Heme oxygenase 1 mediates anti-inflammatory effects of 2',4',6'-tris(methoxymethoxy) chalcone

In silico screening of chalcone derivatives as promising EGFR-TK inhibitors for the clinical treatment of cancer

Epidermal growth factor receptor (EGFR) promotes tumorigenic characteristics and activates cancer-associated signaling pathways such as Wnt/-catenin, transforming growth factor (TGF-β), and phosphoinositide-3-kinase (PI3K). Several inhibitors have been reported to suppress the activity of EGFR and are being used in cancer treatment. However, patients in the malignant stage of cancer show resistance to those inhibitors, opening a wide space for research to discover novel inhibitors. Therefore, we carried out machine learning and virtual screening to discover novel inhibitors with high affinity against EGFR-TK. Initially, a library of 2640 chalcones were screened out using a machine-learning model developed based on the random forest algorithm, exhibiting high sensitivity and a Receiver Operating Characteristic curve (ROC area) of 0.99. Furthermore, out of the initial 2640 screened compounds, 412 compounds exhibiting potential activity are subjected to evaluation for drug-likeness properties through different filters: Blood-brain barrier penetration, Lipinski's rule, CMC-50 like rule, Veber rule, and Ghose filter, alongside Cell Line Cytotoxicity Prediction. A total of 30 compounds that successfully pass through all these filters are selected for molecular docking. Of these, 6 compounds display substantial binding affinity and closer interaction with the conserved catalytic residues of the target EGFR-TK compared to the reference molecule (erlotinib). Furthermore, molecular dynamics simulation studies were conducted on four compounds (CID-375861, CID-375862, CID-23636403, and CID-259166) to confirm the stability of the docked complexes over a 100 ns simulation trajectory. Additionally, the binding free energy calculations by MMPBSA reveal that these four chalcone compounds exhibit strong affinity towards the EGFR-TK enzyme, with binding free energies of - 65.421 kJ/mol, - 94.266 kJ/mol, - 80.044 kJ/mol, and - 79.734 kJ/mol, respectively. The findings from this investigation highlight a set of promising chalcone compounds that have the potential to be developed into effective drugs for the treatment of various cancers. Further research and development on these compounds could pave the way for novel therapeutic interventions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03858-8.

Highlights on Steroidal Arylidene Derivatives as a Source of Pharmacologically Active Compounds: A Review

Steroids constitute a unique class of chemical compounds, playing an important role in physiopathological processes, and have high pharmacological interest. Additionally, steroids have been associated with a relatively low toxicity and high bioavailability. Nowadays, multiple steroidal derivatives are clinically available for the treatment of numerous diseases. Moreover, different structural modifications on their skeleton have been explored, aiming to develop compounds with new and improved pharmacological properties. Thus, steroidal arylidene derivatives emerged as a relevant example of these modifications. This family of compounds has been mainly described as 17β-hydroxysteroid dehydrogenase type 1 and aromatase inhibitors, as well as neuroprotective and anticancer agents. Besides, due to their straightforward preparation and intrinsic chemical reactivity, steroidal arylidene derivatives are important synthetic intermediates for the preparation of other compounds, particularly bearing heterocyclic systems. In fact, starting from arylidenesteroids, it was possible to develop bioactive steroidal pyrazolines, pyrazoles, pyrimidines, pyridines, spiro-pyrrolidines, amongst others. Most of these products have also been studied as anti-inflammatory and anticancer agents, as well as 5α-reductase and aromatase inhibitors. This work aims to provide a comprehensive overview of steroidal arylidene derivatives described in the literature, highlighting their bioactivities and importance as synthetic intermediates for other pharmacologically active compounds.

Discovery and Development of Inflammatory Inhibitors from 2-Phenylchromonone (Flavone) Scaffolds

Flavonoids are compounds based on a 2-phenylchromonone scaffold. Flavonoids can be divided into flavonoids, flavonols, dihydroflavones, anthocyanins, chalcones and diflavones according to the oxidation degree of the central tricarbonyl chain, the connection position of B-ring (2-or 3-position), and whether the tricarbonyl chain forms a ring or not. There are a variety of biological activities about flavonoids, such as anti-inflammatory activity, anti-oxidation and anti-tumor activity, and the antiinflammatory activity is apparent. This paper reviews the anti-inflammatory activities and mechanisms of flavonoids and their derivatives reported in China and abroad from 2011 till date (2011-2020), in order to find a good drug scaffold for the study of anti-inflammatory activities.

