Viscolin, a new chalcone from Viscum coloratum, inhibits human neutrophil superoxide anion and elastase release via a cAMP-dependent pathway

Viscolin-mediated antiapoptotic and neuroprotective effects in cortical neurons exposed to oxygen-glucose deprivation and rats subjected to transient focal cerebral ischemia

OBJECTIVE

Previously, we have successfully purified and synthesized viscolin, an agent derived from Viscum coloratum extract, which has shown significant potential in the treatment of stroke. Our study aimed to evaluate the neuroprotective effects of viscolin.

METHODS

We first assessed the cytotoxicity of viscolin on primary neuronal cultures and determined its antioxidant and radical scavenging properties. Subsequently, we identified the optimal dose-response of viscolin in protecting against glutamate-induced neurotoxicity.

RESULTS

Our results demonstrated that viscolin at a concentration of 10 μM effectively reduced neuronal cell death up to 6 hours after glutamate-induced neurotoxicity. Additionally, we investigated the therapeutic window of opportunity and the potential of viscolin in preventing necrotic and apoptotic damage in cultured neurons exposed to oxygen glucose deprivation-induced neurotoxicity. Our findings showed that viscolin treatment significantly reduced DNA breakage, prevented the release of cytochrome c from mitochondria to cytosol, increased the expression of anti-apoptotic protein Bcl-2, decreased the expression of pro-apoptotic protein Bax, and reduced the number of TUNEL-positive cells. Additionally, our in vivo investigation demonstrated a reduction in brain infarction following middle cerebral artery occlusion.

CONCLUSION

Viscolin has potential utility as a therapeutic agent in the treatment of stroke.

Ribociclib leverages phosphodiesterase 4 inhibition in the treatment of neutrophilic inflammation and acute respiratory distress syndrome

INTRODUCTION

Overwhelming neutrophil activation and oxidative stress significantly contribute to acute respiratory distress syndrome (ARDS) pathogenesis. However, the potential of repurposing ribociclib, a cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor used clinically in cancer treatment, for treating neutrophilic ARDS remains uncertain. This study illustrated the ability and underlying mechanism of ribociclib for treating ARDS and neutrophilic inflammation.

METHODS

Primary human neutrophils were used to determine the therapeutic effects of ribociclib on respiratory bursts, chemotactic responses, and inflammatory signaling. In vitro and silico analyses were performed to determine the underlying molecular mechanisms. The potential of ribociclib repurposing was evaluated using an in vivo ARDS model in lipopolysaccharide (LPS)-primed mice.

RESULTS

We found that treatment using ribociclib markedly limited overabundant oxidative stress (reactive oxygen species [ROS]) production and chemotactic responses (integrin levels and adhesion) in activated human neutrophils. Ribociclib was also shown to act as a selective inhibitor of phosphodiesterase 4 (PDE4), thereby promoting the cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) pathway, leading to the inhibition of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) phosphorylation, and calcium influx. Notably, prophylactic administration and post-treatment with ribociclib ameliorated neutrophil infiltration, lung inflammation, accumulation of oxidative stress, pulmonary destruction, and mortality in mice with LPS-induced ARDS.

CONCLUSION

We demonstrated for the first time that ribociclib serves as a novel PDE4 inhibitor for treating neutrophilic inflammation and ARDS. The repurposing ribociclib and targeting neutrophilic PDE4 offer a potential off-label alternative for treating lung lesions and other inflammatory conditions.

Drug repurposing of cyclin-dependent kinase inhibitors for neutrophilic acute respiratory distress syndrome and psoriasis

BACKGROUND

Neutrophilic inflammation, characterized by dysregulated neutrophil activation, triggers a variety of inflammatory responses such as chemotactic infiltration, oxidative bursts, degranulation, neutrophil extracellular traps (NETs) formation, and delayed turnover. This type of inflammation is pivotal in the pathogenesis of acute respiratory distress syndrome (ARDS) and psoriasis. Despite current treatments, managing neutrophil-associated inflammatory symptoms remains a significant challenge.

AIM OF REVIEW

This review emphasizes the role of cyclin-dependent kinases (CDKs) in neutrophil activation and inflammation. It aims to highlight the therapeutic potential of repurposing CDK inhibitors to manage neutrophilic inflammation, particularly in ARDS and psoriasis. Additionally, it discusses the necessary precautions for the clinical application of these inhibitors due to potential off-target effects and the need for dose optimization.

KEY SCIENTIFIC CONCEPTS OF REVIEW

CDKs regulate key neutrophilic functions, including chemotactic responses, degranulation, NET formation, and apoptosis. Repurposing CDK inhibitors, originally developed for cancer treatment, shows promise in controlling neutrophilic inflammation. Clinical anticancer drugs, palbociclib and ribociclib, have demonstrated efficacy in treating neutrophilic ARDS and psoriasis by targeting off-label pathways, phosphoinositide 3-kinase (PI3K) and phosphodiesterase 4 (PDE4), respectively. While CDK inhibitors offer promising therapeutic benefits, their clinical repurposing requires careful consideration of off-target effects and dose optimization. Further exploration and clinical trials are necessary to ensure their safety and efficacy in treating inflammatory conditions.

Effects of Viscum coloratum (Kom.) Nakai on collagen-induced rheumatoid arthritis

ETHNOPHARMACOLOGICAL RELEVANCE

Viscum coloratum (Kom.) Nakai has been traditionally used in China for nearly a thousand years to treat rheumatic diseases. However, its efficacy and mechanisms in treating rheumatoid arthritis (RA) have not been demonstrated.

AIM OF THE STUDY

To investigate the anti-arthritic effects and molecular mechanisms of Viscum coloratum (Kom.) Nakai on collagen-induced arthritic mice through network pharmacology technology and experimental validation.

MATERIALS AND METHODS

First, the main ingredients of the extract of Viscum coloratum (Kom.) Nakai (EVC) were identified through chemical composition characterization using Ultra Performance Liquid Chromatography Tandem Mass Spectrometry (UPLC-MS). Then, the collagen-induced arthritis (CIA) model was established in DBA/1 J mice and the ameliorative effects of EVC on the progression of CIA mice were evaluated by oral treatment with different doses of the EVC for 28 days. After that, cytokine antibody microarray assay was used to detect the levels of multiple inflammation-related cytokines and chemokines in each group, and performed Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genome (KEGG) enrichment analysis. Subsequently, the potential target for the effective chemical components of EVC in treating RA was identified using various databases. Additionally, a drug-disease target protein-protein interaction network (PPI) was conducted using Cytoscape for visualization and clustering, while GO and KEGG enrichment analyses were performed with the Metascape database. Finally, identified phenotypes and targets by network pharmacology analysis were experimentally validated in vivo.

