Investigating the Pharmacological Mechanisms of Total Flavonoids from Eucommia ulmoides Oliver Leaves for Ischemic Stroke Protection.

The aim of this study was to explore how the total flavonoids from Eucommia ulmoides leaves (EULs) regulate ischemia-induced nerve damage, as well as the protective effects mediated by oxidative stress. The cell survival rate was significantly improved compared to the ischemic group (p < 0.05) after treatment with the total flavonoids of EULs. The levels of reactive oxygen species (ROS), lactate dehydrogenase (LDH), and malondialdehyde (MDA) decreased, while catalase (CAT) and glutathione (GSH) increased, indicating that the total flavonoids of EULs can significantly alleviate neurological damage caused by ischemic stroke by inhibiting oxidative stress (p < 0.01). The mRNA expression level of VEGF increased (p < 0.01), which was consistent with the protein expression results. Meanwhile, the protein expression of ERK and CCND1 increased (p < 0.01), suggesting that the total flavonoids of EULs could protect PC12 cells from ischemic injury via VEGF-related pathways. MCAO rat models indicated that the total flavonoids of EULs could reduce brain ischemia-reperfusion injury. In conclusion, this study demonstrates the potential mechanisms of the total flavonoids of EULs in treating ischemic stroke and their potential therapeutic effects in reducing ischemic injury, which provides useful information for ischemic stroke drug discovery.

Design, Synthesis and Biological Evaluation of Multi-Target Anti-Cancer Agent PYR26.

This study investigates the synthesis of a new compound, PYR26, and the multi-target mechanism of PYR26 inhibiting the proliferation of HepG2 human hepatocellular carcinoma cells. PYR26 significantly inhibits the growth of HepG2 cells (p < 0.0001) and this inhibition has a concentration effect. There was no significant change in ROS release from HepG2 cells after PYR26 treatment. The mRNA expressions of CDK4, c-Met and Bak genes in HepG2 cells were significantly inhibited (p < 0.05), while mRNA expression of pro-apoptotic factors such as caspase-3 and Cyt c was significantly increased (p < 0.01). The expression of PI3K, CDK4 and pERK proteins decreased. The expression level of caspase-3 protein was increased. PI3K is a kind of intracellular phosphatidylinositol kinase. PI3K signaling pathway is involved in signal transduction of a variety of growth factors, cytokines and extracellular matrix and plays an important role in preventing cell apoptosis, promoting cell survival and influencing cell glucose metabolism. CDK4 is a catalytic subunit of the protein kinase complex and is important for G1 phase progression of the cell cycle. PERK refers to phosphorylated activated ERK, which is translocated from cytoplasm to the nucleus after activation, and then participates in various biological reactions such as cell proliferation and differentiation, cell morphology maintenance, cytoskeleton construction, cell apoptosis and cell canceration. Compared with the model group and the positive control group, the tumor volume of the nude mice in the low-concentration PYR26 group, the medium-concentration group and the high-concentration group was smaller, and the organ volume was smaller than that in the model group and the positive control group. The tumor inhibition rates of low-concentration group PYR26, medium-concentration group and high-concentration group reached 50.46%, 80.66% and 74.59%, respectively. The results showed that PYR26 inhibited the proliferation of HepG2 cells and induced apoptosis of HepG2 cells by down-regulating c-Met, CDK4 and Bak, up-regulating the mRNA expression of caspase-3 and Cyt c genes, down-regulating PI3K, pERK and CDK4 proteins and up-regulating the protein level of caspase-3. In a certain range, with the increase in PYR26 concentration, the tumor growth was slower and the tumor volume was smaller. Preliminary results showed that PYR26 also had an inhibitory effect on the tumors of Hepa1-6 tumor-bearing mice. These results suggest that PYR26 has an inhibitory effect on the growth of liver cancer cells, therefore it has potential to be developed into a new anti-liver cancer drug.

Design, Synthesis and Molecular Docking of Novel Quinazolinone Hydrazide Derivatives as EGFR Inhibitors.