Crystal structure and Hirshfeld surface analysis of (E)-2-(2,4,6-tri-methyl-benzyl-idene)-3,4-di-hydro-naphthalen-1(2H)-one

A novel chalcone, C20H20O, derived from benzyl-idene-tetra-lone, was synthesized via Claissen-Schmidt condensation between tetra-lone and 2,4,6-tri-methyl-benzaldehyde. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds, producing R 2 2(20) and R 2 4(12) ring motifs. In addition, weak C-H⋯π and π-stacking inter-actions are observed. The inter-molecular inter-actions were investigated using Hirshfeld surface analysis and two-dimensional fingerprint plots, revealing that the most important contributions for the crystal packing are from H⋯H (66.0%), H⋯C/ C⋯H (22.3%), H⋯O/O⋯H (9.3%), and C⋯C (2.4%) inter-actions. Shape-index plots show π-π stacking inter-actions and the curvedness plots show flat surface patches characteristic of planar stacking.

Biological Evaluation and Molecular Dynamics Simulation of Chalcone Derivatives as Epidermal Growth Factor-Tyrosine Kinase Inhibitors

Targeted cancer therapy has become a high potential cancer treatment. Epidermal growth factor receptor (EGFR), which plays an important role in cell signaling, enhanced cell survival and proliferation, has been suggested as molecular target for the development of novel cancer therapeutics. In this study, a series of chalcone derivatives was screened by in vitro cytotoxicity against the wild type (A431 and A549) and mutant EGFR (H1975 and H1650) cancer cell lines, and, subsequently, tested for EGFR-tyrosine kinase (TK) inhibition. From the experimental screening, all chalcones seemed to be more active against the A431 than the A549 cell line, with chalcones 1c, 2a, 3e, 4e, and 4t showing a more than 50% inhibitory activity against the EGFR-TK activity and a high cytotoxicity with IC₅₀ values of < 10 µM against A431 cells. Moreover, these five chalcones showed more potent on H1975 (T790M/L858R mutation) than H1650 (exon 19 deletion E746-A750) cell lines. Only three chalcones (1c, 2a and 3e) had an inhibitory activity against EGFR-TK with a relative inhibition percentage that was close to the approved drug, erlotinib. Molecular dynamics studies on their complexes with EGFR-TK domain in aqueous solution affirmed that they were well-occupied within the ATP binding site and strongly interacted with seven hydrophobic residues, including the important hinge region residue M793. From the above information, as well as ADMET (absorption, distribution, metabolism, excretion, and toxicity) properties, all three chalcones could serve as lead compounds for the development of EGFR-TK inhibitors.

Crystal structure and Hirshfeld surface analysis of (E)-1-(3,5-di-chloro-2-hy-droxy-phen-yl)-3-(5-methyl-furan-2-yl)prop-2-en-1-one

The title chalcone derivative, C14H10Cl2O3, is almost planar, with a dihedral angle of 7.0 (2) ° between the 3,5-di-chloro-2-hy-droxy-phenyl and 5-methyl-furan rings. There is an intra-molecular O-H⋯O hydrogen bond present forming an S(6) ring motif. In the crystal, mol-ecules are linked by bifurcated C-H/H⋯O hydrogen bonds, enclosing an R 1 2(6) ring motif, forming a 21 helix propagating along the b-axis direction. The inter-molecular inter-actions were qu-anti-fied using Hirshfeld surface analysis.

Synthesis of novel 4'-acylamino modified 21E-benzylidene steroidal derivatives and their cytotoxic activities

A series of 4'-acylamino modified Δ^1,4-pregnadien-21E-benzylidene-3,20-dione derivatives (6a-v) was synthesized from the commercially available progesterone (1). These title compounds were evaluated for their toxicity against brine shrimp (Artemia salina) and cytotoxic activities against two human cancer cell lines (HeLa and MCF-7). The results revealed that compound 6f exhibited promising in vitro cytotoxic activity to the two cancer cell lines and the nature of acylamino functional group in the benzylidene moiety had a significant influence on cytotoxicity.

Chalcone: A Privileged Structure in Medicinal Chemistry

Privileged structures have been widely used as an effective template in medicinal chemistry for drug discovery. Chalcone is a common simple scaffold found in many naturally occurring compounds. Many chalcone derivatives have also been prepared due to their convenient synthesis. These natural products and synthetic compounds have shown numerous interesting biological activities with clinical potentials against various diseases. This review aims to highlight the recent evidence of chalcone as a privileged scaffold in medicinal chemistry. Multiple aspects of chalcone will be summarized herein, including the isolation of novel chalcone derivatives, the development of new synthetic methodologies, the evaluation of their biological properties, and the exploration of the mechanisms of action as well as target identification. This review is expected to be a comprehensive, authoritative, and critical review of the chalcone template to the chemistry community.