RESULTS

Treatment with EVC significantly suppressed the severity of CIA with a dramatic reduction of paw swelling, arthritis index, levels of IgGs (IgG, IgG1, IgG2a, and IgG2b), multi-inflammation-related cytokines and chemokines on the progression of CIA. Histopathological examinations showed EVC could markedly inhibit inflammatory cell infiltration, tartrate-resistant acid phosphatase (TRAP) activity of osteoclast, and bone destruction. Furthermore, GO and KEGG enrichment analyses revealed that EVC could ameliorate RA by inhibiting osteoclast differentiation and regulating multiple signaling pathways including Osteoclast differentiation, IL-17, and TNF. PPI network analysis demonstrated that AKT1, MMP9, MAPK3, and other genes were highly related to EVC in treating RA. Finally, we proved that EVC could inhibit the expression of NFTAc1, MMP9, Cathepsin K, and AKT which were closely related to osteoclast activity.

CONCLUSIONS

EVC could treat RA through multiple components, multiple targets, and multiple pathways. The present study demonstrated the therapeutic efficacy of EVC and its molecular mechanisms in treating RA, indicating that it would be a potent candidate as a novel botanical drug for further investigation.

Polyphenols: immunonutrients tipping the balance of immunometabolism in chronic diseases

Mounting evidence progressively appreciates the vital interplay between immunity and metabolism in a wide array of immunometabolic chronic disorders, both autoimmune and non-autoimmune mediated. The immune system regulates the functioning of cellular metabolism within organs like the brain, pancreas and/or adipose tissue by sensing and adapting to fluctuations in the microenvironment's nutrients, thereby reshaping metabolic pathways that greatly impact a pro- or anti-inflammatory immunophenotype. While it is agreed that the immune system relies on an adequate nutritional status to function properly, we are only just starting to understand how the supply of single or combined nutrients, all of them termed immunonutrients, can steer immune cells towards a less inflamed, tolerogenic immunophenotype. Polyphenols, a class of secondary metabolites abundant in Mediterranean foods, are pharmacologically active natural products with outstanding immunomodulatory actions. Upon binding to a range of receptors highly expressed in immune cells (e.g. AhR, RAR, RLR), they act in immunometabolic pathways through a mitochondria-centered multi-modal approach. First, polyphenols activate nutrient sensing via stress-response pathways, essential for immune responses. Second, they regulate mammalian target of rapamycin (mTOR)/AMP-activated protein kinase (AMPK) balance in immune cells and are well-tolerated caloric restriction mimetics. Third, polyphenols interfere with the assembly of NLR family pyrin domain containing 3 (NLRP3) in endoplasmic reticulum-mitochondria contact sites, inhibiting its activation while improving mitochondrial biogenesis and autophagosome-lysosome fusion. Finally, polyphenols impact chromatin remodeling and coordinates both epigenetic and metabolic reprogramming. This work moves beyond the well-documented antioxidant properties of polyphenols, offering new insights into the multifaceted nature of these compounds. It proposes a mechanistical appraisal on the regulatory pathways through which polyphenols modulate the immune response, thereby alleviating chronic low-grade inflammation. Furthermore, it draws parallels between pharmacological interventions and polyphenol-based immunonutrition in their modes of immunomodulation across a wide spectrum of socioeconomically impactful immunometabolic diseases such as Multiple Sclerosis, Diabetes (type 1 and 2) or even Alzheimer's disease. Lastly, it discusses the existing challenges that thwart the translation of polyphenols-based immunonutritional interventions into long-term clinical studies. Overcoming these limitations will undoubtedly pave the way for improving precision nutrition protocols and provide personalized guidance on tailored polyphenol-based immunonutrition plans.

Biological activities of Viscum tuberculatum aqueous leaf extract

CONTENT

Plant-based natural products have served as sources of remedies against pathogenic microorganisms. Although the biological activities of Viscum (Santalaceae) species are widely recognized, there is no scientific evidence for Viscum tuberculatum A. Rich. in Ethiopia.

OBJECTIVE

To investigate the antimicrobial, acute toxicity, anti-inflammatory properties and phytochemical constituents of an aqueous extract of V. tuberculatum from Ethiopia.

MATERIALS AND METHODS

The antibacterial activity of the aqueous leaf extract of V. tuberculatum was tested against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of this extract were determined using the broth macrodilution method. The acute toxicity and anti-inflammatory effects of the extract were investigated using standard procedures on female and male white albino mice, aged 8 and 10 weeks, respectively. The phytochemical constituents of V. tuberculatum were determined using LC-MS QTOF.

RESULTS

The MIC and MBC values against S. aureus were found to be 6.25 and 100 mg/mL. The LD₅₀ value was more than 2000 mg/kg body weight of the mouse. The 400 mg/kg dose exerts 87% inhibition after 5 h of carrageenan injection. Twenty-five different metabolites, mainly flavonoids, phenolic acids and alkaloids, were identified.

CONCLUSIONS

These findings demonstrate the potential antimicrobial and anti-inflammatory potential of the aqueous extract of V. tuberculatum.

Apremilast ameliorates acute respiratory distress syndrome by inhibiting neutrophil-induced oxidative stress

BACKGROUND

The pathogenesis of acute respiratory distress syndrome (ARDS) is attributed to the dysregulation of oxidative stress and neutrophil recruitment. We aimed to investigate the anti-inflammatory effects of apremilast on human neutrophils and assess its efficacy for treating ARDS.

METHODS

We analysed superoxide anion generation, integrin expression, and adhesion in activated human neutrophils using spectrophotometry, flow cytometry, and immunofluorescence microscopy. Phosphorylation of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) was determined using immunoblotting. A murine lipopolysaccharide (LPS)-induced ARDS model was used to evaluate the therapeutic effects of apremilast.

RESULTS

Apremilast significantly decreased superoxide anion production, reactive oxygen species (ROS) generation, cluster of differentiation (CD)11 b expression, and neutrophil adhesion in formyl-l-methionyl-l-leucyl-l-phenylalanine activated human neutrophils. Apremilast elevated cyclic 3',5'-adenosine monophosphate (cAMP) and protein kinase A (PKA) activity in activated neutrophils. It reduced cellular cAMP-specific phosphodiesterase (PDE) activity and selectively inhibited enzymatic PDE4 activity. The activated cAMP/PKA pathway suppressed the phosphorylation of ERK and JNK as well as Ca2+ mobilization in activated neutrophils. All inhibitory effects of apremilast on activated neutrophils were reversed by a PKA inhibitor. In vivo examinations indicated that apremilast alleviated lung neutrophil infiltration, myeloperoxidase (MPO) activity, pulmonary oedema, and alveolar damage in LPS-induced ARDS.

