Latest ArticlesStudies have found that metformin is not only the preferred drug for lowering blood sugar, but also shows lipid-lowering and weight-loss effects. The purpose of this study was to use a hyperlipidemia hamster model to investigate the lipid-lowering effect of metformin and its effect on important metabolic pathways in lipid metabolism disorders. Fifty golden hamsters were divided into a control group, a model group, metformin high- and low-dose groups, and a simvastatin group. A high-fat diet was fed for 1 week to create the model, and then drug was administered for 11 weeks with the high-fat diet. Serum was taken for measurement of blood lipid and blood glucose at 2, 6, and 9 weeks after administration, and at weeks 3, 5, and 9 feces and urine were collected for 1H NMR metabolomics tests. After 11 weeks of intravenous injection of[U-13C6] glucose, serum was collected for a 13C NMR metabolic flux test. The results showed that the administration of metformin can significantly reduce blood lipids and glucose levels and can significantly affect metabolic pathways such as sugar metabolism, lipid metabolism, ketone metabolism, amino acid metabolism, and intestinal flora metabolism. The results of the metabolic flux analysis showed that the high-fat diet reduced the metabolism of tricarboxylic acids by 37.48%. After administration of low and high doses of metformin the metabolism of tricarboxylic acid increased by 98.14% and 143.10%, respectively. After administration of simvastatin tricarboxylic acid metabolism increased by 33.18%. The results indicate that metformin has a significant effect on promoting energy metabolism. This study used a combination of metabolomics and metabolic flow to explore the effect of metformin on lipid metabolism disorders and quantifies changes in the key pathway of energy metabolism-the tricarboxylic acid cycle. This study provides useful information for the study of the efficacy and mechanism of metformin, as well as a practical technical method for the screening of lipid-lowering drugs based on a hamster model.
Acetaminophen (APAP, also known as paracetamol)-induced liver injury is the leading cause of drug-induced liver injury in the world. Wuzhi Tablet (WZ, an ethanol extract of Schisandra sphenanthera) is widely used in clinical practice to protect liver function. Our previous studies have shown that pretreatment with WZ for 3 days can significantly protect against APAP-induced liver injury; however, the effect of different intervals between APAP and WZ treatment on APAP-induced liver injury remains unclear. In this study, the change in liver injury indexes, APAP metabolites, and the activity of cytochrome P450 (CYP450) enzymes after treatment with WZ and APAP at different intervals were determined. The animal experiment was reviewed and approved by the Animal Ethics Committee of Sun Yat-sen University. The results show that 0 h, 0.5 h, and 2 h pretreatment with WZ significantly protected against APAP-induced liver injury in mice, as evidenced by a significant decrease in biochemical parameters such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), and malonaldehyde (MDA). WZ inhibited the metabolic activation of APAP mediated by CYP450 enzymes and reduced the formation of APAP metabolites. This study further demonstrates that pretreatment with WZ at different intervals (0 h, 0.5 h, and 2 h before APAP dosing) exerts a significant hepatoprotective effect against APAP-induced liver injury, and a single-dose of WZ inhibits the activity of CYP450 enzymes related to APAP metabolic activation, thereby protecting against APAP-induced hepatotoxicity.
Lefamulin (BC-3781) is a semi-synthetic pleuromutilin antibiotic, approved for the treatment of community-acquired bacterial pneumonia (CABP) by Food and Drug Administration (USA) in August 2019, with the commodity name of Xenleta. It is the first pleuromutilin antibiotics used for systemic treatment of bacterial infections in human. Lefamulin binds to the peptidyl transferase center of the 50S ribosomal subunit to prevent peptide transfer, thus inhibits protein synthesis. Lefamulin displays expanded activity against gram-positive organisms, and also shows high activity against atypical microorganism like Mycoplasma pneumoniae. This review discusses the mechanism, bacterial spectrum of activity, preclinical and clinical data of Lefamulin.