Immunosuppressive Effects of Natural α,β-Unsaturated Carbonyl-Based Compounds, and Their Analogs and Derivatives, on Immune Cells: A Review

The immune system is complex and pervasive as it functions to prevent or limit infections in the human body. In a healthy organism, the immune system and the redox balance of immune cells maintain homeostasis within the body. The failure to maintain the balance may lead to impaired immune response and either over activity or abnormally low activity of the immune cells resulting in autoimmune or immune deficiency diseases. Compounds containing α,β-unsaturated carbonyl-based moieties are often reactive. The reactivity of these groups is responsible for their diverse pharmacological activities, and the most important and widely studied include the natural compounds curcumin, chalcone, and zerumbone. Numerous studies have revealed the mainly immunosuppressive and anti-inflammatory activities of the aforesaid compounds. This review highlights the specific immunosuppressive effects of these natural α,β-unsaturated carbonyl-based compounds, and their analogs and derivatives on different types of immune cells of the innate (granulocytes, monocytes, macrophages, and dendritic cells) and adaptive (T cells, B cells, and natural killer cells) immune systems. The inhibitory effects of these compounds have been comprehensively studied on neutrophils, monocytes and macrophages but their effects on T cells, B cells, natural killer cells, and dendritic cells have not been well investigated. It is of paramount importance to continue generating experimental data on the mechanisms of action of α,β-unsaturated carbonyl-based compounds on immune cells to provide useful information for ensuing research to discover new immunomodulating agents.

Anti-inflammatory effects of trans-1,3-diphenyl-2,3-epoxypropane-1-one in zebrafish embryos in vivo model

In this study, trans-1,3-diphenyl-2,3-epoxypropane-1-one (DPEP) was evaluated for its anti-inflammatory activity in lipopolysaccharide (LPS)-stimulated zebrafish embryos. In the present study, DPEP exhibited potential protective effect in the zebrafish embryos as confirmed by survival rate. DPEP acts as an effective agent against reactive oxygen species (ROS) formation induced by LPS. Moreover, DPEP effectively inhibited LPS-induced nitric oxide (NO) production in zebrafish embryos. In addition, DPEP significantly reduced the expression of inducible NOS (iNOS) and cycloxygenase 2 (COX-2), which generate NO as a key mediator of inflammation in a concentration-dependent manner. According to these results, DPEP could be considered an effective anti-inflammatory agent, which might be further developed as a functional ingredient. This is the first report of the anti-inflammatory activity of DPEP in the LPS-stimulated zebrafish model.

Butein inhibits metastatic behavior in mouse melanoma cells through VEGF expression and translation-dependent signaling pathway regulation

Background

Melanoma is an aggressive skin cancer and a predominant cause of skin cancer-related deaths. A previous study has demonstrated the ability of butein to inhibit tumor proliferation and invasion. However, the anti-metastatic mechanisms and in vivo effects of butein have not been fully elucidated.

Methods

MTT cell viability assays were used to evaluate the antitumor effects of butein in vitro. Cytotoxic effects of butein were measured by lactate dehydrogenase assay. Anti-migratory effects of butein were evaluated by two-dimensional scratch and transwell migration assays. Signaling transduction and VEGF-releasing assays were measured by Western blotting and ELISA. We also conducted an experimental analysis of the metastatic potential of tumor cells injected into the tail vein of C57BL/6 mice.

Results

We first demonstrated the effect of butein on cell viability at non-cytotoxic concentrations (1, 3, and 10 μM). In vitro, butein was found to inhibit the migration of B16F10 cells in a concentration-dependent manner using transwell and scratch assays. Butein had a dose-dependent effect on focal adhesion kinase, Akt, and ERK phosphorylation in B16F10 cells. Butein efficiently inhibited the mTOR/p70S6K translational inhibition machinery and decreased the production of VEGF in B16F10 cells. Furthermore, the in vivo antitumor effects of butein were demonstrated using a pulmonary metastasis model.

Conclusion

The results of the present study indicate the potential utility of butein in the treatment of melanoma.

Synthesis and cytotoxic evaluation of alkoxylated chalcones

A series of chalcones a1–20 bearing a 4-OMe groups on the A-ring were initially synthesized and their anticancer activities towards HepG2 cells evaluated. Subsequently, a series of chalcones b1–42 bearing methoxy groups at the 2' and 6'-positions of the B-ring were synthesized and their anticancer activities towards five human cancer cell lines (HepG2, HeLa, MCF-7, A549 and SW1990) and two non-tumoral human cell lines evaluated. The results showed that six compounds (b6, b8, b11, b16, b18, b22, b23 and b29) displayed promising activities, with compounds b22 and b29 in particular showing higher levels of activity than etoposide against all five cancer cell lines. Compound b29 showed a promising SI value compared with both HMLE and L02 (2.1–6.5 fold in HMLE and > 33 > 103.1 fold in L02, respectively).