A series of novel quinazolinone hydrazide derivatives were designed and synthesized as EGFR inhibitors. The results indicated that most of the aimed compounds had potential anti-tumor cell proliferation and EGFR inhibitory activities. In the comprehensive analysis of all the tested compounds, the target compound 9c showed the best anti-tumor cell proliferation activity, (IC50 =1.31 µM for MCF-7, IC50 =1.89 µM for HepG2, IC50 =2.10 µM for SGC), and IC50 =0.59 µM for the EGFR inhibitory activity. Docking results showed that compound 9c could ideally insert the active site and interact with the critical amino acid residues (Val702, Lys721, Met769, Asp831) in the active site.

The Protective Effects of Hydrogen Sulfide New Donor Methyl S-(4-Fluorobenzyl)-N-(3,4,5-Trimethoxybenzoyl)-l-Cysteinate on the Ischemic Stroke.

In this paper, we report the design, synthesis and biological evaluation of a novel S-allyl-l-cysteine (SAC) and gallic acid conjugate S-(4-fluorobenzyl)-N-(3,4,5-trimethoxybenzoyl)-l-cysteinate (MTC). We evaluate the effects on ischemia-reperfusion-induced PC12 cells, primary neurons in neonatal rats, and cerebral ischemic neuronal damage in rats, and the results showed that MTC increased SOD, CAT, GPx activity and decreased LDH release. PI3K and p-AKT protein levels were significantly increased by activating PI3K/AKT pathway. Mitochondrial pro-apoptotic proteins Bax and Bim levels were reduced while anti-apoptotic protein Bcl-2 levels were increased. The levels of cleaved caspase-9 and cleaved caspase-3 were also reduced in the plasma. The endoplasmic reticulum stress (ERS) was decreased, which in turns the survival rate of nerve cells was increased, so that the ischemic injury of neurons was protected accordingly. MTC activated the MEK-ERK signaling pathway and promoted axonal regeneration in primary neurons of the neonatal rat. The pretreatment of MEK-ERK pathway inhibitor PD98059 and PI3K/AKT pathway inhibitor LY294002 partially attenuated the protective effect of MTC. Using a MCAO rat model indicated that MTC could reduce cerebral ischemia-reperfusion injury and decrease the expression of proinflammatory factors. The neuroprotective effect of MTC may be due to inhibition of the over-activation of the TREK-1 channel and reduction of the current density of the TREK1 channel. These results suggested that MTC has a protective effect on neuronal injury induced by ischemia reperfusion, so it may have the potential to become a new type of neuro-ischemic drug candidate.

Design, synthesis and bioactivity evaluation of thiazolidinedione derivatives as partial agonists targeting PPARγ.

Thiazolidinedione (TZD) is a novel peroxides proliferator activated receptor γ (PPARγ) agonist with many side effects. Herein, we developed a series of novel TZD analogues as partial agonists targeting PPARγ. The study of anti-hyperglycemic activity and anti-inflammatory activity enabled us to identify a novel compound, 4 g, which quickly recover the blood glucose of mice at the concentration of 100 mg/kg, and show similar anti-inflammatory activity to ibuprofen at the concentration of 20 mg/kg. The competitive binding assay confirmed direct binding of 4 g to the LBD of PPARγ with IC50 being 1790 nM, and dose-dependently increased the transcriptional activity of PPARγ. Besides, through computer-aided drug design software simulation docking, it was found that compound 4 g showed the best binding ability to target protein PPARγ. Furthermore, because of the introduction of benzene containing group at N3 position, the stability of H12 in the active pocket is reduced and the stability of H3 and ß-fold is increased, showing the characteristics of some PPARγ agonists, based on the docking model analysis. Together, these results suggest that 4 g is a promising PPARγ agonist that deserves further investigation.

Research Progress of Small Molecule Fluorescent Probes for Detecting Hypochlorite.

