Suppression of LPS-induced NF-κB activity in macrophages by the synthetic aurone, (Z)-2-((5-(hydroxymethyl) furan-2-yl) methylene) benzofuran-3(2H)-one

Synthesis, characterization and biological evaluation of aurones as potential neuroprotective agents

Aim: To synthesize aurone (Ar) derivatives and to demonstrate their effects against diabetes mellitus (DM) and neurodegeneration. Materials & methods: Five Ar (A-E) derivatives were synthesized, characterized by proton NMR and screened for antioxidant, anti-diabetic and anti-cholinesterase activities. They were further evaluated for neuroprotective effects in streptozotocin (STZ)-induced neurodegenerative model. Results: Among the aurone derivatives ArE demonstrated significant reversal of cognitive impairment, oxidative stress and neuroinflammation. Biochemical analysis revealed anti-diabetic and neuroprotective effects, possibly through downregulation of inflammatory markers and upregulation of antioxidant enzymes. Conclusion: Synthesized Ar (A-E) exhibits promising therapeutic potential against STZ-induced neurodegeneration and DM by modulating inflammatory and oxidative pathways, suggesting a novel avenue for disease management.

Minor ergosteroids and a 19-nor labdane-type diterpenoid with anti-inflammatory effects from Ganoderma lucidum

A chemical investigation on the fruiting bodies of Ganoderma lucidum led to the isolation and identification of five undescribed ergosteroids including two des-D-steroids (3 and 4) and one rare 6/6/7/5-fused carbon skeletal ergosterol (5) along with one 19-nor labdane-type diterpenoid (6). Their structures including their absolute configurations, were assigned by spectroscopic methods, ECD calculations, and X-ray diffraction analysis. In addition, the anti-inflammatory activities of all the isolates were evaluated. The results indicated that compound 1 can significantly down-regulate the protein expression of iNOS and COX-2 at 20 μM in LPS- stimulated RAW264.7 cells.

Parallel Synthesis of Aurones Using a Homogeneous Scavenger

The ability to synthesize arrays of related compounds quickly and with good purity has become critical for a rapid exploration of their properties for biological or material applications. While a number of methods have been developed to enable this combinatorial synthesis, the existing options were not readily appliable to the synthesis of aurones using the simple Knoevenagel condensation approach. In order to avoid the time, expense, and lowered yields associated with flash column chromatography, we developed a scavenging approach for their synthesis. This method uses an excess of aldehyde to ensure complete conversion to aurones, followed by selective removal of the remaining aldehyde using a simple, inexpensive scavenger – isoniazid – and subsequent extraction with dilute acid, to produce the desired compounds with good purity under operationally simple conditions. This approach is expected to be applicable to many other reactions involving aldehydes as one of the reactants.

Bioactive Aurones, Indanones, and Other Hemiindigoid Scaffolds: Medicinal Chemistry and Photopharmacology Perspectives

Hemiindigoids comprise a range of natural and synthetic scaffolds that share the same aromatic hydrocarbon backbone as well as promising biological and optical properties. The encouraging therapeutic potential of these scaffolds has been unraveled by many studies over the past years and uncovered representants with inspiring pharmacophoric features such as the acetylcholinesterase inhibitor donezepil and the tubulin polymerization inhibitor indanocine. In this review, we summarize the last advances in the medicinal potential of hemiindigoids, with a special attention to molecular design, structure-activity relationship, ligand-target interactions, and mechanistic explanations covering their effects. As their strong fluorogenic potential and photoswitch behavior recently started to be highlighted and explored in biology, giving rise to the development of novel fluorescent probes and photopharmacological agents, we also discuss these properties in a medicinal chemistry perspective.

Aurone-derived 1,2,3-triazoles as potential fluorescence molecules in vitro

Aurones are a class of naturally occurring compounds with fluorescent derivatives. Here we show a newly synthesized derivative of aurones containing a 1,2,3-triazole which is fluorescent in aqueous environments and has potential to be used as a probe in vitro.