Chalcones derivatives as potent Cell division cycle 25B phosphatase inhibitors

To discover novel cell division cycle 25 (CDC25) B inhibitors and elucidate the mechanisms of inhibition in cancer cells. Nineteen 2'-hydroxy-4'-isoprenyloxychalcone derivatives (a-s) were evaluated the inhibition CDC25B activity. The enzymatic activities of the CDC25B catalytic domain were determined by monitoring the dephosphorylation of OMFP. Cell growth inhibition was detected by MTT assay. The results showed that sixteen compounds significantly inhibited cycle 25B phosphatase in vitro. Among, three compounds k, r and s had the best inhibition activity and significantly inhibited CDC25B with inhibition rates against CDC25B of 99.95%, 99.75%, and 97.77%, respectively, which is similar to the reference drugs Na3VO4 (98%). Cytotoxic activity assays showed compounds k and r are the potent against HCT116, HeLa, and A549 cells, moreover, compound k delayed the potent tumor inhibitory activity in a colo205 xenograft model in vivo.

Fermented wheat powder induces the antioxidant and detoxifying system in primary rat hepatocytes

Many plants exhibit antioxidant properties which may be useful in the prevention of oxidative stress reactions, such as those mediated by the formation of free radical species in different pathological situations. In recent years a number of studies have shown that whole grain products in particular have strong antioxidant activity. Primary cultures of rat hepatocytes were used to investigate whether and how a fermented powder of wheat (Lisosan G) is able to modulate antioxidant and detoxifying enzymes, and whether or not it can activate Nrf2 transcription factor or inhibit NF-kB activation. All of the antioxidant and detoxifying enzymes studied were significantly up-regulated by 0.7 mg/ml Lisosan G treatment. In particular,

NAD(P)H

quinone oxidoreductase and heme oxygenase-1 were induced, although to different degrees, at the transcriptional, protein and/or activity levels by the treatment. As for the Nrf2 transcription factor, a partial translocation of its protein from the cytosol to the nucleus after 1 h of Lisosan G treatment was revealed by immunoblotting. Lisosan G was also observed to decrease H2O2-induced toxicity Taken together, these results show that this powder of wheat is an effective inducer of ARE/Nrf2-regulated antioxidant and detoxifying genes and has the potential to inhibit the translocation of NF-kB into the nucleus.

Synthesis and evaluation of chalcone analogues based pyrimidines as angiotensin converting enzyme inhibitors

Hypertension is a widespread and frequently progressive ailment that imparts a foremost threat for cardiovascular and renal disorders. Mammoth efforts are needed for the synthesis of innovative antihypertensive agents to combat this lethal disease. Chalcones have shown antihypertensive activity through inhibition of Angiotensin Converting Enzyme (ACE). Hence, a series of chalcone analogues is synthesized and used as precursor for the synthesis of novel series of pyrimidines. Precursor chalcones were prepared by reacting aldehydes and ketones in presence of sodium hydroxide followed by synthesis of corresponding pyrimidines by reaction with urea in presence of potassium hydroxide. Both groups were then evaluated for their effects on ACE. The results depicted that pyrimidines were more active than chalcones with methoxy (C5 and P5) substitution showing best results to inhibit ACE. Given that chalcone analogues and pyrimidines show a potential as the angiotensin converting enzyme inhibitors.

Synthesis and cytotoxicity of some novel 21E-benzylidene steroidal derivatives

A series of novel derivatives of 21E-benzylidene-pregn-1,4-diene-3,20-dione 7a-g and 21E-benzylidene-4-chloro-pregn-1,4-diene-3,20-dione 8a-g was synthesized from the commercially available progesterone. These title compounds were evaluated for their cytotoxic activity against brine shrimp (Artemia salina) and murine Lewis lung carcinoma cells (LLC). It was found that compounds 7a-g exhibited stronger activities than 8a-g against the brine shrimps, and some of the tested compounds possessed weak inhibition of LLC cells.

Ethyl pyruvate induces heme oxygenase-1 through p38 mitogen-activated protein kinase activation by depletion of glutathione in RAW 264.7 cells and improves survival in septic animals

AIMS

We investigated the molecular mechanism by which ethyl pyruvate (EP) induces heme oxygenase-1 (HO-1) in RAW 264.7 cells and its effect on survival rate in cecal ligation and puncture (CLP)-induced wild-type (WT) and HO-1 knockout (HO-1(-/-)) septic mice.

RESULTS

EP induced HO-1 in a dose- and time-dependent manner, which was mediated through p38 mitogen-activated protein kinase (MAPK) and NF-E2-related factor 2 (Nrf2) signaling cascade in RAW 264.7 cells. EP significantly inhibited the lipopolysaccharide (LPS)-stimulated inducible nitric oxide synthase (iNOS) expression and high-mobility group box 1 (HMGB1) release in RAW 264.7 cells. The inhibitory effect of EP on LPS-stimulated iNOS expression and HMGB1 release was reversed by transfection with siHO-1RNA in RAW 264.7 cells, but EP failed to reduce them in HO-1(-/-) peritoneal macrophages treated with LPS. Moreover, treatment of cells with glutathione ethyl ester (GSH-Et), SB203580 (p38 MAPK inhibitor), siHO-1, or p38-siRNA transfection inhibited anti-inflammatory effect of EP. Interestingly, both HO-1 induction and phosphorylation of p38 by EP were reversed by GSH-Et, and antioxidant redox element-luciferase activity by EP was reversed by SB203580 in LPS-activated cells. EP increased survival and decreased serum HMGB1 in CLP-WT mice, whereas it did not increase survival or decrease circulating HMGB1 in HO-1(-/-) CLP-mice.

