Antidepressant-like effects of penta-acetyl geniposide in chronic unpredictable mild stress-induced depression rat model: Involvement of inhibiting neuroinflammation in prefrontal cortex and regulating hypothalamic-pituitaryadrenal axis.

We previously reported that penta-acetyl geniposide ((Ac)5GP, an acetylated derivative of geniposide) exhibited better pharmacological functions than geniposide, a major active component of Gardenia jasminoides Ellis. This study demonstrated the antidepressant-like effects of (Ac)5GP and its involved mechanisms using a rat depression model caused by chronic unpredictable mild stress (CUMS). Behavioral tests including sucrose preference, open field and forced swimming were applied to evaluate depression symptoms. IL-1ß, IL-6 and TNF-α mRNA and protein levels in prefrontal cortex (PFC) were respectively measured by quantitative PCR and ELISA. The protein levels of IκBα, p-IκBα, NF-κB p65, NLRP3, pro- and mature-IL-1ß in PFC were determined by western blot. The activity of hypothalamic-pituitaryadrenal (HPA) axis was also measured. (Ac)5GP treatment alleviated the CUMS-induced depressive-like behaviors in rats, as indicated by increased sucrose intake, increased total crossing and rearing numbers, improved central activity and reduced immobility time. (Ac)5GP reversed the CUMS-induced elevations of IL-1ß, IL-6 and TNF-α mRNA and protein levels in PFC. (Ac)5GP reduced degradation and phosphorylation of IκBα and protein level of nuclear NF-κB p65 in PFC. (Ac)5GP also decreased the mRNA and protein levels of NLRP3 and reduced the ratio of mature-IL-1ß protein over total IL-1ß protein (pro-IL-1ß + mature-IL-1ß) in PFC. Moreover, (Ac)5GP reduced serum levels of adrenocorticotropic hormone/corticosterone and mRNA level of hypothalamic corticotrophin-releasing hormone. In conclusion, (Ac)5GP treatment improved the depressive-like behaviors in CUMS rats perhaps by suppressing neuroinflammation in PFC and inhibiting activations of NF-κB and NLRP3 and also attenuating HPA axis hyperactivity.

Therapeutic strategies for targeting telomerase in cancer.

Telomere and telomerase play important roles in abnormal cell proliferation, metastasis, stem cell maintenance, and immortalization in various cancers. Therefore, designing of drugs targeting telomerase and telomere is of great significance. Over the past two decades, considerable knowledge regarding telomere and telomerase has been accumulated, which provides theoretical support for the design of therapeutic strategies such as telomere elongation. Therefore, the development of telomere-based therapies such as nucleoside analogs, non-nucleoside small molecules, antisense technology, ribozymes, and dominant negative human telomerase reverse transcriptase are being prioritized for eradicating a majority of tumors. While the benefits of telomere-based therapies are obvious, there is a need to address the limitations of various therapeutic strategies to improve the possibility of clinical applications. In this study, current knowledge of telomere and telomerase is discussed, and therapeutic strategies based on recent research are reviewed.

A rapid-response and ratiometric fluorescent probe for nitric oxide: From the mitochondria to the nucleus in live cells.

Nitric oxide (NO) is a very important signal molecule implicated in numerous physiological and pathological processes, and its detection is the key to understand these processes. For this reason, various fluorescent probes have been developed for detection analysis of NO. However, few rapid-response (<1 min) and ratiometric fluorescent probe are reported for real-time detection of short-time NO in biological systems. In this work, we report a rapid-response (within several seconds) and ratiometric fluorescent probe, RatioTr, which displays selective and sensitive detection of NO in solutions, and detections of exo- and endogenous NO in live RAW 264.7 cells. Unexpectedly, the probe RatioTr and its sensing product (p-Nus) display different cellular localizations, the mitochondria and the nucleus, which were demonstrated by co-stained experiments. The sensing process of RatioTr toward NO from mitochondria to nucleus was observed in live cells by confocal fluorescence images. Furthermore, the subcellular localizations were demonstrated by measurements of pKa and interaction of p-Nus and DNA. In the presence of a natural DNA, calf thymus DNA, RatioTr is more sensitive to NO (LOD = 2.8 nM). Therefore, due to the nucleus localization together with a high fluorescence efficiency in the nucleus, p-Nus is a good candidate of cell-permeant nucleic acid stain or a fluorescent probe for the nucleus.