Hypochlorous acid (HOCl) generates from the reaction between hydrogen peroxide and chloride ions via myeloperoxidase (MPO)-mediated in vivo. As very important reactive oxygen species (ROS), hypochlorous acid (HOCl)/hypochlorite (OCl-) play a crucial role in a variety of physiological and pathological processes. However, excessive or misplaced production of HOCl/OCl- can cause variety of tissue damage and human diseases. Therefore, rapid, sensitive, and selective detection of OCl- is very important. In recent years, the fluorescent probe method for detecting hypochlorous acid has been developed rapidly due to its simple operation, low toxicity, high sensitivity, and high selectivity. In this review, the progress of recently discovered fluorescent probes for the detection of hypochlorous acid was summarized with the aim to provide useful information for further design of better fluorescent probes.

Discovery and development of novel rhodanine derivatives targeting enoyl-acyl carrier protein reductase.

A series of rhodanine derivatives RB1-RB23 were synthesized through a two-round screening. Their Mycobacterial tuberculosis (Mtb) InhA inhibitory activity and Mtb growth blocking capability were evaluated. The most potent hit compound RB23 indicated comparable InhA inhibiton (IC50 = 2.55 µM) with the positive control Triclosan (IC50 = 6.14 µM) and Isoniazid (IC50 = 8.29 µM). Its improved growth-blocking effect on Mtb and low toxicity were attractive for further development. The docking simulation revealed the possible binding pattern of this series and picked the key interacted residues as Ser20, Phe149, Lys165 and Thr196. The 3D-QSAR model visualized the SAR discussion and hinted new information. Modifying the surroundings near rhodanine moiety might be promising attempts in later investigations.

Evaluation of Nonpeptidic Ligand Conjugates for SPECT Imaging of Hypoxic and Carbonic Anhydrase IX-Expressing Cancers.

As tumors grow, vasculature is often deficient or malformed, resulting in many localized areas of hypoxia. Cells located in these hypoxic regions exhibit an altered gene expression pattern that can significantly alter resistance to conventional anticancer treatments such as ionizing radiation and chemotherapeutic drugs. A priori knowledge of the level of hypoxia within a tumor may better guide clinical care. In an effort to create a hypoxia specific imaging agent, a ligand for the tissue hypoxia marker, carbonic anhydrase IX (CA IX), was synthesized and used as a targeting ligand to deliver an attached (99m)Tc-chelating agent. Binding of the resulting conjugates to hypoxic cancer cells was first characterized in vitro. Whole animal imaging and biodistribution studies then were performed to determine tumor specificity in vivo. Several conjugates were found to bind selectively to CA IX expressing tumors in a receptor-dependent manner. We suggest that such conjugates could prove useful in identifying hypoxic cancers and/or quantitating the level of hypoxia within a tumor.

Evaluation of a Carbonic Anhydrase IX-Targeted Near-Infrared Dye for Fluorescence-Guided Surgery of Hypoxic Tumors.

Proof-of-principle studies in ovarian, lung, and brain cancer patients have shown that fluorescence-guided surgery can enable removal of otherwise undetectable malignant lesions, decrease the number of cancer-positive margins, and permit identification of disease-containing lymph nodes that would have normally evaded resection. Unfortunately, the current arsenal of tumor-targeted fluorescent dyes does not permit identification of all cancers, raising the need to design new tumor-specific fluorescent dyes to illuminate the currently undetectable cancers. In an effort to design a more universal fluorescent cancer imaging agent, we have undertaken to synthesize a fluorophore that could label all hypoxic regions of tumors. We report here the synthesis, in vitro binding, and in vivo imaging of a near-infrared (NIR) fluorescent dye that is targeted to carbonic anhydrase IX (CA IX), i.e., a widely accepted marker of hypoxic tissues. The low molecular weight NIR probe, named Hypoxyfluor, is shown to bind CA IX with high affinity and accumulate rapidly and selectively in CA IX positive tumors. Because nearly all human cancers contain hypoxic regions that express CA IX abundantly, this NIR probe should facilitate surgical resection of a wide variety of solid tumors.