CONCLUSION

Apremilast inhibits inflammatory responses after neutrophil activation via cAMP/PKA-dependent inhibition of ERK and JNK activation. Our study revealed apremilast suppresses oxidative stress and chemotaxis by selectively inhibiting PDE4 in neutrophils and thus protects against endotoxin-induced ARDS in mice. Apremilast can be used as an alternative off-label drug in treating acute lung damage.

Comparative LC-LTQ-MS-MS Analysis of the Leaf Extracts of Lantana camara and Lantana montevidensis Growing in Egypt with Insights into Their Antioxidant, Anti-Inflammatory, and Cytotoxic Activities

Lantana camara L. and Lantana montevidensis Briq. (F. Verbenaceae) are invasive ornamental weeds native to the tropical regions of Africa and America. The leaves of both species have been traditionally used as infusions for treating fever, rheumatism, and cancer. LC-MS-MS-guided profiling of the methanolic extracts of the leaves of L. camara and L. montevidensis growing in Egypt led to the putative identification of 59 compounds belonging to terpenoids, flavonoids, iridoid glycosides, phenolic acids, and their derivatives. The in-vitro antioxidants and anti-inflammatory and anticancer activities of the two extracts were investigated. L. camara and L. montevidensis inhibited DPPH^• (IC₅₀ = 34.01 ± 1.32 and 47.43 ± 1.74 µg/mL), ABTS⁺ (IC₅₀ = 30.73 ± 1.42 and 40.37 ± 1.51 µg/mL), and superoxide anion (IC₅₀ = 1.57 ± 0.19 and 1.31 ± 0.14 μg/mL) free radicals. A potent anti-inflammatory effect was observed for both species through the inhibition of elastase release in fMLF/CB-induced human neutrophils (IC₅₀ = 2.40 ± 0.16 and 1.90 ± 0.07 μg/mL). The extracts showed significant cytotoxic activity against a panel of cancer cell lines with the most potent activity against Caco cells (IC₅₀ = 45.65 ± 1.64 and 40.67 ± 1.52 µg/mL for L. camara and L. montevidensis, respectively). Western blotting supported by FACS analysis revealed that the extracts inhibited cancer cell proliferation, reduced metastasis, and induced apoptosis resulting in cell cycle arrest. This was achieved via increasing mRNA and protein expressions of p53 and GSK-3β as well as decreasing the expression of PI3K, Akt, and cyclin D1.

Anti-Inflammatory and Antimicrobial Volatile Oils: Fennel and Cumin Inhibit Neutrophilic Inflammation via Regulating Calcium and MAPKs

Neutrophilic inflammatory diseases, such as chronic obstructive pulmonary disease (COPD), acute respiratory distress syndrome (ARDS), or psoriasis, exert a huge burden on the global health system due to the lack of safe and effective treatments. Volatile oils from terrestrial plants showed impressive therapeutic effects against disorders of the skin, digestive system, lungs, liver, metabolism, and nervous system. However, their effect on the immune system and neutrophil function is still elusive. Fennel, cumin, marjoram, lavender, caraway, and anise are the common nutraceuticals that are widely used in the Mediterranean diet. The volatile oils of these herbs were screened for various biological activities, including anti-inflammatory, anti-allergic, antimicrobial, and antiviral effects. Several oils showed anti-inflammatory and antimicrobial potential. Fennel (Foeniculum vulgare) and cumin (Cuminum cyminum) fruits' volatile oils significantly suppressed the activation of human neutrophils, including respiratory burst and the degranulation induced by formyl peptide receptor agonists fMLF/CB and MMK1 in the human neutrophils (IC₅₀, 3.8–17.2 µg/ml). The cytotoxic effect and free-radical scavenging effects (ABTS, DPPH) of these oils did not account for the observed effects. Both fennel and cumin volatile oils significantly shortened calcium influx recovery time and inhibited phosphorylation of mitogen-activated protein kinases (p38, JNK, and ERK) expression. The gas chromatography–mass spectrometry analysis of these oils revealed the presence of estragole and cuminaldehyde as the major components of fennel and cumin volatile oils, respectively. Our findings suggested that cumin and fennel, common in the Mediterranean diet, hold the potential to be applied for the treatment of neutrophilic inflammatory diseases.

Exploring the resources of the genus Viscum for potential therapeutic applications

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Viscum comprises approximately 100 species that are mainly distributed across Africa, Asia and Europe. The extracts and preparations of Viscum species are widely used as common complementary and alternative medicines in the treatment of rheumatism and cancer.

AIM OF THE REVIEW

This review aims to explore the medicinal properties of twelve species belonging to the genus Viscum for potential therapeutic applications.

MATERIALS AND METHODS

We collected online information (including PubMed, CNKI, Google Scholar, and Web of Science) from January 1915 to April 2021 and knowledge from classical books on Chinese herbal medicines available for 12 species of the genus Viscum, including Viscum coloratum (Kom.) Nakai, Viscum album L., Viscum articulatum Burm. f., Viscum liquidambaricola Hayata, Viscum ovalifolium DC., Viscum capitellatum Sm., Viscum cruciatum Sieber ex Boiss., Viscum nudum Danser, Viscum angulatum B.Heyne ex DC., Viscum tuberculatum A.Rich., Viscum multinerve Hayata, and Viscum diospyrosicola Hayata.

RESULTS

At least 250 different compounds have been reported across twelve Viscum species, including amino acid and peptides, alkaloids, phenolic acids, flavonoids, terpenoids, carbohydrates, fatty acids, lipids, and other types of compounds. In particular, for Viscum coloratum (Kom.) Nakai and Viscum album L., the plants, preparations, and bioactive components have been thoroughly reviewed. This has allowed to elucidate the role of active components, including lectins, viscotoxins, flavonoids, terpenoids, phenolic acids, and polysaccharides, in multiple bioactivities, such as anti-cancer, anti-rheumatism arthralgia, anti-inflammation, anti-cardiovascular diseases, enhancing immunity, and anti-chemotherapy side effects. We also evaluated quality control methods based on active compounds, in vivo exposure compounds, and discriminated chemical markers.

CONCLUSIONS

This is the first report to systematically review the pharmaceutical development history, chemical composition, clinical evidence, pharmacological activity, discriminated chemical markers, in vivo exposure, and quality control on twelve distinct species of Viscum plants with medicinal properties. The significant safety and efficacy, along with the minor side effects are constantly confirmed in clinics. The genus Viscum is thus an important medicinal resource that is worth exploring and developing in future pharmacological and chemical studies.