Novel Pyrazolo[4,3- d]pyrimidine as Potent and Orally Active Inducible Nitric Oxide Synthase (iNOS) Dimerization Inhibitor with Efficacy in Rheumatoid Arthritis Mouse Model.

In order to discover novel anti-inflammatory agents for treatment of arthritis and based on preliminary structure-activity relationships, four series (A-D) of total 90 new pyrazolo[4,3- d]pyrimidine compounds were designed and synthesized. All the compounds have been tested for their anti-inflammatory activities by inhibiting of LPS-induced NO production. A clear structure-activity relationship has been concluded step by step, and finally 3,4,5-trimethoxystyryl-1 H-pyrazolo[4,3- d]pyrimidine was found to be the most active scaffold. Among them, compound D27 was discovered as the most potent anti-inflammatory agent (IC50 = 3.17 µM) with low toxicity and strong inhibitory of NO release (IR = 90.4% at 10 µM). This compound also showed potent inhibition of iNOS with IC50 value of 1.12 µM. Preliminary mechanism studies indicated that it could interfere with the stability and formation of active dimeric iNOS. The anti-inflammatory effect of this compound was determined by adjuvant-induced arthritis in rat model. We believe these findings would further support the study of rational design of more efficient iNOS inhibitors in the future.

Design, synthesis and biological evaluation of tricyclic pyrazolo[1,5-c][1,3]benzoxazin-5(5H)-one scaffolds as selective BuChE inhibitors.

Based on the structural analysis of tricyclic scaffolds as butyrylcholinesterase (BuChE) inhibitors, a series of pyrazolo[1,5-c][1,3]benzoxazin-5(5H)-one derivatives were designed, synthesized and evaluated for their acetylcholinesterase (AChE) and BuChE inhibitory activity. Compounds with 5-carbonyl and 7- or/and 9-halogen substitutions showed potential BuChE inhibitory activity, among which compounds 6a, 6c and 6g showed the best BuChE inhibition (IC50 = 1.06, 1.63 and 1.63 µM, respectively). The structure-activity relationship showed that the 5-carbonyl and halogen substituents significantly influenced BuChE activity. Compounds 6a and 6g were found nontoxic, lipophilic and exhibited remarkable neuroprotective activity and mixed-type inhibition against BuChE (Ki = 7.46 and 3.09 µM, respectively). Docking studies revealed that compound 6a can be accommodated into BuChE via five hydrogen bonds, one Pi-Sigma interaction and three Pi-Alkyl interactions.

Therapeutic Effect of Penta-acetyl Geniposide on Adjuvant-Induced Arthritis in Rats: Involvement of Inducing Synovial Apoptosis and Inhibiting NF-κB Signal Pathway.