INNOVATION AND CONCLUSION

Our work provides new insights into the understanding the molecular mechanism by showing that EP induces HO-1 through a p38 MAPK- and NRF2-dependent pathway by decreasing GSH cellular levels. We conclude that EP inhibits proinflammatory response to LPS in macrophages and increases survival in CLP-induced septic mice by upregulation of HO-1 level, in which p38 MAPK and Nrf2 play an important role.

Antirestenosis effect of butein in the neointima formation progression

The development of restenosis involves migration and hyperproliferation of vascular smooth muscle cells (VSMCs). Platelet-derived growth factor (PDGF) is one of the major factors. Butein modulates inflammatory pathways and affects the proliferation and invasion of the tumor. We investigated the hypothesis that butein might prevent the restenosis process via a similar pathway. Our results demonstrated that butein inhibited PDGF-induced VSMC proliferation and migration as determined by BrdU proliferation and two-dimensional migration scratch assay. Butein also concentration-dependently repressed PDGF-induced phosphorylation of PDGF-receptor β, mitogen-activated protein kinases, phosphoinositide 3-kinase/Akt, and phopholipase Cγ/c-Src in VSMCs. In addition, in vivo results showed that butein attenuated neointima formation in balloon-injured rat carotid arteries. These results indicate that butein may inhibit PDGF-induced VSMC proliferation and migration, resulting in attenuation of neointima formation after percutaneous transluminal coronary angioplasty. Our study demonstrates for the first time that systemic administration of butein is able to reduce neointima formation after vascular injury.

The effect of oxidized low density lipoprotein (oxLDL)-induced heme oxygenase-1 on LPS-induced inflammation in RAW 264.7 macrophage cells

Macrophages take up oxidized low density lipoprotein (oxLDL) after being exposed to it in the blood vessels. oxLDL transforms macrophages into foam cells, which are a hallmark of atherosclerosis. The effects that oxLDL have on the inflammatory responses of foam cells are not clear. Here, we investigated how oxLDL modulates lipopolysaccharide (LPS)-induced inflammatory mediators in RAW 264.7 murine macrophages. Our results showed that oxLDL dramatically induced HO-1 expression, but did not increase pro-inflammatory mediators such as interleukin-1β, tumor necrosis factor-α, iNOS, and monocyte chemoattractant protein (MCP)-1. In RAW 264.7 macrophages, oxLDL markedly inhibited LPS-induced inflammatory mediators such as inducible nitric oxide synthase (iNOS), IL-1β, IL-6, granulocyte macrophage colony-stimulating factor and stromal cell-derived factor-1. Interestingly, however, the down-regulation of HO-1 by siRNA did not recover the inhibition of LPS-induced expression and/or the secretion of inflammatory mediators. oxLDL blocked LPS-induced NF-κB nuclear translocation by inhibiting inhibitory κB (IκB) degradation. Taken together, our results suggest that oxLDL could modulate LPS-induced inflammatory responses by inhibiting NF-κB signaling independently of HO-1 expression.

(E)-1-(Furan-2-yl)-3-(2,4,5-trimeth-oxy-phen-yl)prop-2-en-1-one

In the title chalcone derivative, C(16)H(16)O(5), the dihedral angle between the furan and benzene rings is 2.06 (17)°. The two meth-oxy groups at the ortho and para positions are essentially coplanar with the benzene ring [C-O-C-C angles = -1.0 (5) and 178.5 (3)°], whereas the third one at the meta position is slightly twisted [C-O-C-C = 9.6 (5)°]. In the crystal, weak C-H⋯O inter-actions link the mol-ecules into a sheet parallel to ([Formula: see text]02). An inter-molecular π-π inter-action between the furan and benzene rings is present [centroid-centroid distance = 3.772 (2) Å]. A short C⋯C contact [3.173 (5) Å] is also observed between neighbouring furan rings.

Anti-breast cancer activity of heteroaryl chalcone derivatives

In an attempt to develop effective anticancer therapeutics, a new series of heteroaryl chalcone compounds were designed, synthesized, and examined for their antiproliferative effects on two breast cancer cell lines and one matching non-cancer breast cell line. The structure-activity relationship (SAR) analysis suggested that the compounds derived from thiophene chalcones (6-17) exhibited generally better antiproliferative activity than those derived from bioisoteric replacement of furan chalcones (18-29) on MDA-MB231 breast cancer cells. In contrast, the compounds derived from furan chalcones showed generally better antiproliferative activity on MDA-MB468 breast cancer cells. Among 24 compounds examined, compounds 21 and 23 showed significantly improved antiproliferative activity against MDA-MB231 and MDA-MB468 cancer cells. However, compound 23 ((E)-1-(4-chlorophenyl)-3-(5-(4-methoxyphenyl)furan-2-yl)prop-2-en-1-one) is considered to be most desirable among this series, since its antiproliferative activity was 3 to 7-fold higher on cancer than non-cancer cells. Compound 23 showed not only more effective activity than the widely prescribed cisplatin on cancer cells, but it also showed differential antiproliferative activity against cancer cells, a property that is not shown with cisplatin. If this property shown in cell culture stands in vivo test, compound 23 can be an effective and safe anticancer drug.