Secoiridoid Glucosides and Anti-Inflammatory Constituents from the Stem Bark of Fraxinus chinensis

Qin Pi (Fraxinus chinensis Roxb.) is commercially used in healthcare products for the improvement of intestinal function and gouty arthritis in many countries. Three new secoiridoid glucosides, (8E)-4''-O-methylligstroside (1), (8E)-4''-O-methyldemethylligstroside (2), and 3'',4''-di-O-methyl-demethyloleuropein (3), have been isolated from the stem bark of Fraxinus chinensis, together with 23 known compounds (4-26). The structures of the new compounds were established by spectroscopic analyses (1D, 2D NMR, IR, UV, and HRESIMS). Among the isolated compounds, (8E)-4''-O-methylligstroside (1), (8E)-4''-O-methyldemethylligstroside (2), 3'',4''-di-O-methyldemethyloleuropein (3), oleuropein (6), aesculetin (9), isoscopoletin (11), aesculetin dimethyl ester (12), fraxetin (14), tyrosol (21), 4-hydroxyphenethyl acetate (22), and (+)-pinoresinol (24) exhibited inhibition (IC50 ≤ 7.65 μg/mL) of superoxide anion generation by human neutrophils in response to formyl-L-methionyl-L-leuckyl-L-phenylalanine/cytochalasin B (fMLP/CB). Compounds 1, 9, 11, 14, 21, and 22 inhibited fMLP/CB-induced elastase release with IC50 ≤ 3.23 μg/mL. In addition, compounds 2, 9, 11, 14, and 21 showed potent inhibition with IC50 values ≤ 27.11 μM, against lipopolysaccharide (LPS)-induced nitric oxide (NO) generation. The well-known proinflammatory cytokines, tumor necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6), were also inhibited by compounds 1, 9, and 14. Compounds 1, 9, and 14 displayed an anti-inflammatory effect against NO, TNF-α, and IL-6 through the inhibition of activation of MAPKs and IκBα in LPS-activated macrophages. In addition, compounds 1, 9, and 14 stimulated anti-inflammatory M2 phenotype by elevating the expression of arginase 1 and Krüppel-like factor 4 (KLF4). The above results suggested that compounds 1, 9, and 14 could be considered as potential compounds for further development of NO production-targeted anti-inflammatory agents.

Anti-inflammatory, hepatoprotective and antioxidant activity of ellagitannin isolated from Melaleuca styphelioides

Ellagitannins have a marked antioxidant effect and can prevent liver injury induced by free radicals. An undescribed ellagitannin named styphelioidin was isolated from Melaleuca styphelioides Sm. The structure of styphelioidin was elucidated by using various spectroscopic methods. The hepatoprotective activity of styphelioidin (25, 50, and 100 μM) was tested using the CCl₄-challenged HepG2 cell model by measuring alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels in HepG2 cells treated with styphelioidin for 1 h followed by 40 mM CCl₄. Glutathione (GSH), superoxide dismutase activity (SOD) and lipid peroxidation (MDA) were evaluated to determine the mechanisms of the hepatoprotective activity. Styphelioidin significantly reduced the levels of ALT, AST, and MDA at all tested concentrations. Moreover, it conferred a marked increase in the GSH levels and the SOD activity compared to the CCl₄-treated groups. Styphelioidin also exerted DPPH· radical-scavenging effects with an IC₅₀ value of 3.67 μM. Results indicated the hepatoprotective therapeutic potential of styphelioidin comparable to silymarin. Moreover, anti-inflammatory activity was assessed and styphelioidin inhibited fMLF/CB-induced elastase release in human neutrophils with IC₅₀ 2.51 μM. Cell-free experiments with human neutrophil elastase indicated a direct enzymatic inhibitory effect of styphelioidin on the enzyme activity (IC₅₀ 2.58 μM). The potential of styphelioidin to interact with human neutrophil elastase binding sites was further confirmed by molecular docking of styphelioidin into human neutrophil elastase crystal structure using AutoDock 4.2. Styphelioidin represents a potent hepatoprotective and antioxidant agent with effects on ALT, AST, MDA, GSH, and SOD comparable to silymarin. The beneficial anti-elastase properties hold the potential for drug development against elastase-related inflammatory diseases. This study highlights a promising natural hepatoprotective and anti-inflammatory candidate derived from M. styphelioides.

Anti-inflammatory alkaloids from the root bark of Hernandia nymphaeifolia

Four undescribed alkaloids, 7-ethoxy-6-methoxy-2-methylisoquinolin-1(2H)-one, 7,8-dihydroxy-6-methoxy-2-methylisoquinolin-1(2H)-one, N-formylhernagine, and 5,6-dihydroxy-N-methylphthalimide, were obtained from the root bark of Hernanadia nymphaeifolia, along with fourteen known compounds. The structures of these compounds were determined through spectroscopic and MS analyses. 7,8-Dihydroxy-6-methoxy-2-methylisoquinolin-1(2H)-one, N-formylhernagine, 5,6-dihydroxy-N-methylphthalimide, oxohernagine, hernandonine, and N-trans-feruloylmethoxytyramine inhibited the superoxide anion (O₂^-) production (IC₅₀ values ≤ 6.23 μg/mL) by neutrophils stimulated with formyl-L-methionyl-L-leuckyl-L-phenyl-alanine/cytochalasin B (fMLP/CB). Furthermore, 7,8-dihydroxy-6-methoxy-2-methylisoquinolin-1(2H)-one, N-formylhernagine, 5,6-dihydroxy-N-methylphthalimide, oxohernagine, and N-trans-feruloylmethoxytyramine inhibited fMLP/CB-induced elastase release with IC₅₀ values ≤ 7.41 μg/mL. In addition, 7,8-dihydroxy-6-methoxy-2-methylisoquinolin-1(2H)-one, N-formylhernagine, oxohernagine, and N-trans-feruloylmethoxytyramine showed potent inhibition with IC₅₀ values ≤ 28.55 μM, against lipopolysaccharide (LPS)-induced nitric oxide (NO) generation.

Cytotoxic and anti-inflammatory effects of lignans and diterpenes from Cupressus macrocarpa

Cupressus macrocarpa is a windbreak tree and is reported to have various cytotoxic effects. A natural product study on the leaves of C. macrocarpa has yielded ten secondary metabolites, including three new diterpenoids (1-3), four known diterpenoids (4-7), and three known lignans (8-10). The structures of all isolated compounds were elucidated via the interpretation of spectroscopic methods, especially 2D NMR and mass analyses. In the cytotoxic assays, compounds 1-3 and 7-10 showed inhibition effect against HepG2, MDA-MB-231, and A549 cells with IC₅₀ values ranging from 0.004 to 19.9 μg/mL. Moreover, the anti-inflammatory assays revealed that (-)-matairesinol (8) had significant inhibitory activities on superoxide anion generation (IC₅₀ = 2.7 ± 0.3 μM) and elastase release (IC₅₀ = 6.6 ± 0.7 μM).