Previous studies demonstrated that penta-acetyl geniposide ((Ac)5GP, an acetylated derivative of geniposide) exhibited better pharmacological functions than geniposide. This study was aimed to observe the potential effect of (Ac)5GP on adjuvant-induced arthritis (AIA) in rat and explore the involved mechanisms. Rat AIA was induced by complete Freund's adjuvant. (Ac)5GP (30, 60, 120 mg/kg) was given to AIA rats by intragastric administration. Paw swelling, polyarthritis index, serum pro-inflammatory cytokines levels, histological assessments of ankle joint, and proteoglycan expression were respectively measured to evaluate the therapeutic effect of (Ac)5GP on rat AIA. Immunohistochemistry for Ki67 and TUNEL assay were performed to reveal the anti-proliferative and pro-apoptotic effects of (Ac)5GP on AIA synoviocytes in vivo. Protein levels of Bcl-2, Bax, caspase 3, IκBα, p-IκBα, and NF-κB p65 in synovial tissues were detected by Western blot. We found that (Ac)5GP treatment could suppress secondary hind paw swelling, reduce polyarthritis index, decrease TNF-α and IL-1ß serum levels, attenuate pathological damage of ankle joint, and promote proteoglycans expression. (Ac)5GP treatment also could reduce Ki67 positive expression rate and raise the synovial apoptosis index in synovial tissues. Additionally, (Ac)5GP (120 mg/kg) could significantly decrease Bcl-2 protein level, increase Bax and cleaved caspase 3 protein levels, and normalize the ratio of Bcl-2 to Bax. Moreover, (Ac)5GP (120 mg/kg) could inhibit the degradation and phosphorylation of IκBα and reduce NF-κB p65 protein level in nuclear extracts. In conclusion, (Ac)5GP showed a potent anti-arthritic effect on AIA rats via inducing synovial apoptosis and inhibiting NF-κB activation in synovial tissues.

Novel curcumin analogue hybrids: Synthesis and anticancer activity.

In this study, twenty curcumin analogue hybrids as potential anticancer agents through regulation protein of TrxR were designed and synthesized. Results of anticancer activity showed that 5,7-dimethoxy-3-(3-(2-((1E, 4E)-3-oxo-5-(pyridin-2-yl)penta-1,4-dien-1- yl)phenoxy)propoxy)-2-(3,4,5-trimethoxyphenyl)-4H-chromen-4-one (compound 7d) could induce gastric cancer cells apoptosis by arresting cell cycle, break mitochondria function and inhibit TrxR activity. Meanwhile, western blot revealed that this compound could dramatically up expression of Bax/Bcl-2 ratio and high expression of TrxR oxidation. These results preliminarily show that the important role of ROS mediated activation of ASK1/MAPK signaling pathways by this title compound.

Tricyclic pyrazolo[1,5-d][1,4]benzoxazepin-5(6H)-one scaffold derivatives: Synthesis and biological evaluation as selective BuChE inhibitors.

BuChE inhibitors play important roles in treatment of patients with advanced Alzheimer's disease (AD). A series of tricyclic pyrazolo[1,5-d][1,4]benzoxazepin-5(6H)-one derivatives were synthesized and evaluated as acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitors. Some derivatives showed selective BuChE inhibitory activity, which was influenced by the volumes of the substituted groups at the C6 position and halogen substituents at the benzene ring of tricyclic scaffold. Among them, compounds 3f and 3o with dihalogen and 6-ethyl substituent showed the most potent activity (IC50 = 2.95, 2.04 µM, and mixed-type, non-competitive inhibition against BuChE, respectively). Eutomer (6R)-3o exhibited better BuChE inhibitory activity than (6S)-3o. Compound 3o exhibited nontoxic, good ADMET properties, and remarkable neuroprotective activity. Docking studies revealed the same binding orientation within the active site of target enzyme. Compound 3o was nicely bound to BuChE via three hydrogen bonds, one Alkyl interaction and three Pi-Alkyl interactions. The selective BuChE inhibitors had a potential use in progressive neurodegenerative disorder.

New pentadienone oxime ester derivatives: synthesis and anti-inflammatory activity.

To develop novel anti-inflammatory agents, a series of new pentadienone oxime ester compounds were designed and synthesized. The structures were determined by IR, 1H NMR, 13 C NMR, and HRMS. All compounds have been screened for their anti-inflammatory activity by evaluating their inhibition against LPS-induced nitric oxide (NO) release in RAW 264.7 cell. Among them, compound 5j was found to be one of the most potent compounds in inhibiting NO and IL-6 (IC50 values were 6.66 µM and 5.07 µM, respectively). Preliminary mechanism studies show that title compound 5j could significantly suppress expressions of nitric oxide synthase, COX-2, and NO, IL-6 through Toll-like receptor 4/mitogen-activated protein kinases/NF-κB signalling pathway. These data support further studies to assess rational design of more efficient pentadienone oxime ester derivatives with anti-inflammatory activity in the future.