Bioorthogonal fluorogenic probes are becoming an ideal tool for live-cell fluorescence imaging. With the tetrazine bioorthogonal fluorogenic probe that displays fluorescence enhancement, the tetrazine plays the dual-role of a bioorthogonal reaction unit and the fluorescence quenching unit. The "off" and "on" states of the fluorescence probe are mainly controlled through inverse electron demand Diels-Alder (IEDDA) bioorthogonal reaction. We designed a series of turn-on tetrazine fluorescent probes with Donor-π-Acceptor (D-π-A) structure to achieve a high signal-to-noise ratio and specificity of fluorescence imaging. This series of probes reacted with the dienophile bicyclononyne, and then generated pyridazine structure in-situ that acted as an electron acceptor, resulting in a new D-π-A effect of fluorescent dyes, turning on the intramolecular charge transfer (ICT) effect. By adjusting the electron-donating groups and the degree of conjugation, tunable fluorescence spectra between 400-647 nm with fluorescence turn-on enhanced up to 500-fold have been achieved. This research lays the foundation for the further optimization of tetrazine bioorthogonal fluorescent probes and their applications in molecular imaging and biomedical fields.
This study aims to establish the design space of the key processes for drop-on-powder 3D printing based on design of experiment (DoE). By utilizing Minitab, an experimental scheme with three factors, two levels and three center points was designed to analyze the factors that significantly affected the tablet quality attributes. Furthermore, the factor interactions were analyzed using Minitab. subsequently, the computer aided drafting (CAD) software was used to adjust the model volume with fixed radius/height ratio (r/h=1.25) and establish a linear regression equation between model volume and dose. As a result, the drug dose could be controlled in a flexible manner. The finally determined process parameters were: ink-jet level is 12, layer thickness is 150 μm, and the X-axis printing head speed of 635 mm·s-1. Regression equation between drug content (y) and model volume (x) was y=0.062 x-0.582 7 (R2=0.999 9) showing good linear relationship. This indicated that robust and feasible process parameters were obtained through DoE, and the preparation of personalized-dose tablets was realized with good reproducibility.
Using a H2O2-induced BRL cell senescence model, we investigated the anti-aging effects of drug-containing serums of Erzhi Wan (EZW) and various polar extracts (petroleum ether, ethyl acetate, n-butanol, water, and iridoid glycoside-enriched fractions). Cell viability was detected by MTT assay. Cell senescence was evaluated with β-galactosidase staining assay. Intracellular reactive oxygen species (ROS) were measured by flow cytometry. UFLC-Q-TOF-MS/MS was used to identify chemical components in EZW and the extracts, and molecular docking technology was used to predict the anti-aging components of EZW. Results showed that treatment of cells with 600 μmol·L-1 H2O2 for 72 h markedly induced cell senescence, inhibited cell proliferation and increased intracellular β-galactosidase activity and ROS levels. If cells were pretreated with drug-containing serum of EZW this induction of senescence was decreased. A total of 49 chemical compounds were identified in EZW by liquid chromatography-mass spectrometry, 14 of these were identified by molecular docking as potential active ingredients. Based on these analyses, and the in vitro experiments with polar extracts, we conclude that the anti-aging components of EZW are triterpenes, flavonoids and phenyl alcohols, providing a basis for further elucidation of the active agents and mechanism of the anti-aging effect of EZW.
The structure and diversity of the intestinal flora in rats exposed to high altitude hypoxia was investigated. Animal experiments strictly follow the regulations of Medical Laboratory Animal Ethics Committee of Qinghai University, School of Medicine. SD rats were randomly divided into a control group, a moderate altitude hypoxia group, and a high altitude hypoxia group. The pH value of the feces was measured and histopathological changes in the small intestine were determined by HE staining, and the intestinal flora were characterized by 16S rDNA high throughput sequencing technology on the 3rd, 7th, 15th, and 30th day of hypoxia exposure. Compared with the control group, the fecal pH value of rats in the moderate altitude hypoxia group and the high altitude hypoxia group was decreased significantly. The lamina propria and submucosa capillaries were slightly dilated and congested on the 3rd day in the moderate altitude hypoxia group. In the high altitude hypoxia group the submembrane capillaries were dilated and congested, the lamina propria of the mucosa showed mild edema, and the lymphatic vessels were dilated on the 7th day. The composition and diversity of intestinal flora in these rats changed significantly with prolonged exposure to the high altitude hypoxic environment. A total of 35 phyla, 87 classes, 205 orders, 337 families, 638 genera, and 256 species were annotated in the three groups of rats, including Firmicutes, Clostridia, Clostridiales, Ruminococcaceae, Akkermansia, and Lactobacillus_murinus. Compared with the control group, the intestinal flora of the hypoxic groups showed the most significant changes by the 15th day. There were 9 microbiota of gut microorganisms with relative abundance in the moderate altitude hypoxia group, of which Rikenellaceae_RC9_gut_group bacteria was the most common, there were 19 different microbiota of gut microorganisms with higher relative abundance in the high altitude hypoxia group, of which Ruminococcaceae bacteria was the most common. The results of this study indicate significant changes in the intestinal flora with high altitude hypoxia, and establish a foundation for further research on the initiation and development of diseases and drug metabolism in high altitude hypoxia.