Resveratrol suppresses neutrophil activation via inhibition of Src family kinases to attenuate lung injury

The natural stilbenoid, Resveratrol (RSV; 3,5,4'-trihydroxystilbene) has been shown to have beneficial effects on inflammatory diseases as well as cancer, neurodegenerative diseases, and cardiovascular disorders. The underlying mechanism by which RSV affects neutrophil activation has yet to be fully elucidated. In this study, we tested the hypothesis that RSV modulates the inflammatory activities of formyl-Met-Leu-Phe-stimulated human neutrophils. We employed a well-established isolated-neutrophil model to investigate the effects of RSV on neutrophil functions and the underlying mechanism of signaling transduction. The lipopolysaccharide-induced ALI murine model was employed to evaluate the therapeutic effects of RSV. Experiment results demonstrate that RSV reduces respiratory burst, degranulation, integrin expression, and cell adhesion in activated neutrophils in dose-dependent manners. RSV inhibited phosphorylation of Src family kinases (SFKs) and reduced their enzymatic activities. Moreover, RSV and a selective inhibitor of SFKs (PP2) reduced the phosphorylation of Bruton's tyrosine kinase and Vav. There results indicated that the inhibitory effects of RSV are mediated through the inhibition of the SFKs-Btk-Vav pathway. This study also revealed that RSV attenuates endotoxin-induced lung injury. We surmise that the therapeutic effects of RSV on ALI may derive from its anti-neutrophilic inflammation function and free radical-scavenging effects.

Herbal compounds for rheumatoid arthritis: Literatures review and cheminformatics prediction

Rheumatoid arthritis (RA) is a systemic disease characterized by autoimmunity, joint inflammation, and cartilage destruction, which affects 0.5-1% of the population. Many compounds from herbal medicines show the potentials to treat RA. On this basis, the compounds with good pharmacokinetic behaviors and drug-likeness properties will be further studied and developed. Therefore, the herbal compounds with anti-RA activities were reviewed in this paper, and the cheminformatics tools were used to predict their drug-likeness properties and pharmacokinetic parameters. A total of 90 herbal compounds were analyzed, which were reported to be effective on RA models through anti-inflammation, chondroprotection, immunoregulation, antiangiogenesis, and antioxidation. Most of the herbal compounds have good drug-likeness properties. Most of the compounds can be an alternative and valuable source for anti-RA drug discovery.

Propofol inhibits endogenous formyl peptide-induced neutrophil activation and alleviates lung injury

Critically ill patients have a high risk of sepsis. Various studies have demonstrated that propofol has anti-inflammatory effects that may benefit critically ill patients who require anesthesia. However, the mechanism and therapeutic effect remain incompletely understood. Our previous data suggest that propofol can act as a formyl peptide receptor 1 (FPR1) antagonist. Here, we hypothesize that propofol mitigates sepsis-induced acute lung injury (ALI) by inhibiting mitochondria-derived N-formyl peptide-mediated neutrophil activation. Oxidative stress caused by activated neutrophils is involved in the pathogenesis of ALI. In human neutrophils, propofol competitively reduced the release of superoxide and associated reactive oxygen species induced by fMMYALF, a human mitochondria-derived N-formyl peptide, suggesting that propofol effectively suppresses neutrophilic oxidative stress. In addition, propofol significantly inhibited fMMYALF-induced elastase release, chemotaxis, calcium mobilization, and phosphorylation of protein kinase B and mitogen-activated protein kinases. These results indicate that propofol suppresses neutrophil activation by blocking the interaction between endogenous N-formyl peptide and its receptor, FPR1, thus inhibiting downstream signaling. Furthermore, propofol alleviated alveolar wall disruption, edematous changes, and neutrophil infiltration in lipopolysaccharide-induced ALI in mice. Noticeably, propofol improved the survival of sepsis mice. This study indicates that the anti-neutrophil effects of propofol may benefit critically ill septic patients.

New Anti-Inflammatory Aporphine and Lignan Derivatives from the Root Wood of Hernandia nymphaeifolia

A new aporphine, 3-hydroxyhernandonine (1) and a new lignin, 4′-O-demethyl-7-O-methyldehydropodophyllotoxin (2), have been isolated from the root wood of Hernanadia nymphaeifolia, together with thirteen known compounds (3–15). The structures of these compounds were determined through mass spectrometry (MS) and spectroscopic analyses. The known isolate, 2-O-methyl-7-oxolaetine (3), was first isolated from natural sources. Among the isolated compounds, 3-hydroxyhernandonine (1), 4′-O-demethyl-7-O-methyldehydropodophyllotoxin (2), hernandonine (4), oxohernangerine (5), and oxohernagine (6) displayed inhibition (IC₅₀ values ≤5.72 μg/mL) of superoxide anion production by human neutrophils in response to formyl-l-methionyl-l-leucyl-l-phenylalanine/cytochalasin B (fMLP/CB). In addition, 3-hydroxyhernandonine (1), 4′-O-demethyl-7-O-methyldehydropodophyllotoxin (2), oxohernangerine (5), and oxohernagine (6) suppressed fMLP/CB-induced elastase release with IC₅₀ values ≤5.40 μg/mL.

Cembranoid-Related Metabolites and Biological Activities from the Soft Coral Sinularia flexibilis

Five new cembranoid-related diterpenoids, namely, flexibilisins D and E (1 and 2), secoflexibilisolides A and B (3 and 4), and flexibilisolide H (5), along with nine known compounds (6–14), were isolated from the soft coral Sinularia flexibilis. Their structures were established by extensive spectral analysis. Compound 3 possesses an unusual skeleton that could be biogenetically derived from cembranoids. The cytotoxicity and anti-inflammatory activities of the isolates were investigated, and the results showed that dehydrosinulariolide (7) and 11-epi-sinulariolide acetate (8) exhibited cytotoxicity toward a limited panel of cancer cell lines and 14-deoxycrassin (9) displayed anti-inflammatory activity by inhibition of superoxide anion generation and elastase release in N-formyl-methionyl-leucyl-phenylalanine/cytochalasin B (fMLF/CB)-induced human neutrophils.