Echinacea alkamides prevent lipopolysaccharide/D-galactosamine-induced acute hepatic injury through JNK pathway-mediated HO-1 expression

This study aimed to shed light on the anti-inflammatory and hepatoprotective effect of the major alkamides dodeca-2E,4E,8Z,10Z(E)-tetraenoic acid isobutylamides (Alk-8/9), isolated from Echinacea purpurea roots, against acute fulminant hepatitis induced by lipopolysaccharide/D-galactosamine (LPS/D-GalN) in mice. The results show that Alk-8/9 dose-dependently induced heme oxygenase (HO)-1 protein expression in LPS-stimulated murine macrophages that was likely regulated by the JNK-mediated pathway through increasing SAPK/JNK phosphorylation, c-jun protein expression, and phosphorylation, and transcription factor AP-1 binding consensus DNA activity. The HO-1 inhibitor or CO scavenger significantly reversed the inhibitory effect of Alk-8/9 on TNF-α expression, whereas N-acetyl-L-cysteine was observed to reduce Alk-8/9-induced HO-1 expression in LPS-treated macrophages. Furthermore, Alk-8/9 markedly induced c-jun and HO-1 protein expression and suppressed serum aminotransferase activities, TNF-α expression, and hepatocyte damage in liver tissues of LPS/d-GalN-treated mice. This paper suggests a new application of Echinacea, a top-selling herbal supplement, as a hepatoprotective agent.

Synthesis and antimicrobial studies of chalconyl pregnenolones

An efficient and facile synthesis of 17-chalconyl derivatives of pregnenolone and their evaluation as antimicrobial agents against various microbial strains is reported. The scheme involves the transformation of the starting pregnenolone acetate into pregnenolone, conversion of pregnenolone to the corresponding chalcone derivatives. The compounds 3a-3j showed significant antimicrobial activity against all microbial strains used for testing.

2',4',6'-Tris(methoxymethoxy) chalcone (TMMC) attenuates the severity of cerulein-induced acute pancreatitis and associated lung injury

Acute pancreatitis (AP) is an inflammatory disease involving acinar cell injury and rapid production and release of inflammatory cytokines, which play a dominant role in local pancreatic inflammation and systemic complications. 2',4',6'-Tris (methoxymethoxy) chalcone (TMMC), a synthetic chalcone derivative, displays potent anti-inflammatory effects. Therefore, we aimed to investigate whether TMMC might affect the severity of AP and pancreatitis-associated lung injury in mice. We used the cerulein hyperstimulation model of AP. Severity of pancreatitis was determined in cerulein-injected mice by histological analysis and neutrophil sequestration. The pretreatment of mice with TMMC reduced the severity of AP and pancreatitis-associated lung injury and inhibited several biochemical parameters (activity of amylase, lipase, trypsin, trypsinogen, and myeloperoxidase and production of proinflammatory cytokines). In addition, TMMC inhibited pancreatic acinar cell death and production of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 by inhibiting NF-κB and extracellular signal-regulated protein kinase 1/2 (ERK1/2) activation. Neutralizing antibodies for TNF-α, IL-1β, and IL-6 inhibited cerulein-induced cell death in isolated pancreatic acinar cells. Moreover, pharmacological blockade of NF-κB/ERK1/2 reduced acinar cell death and production of TNF-α, IL-1β, and IL-6 in isolated pancreatic acinar cells. In addition, posttreatment of mice with TMMC showed reduced severity of AP and lung injury. Our results suggest that TMMC may reduce the complications associated with pancreatitis.

(E)-1-(2-Hy-droxy-phen-yl)-3-(2,4,5-trimeth-oxy-phen-yl)prop-2-en-1-one

In the title chalcone derivative, C₁₈H₁₈O₅, the dihedral angle between the hy­droxy-substituted benzene ring and the trimeth­oxy-substituted benzene ring is 16.3 (1)°. The three meth­oxy groups are essentially coplanar with the benzene ring to which they are attached, with an r.m.s. deviation of 0.0208 Å. An intra­molecular O—H⋯O hydrogen bond generates an S(6) ring motif. In the crystal, weak C—H⋯O inter­actions link mol­ecules into helical chains along the b axis. These chains are connected into sheets parallel to the bc plane by further weak C—H⋯O inter­actions.

2',4',6'-Tris(methoxymethoxy) chalcone induces apoptosis by enhancing Fas-ligand in activated hepatic stellate cells

Suppression of hepatic stellate cell (HSC) activation and proliferation, and induction of apoptosis in activated HSCs have been proposed as therapeutic strategies for the treatment and prevention of the hepatic fibrosis. We previously showed that 2',4',6'-tris(methoxymethoxy) chalcone (TMMC), a synthesized chalcone derivative, inhibits platelet-derived growth factor-induced HSC proliferation at 5-20 μM. Here, we showed that TMMC induces apoptosis in activated HSCs at higher concentrations (30-50 μM), but is not cytotoxic to primary hepatocytes. Moreover, TMMC induces hyperacetylation of histone by inhibiting histone deacetylase (HDAC) in activated HSCs. Interestingly, TMMC treatment remarkably increased Fas-ligand (FasL) mRNA expression in a dose-dependent manner. Cycloheximide treatment reversed the induction of TMMC on apoptosis, indicating that de novo protein synthesis was required for TMMC-induced apoptosis in activated HSCs. In addition, FasL synthesis by TMMC is closely associated with maximal procaspase-3 proteolytic processing. In vivo, TMMC reduced activated HSCs in CCl(4)-intoxicated rats during liver injury recovery, as demonstrated by α-smooth muscle actin expression in rat liver. TMMC treatment also resulted in apoptosis, as demonstrated by cleavage of poly(ADP-ribose) polymerase in rat liver. In conclusion, TMMC may have therapeutic potential by inducing HSC apoptosis for the treatment of hepatic fibrosis.

Dietary chalcones with chemopreventive and chemotherapeutic potential

Chalcones are absorbed in the daily diet and appear to be promising cancer chemopreventive agents. Chalcones represent an important group of the polyphenolic family, which includes a large number of naturally occurring molecules. This family possesses an interesting spectrum of biological activities, including antioxidative, antibacterial, anti-inflammatory, anticancer, cytotoxic, and immunosuppressive potential. Compounds of this family have been shown to interfere with each step of carcinogenesis, including initiation, promotion and progression. Moreover, numerous compounds from the family of dietary chalcones appear to show activity against cancer cells, suggesting that these molecules or their derivatives may be considered as potential anticancer drugs. This review will focus primarily on prominent members of the chalcone family with an 1,3-diphenyl-2-propenon core structure. Specifically, the inhibitory effects of these compounds on the different steps of carcinogenesis that reveal interesting chemopreventive and chemotherapeutic potential will be discussed.

2'-Methoxy-4'6'-bis(methoxymethoxy)chalcone inhibits nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 macrophages

Chalcones have anti-inflammatory properties. Here, we synthesized 2'-methoxy-4'6'-bis(methoxymethoxy)chalcone (MBMC) and examined its anti-inflammatory effects. MBMC inhibited nitric oxide production and inducible nitric oxide synthase (iNOS) expression in lipopolysaccharide (LPS)-stimulated RAW 264.7 murine macrophages. MBMC also blocked LPS-induced activation of nuclear factor kappaB (NF-kappaB), p38 mitogen-activated protein kinase and c-Jun N-terminal kinase (JNK). MBMC increased haem oxygenase 1 (HO-1) expression and nuclear accumulation of nuclear factor-erythroid 2-related factor 2 (Nrf2), an essential transcription factor for HO-1 induction. Treatment with tin protoporphyrin, a selective inhibitor of HO-1, reversed the inhibition of nitric oxide production by MBMC, suggesting that HO-1 induction mediates MBMC-mediated suppression of nitric oxide production. MBMC treatment rapidly and transiently decreased glutathione (GSH) levels, and treatment with GSH-Et (cell permeable form of GSH) or N-acetylcysteine (precursor of GSH) counteracted the HO-1 and Nrf2 expression elicited by MBMC, indicating that MBMC-induced HO-1 expression requires transient depletion of GSH. In summary, MBMC inhibits LPS-stimulated nitric oxide production via down-regulation of inflammatory pathways (NF-kappaB, p38 and JNK) and induction of the protective enzyme, HO-1.

Comparative metabolomics approach coupled with cell- and gene-based assays for species classification and anti-inflammatory bioactivity validation of Echinacea plants