Discovery of (4-bromophenyl)(3-hydroxy-4-methoxyphenyl)methanone through upregulating hTERT induces cell apoptosis and ERS.

Dominant-negative mutants of telomerase hTERT were demonstrated to have selective effects in tumor cells. However, no any effective and highly selective hTERT inhibitor has been developed so far. We focused on developing new hTERT modulators and synthesized a small molecular compound, named (4-bromophenyl)(3-hydroxy-4-methoxyphenyl)methanone. Our in vitro studies found that title compound showed high inhibitory activity against telomerase, had high antiproliferative capacity on SMMC-7721 cells with IC50 value 88 nm, and had no obvious toxic effect on human normal hepatocyte cells with IC50 value 10 µM. Our in vivo studies showed that this compound significantly inhibited tumor growth in xenograft tumor models. The further molecular mechanisms of title compound inhibition SMMC-7721 cell proliferation by modulating hTERT were explored; the results showed that endoplasmic reticulum stress (ERS) through ER over response (EOR) activates the expression of hTERT, and then induces ERS, which is believed to be intricately associated with oxidative stress and mitochondrial dysfunction, resulting in apoptotic cell death, thereby modulating the expression of downstream signaling molecules including CHOP (CAAT/enhancer-binding protein homologous protein)) and mitochondrion pathway of apoptosis, leading to inhibition of cell proliferation.

Novel unsaturated glycyrrhetic acids derivatives: Design, synthesis and anti-inflammatory activity.

To develop novel anti-inflammatory agents, a series of unsaturated glycyrrhetic acids were designed, synthesized and evaluated for anti-inflammatory activity using RAW264.7 cells. The structure-activity relationship (SAR) of NO inhibitory activity was analyzed. α,ß-Unsaturated glycyrrhetic acids showed better activity, among them, compounds 6k and 6l with piperazine unit exhibited the most potent nitric oxide (NO) and interleukin-6 (IL-6) inhibitory activity (IC50 = 13.3 and 15.5 µM respectively). Furthermore, compound 6k could also significantly suppress LPS-induced iNOS and COX-2 expression and IL-6 production through MAPKs and NF-kB signaling pathway.

New arylpyrazoline-coumarins: Synthesis and anti-inflammatory activity.

To develop new anti-inflammatory agents with improved pharmaceutical profiles, a series of new phenyl-pyrazoline-coumarin derivatives (4a∼4m) were designed and synthesized. Compounds 4a and 4b were determined by X-ray crystallography. All of the compounds have been screened for their anti-inflammatory activity characterized by evaluating their inhibition against LPS-induced IL-6 release. Among them, compound 4m showed the highest anti-inflammatory activity with inhibiting IL-6, TNF-α and nitric oxide (NO) production lipopolysaccharide (LPS)-stimulated. The further study showed that title compound 4m could significantly suppress expressions of nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and the productions of IL-6, TNF-α, NO through NF-κB/MAPK signaling pathway. The anti-inflammatory activity of compound 4m was determined by carrageenan induced paw edema. Furthermore in vivo evaluation results indicated that compound 4m could inhibit AA-induced rat ankle joints.

Novel benzopyran derivatives and their therapeutic applications: a patent review (2009-2016).

INTRODUCTION: The benzopyran derivatives present a wide variety of biological activity and behaviour. At the same time the benzopyran derivatives support their use as therapeutic agents for multiple diseases. Their structural characteristics correlated to physicochemical properties seem to define the extent of the biological activity. Areas covered: This review summarizes new patents published on new benzopyran derivatives from 2009 to 2016. Expert opinion: Many benzopyran derivatives have vivo/vitro biological responses. Their clinical evaluation will be critical to assess therapeutic utility. The compounds containing benzopyran moiety is well defined as lead compounds for design of new more promising molecules.