Isoflavones and anti-inflammatory constituents from the fruits of Psoralea corylifolia

The fruits of Psoralea corylifolia, known as Psoraleae Fructus (Buguzhi in Chinese), are traditionally used for the treatment of spermatorrhea, nephritis, asthma, pollakiuria, and various inflammatory diseases. Three previously undescribed isoflavone derivatives, 7-O-methylcorylifol A, 7-O-isoprenylcorylifol A, and 7-O-isoprenylneobavaisoflavone, have been isolated from the fruits of P. corylifolia, together with 9 known compounds. The structures of these compounds were determined through spectroscopic and MS analyses. Among the isolated compounds, 7-O-methylcorylifol A and psoralen exhibited potent inhibition (IC₅₀ values ≤ 10.89 μM) of superoxide anion generation by human neutrophils in response to N-formyl-L-methionyl-L-leucyl-L-phenylalanine/cytochalasin B (fMLP/CB). 7-O-Isoprenylcorylifol A, 7-O-isoprenylneobavaisoflavone, and 12,13-dihydro-12,13-epoxybakuchiol inhibited fMLP/CB-induced elastase release with IC₅₀ values ≤ 14.30 μM. In addition, 7-O-isoprenylcorylifol A, bakuchiol, 12,13-dihydro-12,13-epoxybakuchiol, and psoralidin showed potent inhibition with IC₅₀ values ≤ 36.65 μM, against lipopolysaccharide (LPS)-induced nitric oxide (NO) generation.

Anti-allergic Hydroxy Fatty Acids from Typhonium blumei Explored through ChemGPS-NP

Increasing prevalence of allergic diseases with an inadequate variety of treatment drives forward search for new alternative drugs. Fatty acids, abundant in nature, are regarded as important bioactive compounds and powerful nutrients playing an important role in lipid homeostasis and inflammation. Phytochemical study on Typhonium blumei Nicolson and Sivadasan (Araceae), a folk anti-cancer and anti-inflammatory medicine, yielded four oxygenated fatty acids, 12R-hydroxyoctadec-9Z,13E-dienoic acid methyl ester (1) and 10R-hydroxyoctadec-8E,12Z-dienoic acid methyl ester (2), 9R-hydroxy-10E-octadecenoic acid methyl ester (3), and 12R^*-hydroxy-10E-octadecenoic acid methyl ester (4). Isolated compounds were identified by spectroscopic methods along with GC-MS analysis. Isolated fatty acids together with a series of saturated, unsaturated and oxygenated fatty acids were evaluated for their anti-inflammatory and anti-allergic activities in vitro. Unsaturated (including docosahexaenoic and eicosapentaenoic acids) as well as hydroxylated unsaturated fatty acids exerted strong anti-inflammatory activity in superoxide anion generation (IC₅₀ 2.14-3.73 μM) and elastase release (IC₅₀ 1.26-4.57 μM) assays. On the other hand, in the anti-allergic assays, the unsaturated fatty acids were inactive, while hydroxylated fatty acids showed promising inhibitory activity in A23187- and antigen-induced degranulation assays (e.g., 9S-hydroxy-10E,12Z-octadecadienoic acid, IC₅₀ 92.4 and 49.7 μM, respectively). According to our results, the presence of a hydroxy group in the long chain did not influence the potent anti-inflammatory activity of free unsaturated acids. Nevertheless, hydroxylation of fatty acids (or their methyl esters) seems to be a key factor for the anti-allergic activity observed in the current study. Moreover, ChemGPS-NP was explored to predict the structure-activity relationship of fatty acids. The anti-allergic fatty acids formed different cluster distant from clinically used drugs. The bioactivity of T. blumei, which is historically utilized in folk medicine, might be related to the content of fatty acids and their metabolites.

Inflammation Modulatory Phorbol Esters from the Seeds of Aquilaria malaccensis

The tree Aquilaria malaccensis is a valuable source of agarwood, which is used in herbal medicinal preparations. Phytochemical research on A. malaccensis seeds has led to the isolation of four new phorbol esters (1-4), two known phorbol esters (5, isolated from Nature for the first time, and 6), and two known glycerides (7 and 8). The structures of these isolates were elucidated by means of spectroscopic data interpretation. The inflammation-modulatory activities of the isolates on elastase release and superoxide anion generation in human neutrophils were evaluated. Interestingly, phorbol esters 1, 5, and 6 showed potent inhibitory activity on elastase release in human neutrophils, with IC₅₀ values of 2.7, 0.8, and 2.1 μM, respectively. All isolated phorbol esters exerted enhancing activity on superoxide anion generation. The results indicated that phorbol esters may play a bilateral modulatory role in the processes of inflammation. In addition, the compounds were evaluated for their cytotoxic properties against HepG2 (hepatoma), MDA-MB-231 (breast), and A549 (lung) cancer cells, but all compounds were inactive for all cell lines used (IC₅₀ > 10 μM).

Dipeptide HCH6-1 inhibits neutrophil activation and protects against acute lung injury by blocking FPR1

Formyl peptide receptor 1 (FPR1) is an emerging therapeutic target for the discovery of drugs to treat neutrophilic inflammatory diseases. However, development of FPR1 antagonists for clinical use is still inadequate. The purpose of this study was to identify a synthetic dipeptide N-(N-benzoyl-L-tryptophanyl)-D-phenylanlanine methyl ester (HCH6-1) as a FPR1 inhibitor and to investigate its protective effects against acute lung injury (ALI). HCH6-1 inhibited superoxide anion generation, elastase release, and chemotaxis in human neutrophils specifically activated by formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLF), an FPR1 agonist. HCH6-1 produced right shifts in the concentration-response curves of fMLF, suggesting that HCH6-1 was a competitive antagonist of FPR1. Indeed, HCH6-1 bound to FPR1 in human neutrophils and neutrophil-like THP-1 as well as hFPR1-transfected HEK293 cells. Also, the FPR1 downstream signaling pathways were competitively inhibited by HCH6-1. Furthermore, HCH6-1 prevented pulmonary neutrophil infiltration and edema along with alveolar damage in LPS-induced ALI in mice. Our findings suggest that HCH6-1, a FPR1 antagonist, may have potential as a new therapeutic agent for treating FPR1-involved inflammatory lung diseases.