Sulfonamide derivatives containing dihydropyrazole moieties selectively and potently inhibit MMP-2/MMP-9: Design, synthesis, inhibitory activity and 3D-QSAR analysis.

New series of sulfonamide derivatives containing a dihydropyrazole moieties inhibitors of MMP-2/MMP-9 were discovered using structure-based drug design. Synthesis, antitumor activity, structure-activity relationship and optimization of physicochemical properties were described. In vitro the bioassay results revealed that most target compounds showed potent inhibitory activity in the enzymatic and cellular assays. Among the compounds, compound 3i exhibited the most potent inhibitory activity with IC50 values of 0.21 µM inhibiting MMP-2 and 1.87 µM inhibiting MMP-9, comparable to the control positive compound CMT-1 (1.26 µM, 2.52 µM). Docking simulation was performed to position compound 3i into the MMP-2 active site to determine the probable binding pose. Docking simulation was further performed to position compound 3i into the MMP-2 active site to determine the probable binding model the 3D-QSAR models were built for reasonable design of MMP-2/MMP-9 inhibitors at present and in future.

Synthesis, biological evaluation and 3D-QSAR study of novel 4,5-dihydro-1H-pyrazole thiazole derivatives as BRAF(V6°°E) inhibitors.

Many reports implied that the BRAF serine/threonine kinase was mutated in various types of human tumors, which were related with cell growth, survival and differentiation. To provide new therapeutic opportunities, a series of novel 4,5-dihydro-1H-pyrazole derivatives (6a-10d) containing thiazole moiety as potential V600E mutant BRAF kinase (BRAF(V600E)) inhibitors were designed and synthesized. All compounds were evaluated in vitro for anticancer activities against WM266.4 human melanoma cell line and breast cancer MCF-7 cell line. Compound 10d displayed the most potential antiproliferative activity with an IC50 value of 0.12µM against cell line WM266.4 and 0.16µM against MCF-7 with positive control Sorafenib. Results of the inhibitory activity against BRAF(V600E) revealed that compound 10d was bearing the best bioactivity with IC50 of 0.05µM as well. On the basis of the result of flow cytometry, with the dose of compound 10d increasing, more and more cancer cell gradually encountered apoptosis or died, which indicated the compound 10d could induce remarkable apoptosis of MCF-7 and WM266.4 cells in a dose dependent manner. Furthermore, docking simulation of inhibitor analogues and 3D-QSAR modeling provided potential binding model and further knowledge of pharmacophore.

6,7-Dihydrobenzo[f]benzo[4,5]imidazo[1,2-d][1,4]oxazepine derivatives as selective inhibitors of PI3Kα.

Twenty eight 6,7-dihydrobenzo[f]benzo[4,5]imidazo[1,2-d][1,4]oxazepine derivatives were synthesized and evaluated their biological activities as PI3K inhibitors. Biological evaluation against four human tumor cell lines revealed that most target compounds showed impressively better antiproliferative activities than that of LY294002. Among these compounds, compound 25 exhibited the most potent and selective activity for PI3Kα, with the IC50 value of 0.016µM, an approximately 30-fold increase in comparison with LY294002, it also has an increased potency of approximately 11-fold for PI3Kß. It indicated the potential of developing 6,7-dihydrobenzo[f]benzo[4,5]imidazo[1,2-d][1,4]oxazepine derivatives as the new PI3Kα selective inhibitors for tumor treatment.

Discovery and synthesis of a novel series of potent, selective inhibitors of the PI3Kα: 2-alkyl-chromeno[4,3-c]pyrazol-4(2H)-one derivatives.

A series of novel 2-alkyl-chromeno[4,3-c]pyrazol-4(2H)-one derivatives were synthesized and evaluated for their biological activities as PI3K inhibitors. In vitro biological evaluation against four human tumor cell lines revealed that most target compounds showed impressively better antiproliferative activities than that of LY294002. Among these compounds, compound 4l exhibited the most potent and selective activity for PI3Kα, with the value of 0.014 µM, an approximately 30-fold increase in comparison with LY294002. Docking simulation was performed to position compound 4l into the PI3Kα active site and the result showed that compound 4l could bind well at the PI3Kα active site and it indicated that compound 4l could be a potential inhibitor of PI3Kα.

