Rapid Determination of Dapagliflozin in Rat Plasma by UHPLC-Q-Orbitrap MS and Its Application to a Pharmacokinetic Study.

Dapagliflozin (DAPA), sodium-glucose co-transporter 2 (SGLT-2) inhibitor, is used to treat Type 2 diabetes. In this study, a highly sensitive and selective analytical method based on ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) was established and validated for the determination of DAPA in rat plasma. The separation of DAPA and internal standard (DAPA-d5) were performed on a reversed-phase ACQUITY UPLC® BEH C18 column (100 × 3.0 mm, 1.7 µm). The mobile phase is composed of 0.1% formic acid in water (solvent A) and methanol (solvent B) in gradient elution. Under the negative ion mode, full MS/dd-MS2 was adopted to collect data via Q-Orbitrap. DAPA was effectively separated from matrix backgrounds within 10 min, and DAPA in plasma showed a good linear relationship in the range of 10-10000 µg/L. The determination coefficient (R2) was 0.9987, and the lower limit of quantification (LLOQ) was 10 µg/L. The precision and accuracy were all less than 10%, and the extraction recovery of DAPA was 86.16-96.06% from plasma. This study offered an efficient separation and quantification method for DAPA. The improved and validated method succeeded in evaluating the pharmacokinetics of DAPA in rat plasma samples after a single oral administration of 1 mg/kg.

Virtual screening and molecular growth guide the design of inhibitors for the influenza virus drug-resistant mutant M2-V27A/S31N.

The influenza A virus matrix protein 2 (AM2) protein is a proton-gated, proton-selective ion channel essential for influenza replication that has been identified as an antiviral target. The drug-resistance of the M2-V27A/S31N strain, which has been growing more prevalent in recent years and has the potential to spread globally, prevents current amantadine inhibitors from having the desired impact. In this study, we compiled the most common influenza A virus strains from 2001-2020 from the U.S. National Center for Biotechnology Information database and hypothesized that M2-V27A/S31N would become a common strain. The lead compound ZINC299830590 was screened for M2-V27A/S31N in the ZINC15 database using a pharmacophore model and molecular descriptors. This lead compound was then optimized by molecular growth, which allowed us to identify important amino acid residues and create interactions with them to produce compound 4. Molecular dynamics simulation showed that the complex of compound 4 and M2-V27A/S31N had certain degrees of stability and flexibility. The binding free energy of compound 4 was calculated using the MM/PB(GB)SA method and totaled -106.525 kcal/mol. Finally, physicochemical and pharmacokinetic profiles were predicted using the Absorption, Distribution, Metabolism, Excretion, and Toxicity model, which indicated the good bioavailability of compound 4. These results provide the basis for further in vivo and in vitro studies to demonstrate that compound 4 is a promising drug candidate against M2-V27A/S31N.Communicated by Ramaswamy H. Sarma.

Comparison of Target Pocket Similarity and Progress into Research on Inhibitors of Picornavirus 3C Proteases.

The 3C protease (3C Pro) plays a significant role in the life cycle of picornaviruses from replication to translation, making it an attractive target for structure-based design of drugs against picornaviruses. The structurally related 3C-like protease (3CL Pro) is an important protein involved in the replication of coronaviruses. With the emergence of COVID-19 and consequent intensive research into 3CL Pro, development of 3CL Pro inhibitors has emerged as a popular topic. This article compares the similarities of the target pockets of various 3C and 3CL Pros from numerous pathogenic viruses. This article also reports several types of 3C Pro inhibitors that are currently undergoing extensive studies and introduces various structural modifications of 3C Pro inhibitors to provide a reference for the development of new and more effective inhibitors of 3C Pro and 3CL Pro.

Recent advances in anti-coxsackievirus A16 viral drug research.

Hand, foot and mouth disease, a childhood disorder caused by enteroviruses, is intermittently endemic in the Asia-Pacific region and endangers the lives of many infants and young children. Coxsackievirus A16 (CV-A16) is one of the major pathogens causing hand, foot, and mouth disease on occasion, resulting in catastrophic neurological sequelae and patient death. Currently, no clinical interventions are available that completely block the CV-A16 infection. Therefore, research on anti-CV-A16 treatment continues to be a significant focus of interest. This report provides a detailed background on and an introduction to CV-A16; a description of the viral gene and protein structures and a summary of the current advances in pharmaceutical targets, drug research and other related areas.

Inhibition of HIF-1a-mediated TLR4 activation decreases apoptosis and promotes angiogenesis of placental microvascular endothelial cells during severe pre-eclampsia pathogenesis.

OBJECTIVE: Hypoxia-induced factor 1a (HIF-1a) and Toll-like receptor 4 (TLR4) are involved in pre-eclampsia (PE) pathogenesis. However, little is known about their relationships. This study aimed to investigate the interaction of HIF-1a and TLR4 in PE pathogenesis. METHODS: The expression of HIF-1a and TLR4 were analyzed by qRT-PCR. Celluar PE model was established by hypoxia/reoxygenation treatment of human placental microvascular endothelial cells (hPMEC). Cell proliferation, apoptosis, invasion and migration were analyzed by CCK-8, flow cytometry, Transwell and scratch adhesion test, respectively. Angiogenesis was performed by tube formation, Ang-1 in culture supernatant was analyzed by ELISA. RESULTS: HIF-1a and TLR4 expression were significantly elevated in placental tissues from early-onset and late-onset severe pre-eclampsia patients compared with control, with increased Bax, TRIF and PUMA, and decreased Bcl-2 and VEGFA; Down-regulation of HIF-1a expression decreased TLR4 expression, promoted proliferation, invasion, migration and angiogenesis but suppressed apoptosis in cellular model. In addition, silencing HIF-1a and TAK232 treatment synergically promoted some more proliferation, invasion, migration and angiogenesis but suppressed apoptosis in cellular model. CONCLUSION: HIF-1a could promote hPMEC apoptosis by regulating TLR4 expression during PE pathogenesis.