6-Hydroxy-5,7-dimethoxy-flavone suppresses the neutrophil respiratory burst via selective PDE4 inhibition to ameliorate acute lung injury

Over-activated neutrophils produce enormous oxidative stress and play a key role in the development of acute and chronic inflammatory diseases. 6-Hydroxy-5,7-dimethoxy-flavone (UFM24), a flavone isolated from the Annonaceae Uvaria flexuosa, showed inhibitory effects on human neutrophil activation and salutary effects on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. UFM24 potently inhibited superoxide anion (O₂^•-) generation, reactive oxidants, and CD11b expression, but not elastase release, in N-formyl-l-methionyl-l-leucyl-l-phenylalanine (fMLF)-activated human neutrophils. However, UFM24 failed to scavenge O₂^•- and inhibit the activity of subcellular NADPH oxidase. fMLF-induced phosphorylation of protein kinase B (Akt) was inhibited by UFM24. Noticeably, UFM24 increased cyclic adenosine monophosphate (cAMP) concentration and protein kinase (PK) A activity in activated human neutrophils. PKA inhibitors significantly reversed the inhibitory effects of UFM24, suggesting that the effects of UFM24 were through cAMP/PKA-dependent inhibition of Akt activation. Additionally, activity of cAMP-related phosphodiesterase (PDE)4, but not PDE3 or PDE7, was significantly reduced by UFM24. Furthermore, UFM24 attenuated neutrophil infiltration, myeloperoxidase activity, and pulmonary edema in LPS-induced ALI in mice. In conclusion, our data demonstrated that UFM24 inhibits oxidative burst in human neutrophils through inhibition of PDE4 activity. UFM24 also exhibited significant protection against endotoxin-induced ALI in mice. UFM24 has potential as an anti-inflammatory agent for treating neutrophilic lung damage.

Inhibition of Phosphodiesterase 5 and Increasing the Level of Cyclic Guanosine 3',5' Monophosphate by Hydroalcoholic Achillea wilhelmsii C. Koch Extract in Human Breast Cancer Cell Lines MCF-7 and MDA-Mb-468

This study aimed to investigate the effect of hydroalcoholic Achillea wilhelmsii C. Koch extract (HAWE) on phosphodiesterase 5 (PDE5) gene expression and cyclic guanosine 3',5' monophosphate (cGMP) signaling in the MCF-7 and MDA-Mb-468 cell lines. The effective dose (ED50) of HAWE was examined in both cell lines using a 3-(4,5-dimethylhiazol-2-yl)-2,5-diphenyltetrazolium bromide viability test, and the type of cell death was detected by flow cytometry. The expression of PDE5 and the concentration of cGMP were measured in a time-dependent manner in the ED50 by real-time polymerase chain reaction and a colorimetric assay, respectively. Treatment with HAWE showed 25 µg/mL to be the ED50 for both cell lines, and HAWE led to a reduction in the PDE5 messenger RNA expression. The intracellular cGMP increased in a time-dependent manner. The results showed that HAWE has an antiproliferative property in MCF-7 and MDA-Mb-468 cell lines through the cGMP pathway. Therefore, HAWE is a potential source to effectively isolate inhibitory PDE5.

Synthesis and biological evaluation of chalcone, dihydrochalcone, and 1,3-diarylpropane analogs as anti-inflammatory agents

Twenty-one chalcones were prepared via aldol condensation and subsequent reduction of these compound led to the corresponding dihydrochalcone and 1,3-diphenylpropane derivatives. The synthetic products were examined for their effects on NO inhibition in LPS-activated mouse peritoneal macrophages. Among the tested compounds, a 1,3-diarylpropane analog, 2-(3-(3,4-dimethoxyphenyl)propyl)-5-methoxyphenol (3p), displayed the most significant inhibitory effects against NO production. To investigate the mechanism of action, the effects of 3p on iNOS and COX-2 protein expression were studied by immunoblot. The results concluded that 3p is capable of inhibiting iNOS expression in LPS-induced RAW264.7 cells via attenuation of NF-κB signaling by ERK, p38, and JNK.

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.

Viscolin Inhibits In Vitro Smooth Muscle Cell Proliferation and Migration and Neointimal Hyperplasia In Vivo

Viscolin, an extract of Viscum coloratum, has anti-inflammatory and anti-proliferative properties against harmful stimuli. The aim of the study was to examine the anti-proliferative effects of viscolin on platelet derived growth factor-BB (PDGF)-treated human aortic smooth muscle cells (HASMCs) and identify the underlying mechanism responsible for these effects. Viscolin reduced the PDGF-BB-induced HASMC proliferation and migration in vitro; it also arrested HASMCs in the G0/G1 phase by decreasing the protein expression of Cyclin D1, CDK2, Cyclin E, CDK4, and p21^Cip1 as detected by Western blot analysis. These effects may be mediated by reduced PDGF-induced phosphorylation of ERK1/2, JNK, and P38, but not AKT as well as inhibition of PDGF-mediated nuclear factor (NF)-κB p65 and activator protein 1 (AP-1)/c-fos activation. Furthermore, viscolin pre-treatment significantly reduced neointimal hyperplasia of an endothelial-denuded femoral artery in vivo. Taken together, viscolin attenuated PDGF–BB-induced HASMC proliferation in vitro and reduced neointimal hyperplasia in vivo. Thus, viscolin may represent a therapeutic candidate for the prevention and treatment of vascular proliferative diseases.

Bioactive Steroids from the Formosan Soft Coral Umbellulifera petasites

Three new steroids, petasitosterones A and B (1 and 2) and a spirosteroid petasitosterone C (3), along with eight known steroids (4–11), were isolated from a Formosan marine soft coral Umbellulifera petasites. The structures of these compounds were elucidated by extensive spectroscopic analysis and comparison of spectroscopic data with those reported. Compound 3 is a marine steroid with a rarely found A/B spiro[4,5]decane ring system. Compounds 1–3 and 5 displayed inhibitory activity against the proliferation of a limited panel of cancer cell lines, whereas 2 and 5 exhibited significant anti-inflammatory activity to inhibit nitric oxide (NO) production. The inhibitory activities for superoxide anion generation and elastase release of compounds 1–11 were also examined to evaluate the anti-inflammatory potential, and 2–4 were shown to exhibit significant activities.

Antiallergic Phorbol Ester from the Seeds of Aquilaria malaccensis

The Aquilaria malaccensis (Thymelaeaceae) tree is a source of precious fragrant resin, called agarwood, which is widely used in traditional medicines in East Asia against diseases such as asthma. In our continuous search for active natural products, A. malaccensis seeds ethanolic extract demonstrated antiallergic effect with an IC₅₀ value less than 1 µg/mL. Therefore, the present research aimed to purify and identify the antiallergic principle of A. malaccensis through a bioactivity-guided fractionation approach. We found that phorbol ester-rich fraction was responsible for the antiallergic activity of A. malaccensis seeds. One new active phorbol ester, 12-O-(2Z,4E,6E)-tetradeca-2,4,6-trienoylphorbol-13-acetate, aquimavitalin (1) was isolated. The structure of 1 was assigned by means of 1D and 2D NMR data and high-resolution mass spectrometry (HR-MS). Aquimavitalin (1) showed strong inhibitory activity in A23187- and antigen-induced degranulation assay with IC₅₀ values of 1.7 and 11 nM, respectively, with a therapeutic index up to 71,000. The antiallergic activities of A. malaccensis seeds and aquimavitalin (1) have never been revealed before. The results indicated that A. malaccensis seeds and the pure compound have the potential for use in the treatment of allergy.