Synthesis, molecular docking and biological evaluation of coumarin derivatives containing piperazine skeleton as potential antibacterial agents.

A series of 4-hydroxycoumarin derivatives were designed and synthesized in order to find some more potent antibacterial drugs. Their antibacterial activities against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus were tested. These compounds showed good antibacterial activities against Gram-positive strains. Compound 4 g represented the most potent antibacterial activity against Bacillus subtilis and S. aureus with MIC of 0.236, 0.355 µg/mL, respectively. What's more, it showed the most potent activity against SaFabI with IC50 of 0.57 µM. Molecular docking of 4 g into S. aureus Enoyl-ACP-reductase active site were performed to determine the probable binding mode, while the QSAR model was built to check the previous work as well as to introduce new directions.

Design, synthesis and biological evaluation of novel 5-phenyl-1H-pyrazole derivatives as potential BRAF(V600E) inhibitors.

A series of novel 5-phenyl-1H-pyrazole derivatives (5 a-5 u) containing niacinamide moiety were synthesized and evaluated for biological activity as potential BRAF(V600E) inhibitors. Among them, compound 5h exhibited the most potent inhibitory activity with an IC50 value of 0.33 µM for BRAF(V600E). Antiproliferative assay results indicated that compound 5h has better antiproliferative activity against WM266.4 and A375 in vitro with IC50 value of 2.63 and 3.16 µM, respectively, being comparable with the positive control vemurafenib. Molecular docking of 5h into the BRAF(V600E) active site was performed to determine the probable binding mode. Furthermore, molecular docking and 3D QSAR study by means of DS 3.5 (Discovery Studio 3.5, Accelrys, Co. Ltd) explored the binding modes and the structure and activity relationship (SAR) of these derivatives.

Design, synthesis and biological evaluation of (E)-3-(3,4-dihydroxyphenyl)acrylylpiperazine derivatives as a new class of tubulin polymerization inhibitors.

A series of novel (E)-3-(3,4-dihydroxyphenyl)acrylylpiperazine derivatives had been synthesized and evaluated their biological activities as potential tubulin polymerization inhibitors. Among these compounds, compound 3q exhibited potent antiproliferative activities against three cancer cell lines in vitro, and antitubulin polymerization activity with IC50 of 0.92 µM, which was superior to that of colchicine (IC50=1.34 µM). Docking simulation was performed to insert compound 3q into the crystal structure of tubulin at colchicine binding site to determine the probable binding model. These results suggested that compound 3q may be a promising antitubulin agent for the potential treatment of cancer.

Different drought recovery strategy between Larix spp. and Quercus mongolica in temperate forests.

Forests are experiencing increasingly severe drought stress worldwide. Although most studies have quantified how tree growth was affected by extreme droughts, how trees recover from different drought intensities are still poorly understood for different species. We used a network of tree-ring data comprising 731 Quercus mongolica trees across 29 sites, 312 Larix olgensis Henry trees from 13 sites, and 818 Larix principis-rupprechtii trees from 34 sites, covering most of their distribution range in northern China, to compare the influences of drought intensity on post-drought recovery. The results showed that summer droughts had strong negative influences on tree growth. Post-drought growth varied with drought intensity for the three species. Larix species exhibited strong legacy effects after severe droughts, which is related to the lack of compensatory growth. In contrast, the compensatory growth of Q. mongolica reduced drought legacy effect. However, the compensatory growth of Q. mongolica gradually weaken with increasing drought intensity and disappeared during severe drought. Our findings indicated that influence of drought on Q. mongolica growth mainly shown in drought years, but Larix species suffered from long-term drought legacy effects, implying Q. mongolica rapidly recovered from droughts but Larix species need several years to recover from droughts, thus the two genera have different recovery strategy.

Repair of a "long and narrow" skin defect of the upper extremity with a modified design of a compound SCIP flap: a series of 12 cases.