Effects of 1,25-Dihydroxyvitamin D3 on the Prevention of Chronic Obstructive Pulmonary Disease (COPD) in Rats Exposed to Air Pollutant Particles Less than 2.5 Micrometers in Diameter (PM2.5).

BACKGROUND This study aimed to investigate the effects of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) on airway changes in chronic obstructive pulmonary disease (COPD) rats exposed to air pollutant particles less than 2.5 micrometers in diameter (PM2.5), and to evaluate the mechanisms. MATERIAL AND METHODS Three groups were included in this study: a normal group, a COPD model group, and a COPD with 1,25(OH)2D3 treatment group. In each group, the rats were divided into four subgroups: control and different doses of PM2.5 (1.6, 8 and 40 mg/kg body weight). Apoptosis in lung tissue was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL). The expression of c-Jun N-terminal kinase 1 (JNK1) and mucin 5AC (MUC5AC) were detected by real-time polymerase chain reaction (RT-PCR), Western blotting and immunofluorescence staining. RESULTS Compared with corresponding subgroups in normal group, the apoptotic rates in COPD group were significantly increased. By contrast, 1,25(OH)2D3 treatment group significantly reduced COPD-induced apoptosis in lung tissue. Upon the dose increase of PM2.5, the apoptotic rate was also elevated in each group. Compared with the corresponding control in each group, PM2.5 increased apoptosis in a dose-dependent manner. Importantly, 1,25(OH)2D3 also prevented apoptosis in COPD rats exposed to PM2.5. Mechanically, the expression of MUC5AC and JNK1 in COPD group was significantly upregulated, compared with corresponding subgroups in the normal group. Treatment with 1,25(OH)2D3 reduced expression of MUC5AC and JNK1 in COPD rats. It was found that the expression of MUC5AC and JNK1 was elevated with the dose increase of PM2.5 in each group. Consistently, 1,25(OH)2D3 also reduced the expression of MUC5AC and JNK1 in COPD rats exposed to PM2.5. CONCLUSIONS 1,25(OH)2D3 prevented lung injury in COPD rats with or without PM2.5 exposure. Our results suggest that 1,25(OH)2D3 is useful to mitigate the injury caused by COPD.

Clinical evaluation of various thyroid hormones on thyroid function.

To clarify the clinical value of serums total triiodothyronine (TT3), total thyroxine (TT4), free triiodothyronine (FT3), and free thyroxine (FT4) and provide a more eligible and economic strategy to assess thyroid function. A total of 2,673 participants (500 patients with hyperthyroidism, 500 patients with hypothyroidism, and 1,673 healthy people) were involved in our study. Serums TT3, TT4, FT3, and FT4 and thyrotropin (TSH) were measured with VIDAS fluorescent enzyme immunoassay. The Pearson correlation between TT3, TT4, FT3, and FT4 and TSH was determined to identify the most important indicator for thyroid function besides TSH. The correlation of TT4, and FT4 with TSH was statistically significant in healthy individuals (P < 0.01), and the R-values were -0.065 and -0.152, respectively. The correlation of TT4, FT4, TT3, and FT3 with TSH was statistically significant in patients with hyperthyroidism, and the R-values were -0.241, -0.225, -0.195, and -0.176, respectively. The correlation of TT4, FT4, TT3, and FT3 with TSH was statistically significant in patients with hypothyroidism, and the R-values were -0.322, -0.262, -0.179, and -0.136, respectively. In our opinion, TSH and FT4 are the most valuable indicators in assessing thyroid function in a healthy population, and TSH and TT4 are the most meaningful in hyperthyroidism and hypothyroidism.

Association between metabolic syndrome and osteoporosis: a meta-analysis.

Metabolic syndrome (MetS) consists of several independent clinically recognisable features that have their own independent effects on bone metabolism, and even a single disease could have apparently contradictory effects on bone metabolism. This meta-analysis aimed to detect a relationship between MetS and osteoporosis. The PubMed, Embase, and Cochrane library databases were searched for relevant studies published before April 1, 2013. On June 22, 2013, the databases were searched again for additional studies. Studies clearly reporting a comparison of bone mineral density (BMD) in subjects with or without MetS were selected for our analysis. From these results, we analysed the crude BMD and the BMD adjusted for all covariates (age, weight, height, alcohol intake, cigarette smoking and exercise). Weighted mean differences were calculated using a random-effects model. Nine studies were included in this meta-analysis. No significant differences were found when analysing the crude lumbar spine BMD and the femoral neck BMD. However, the MetS (-) group showed a significantly higher BMD when all covariates were adjusted for femoral neck BMD (0.02, p=0.0002) and lumbar spine BMD (0.01, p=0.007). Subgroup analysis suggested a negative effect of MetS on BMD in men but not in women. These findings suggest that MetS is a risk factor for developing osteoporosis in men.