Competition between "Meta Effect" Photochemical Reactions of Selected Benzophenone Compounds Having Two Different Substituents at Meta Positions.

Recent studies conducted on some "meta effect" photochemical reactions focused on aromatic carbonyls having a substitution on one meta position of the benzophenone (BP) and anthraquinone parent compound. In this paper, two different substitutions were introduced with one at each meta position of the BP parent compound to investigate possible competition between different types of meta effect photochemistry observed in acidic solutions containing water. The photochemical pathways of 3-hydroxymethyl-3'-fluorobenzophenone (1) and 3-fluoro-3'-methylbenzophenone (2) were explored in several solvents, including acidic water-containing solutions, using time-resolved spectroscopic experiments and density functional theory computations. It is observed that 1 can undergo a photoredox reaction and 2 can undergo a meta-methyl deprotonation reaction in acidic water-containing solutions. Comparison of these results to those previously reported for the analogous BP derivatives that contain only one substituent at a meta position indicates the introduction of electron-donating (such as hydroxyl) and electron-withdrawing groups (such as F) on the meta positions of BP can influence the meta effect photochemical reactions. It was found that involvement of an electron-donating moiety facilitates the meta effect photochemical reactions by stabilizing the crucial reactive biradical intermediate associated with the meta effect photochemical reactions.

Benzophenone-nucleoside derivatives as telomerase inhibitors: Design, synthesis and anticancer evaluation in vitro and in vivo.

Based on telomerase, thirteen novel phenstatin moiety linked stavudine derivatives (8a∼8e and 11a∼11f) were synthesized. The structures were determined by NMR and TOF-HRMS. The screening results showed that some compounds had better anti-cancer activity in vivo and in vitro. Among them, Compound 8d showed high inhibitory activity against telomerase and showed good antiproliferative activity against SGC-7901 cell with IC50 value 0.77 µM by inducing cell cycle arrest at G2 phase. It also could improve SGC-7901 cell apoptosis, mitochondrial membrane potential assay indicated that the dissipation of MMP might participate in apoptosis induced by title compound. In vivo studies showed that compound 8d displayed potent anticancer activity with inhibition tumor growth.

Novel tricyclic pyrazolo[1,5-d][1,4]benzoxazepin-5(6H)-one: Design, synthesis, model and use as hMAO-B inhibitors.

Based on our recently reported selective hMAO-A inhibitors, on which, the intramolecular cyclization led to a very interesting change of isoform selectivity. A series of selective hMAO-B inhibitors (3a-3u) with novel scaffold of tricyclic pyrazolo[1,5-d][1,4]benzoxazepin-5(6H)-one were designed and synthesized. Compound 3u (IC50=221 nM) exhibited the best inhibitory activity and isoform selectivity against hMAO-B, superior to selegiline (IC50=321 nM), which is a commercial selective hMAO-B inhibitor used to Parkinson's disease. Modeling study indicated that the selectivity of our compounds to hMAO-B is determined by at least two residues, i.e., Ile 199 and Cys 172 (or corresponded Phe 208 and Asn 181 of hMAO-A). These data support further studies to assess rational design of more efficiently selective hMAO-B inhibitors.

Dihydropyrazole derivatives as telomerase inhibitors: Structure-based design, synthesis, SAR and anticancer evaluation in vitro and in vivo.