Osthol attenuates neutrophilic oxidative stress and hemorrhagic shock-induced lung injury via inhibition of phosphodiesterase 4

Oxidative stress caused by neutrophils is an important pathogenic factor in trauma/hemorrhagic (T/H)-induced acute lung injury (ALI). Osthol, a natural coumarin found in traditional medicinal plants, has therapeutic potential in various diseases. However, the pharmacological effects of osthol in human neutrophils and its molecular mechanism of action remain elusive. In this study, our data showed that osthol potently inhibited the production of superoxide anion (O2(•-)) and reactive oxidants derived therefrom as well as expression of CD11b in N-formylmethionylleucylphenylalanine (FMLP)-activated human neutrophils. However, osthol inhibited neutrophil degranulation only slightly and it failed to inhibit the activity of subcellular NADPH oxidase. FMLP-induced phosphorylation of extracellular signal-regulated kinase (ERK) and protein kinase B (Akt) was inhibited by osthol. Notably, osthol increased the cAMP concentration and protein kinase A (PKA) activity in activated neutrophils. PKA inhibitors reversed the inhibitory effects of osthol, suggesting that these are mediated through cAMP/PKA-dependent inhibition of ERK and Akt activation. Furthermore, the activity of cAMP-specific phosphodiesterase (PDE) 4, but not PDE3 or PDE7, was significantly reduced by osthol. In addition, osthol reduced myeloperoxidase activity and pulmonary edema in rats subjected to T/H shock. In conclusion, our data suggest that osthol has effective anti-inflammatory activity in human neutrophils through the suppression of PDE4 and protects significantly against T/H shock-induced ALI in rats. Osthol may have potential for future clinical application as a novel adjunct therapy to treat lung inflammation caused by adverse circulatory conditions.

New Flavones, a 2-(2-Phenylethyl)-4H-chromen-4-one Derivative, and Anti-Inflammatory Constituents from the Stem Barks of Aquilaria sinensis

In the current study, two new flavones, 4′-O-geranyltricin (1) and 3′-O-geranylpolloin (2), and a new 2-(2-phenylethyl)-4H-chromen-4-one derivative, 7-hydroxyl-6-methoxy-2-(2-phenylethyl)chromone (3), have been isolated from the stem barks of A. sinensis, together with 21 known compounds 4–24. The structures of new compounds 1–3 were determined through spectroscopic and MS analyses. Compounds 2, 3, 5, 6, and 8–10 exhibited inhibition (IC₅₀ ≤ 12.51 μM) of superoxide anion generation by human neutrophils in response to formyl-l-methionyl-l-leucyl-l-phenylalanine/cytochalasin B (fMLP/CB). Compounds 3, 6, 8, 10, and 19 inhibited fMLP/CB-induced elastase release with IC₅₀ values ≤ 15.25 μM. This investigation reveals bioactive isolates (especially 2, 3, 5, 6, 8, 9, 10, and 19) could be further developed as potential candidates for the treatment or prevention of various inflammatory diseases.

Glaucumolides A and B, Biscembranoids with New Structural Type from a Cultured Soft Coral Sarcophyton glaucum

Glaucumolides A (1) and B (2), novel biscembranes composed of an unprecedented α,β-unsaturated ε-lactone, along with the known metabolites ximaolide A (3) and isosarcophytonolide D (4), were isolated from the cultured soft coral Sarcophyton glaucum. The structures of the new metabolites were determined by extensive spectroscopic analyses. Compounds 1 and 2 were shown to exhibit cytotoxicity against a limited panel of cancer cell lines. In anti-inflammation assay, compounds 1 and 2 displayed strong inhibition of superoxide anion generation and elastase release in human neutrophils stimulated by fMLP/CB. Furthermore, both 1 and 2 were shown to significantly inhibit the accumulation of the pro-inflammatory inducible nitric oxide synthase protein, and compounds 1−3 were found to effectively reduce the expression of cyclooxygenase-2 protein, in lipopolysaccharide-stimulated RAW264.7 macrophage cells.

Immunomodulatory effects of Santolina chamaecyparissus leaf extracts on human neutrophil functions

CONTEXT

Santolina chamaecyparissus L. (Asteraceae) is an aromatic plant wide spread in the Mediterranean region. It is used in folk medicine for its anti-inflammatory properties.

OBJECTIVE

The effects of S. chamaecyparissus aqueous extract (SCAE) and polyphenolic extract (SCPE) on human polymorphonuclear neutrophil (PMN) degranulation, chemotaxis, phagocytosis, and microbicidal capacity were examined in vitro.

MATERIALS AND METHODS

Aqueous and polyphenolic extracts were prepared from S. chamaecyparissus leaves. The elastase release was used as a marker for measuring PMN degranulation, while chemotaxis was performed using a 48-microwell chemotaxis chamber. The phagocytosis and the microbicidal capacity were evaluated using fresh cultures of Candida albicans.

RESULTS

The treatment of neutrophils with different concentrations (10-200 µg/ml) of SCAE and SCPE caused a significant (p < 0.001) and dose-dependent inhibitory effect on elastase release in fMLP/Cytochalasin B (CB)-stimulated neutrophils. Indeed, 100 µg/ml of SCAE exerted an inhibitory effect of 51.97 ± 6.2%, whereas SCPE at the same concentration abolished completely PMN degranulation. Moreover, both extracts inhibited markedly (p < 0.01) fMLP-induced chemotactic migration. At 200 µg/ml, SCAE and SCPE exerted an inhibitory effect of 54.61 ± 7.3% and 57.71 ± 7.44%, respectively. In addition, a decline in both phagocytosis and microbicidal capacity against Candida albicans was observed when PMNs were exposed to 100 and 200 µg/ml of SCAE or SCPE.

CONCLUSION

The exerted effects on neutrophil functions support the anti-inflammatory activity and show new mechanisms of action and effectiveness of S. chamaecyparissus leaf extracts. This plant may be considered as an interesting source of anti-inflammatory and immunomodulatory agents.

Antagonism of human formyl peptide receptor 1 with natural compounds and their synthetic derivatives

Formyl peptide receptor 1 (FPR1) regulates a wide variety of neutrophil functional responses and plays an important role in inflammation and the pathogenesis of various diseases. To date, a variety of natural and synthetic molecules have been identified as FPR1 ligands. