Design, synthesis, and LFA-1/ICAM-1 antagonist activity evaluation of Lifitegrast analogues.

The interaction between Lymphocyte function-associated antigen 1 (LFA-1) and intercellular-adhesion molecule-1 (ICAM-1) plays important roles in the cell-mediated immune response and inflammation associated with dry eye disease. LFA-1/ICAM-1 antagonists can be used for the treatment of dry eye disease, such as Lifitegrast which has been approved by the FDA in 2016 as a new drug for the treatment of dry eye disease. In this study, we designed and synthesized some new structure compounds that are analogues to Lifitegrast, and their biological activities were evaluated by in vitro cell-based assay and also by in vivo mouse dry eye model. Our results demonstrated that one of these analogues of Lifitegrast (compound 1b) showed good LFA-1/ICAM-1 antagonist activity in in vitro assay; meanwhile, it also significantly reduced ocular surface epithelial cells damage, increased goblet cell density in dry eye mouse and highly improved the symptoms of dry eye mouse. Graphical abstract.

Bavachinin, as a novel natural pan-PPAR agonist, exhibits unique synergistic effects with synthetic PPAR-γ and PPAR-α agonists on carbohydrate and lipid metabolism in db/db and diet-induced obese mice.

AIMS/HYPOTHESIS: Pan-peroxisome proliferator-activated receptor (PPAR) agonists have long been sought as therapeutics against the metabolic syndrome, but current PPAR agonists show limited efficacy and adverse effects. Natural herbs provide a structurally untapped resource to prevent and treat complicated metabolic syndrome. METHODS: Natural PPAR agonists were screened using reporter gene, competitive binding and 3T3-L1 pre-adipocyte differentiation assays in vitro. The effects on metabolic phenotypes were verified in db/db and diet-induced obese mice. In addition, potentially synergistic actions of bavachinin (BVC, a novel natural pan-PPAR agonist from the fruit of the traditional Chinese glucose-lowering herb malaytea scurfpea) and synthetic PPAR agonists were studied through nuclear magnetic resonance, molecular docking, reporter gene assays and mouse studies. RESULTS: BVC exhibited glucose-lowering properties without inducing weight gain and hepatotoxicity. Importantly, BVC synergised with thiazolidinediones, which are synthetic PPAR-γ agonists, and fibrates, which are PPAR-α agonists, to induce PPAR transcriptional activity, as well as to lower glucose and triacylglycerol levels in db/db mice. We further found that BVC occupies a novel alternative binding site in addition to the canonical site of synthetic agonists of PPAR, and that the synthetic PPAR-γ agonist rosiglitazone can block BVC binding to this canonical site but not to the alternative site. CONCLUSIONS/INTERPRETATION: This is the first report of a synergistic glucose- and lipid-lowering effect of BVC and synthetic agonists induced by unique binding with PPAR-γ or -α. This combination may improve the efficacy and decrease the toxicity of marketed drugs for use as adjunctive therapy to treat the metabolic syndrome.

Structural elucidation of in vitro metabolites of bavachinin in rat liver microsomes by LC-ESI-MSn and chemical synthesis.

1. Bavachinin isolated from Psoralea corylifolia has various activities, such as antimicrobial, antiallergic, antitumor and so on. Our previous study showed that natural bavachinin exhibits peroxisome proliferator-activated receptor γ-agonist activity. 2. In vitro studies on bavachinin metabolism were conducted using rat liver microsomes incubated at 37 °C for 60 min. 3. Structures of eight metabolites of the incubation mixtures were cautiously characterized using electrospray tandem mass spectra and three synthetic compounds. The results indicated that eight metabolites of bavachinin were biotransformed mainly through oxidation. 4. The metabolic pathways of bavachinin were elucidated in vitro. These results contribute to the understanding of bavachinin's in vivo metabolism.

Separation and peroxisome proliferator-activated receptor-γ agonist activity evaluation of synthetic racemic bavachinin enantiomers.

Bavachinin, isolated from Psoralea corylifolia seeds, has been reported to demonstrate peroxisome proliferator-activated receptor-γ (PPAR-γ) agonist activity. However, isolated bavachinin is actually a mixture of S and R configurations, with an enantiomeric excess value of approximately 24.3%. For further study on the structure-activity relationships of bavachinin, investigating the PPAR-γ agonist activity of the two enantiomers is crucial. Considering the limited availability, racemic bavachinin was prepared in this study using chemical synthesis. The enantiomers of racemic bavachinin were then separated using supercritical fluid chromatography. This concise strategy yielded (S)- and (R)-bavachinin in optical purity as high as ⩾97.5%. The PPAR-γ agonist activity of the two enantiomers was evaluated using a time-resolved fluorescence resonance energy transfer-based competitive binding assay method; IC50 values of (S)- and (R)-bavachinin were 616.7 and 471.2 nM, respectively. The interaction between the compounds and PPAR-γ was further explored using a molecular docking method. This study suggests that (S)- and (R)-bavachinin demonstrate similar PPAR-γ agonist activities.