Qualitative and quantitative methods were used to establish the quality of different medicinal parts of Poria cocos (Poriae Cutis, rubra Poria, white Poria, Poria cum Radix Pini) by using ultra-performance convergence chromatography coupled with photo-diode array and quadrupole time-of-flight mass spectrometry (UPC2-PDA-Q-TOF/MSE). A total of 18 chromatographic peaks were detected from Poria cocos by UPC2-PDA. Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were used to compare the four medicinal parts. The results showed that there were significant differences in the components of different medicinal parts, and the main triterpenoic acids were poricoic acid A, poricoic acid B, dehydroeburicoic acid, and dehydrotrametenolic acid. When combined with the common active component polyporenic acid C, a method for determination of five triterpenoic acids in different parts of Poria cocos was established. These components could be separated within 15 min, and the amount of methanol was 3.63% of that of HPLC method. Taking the five triterpenoid acids as an index, the content of triterpenoid acids in different parts of Poria cocos from high to low were Poriae Cutis, rubra Poria, white Poria and Poria cum Radix Pini. The method is simple, rapid, and uses minimal solvent. The mobile phase of environment-friendly gas carbon dioxide has unique advantages in reducing environmental pollution, which can provide a basis for the development and standard formulation of Poria cocos and its related products.
Abnormal aggregation of amyloid-β protein (Aβ) in brain plays a vital role in the occurrence of Alzheimer's disease (AD). Hence, inhibiting Aβ aggregation is one major tactic for therapy of AD. Previous studies have found that tolcapone can inhibit Aβ42 aggregation and reduce the cytotoxicity induced by Aβ42 aggregates, but clinical studies have found that tolcapone has strong liver toxicity. To reduce the liver toxicity of tolcapone, its side chain structure was modified to obtain its derivative phenethyl (E)-2-cyano-3-(3, 4 dihydroxy-5-nitrobenzene)-acrylate (PCDNA). Thioflavin T (ThT) and atomic force microscopy (AFM) assays were used to explore the inhibitory effect of PCDNA on Aβ42 fibrillogenesis. The cytotoxicity assays were used to explore the inhibitory effect of PCDNA against the cytotoxicity induced by Aβ42 aggregates. In addition, the depolymerization effect of PCDNA on mature Aβ42 fibrils was also explored. Finally, molecular docking was used to explore the interaction between PCDNA and Aβ42 pentamer. These results lay the foundation for the study of the structural analogues of tolcapone as Aβ inhibitors.
E2F transcription factor 1 (E2F1) is a major member of the E2F transcription factor family and participates in a wide range of physiological regulatory processes, such as cell cycle, survival, apoptosis, and metabolism. It is proved that the activity of E2F1 is related to the G1/S phase regulation of the cell cycle dependent on tumor suppressor retinoblastoma protein (RB). Recent studies have shown that E2F1 is highly expressed in prostate cancer cells, manifested as an oncogene, and its expression level is closely related to the occurrence, development, and poor clinical prognosis of prostate cancer. Androgen receptor (AR) is the main driving factor for the growth and progression of prostate cancer, and the changes of AR pathway play a key role in the pathological progression of prostate cancer. This article provide a systematic and comprehensive summary on recently published articles to review the role of the E2F1 pathway in prostate cancer.