BACKGROUND: Large skin lesions of the upper extremity tend to be ''long and narrow'' in shape, and the currently used repair and reconstruction protocols still have some drawbacks, including difficulty in closure of the donor area, poor cosmetic appearance of the donor and recipient areas, and low flap survival rates. The ilioinguinal flap has been more widely used for repair and reconstruction of various complex conditions. In order to improve the versatility of the flap design and to achieve better aesthetic results, we report a study on the improved design of Compound SCIP flap for repairing "long and narrow" large skin defects of the upper extremity by using a modified design of the ilioinguinal flap for the procurement of perforating blood vessels and flap excision. METHODS: From April 2005 to August 2015, a total of 12 patients underwent this modified design procedure, in which the anterior branch of the fourth lumbar artery or the posterior intercostal artery was selected to provide blood supply for the perforator flap together with the superficial branch of the superficial iliac artery to meet the blood supply needs of the flap for the one-time repair of a large "long and narrow" skin defect in the upper limb. Patient demographics, flap characteristics, and associated complications were retrospectively analyzed. RESULTS: 3 females and 9 males were included in this study, the mean age of the patients was 31.7 years (range, 22-44 years), the mean follow-up period was 15.3 ± 5.6 months (range, 7-24 months), and all patients had complete closure of the defect site and donor area, and all flaps survived. CONCLUSIONS: The Compound SCIP flap presents some advantages in repairing 'long and narrow' skin defects in the upper limb. While ensuring the survival rate of the elongated ilioinguinal flap, it amplifies the benefits of the ilioinguinal flap and enhances skin utilization. This can serve as a beneficial choice for repairing 'long and narrow' skin defects in the upper limb.

Spatio-Temporal Distribution Characteristics and Drivers of PM2.5 Pollution in Henan Province, Central China, before and during the COVID-19 Epidemic.

PM2.5 is the main cause of haze pollution, and studying its spatio-temporal distribution and driving factors can provide a scientific basis for prevention and control policies. Therefore, this study uses air quality monitoring information and socioeconomic data before and during the COVID-19 outbreak in 18 prefecture-level cities in Henan Province from 2017 to 2020, using spatial autocorrelation analysis, ArcGIS mapping, and the spatial autocorrelation analysis. ArcGIS mapping and the Durbin model were used to reveal the characteristics of PM2.5 pollution in Henan Province in terms of spatial and temporal distribution characteristics and analyze its causes. The results show that: (1) The annual average PM2.5 concentration in Henan Province fluctuates, but decreases from 2017 to 2020, and is higher in the north and lower in the south. (2) The PM2.5 concentrations in Henan Province in 2017-2020 are positively autocorrelated spatially, with an obvious spatial spillover effect. Areas characterized by a high concentration saw an increase between 2017 and 2019, and a decrease in 2020; values in low-concentration areas remained stable, and the spatial range showed a decreasing trend. (3) The coefficients of socio-economic factors that increased the PM2.5 concentration were construction output value > industrial electricity consumption > energy intensity; those with negative effects were: environmental regulation > green space coverage ratio > population density. Lastly, PM2.5 concentrations were negatively correlated with precipitation and temperature, and positively correlated with humidity. Traffic and production restrictions during the COVID-19 epidemic also improved air quality.

Synthesis and biological evaluation of novel N, N'-disubstituted urea and thiourea derivatives as potential anti-melanoma agents.

Two series of urea and thiourea derivatives (1a-11a, 1b-11b) have been synthesized; all the 22 compounds were reported for the first time. Their anti-proliferative activities against the melanoma cell line B16-F10 were evaluated. Among the compounds tested, compound 6b exhibited the most potent activity in melanoma cells growth inhibition (IC(50) = 0.33 µM). The bioassay tests showed that anti-proliferative activities of these novel compounds were possibly caused by inhibition of ERK1/2 phosphorylation level. Therefore, compound 6b can be a potential anti-melanoma agent and an inhibitor of ERK1/2 phosphorylation deserving further research.