Aurones: A Golden Resource for Active Compounds

Deemed as poorly represented in nature, aurones have been often overlooked by researchers compared to other members of the flavonoid superfamily. However, over the past two decades, they have been reassessed by the scientific community, who are increasingly appreciating their ability to modulate several biological pathways. This review summarizes the recent literature on this class of compounds, which has been analyzed from both a chemical and a functional point of view. Original articles, reviews and editorials featured in Pubmed and Scifinder over the last twenty years have been taken into account to provide the readers with a view of the chemical strategies to obtain them, their functional properties, and their potential of technological use. The resulting comprehensive picture aims at raising the awareness of these natural derivatives as effective drug candidates, fostering the development of novel synthetic analogues.

Recent advances on synthesis and biological activities of aurones

Aurones are naturally occurring structural isomerides of flavones that have diverse bioactivities including antiviral, antibacterial, antifungal, anti-inflammatory, antitumor, antimalarial, antioxidant, neuropharmacological activities and so on. They constitute an important class of pharmacologically active scaffolds that exhibit multiple biological activities via diverse mechanisms. This review article provides an update on the recent advances (2013-2020.4) in the synthesis and biological activities of these derivatives. In the cases where sufficient information is available, some important structure-activity relationships (SAR) of their biological activities were presented, and on the strength of our expertise in medicinal chemistry and careful analysis of the recent literature, for the potential of aurones as medicinal drugs is proposed.

An acidic polysaccharide (AGC3) isolated from North American ginseng (Panax quinquefolius) suspension culture as a potential immunomodulatory nutraceutical

Polysaccharides isolated from Panax quinquefolius roots are widely used as nutraceuticals due to their immunomodulatory properties. Despite their popularity, several challenges exist in isolating ginseng root polysaccharides such as batch-to-batch structural inconsistencies and bacterial endotoxin contamination. A plant tissue culture-based platform offers a potential solution to isolate natural polysaccharide fractions with consistent chemical characteristics and reduced endotoxin content. In this study, an acidic polysaccharide fraction (AGC3) with immunomodulatory properties was isolated from Panax quinquefolius suspension cultures. The heterogeneous fraction (molecular weight: 4.81 and 32.14 kDa), purified by anion exchange chromatography, was predominantly composed of galactose (>60%) along with the presence of rhamnose, arabinose, glucose, glucuronic acid and galacturonic acid. The major glycosidic linkages were found to be t-Galp (47.7%), 4-Galp (15.6%), 2,4-Rhap (8.1%), 6-Galp (8.1%) and 4-GalAp (6.8%). Structural analyses indicated the presence of a pectic rhamnogalacturonan I polysaccharide in AGC3. AGC3 significantly (p < 0.05) stimulated RAW 264.7 murine macrophage cells and primary murine splenocytes by enhancing the production of several immunomodulatory mediators such as IL-6, TNF-α, GM-CSF and MCP-1. The results also indicated the putative roles of NF-κB (p65/RelA) and MAPK (p38) signaling pathways in the immunostimulatory response. Additionally, AGC3 induced murine splenocyte proliferation, another major indicator of immunostimulation. Overall, AGC3 has the potential to be used as an immunostimulatory nutraceutical.

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American ginseng suspension culture as source of natural bioactive polysaccharides.

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Acidic polysaccharide, AGC3 displayed potent immunostimulatory properties.

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Putative mechanism of action includes NF-κB (p65/RelA) and MAPK (p38) pathways.

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AGC3 predominantly composed of RGI-type pectins.

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Potential nutraceutical that can be used as an exogenous immunomodulator.

Anti-neuroinflammatory triterpenoids from the seeds of Quercus serrata Thunb

The seeds of Quercus serrata Thunb. (acorns) have been served as a healthy food in Asia. In this study, five previously undescribed triterpenoids, along with nineteen known triterpenoids were isolated from acorns. Their structures were identified on account of spectroscopic analysis and GC-MS analysis after acid hydrolysis. Meanwhile, the inhibitory effects on nitric oxide (NO) production induced by lipopolysaccharide (LPS) in microglia cells (BV-2) of the identified triterpenoids were evaluated. All these compounds revealed overt anti-neuroinflammatory activity expect for 7. Compounds 1, 16 and 17 had potent inhibitory effects on protein and mRNA expression of iNOS and COX-2 in LPS-induced BV-2 cells. Bioactive triterpenoids 1, 2, 16 and 17 could block LPS-induced NF-κB nuclear translocation. This study suggested that acorns could be served as natural healthy product against neuroinflammatory-associated diseases, such as Alzheimer's disease.

