Synthesis and biological evaluation of triazolones/oxadiazolones as novel urease inhibitors.

Urease is the main virulence factor of infectious gastritis and gastric ulcers. Urease inhibitors are regarded as the first choice for the treatment of such diseases. Based on the triazolone/oxadiazolone skeleton, a urea-like fragment being able to specifically bind the urease activity pocket and prevent urea from hydrolysis, we designed and synthesized 45 triazolones/oxadiazolones as urease inhibitors. Eight compounds were proved to show excellent inhibitory activity against Helicobacter pylori urease, being more potency than the clinically used urease inhibitor acetohydroxamic acid. The most active inhibitor with IC50 value of 1.2 µM was over 20-fold higher potent than the positive control. Enzymatic kinetic assays showed that these novel inhibitors reversibly inhibited urease with a mixed competitive mechanism. Molecular dockings provided evidence for the observations in enzyme assays. Furthermore, these novel inhibitors were proved as drug-like compounds with very low cytotoxicity to mammalian cells and favorable water solubility. These results suggested that triazolone and oxadiazolone were promising scaffolds for the design and discovery of novel urease inhibitors, and were expected as good candidates for further drug development.

Identification of (N-aryl-N-arylsulfonyl)aminoacetohydroxamic acids as novel urease inhibitors and the mechanism exploration.

Thirty-three (N-aryl-N-arylsulfonyl)aminoacetohydroxamic acids were synthesized in an effort to develop novel urease inhibitors. Among these compounds, 2-(N-(3-nitrophenyl)-N-(4-tert-butylphenylsulfonyl))aminoacetohydroxamic acid (e2) exhibited excellent inhibitory activity against Helicobacter pylori urease with no perceptible cytotoxicity to mammalian cells. Compound e2 showed over 690-fold higher potency than the clinical used urease inhibitor acetohydroxamic acid, reversibly inhibiting urease with a mixed mechanism. Molecular modeling revealed that (N-aryl-N-arylsulfonyl)aminoacetohydroxamic acids may possibly bind Ni ions and two hydrophobic regions with a 'Y'-like shape.

Synthesis, evaluation and mechanism exploration of 2-(N-(3-nitrophenyl)-N-phenylsulfonyl)aminoacetohydroxamic acids as novel urease inhibitors.

Thirteen 2-(N-(3-nitrophenyl)-N-phenylsulfonyl)aminoacetohydroxamic acids which were reported for the first time were designed and synthesized as novel urease inhibitors. Most of them showed higher potency than the positive control acetohydroxamic acid, with 2-(N-(3-nitrophenyl)-N-(4-bromophenylsulfonyl)aminoacetohydroxamic acid (d7) being the most active (IC50 = 0.13 ± 0.01 µM). Compound d7 reversibly inhibits urease with mixed mechanism showing excellent binding affinity to urease active site (KD = 0.34 nM, Ki=0.065 ± 0.003 µM andKi' = 1.20 ± 0.09 µM) and very low cytotoxicity against mammalian cells (cell viability of 91.4 % against HepG2 at 250 µg/mL). These positive results indicated that d7 may be used as the lead for further research to develop urease inhibitors with promising properties.

Recent Efforts in the Discovery of Urease Inhibitor Identifications.

Urease is an attractive drug target for designing anti-infective agents against pathogens such as Helicobacter pylori, Proteus mirabilis, and Ureaplasma urealyticum. In the past century, hundreds of medicinal chemists focused their efforts on explorations of urease inhibitors. Despite the FDA's approval of acetohydroxamic acid as a urease inhibitor for the treatment of struvite nephrolithiasis and the widespread use of N-(n-butyl)thiophosphoric triamide as a soil urease inhibitor as nitrogen fertilizer synergists in agriculture, urease inhibitors with high potency and safety are urgently needed. Exploration of novel urease inhibitors has therefore become a hot research topic recently. Herein, inhibitors identified worldwide from 2016 to 2021 have been reviewed. They structurally belong to more than 20 classes of compounds such as urea/thioure analogues, hydroxamic acids, sulfonamides, metal complexes, and triazoles. Some inhibitors showed excellent potency with IC50 values lower than 10 nM, having 10000-fold higher potency than the positive control thiourea.

Synthesis and Biological Evaluation of Dithiobisacetamides as Novel Urease Inhibitors.

Thirty-eight disulfides containing N-arylacetamide were designed and synthesized in an effort to develop novel urease inhibitors. Biological evaluation revealed that some of the synthetic compounds exhibited strong inhibitory potency against both cell-free urease and urease in intact cell with low cytotoxicity to mammalian cells even at concentration up to 250 µM. Of note, 2,2'-dithiobis(N-(2-fluorophenyl)acetamide) (d7), 2,2'-dithiobis(N-(3,5-difluorophenyl)acetamide) (d24), and 2,2'-dithiobis(N-(3-fluorophenyl)acetamide) (d8) were here identified as the most active inhibitors with IC50 of 0.074, 0.44, and 0.81 µM, showing 32- to 355-fold higher potency than the positive control acetohydroxamic acid. These disulfides were confirmed to bind urease without covalent modification of the cysteine residue and to inhibit urease reversibly with a mixed inhibition mechanism. They also showed very good anti-Helicobacter pylori activities with d8 showing a comparable potency to the clinical used drug amoxicillin. The impressive in vitro biological profile indicated their immense potential as therapeutic agents to tackle H. pylori caused infections.

Identification, potency evaluation, and mechanism clarification of α-glucosidase inhibitors from tender leaves of Lithocarpus polystachyus Rehd.

Lithocarpus polystachyus Rehd. known as Sweet Tea in China has attracted lots of interest for its good hypoglycemic effect and the potential as a hypoglycemic agent. Based on affinity separation-UPLC-Q-TOF-MS/MS, 54 potential α-glucosidase inhibitiors were identified and 44 were structurally determined. Out of them, 41 were identified for the first time from this plant including flavonoids, fatty acids, triterpenes, alkaloids, and coumarins. Enzyme assays revealed that flavonoids exhibited higher inhibitory activity against α-glucosidase than others with astilbin (IC50 = 6.14 µg·mL-1), morin (IC50 = 8.46 µg·mL-1), and naringenin (IC50 = 10.03 µg·mL-1) showing 2- to 4-fold higher potency than the positive control acarbose. They were proved as reversible inhibitors with mixed inhibition mechanism. Ki (Ki') values and molecular dockings strongly supported the potency order of astilbin, morin and naringenin that showed in the enzyme assays.

Blocking the EGFR/p38/NF-κB signaling pathway alleviates disruption of BSCB and subsequent inflammation after spinal cord injury.

Epidermal growth factor receptor (EGFR) activation is involved in blood spinal cord barrier (BSCB) disruption and secondary injury after spinal cord injury (SCI). However, the underlying mechanisms of EGFR activation mediating BSCB disruption and secondary injury after SCI remain unclear. An in vitro model of oxygen and glucose deprivation/reoxygenation (OGD/R) induced BSCB damage and in vivo rat SCI model were employed to define the role of EGFR/p38/NF-κB signal pathway activation and its induced inflammatory injury in main cellular components of BSCB. Genetic regulation (lentivirus delivered shRNA and overexpression system) or chemical intervention (agonist or inhibitor) were applied to activate or inactivate EGFR and p38 in astrocytes and microvascular endothelial cells (MEC) under which conditions, the expression of pro-inflammatory factors (TNF-α, iNOS, COX-2, and IL-1ß), tight junction (TJ) protein (ZO-1 and occludin), nuclear translocation of NF-κB and permeability of BSCB were analyzed. The pEGFR was increased in astrocytes and MEC which induced the activation of EGFR and p38 and NF-κB nuclear translocation. The activation of EGFR and p38 increased the TNF-α, iNOS, COX-2, and IL-1ß responsible for the inflammatory injury and reduced the ZO-1 and occludin which caused BSCB disruption. While EGFR or p38 inactivation inhibited NF-κB nuclear translocation, and markedly attenuated the production of pro-inflammatory factors and the loss of TJ protein. This study suggests that the EGFR activation in main cellular components of BSCB after SCI mediates BSCB disruption and secondary inflammatory injury via the EGFR/p38/NF-κB pathway.

Technology-supported lifestyle interventions to improve maternal-fetal outcomes in women with gestational diabetes mellitus: A meta-analysis.

BACKGROUND: The increasing incidence of gestational diabetes mellitus (GDM) is a global health problem. Lifestyle interventions have been recognized as effective measures to enhance maternal and child health. Traditional education approaches, personalized consultation and home visits to promote change in patients' lifestyle are limited by cost, lack of resources and inability to provide broad coverage. The increased use of technological approaches can cross these barriers. OBJECTIVES: The meta-analysis aimed to evaluate the effectiveness of technology-supported lifestyle interventions for women with gestational diabetes mellitus. METHODS: Databases that were reviewed included the Cochrane Library, PubMed, Web of Science, EBSCO, Embase, Medline, CINAHL and ClinicalTrials.gov. from inception to September 2019. Randomized controlled trials (RCTs) of technology-supported lifestyle interventions used for women with gestational diabetes mellitus (GDM) were identified. Two reviewers independently assessed each study using Cochrane Collaboration's tool. Maternal-fetal outcomes as well as weight gain in pregnancy and maternal blood glucose were presented as relative risks (RR) or a mean difference (MD). RESULTS: Of the 3993 articles reviewed, ten RCTs involving 979 women were included. Technology-supported lifestyle interventions reduced pregnancy weight gain (MD = -1.55, 95% CI = [-1.81 to -1.29], P < 0.001) and mean (1-h and 2-h) postprandial blood glucose (MD = -0.31, 95% CI = [-0.58 to -0.03], P = 0.03), with low heterogeneity of 36% and 18%, respectively. No evidence of significant effect existed on other maternal-fetal outcomes, such as weeks of gestation at delivery, caesarean birth, pre-eclampsia/gestational hypertension, instrumental vaginal birth, premature delivery, newborn weight, neonatal hypoglycemia, large-for-gestational age, fetal macrosomia, NICU admission and respiratory morbidity (I2 ranging from 0% to 51%). No significant improvement was noted in glycosylated hemoglobin (HbA1c) and fasting blood glucose (FBG), with strong heterogeneity of 95% and 84%, respectively. CONCLUSIONS: Technology-supported lifestyle interventions are associated with reducing pregnancy weight gain and mean (1-h and 2-h) postprandial blood glucose in women with GDM. Well-designed research studies are needed to identify the full potential of technology-supported lifestyle interventions, especially interventions guided by theoretical models.