Echinacea preparations were the top-selling herbal supplements or medicines in the past decade; however, there is still frequent misidentification or substitution of the Echinacea plant species in the commercial Echinacea products with not well chemically defined compositions in a specific preparation. In this report, a comparative metabolomics study, integrating supercritical fluid extraction, gas chromatography/mass spectrometry and data mining, demonstrates that the three most used medicinal Echinacea species, Echinacea purpurea, E. pallida, and E. angustifolia, can be easily classified by the distribution and relative content of metabolites. A mitogen-induced murine skin inflammation study suggested that alkamides were the active anti-inflammatory components present in Echinacea plants. Mixed alkamides and the major component, dodeca-2E,4E,8Z,10Z(E)-tetraenoic acid isobutylamides, were then isolated from E. purpurea root extracts for further bioactivity elucidation. In macrophages, the alkamides significantly inhibited cyclooxygenase 2 (COX-2) activity and the lipopolysaccharide-induced expression of COX-2, inducible nitric oxide synthase and specific cytokines or chemokines [i.e., TNF-α, interleukin (IL)-1α, IL-6, MCP-1, MIP-1β] but elevated heme oxygenase-1 protein expression. Cichoric acid, however, exhibited little or no effect. The results of high-performance liquid chromatography/electron spray ionization/mass spectrometry metabolite profiling of alkamides and phenolic compounds in E. purpurea roots showed that specific phytocompound (i.e., alkamides, cichoric acid and rutin) contents were subject to change under certain post-harvest or abiotic treatment. This study provides new insight in using the emerging metabolomics approach coupled with bioactivity assays for medicinal/nutritional plant species classification, quality control and the identification of novel botanical agents for inflammatory disorders.

Natural and synthetic 2'-hydroxy-chalcones and aurones: synthesis, characterization and evaluation of the antioxidant and soybean lipoxygenase inhibitory activity

A series of 2'-hydroxy-chalcones and their oxidative cyclization products, aurones, have been synthesized and tested for their antioxidant and lipoxygenase inhibitory activity. The natural product aureusidin (31) was synthesized in high yield by a new approach. An extensive structure-relationship study was performed and revealed that several chalcones and aurones possess an appealing pharmacological profile combining high antioxidant and lipid peroxidation activity with potent soybean LOX inhibition.

Anti-NF-kappaB and anti-inflammatory activities of synthetic isothiocyanates: effect of chemical structures and cellular signaling

Many cancer chemopreventive agents have been associated with lower cancer risk by suppressing nuclear factor-kappaB (NF-kappaB) signaling pathways, which subsequently leads to attenuated pro-inflammatory mediators and activities. Of the natural compounds, the isothiocyanates (ITCs) found in cruciferous vegetables have received particular attention because of their potential anti-cancer effects. However, limited studies regarding the influence of ITCs structure on NF-kappaB transactivation and anti-inflammatory action are reported. In the present study, the anti-inflammatory potential of ten structurally divergent synthetic ITCs were evaluated in HT-29-N9 human colon cancer cells and RAW 264.7 murine macrophages. The effect of ITCs on the basal transcriptional activation of NF-kappaB and the inflammatory response to bacterial lipopolysaccharide (LPS) were assessed. The synthetic ITC analogs suppressed NF-kappaB-mediated pro-inflammatory gene transcription. Among the ITC analogs, tetrahydrofurfuryl isothiocyanate, methyl-3-isothiocyanatopropionate, 3-morpholinopropyl isothiocyanate and 3,4-methyelendioxybenzyl isothiocyanate showed stronger NF-kappaB inhibition as compared to the parent compound, phenylethyl isothiocyanate (PEITC). Molecular analysis revealed that several of the pro-inflammatory mediators and cytokines (iNOS, COX-2, IL-1beta, IL-6 and TNF-alpha) were reduced by ITCs, and correlated with the downregulation of NF-kappaB signaling pathways. Immunoblotting showed that ITCs suppressed LPS-induced phosphorylation and degradation of IkappaB alpha and decreased nuclear translocation of p65. In parallel, ITCs suppressed the phosphorylation of IkappaB kinase alpha/beta (IKKalpha/beta). Taken together, our findings provide the possibility that synthetic ITC analogs might have promising cancer chemopreventive potential, based on their stronger anti-NF-kappaB and anti-inflammatory activities, than the natural ITCs.

Heme oxygenase-1 mediates the anti-allergic actions of quercetin in rodent mast cells

OBJECTIVE AND DESIGN

We investigated the involvement of heme oxygenase (HO)-1 in the anti-allergic action of quercetin against degranulation of rat basophilic leukemia (RBL-2H3) cells, rat peritoneal mast cells, and mouse bone marrow-derived mast cells.

METHODS

The strength of allergic reaction was evaluated by the extent of degranulation in mast cells sensitized with various stimulants. The levels of HO-1, HO-2, and nuclear factor erythroid 2-related factor 2 (Nrf2) expressions were determined by quantitative RT-PCR, western blotting, or immunocytochemistry.

RESULTS

Heme oxygenase activity was upregulated after short exposure to quercetin, followed by the induction of HO-1 expression after long exposure to quercetin. The inhibition of degranulation by quercetin was reversed using tin protoporphyrin IX (SnPP), an HO-1 inhibitor. HO-1 metabolites, bilirubin and CO, led to inhibit degranulation, and quercetin translocated Nrf2 from cytoplasm into nucleus in RBL-2H3 cells.

CONCLUSION

These results strongly suggest that quercetin exerted anti-allergic actions via activation of Nrf2-HO-1 pathway.