Efficient Determination of the Enantiomeric Purity and Absolute Configuration of Flavanones by Using (S)-3,3'-Dibromo-1,1'-bi-2-naphthol as a Chiral Solvating Agent.

The enantiomeric purity and absolute configuration of flavanones were first determined using (S)-3,3'-dibromo-1,1'-bi-2-naphthol as a chiral solvating agent by means of (1)H NMR spectroscopy. The enantiomeric purity results closely matched those based on chiral HPLC analysis.

Spatio-temporal dynamics of arbuscular mycorrhizal fungi associated with glomalin-related soil protein and soil enzymes in different managed semiarid steppes.

Temporal and spatial patterns of arbuscular mycorrhizal fungi (AMF) and glomalin and soil enzyme activities were investigated in different managed semiarid steppes located in Inner Mongolia, North China. Soils were sampled in a depth up to 30 cm from non-grazed, overgrazed, and naturally restored steppes from June to September. Roots of Leymus chinense (Trin.) Tzvel. and Stipagrandis P. Smirn. were also collected over the same period. Results showed that overgrazing significantly decreased the total mycorrhizal colonization of S. grandis; total colonization of L. chinensis roots was not significantly different in the three managed steppes. Nineteen AMF species belonging to six genera were isolated. Funneliformis and Glomus were dominant genera in all three steppes. Spore density and species richness were mainly influenced by an interaction between plant growth stage and management system (P < 0.001). Spore densities were higher in 0-10-cm soil depth. AMF species richness was significantly positively correlated with soil acid phosphatase activity, alkaline phosphatase activity, and two Bradford-reactive soil protein (BRSP) fractions (P < 0.01). It is concluded that the dynamics of AMF have highly temporal and spatial patterns that are related to soil glomalin and phosphatase activity in different managed semiarid steppes. Based on these observations, AMF communities could be useful indicators for evaluating soil quality and function of semiarid grassland ecosystems.

Arbuscular mycorrhizal fungi associated with vegetation and soil parameters under rest grazing management in a desert steppe ecosystem.

The impact of rest grazing on arbuscular mycorrhizal fungi (AMF) and the interactions of AMF with vegetation and soil parameters under rest grazing condition were investigated between spring and late summer in a desert steppe ecosystem with different grazing managements (rest grazing with different lengths of resting period, banned or continuous grazing) in Inner Mongolia, China. AMF diversity and colonization, vegetation biomass, soil properties and soil phosphatase activity were examined. In rest grazing areas of 60 days, AMF spore number and diversity index at a 0-10 cm soil depth as well as vesicular and hyphal colonization rates were higher compared with other grazing treatments. In addition, soil organic matter and total N contents were highest and soil alkaline phosphatase was most active under 60-day rest grazing. In August and September, these areas also had the highest amount of aboveground vegetation. The results indicated that resting grazing for an appropriate period of time in spring has a positive effect on AMF sporulation, colonization and diversity, and that under rest grazing conditions, AMF parameters are positively correlated with some soil characteristics.

The Assessment of Prostate Cancer Aggressiveness Using a Combination of Quantitative Diffusion-Weighted Imaging and Dynamic Contrast-Enhanced Magnetic Resonance Imaging.

OBJECTIVE: To explore the value of combining dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) quantitative parameters with apparent diffusion coefficient (ADC) values in the diagnosis of prostate cancer. METHODS: The clinical data of 146 patients with prostate lesions, including 87 patients with prostate cancer (PCa) and 59 with benign prostatic hyperplasia (BPH), were collected. After DCE-MRI and diffusion-weighted imaging (DWI) prostate scans, the magnitude of the DCE-MRI transfer constant (Ktrans ), rate constant (kep ), the volume of the extravascular extracellular space (ve ), and the ADC between the groups were compared, and the correlations between the DCE-MRI parameters and Gleason scores were analyzed. The diagnostic efficacy of these quantitative parameters was assessed by the area under the receiver operating characteristic (ROC) curve. RESULTS: The DCE-MRI parameters Ktrans and kep were significantly greater in the PCa group than in the BPH group (p < 0.05). The ROC curve showed the area under the Ktrans, kep , and ADC curves to be 0.665, 0.658, and 0.782, respectively. When all three quantitative indicators were combined, the area under the ROC curve was 0.904, with sensitivity and specificity rates of 83.6% and 93.7%, respectively. The Gleason scores were positively correlated with the Ktrans, kep , and ve (r = 0.39, 0.572, 0.30, respectively; p < 0.05) and negatively correlated with the ADC (r = -0.525; p < 0.05). CONCLUSION: The DCE-MRI quantitative parameters Ktrans and kep , as well as the ADC value, provided effective references for the differential diagnosis of PCa and BPH, as well as more precise and reliable quantitative parameters for grading the aggressiveness of PCa.

DTI-based radiomics signature for the detection of early diabetic kidney damage.

