injury of the sciatic nerve model to produce neuropathic pain, and assessed changes that might affect analgesic behaviors. These changes were measured through a combination of behavioral, surgical, and other cellular testings. RESULTS: Our study found that pain expression was elevated in mice given exogenous exosomes isolated from CCI mice, especially at the 2 h and 4 h time interval, in mice given exosomes at the mPFC and NAc, respectively. We also found that inhibiting formation of pain exosomes through GW4869 within the mPFC and NAc can elevate the pain threshold. CONCLUSION: Results from our study supported the idea that the release of mPFC and NAc exosomes of CCI model has elevated the pain sensations in the subjected mice. This study will further help in designing new clinical trials, and will revolutionize the drug-induced anesthetic responses.

The Discovery of Antibacterial Natural Compound Based on Peptide Deformylase.

BACKGROUND: In recent years, Staphylococcus aureus have developed resistance to medicines used for the treatment of human infections. Therefore, the search for antibacterial agents of high potency against Staphylococcus aureus is of great concern. Peptide deformylase (PDF), a metalloprotease catalyzing the removal of a formyl group from newly synthesized proteins, has been considered to be an important antibacterial drug target. OBJECTIVE: To discover novel antibacterial drugs based on Staphylococcus aureus peptide deformylase. METHOD: PDF-based virtual screening of compounds from Traditional Chinese Medicine Database@Taiwan was performed by Sybyl X2.1 Surflex dock software. Compounds which possess high docking score were used for the following antibacterial experiments to evaluate their antibacterial activities. Kanamycin was also used in the antibacterial experiment as a control substance in the assay. Furthermore, molecular docking studies was applied to elucidate binding interaction between some compounds and PDF. In silico pharmacokinetic and toxicity prediction was explored to explain the reasons why these compounds might stand good chance of providing some pharmaceutical benefits. RESULTS: Gentiopicroside, protosappanin B, dihydromyricetin and cryptochlorogenic acid with high docking score were used for our subsequent antibacterial assays. The Minimum Inhibitory Concentration (MIC) of kanamycin and gentiopicroside were 0.008 mg·mL-1 and 0.431 mg·mL-1, respectively, other three compounds, protosappanin B, dihydromyricetin and cryptochlorogenic acid have close MIC value of 0.50 mg·mL-1. CONCLUSION: Dihydromyricetin, with the MIC value of 0.50 mg·mL-1 and relatively high drug score of 0.82, may serve as a novel antibacterial lead compound.

Design, Synthesis, and Biological Evaluation of Vanillin Hydroxamic Acid Derivatives as Novel Peptide Deformylase Inhibitors.

BACKGROUND: Infectious disease is increasingly hampering human health, which challenge the discovery of new antibacterial target. Peptide deformylase (PDF), a metalloenzyme responsible for catalyzing the removal of the N-formyl group from nascent proteins, was considered as an important target in antibacterial drug discovery. OBJECTIVE: Reported here are the design, synthesis and biological evaluation of vanillin hydroxamic acid derivatives. METHODS AND RESULTS: Analysis of the structure-activity relationships lead to the discovery of compound 8, which exhibits promising antibacterial activity against Escherichia coli, Staphylococcus aureus, Aspergillus oryzae, and Aspergillus foetidus with the MIC value of 0.32 µg/ml, 0.32 µg/ml, 0.16 µg/ml and 0.16 µg/ml, respectively. Furthermore, molecular docking study was applied to elucidate binding interaction between compound 8 and PDF, which indicate that compound 8 not only shares the same binding pocket with actinonin, but also has a similar binding pattern. In silico pharmacokinetic and toxicity prediction studies also suggested that compound 8 has a relatively high drug score of 0.80, and has no risk of toxicity. CONCLUSION: Compound 8 might represent a promising scaffold for the further development of novel antibacterial drugs.

Carboxymethyl chitosan/phospholipid bilayer-capped mesoporous carbon nanoparticles with pH-responsive and prolonged release properties for oral delivery of the antitumor drug, Docetaxel.

In this article, a new type of carboxymethyl chitosan/phospholipid bilayer-capped mesoporous carbon nanomatrix (CCS/PL/MC) was fabricated as a potential nano-drug delivery system. In this drug delivery system, a mesoporous carbon nanomatrix (MC) acts as the support for loading drug molecules, a positively charged phospholipid (PL) layer works as the inner shell for prolonged drug release and a negatively charged carboxymethyl chitosan (CCS) layer serves as the outer shell for pH-responsive drug release. Docetaxel (DTX) was selected as a model drug. The drug-loaded CCS/PL/MC was synthesized via a combination approach of double emulsion/solvent evaporation followed by lyophilization. The drug-loaded nanoparticles were characterized for their particle size, structure, morphology, zeta (ζ)-potential, specific surface area, porosity, drug loading and solid state. In vitro drug release tests showed that the drug-loaded CCS/PL/MC nanoparticles possess a good pH-sensitivity and prolonged releasing ability with negligible release in gastric media and controlled release in intestinal media. Compared with MC and PL-capped MC, CCS/PL/MC had a greater mucoadhesiveness. Moreover, cellular uptake study indicated that CCS/PL/MC might improve intracellular drug delivery. These results suggest that this hybrid nanocarrier, combining the beneficial features of CCS, PL and MC, is a promising drug delivery system able to improve the oral absorption of antitumor drugs.

Hydroxypropyl-ß-cyclodextrin functionalized calcium carbonate microparticles as a potential carrier for enhancing oral delivery of water-insoluble drugs.

The objective of the present study was to demonstrate that a novel hydroxypropyl-ß-cyclodextrin functionalized calcium carbonate (HP-ß-CD/CC) based amorphous solid dispersion (ASD) can be used to increase the solubility and oral bioavailability of water-insoluble drugs. Irbesartan (IRB) was selected as a model compound and loaded into the nanoporous HP-ß-CD/CC matrix using an immersion method. The IRB-loaded HP-ß-CD/CC formulation was characterized by various analytical techniques, such as specific surface area analysis, scanning electron microscopy (SEM), dynamic light scattering (DLS), powder X-ray diffraction (PXRD), and differential scanning calorimetry (DSC). Analyses with PXRD and DSC confirmed that IRB was fully converted into the amorphous form in the nanopores of HP-ß-CD/CC. From the solubility and dissolution tests, it was observed that the aqueous solubility and dissolution rate of IRB-loaded HP-ß-CD/CC were increased significantly compared with those of pure IRB and IRB-loaded mesoporous silica. Likewise, the IRB-loaded HP-ß-CD/CC formulation exhibited better absorption compared with that of the commercially available IRB capsules in beagle dogs. The mean peak plasma concentration (C max) and the area under the mean plasma concentration-time curve (AUC[0→48]) of IRB-loaded HP-ß-CD/CC were 1.56- and 1.52-fold higher than that of the commercial product, respectively. Furthermore, the IRB-loaded HP-ß-CD/CC formulation exhibited excellent stability against re-crystallization. These results clearly demonstrate that HP-ß-CD/CC based porous ASD is a promising formulation approach to improve the aqueous solubility and the in vivo absorption performance of a water-insoluble compound like IRB.

Contribution of phenolics and essential oils to the antioxidant and antimicrobial properties of Disporopsis pernyi (Hua) Diels.

This study describes the characterization of essential oil and phenolic compounds in Disporopsis pernyi (Hua) Diels. The essential oil was analyzed by gas chromatography-mass spectroscopy (GC-MS) and twelve volatile bioactive compounds of D. pernyi were identified. Polyphenols were identified by reverse-phase high-performance liquid chromatography (RP-HPLC) coupled to electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS) and quantified by ultrahigh-performance liquid chromatography (UPLC). A total of 4 polyphenolic compounds found in extract were identified as rutin, luteolin, quercetin, and betulinic acid. All obtained extracts and the 4 polyphenolic compounds were evaluated for their antimicrobial and antioxidant properties. The results suggested that the phenolic compounds contributed significantly to the antioxidant and antimicrobial activities of the plant.

Analysis of fatty acids, aliphatic esters, and in vitro studies of antioxidant and antimicrobial activities for Recineckea carnea and Tupistra chinensis from the Guizhou Province.

Recineckea carnea and Tupistra chinensis collected from the Guizhou province (China) were evaluated in this study. Petroleum ether fractions from the two herbs were subjected to gas chromatography-mass spectrometry analysis; 10 species, which were fatty acids or aliphatic esters, were identified. The antimicrobial activities of a variety of extracts were evaluated against four microorganisms. The methanol extract (ME), chloroform fraction, and ethyl acetate fraction from T. chinensis exhibited antimicrobial activities comparable to standard antibiotics, whereas none of the investigated extracts from R. carnea demonstrated any antimicrobial activities. The antioxidant potential was evaluated in vitro using ferric-reducing antioxidant power (FRAP) and the 2,2-diphenyl-1-picrylhydrazil (DPPH) radical method. The FRAP value of the ME from T. chinensis (4.19±0.088 mmol/g) was found to be significantly higher than the analogous extract from R. carnea (2.39±0.092 mmol/g); the EC50 of the ME from R. carnea (0.32±0.011 mg/mL) was found to be significantly higher than that of T. chinensis (0.30±0.015 mg/mL). Total phenolic content was estimated by the Folin-Ciocalteu's colorimetric method. A positive correlation was found between total phenolic content and antioxidant activities (FRAP value and the reciprocal of EC50). The results suggested that the phenolic compounds contributed significantly to the antioxidant capacity of R. carnea and T. chinensis.