It is of our interest to generate and identify novel compounds with regulation telomerase for cancer therapy. In order to carry out more rational design, based on structure-based drug design, several series of N-substituted-dihydropyrazole derivatives, totally 78 compounds as potential human telomerase inhibitors were designed and synthesized. The results demonstrated that some compounds had potent anticancer activity against four tumor cell lines, and showed good selectivity on tumor cells over somatic cells. By the modified TRAP assay, compound 13i exhibited the most potent inhibitory activity against telomerase with an IC50 value of 0.98 µM. In vivo evaluation results indicated that compound 13i could inhibit growth of S180 and HepG2 tumor-bearing mice, and it also significantly enhanced the survival rate of EAC tumor-bearing mice. The further results in vivo confirmed that it could significantly improve pathological changes of N,N-diethylnitrosamine (DEN)-induced rat hepatic tumor. These data support further studies to assess rational design of more efficient telomerase inhibitors in the future.

Hesperetin derivatives: Synthesis and anti-inflammatory activity.

Sixteen novel hesperetin derivatives containing Mannich base moiety were designed and synthesized and their anti-inflammatory activities were evaluated by inhibiting tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in mouse RAW264.7 macrophages. Compounds 3a-3k showed better hydrophilic, while compounds 3l-3p with aromatic groups was hydrophobic. The anti-inflammatory activity of title compounds was correlated with logP values, among them, compounds 3c, 3e and 3i with minus logP values exhibited best anti-inflammatory activity through decreasing both IL-6 and TNF-α. Furthermore, the expression of LPS-induced notch1 and inos was reduced by compounds 3c, 3e, and 3i, and compound 3e attenuated LPS-induced inos protein levels in a dose-dependent manner.

Novel dihydropyrazole-chromen: Design and modulates hTERT inhibition proliferation of MGC-803.

Dominant-negative mutant of telomerase hTERT was demonstrated to show selective anticancer effects in tumor cells. But, an effective hTERT inhibitor with high selectivity has not been developed so far. Focused on hTERT, a novel dihydropyrazole-chromen (13k) controlling hTERT was designed. Title compound 13k occupied high antiproliferative activity against MGC-803 cells with IC50 value 1.41 µM, but it manifested obvious un-toxic effect on human normal gastric mucosa cells with the IC50 2.3 mM. Treated with compound 13k, the further inhibition mechanisms by modulating hTERT was explored, the results showed that expression of hTERT was clearly modulated, and then ß-catenin activation was decreased, thereby the expression of downstream signaling molecules including c-myc and cyclin D1 was modulated, leading to inhibition MGC-803 cells proliferation.

Apoptotic Effect of Geniposide on Fibroblast-Like Synoviocytes in Rats with Adjuvant-Induced Arthritis via Inhibiting ERK Signal Pathway In Vitro.

Stimulating fibroblast-like synoviocyte (FLS) apoptosis in rheumatoid arthritis (RA) is a promising strategy for clinical treatment. Previous studies have confirmed that geniposide shows a certain anti-arthritic effect in vivo. However, whether geniposide can induce RA FLS apoptosis and the underlying mechanisms has not been elucidated. Herein, adjuvant-induced arthritis (AIA) in rat was induced and FLS was isolated from synovial tissues by tissue explant cultivation method. MTT assay, Hoechst staining, and flow cytometric apoptosis assay were applied to evaluate apoptotic effect of geniposide on AIA FLS. Bcl-2, Bax, and caspase 3 messenger RNA (mRNA) levels, and extracellular-signal-regulated kinases (ERKs) and phosphorylated ERK protein levels were examined by real-time PCR and western blot, respectively. We found that geniposide dose-dependently inhibited AIA FLS proliferation in vitro. AIA FLS treated with geniposide displayed typical apoptotic morphological characteristics including nuclear shrinkage and chromatin condensation. Flow cytometric apoptosis assay indicated that geniposide significantly increased the apoptosis rate of AIA FLS. Additionally, geniposide treatment on AIA FLS decreased Bcl-2 mRNA level and increased Bax and caspase 3 mRNA levels, accompanied by reduced protein levels of phosphorylated-ERK1/2, without affecting total ERK1/2. In conclusion, geniposide effectively induces AIA FLS apoptosis through regulating the apoptosis-related gene expressions and inhibiting ERK signal pathway.