Propacin, a coumarinolignoid isolated from durian, inhibits the lipopolysaccharide-induced inflammatory response in macrophages through the MAPK and NF-κB pathways

Durian, known as the king of fruits, is rich in nutrients and bioactive phytochemicals.

An update on benzofuran inhibitors: a patent review

Introduction: Benzofuran is a fundamental unit in numerous bioactive heterocycles. They have attracted chemists and medical researchers due to their broad range of biological activity, where some of them possess unique anticancer, antitubercular, antidiabetic, anti-Alzheimer and anti-inflammatory properties. The benzofuran nucleus is present in a huge number of bioactive natural and synthetic compounds. Benzofuran derivatives have potent applications in pharmaceuticals, agriculture, and polymers. The recent developments considering the biological activities of benzofuran compounds are reported. They have a vital role as pronounced inhibitors against a number of diseases, viruses, fungus, microbes, and enzymes. Areas covered: This review covers the recent developments of biological activities of benzofurans during the period 2014-2019. The covered areas here comprised antimicrobial, anti-inflammatory, antitumor, antitubercular, antidiabetic, anti-Alzheimer, antioxidant, antiviral, vasorelaxant, anti-osteoporotic and enzyme inhibitory activities. Expert opinion: In addition to the already commercialized 34 benzofurans-based drugs in the market, this chapter outlines several potent benzofuran derivatives that may be useful as potential pro-drugs. It is also focused on providing details of SAR and the effect of certain functional groups on the activity of the benzofuran compounds. The presence of -OH, -OMe, sulfonamide, or halogen contributed greatly to increasing the therapeutic activities comparing with reference drugs.

Panax quinquefolius (North American ginseng) cell suspension culture as a source of bioactive polysaccharides: Immunostimulatory activity and characterization of a neutral polysaccharide AGC1

In this study, we propose the use of a plant tissue culture-based system for the production of polysaccharides with consistent chemical characteristics and reduced endotoxin content. Polysaccharides were isolated from suspension cultures of Panax quinquefolius (American ginseng), a widely used medicinal herb. A neutral fraction, AGC1, purified by anion exchange and size exclusion chromatography, displayed immunostimulatory activity in vitro and ex vivo. AGC1 (average molecular weight: 5.2kDa) was predominantly composed of galactose (>60%) along with the presence of several other neutral sugars such as arabinose, xylose, glucose, mannose and rhamnose in minor amounts. The major glycosidic linkages were found to be 3-Galp (48.5%), 3,6-Galp (10.2%), t-Galp (5.2%), 6-Galp (4.4%), 4-Glcp (5.7%), 4-Arap/5-Araf (4.0%) and t-Araf (4.5%). AGC1 significantly (p<0.05) stimulated the expression of a range of proinflammatory mediators in RAW 264.7 murine macrophages such as IL-6, TNF-α, MCP-1 and GM-CSF. Additionally, AGC1 treatment of RAW 264.7 cells stimulated NOS2 gene expression, leading to increased levels of iNOS and downstream NO. Consistent with this, AGC1 was able to act as an immunostimulant in primary murine splenocytes, enhancing cell proliferation, as well as NO and TNF-α production. Our results also indicate the partial role of NF-κB pathway in the immunostimulatory response.

Isolation, structure elucidation, and immunostimulatory activity of polysaccharide fractions from Boswellia carterii frankincense resin

Frankincense has a long history in religious, cultural, and medicinal use. In this study polysaccharides were extracted from frankincense from Boswellia carterii. The polysaccharides were purified by anion exchange chromatography on a DEAE-Sepharose Fast Flow 16/10 FPLC column. Six fractions were obtained and the three most active immunomodulatory fractions were further purified by size exclusion chromatography on a Superdex-200 column. The composition showed the monosaccharides present were predominantly galactose, arabinose, and glucuronic acid along with small amounts of rhamnose and glucose. The monosaccharide composition and glycosyl linkage analysis revealed the polysaccharides belong to the type II arabinogalactans. Fourier-transform infrared spectroscopy and bicinchoninic acid assay showed that the amount of protein in the samples was <1 wt%. One-dimensional ¹H NMR were consistent with high molecular weight compounds. The monosaccharides were primarily in the β conformation. The three fractions exhibited an immunostimulatory effect on RAW 264.7 murine macrophage cells. The most active immunostimulatory fraction FA2, stimulated a range of pro-inflammatory mediators including iNOS, NO, TNF-α, and IL-6 in RAW 264.7 cells. The fractions were effective in proliferating primary murine splenocytes. The results indicate that the polysaccharides isolated from frankincense have the potential to be used as an immunological stimulant or nutraceutical.

Screening for active constituents in Turkish galls against ulcerative colitis by mass spectrometry guided preparative chromatography strategy: in silico, in vitro and in vivo study

Turkish galls have been reported to exhibit remedial effects in ulcerative colitis (UC). However, the active constituents of Turkish galls for the treatment of UC remain unclear. The objective of this study was to screen for anti-inflammatory active constituents and clarify their associated molecular mechanisms. Therefore, systems pharmacology was developed to predict the relationship between constituents and the corresponding targets as well as pathways. In addition, mass spectrometry-guided preparative chromatography technique was used for preparing constituents to evaluate the anti-inflammatory activities and the therapeutic efficacy against UC. In silico, active constituents exhibited a remedial effect on UC possibly by regulating multiple pathways and attacking multiple targets, of which those involved mainly in the NF-κB pathway were selected for verification. In vitro, 5 categories of constituents were screened as active constituents by comparing the cytotoxicity and detecting the level of the pro-inflammatory factors of 9 category constituents. In vivo, dextran sulfate sodium (DSS)-induced UC was significantly ameliorated in active constituents-fed mice. The results indicated that the active fraction comprising methyl gallate, digallic acid, di-O-galloyl-β-d-glucose, and tri-O-galloyl-β-d-glucose primarily contributed to the treatment of UC. Moreover, active fraction could also inhibit the phosphorylation level of IKKβ, thus inhibiting the downstream NF-κB signaling pathway. The approach developed in this study not only clarifies the anti-inflammation effect of Turkish galls but also provides a beneficial reference for the discovery of the base material and functional mechanism of this herbal medicine.

The Protection of Midazolam Against Immune Mediated Liver Injury Induced by Lipopolysaccharide and Galactosamine in Mice

Objectives: Liver macrophages agitated by Lipopolysaccharide (LPS) can enhance immuno-inflammatory responses in the liver which mediate liver injury and result in dysfunction. Midazolam has been reported to have inhibitory effects on activated immunity and escalated inflammation, however, what the effects of midazolam on the liver injury caused by excessive immuno-inflammatory response in sepsis, and what influence it will exert on inflamed liver macrophages need to be elucidated.

Methods: In the present study, LPS and galactosamine-induced acute liver injury mice were used to observe the effect of midazolam in vivo. LPS-stimulated bone marrow cells were used to evaluate the influence of midazolam on monocytes in vitro.

Results: Midazolam prevented liver tissue injury and decreased serum alanine transaminase (ALT) level in LPS plus galactosamine treated mice. Mechanistically, midazolam suppressed tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) produced by LPS stimulated liver macrophages in vivo and bone marrow monocytes in vitro, and reduced the expression of major histocompatibility complex class II (MHC II), cluster of differentiation 40 and 86 (CD40 and CD86) on the cell surface. These results could be reversed by PK-11195, a peripheral benzodiazepine receptor (PBR) blocker.

Conclusion: Midazolam can prevent liver from LPS-induced immune mediated liver injury by inhibiting inflammation and immune activation in liver macrophages.