OBJECTIVE: To explore whether a radiomics signature based on diffusion tensor imaging (DTI) can detect early kidney damage in diabetic patients. MATERIALS AND METHODS: Twenty-eight healthy volunteers (group A) and thirty type 2 diabetic patients (group B) with micro-normoalbuminuria, a urinary albumin-to-creatinine ratio (ACR) < 30 mg/g and an estimated glomerular filtration rate (eGFR) of 60-120 mL/(min 1.73 m2) were recruited. Kidney DTI was performed using 1.5T magnetic resonance imaging (MRI).The radiologist manually drew regions of interest (ROI) on the fractional anisotropy (FA) map of the right kidney ROI including the cortex and medulla. The texture features of the ROIs were extracted using MaZda software. The Fisher coefficient, mutual information (MI), and probability of classification error and average correlation coefficient (POE + ACC) methods were used to select the texture features. The most valuable texture features were further selected by the least absolute shrinkage and selection operator (LASSO) algorithm. A LASSO regression model based on the radiomics signature was established. The diagnostic performance of the model for detecting early diabetic kidney changes was evaluated by the area under the receiver operating characteristic (ROC) curve (AUC). Empower (R), R, and MedCalc15.8 software were used for statistical analysis RESULTS: A total of 279 texture features were extracted from ROI of the kidney, and 30 most valuable texture features were selected from groups A and B using MaZda software. After LASSO-logistic regression, a diagnostic model of diabetic kidney damage based on texture features was established. Model discrimination evaluation: AUC = 0.882 (0.770 ± 0.952). Model calibration evaluation: Hosmer-Lemeshow X2 = 5.3611, P = 0.7184, P > 0.05, the model has good calibration. CONCLUSION: The texture features based on DTI could play a promising role in detecting early diabetic kidney damage.

Use of intravoxel incoherent motion diffusion-weighted imaging to detect early changes in diabetic kidneys.

OBJECTIVE: The purpose of the study was to examine differences in kidney intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) parameters in early-stage diabetic patients versus healthy controls. MATERIALS AND METHODS: Nineteen type 2 diabetic patients (group A) with a urinary albumin-to-creatinine ratio (ACR) < 30 mg/g and an estimated glomerular filtration rate (eGFR) of 80-120 mL/(min 1.73 m2) and twelve healthy volunteers (group B) were recruited. Kidneys were scanned with 1.5-Tesla IVIM-DWI. Nine b values (0, 50, 100, 150, 200, 300, 400, 600, and 800 s/mm2) were used. The parameters derived from IVIM-DWI were calculated for each kidney by two radiologists and included the perfusion fraction (f), diffusion coefficient (D), and pseudo-diffusion coefficient (D*). The mean values of f, D, and D* were calculated by selecting multiple regions of interest in the kidney. The diagnostic performance of the f, D, and D* values for the diagnosis of early diabetic kidney changes was determined by receiver operating characteristic analysis. Three radiologists independently measured the parameters derived from IVIM-DWI in the two groups by free-hand placing regions of interest, and the interclass coefficients (ICCs) were analyzed by SPSS.16.0 software. RESULTS: The f values of the kidneys were significantly higher in diabetic patients than in healthy volunteers. The D value of the kidneys was significantly lower in diabetic patients than in healthy volunteers. No significant differences in the D* values of the kidneys were observed between diabetic patients and healthy volunteers. The D values of the right kidneys were significantly higher than those of the left kidneys in both groups. The results of the receiver operating characteristic analysis were as follows: left kidney-f value AUC = 0.650 (cutoff point ≥ 27.49%) and D value AUC = 0.752 (cutoff point ≤ 1.68 × 10-3 mm2/s); and right kidney-f value AUC = 0.650 (cutoff point ≥ 28.24%) and D value AUC = 0.752 (cutoff point ≤ 1.81 × 10-3 mm2/s). The diagnostic performance of the D* value was very low (AUC < 0.6). No significant differences were present between the areas under the curves of the f and D values (P > 0.05). The ICCs of the f value and D value were between 0.637 and 0.827. The ICC of the D* value was less than 0.3. CONCLUSION: The results of our study suggest that changes in kidneys detected by IVIM-DWI may serve as indicators of early diabetic kidney disease.

Design, Synthesis, and Structure-Activity Relationships of Bavachinin Analogues as Peroxisome Proliferator-Activated Receptor†γ Agonists.

Peroxisome proliferator-activated receptor γ (PPARγ) agonists have been used for the treatment of diabetes with the effect of lowering blood glucose levels and improving insulin sensitivity. Natural compounds such as flavones, flavanones, and isoflavones have shown excellent PPARγ agonist activity. In this study, analogues of bavachinin were designed, synthesized, and evaluated by reporter gene assays for PPARγ agonist activity. Preliminary structure-activity relationships for these bavachinin analogues have been summarized, and seven compounds were found to have higher PPARγ agonist activities than the parent flavanone bavachinin.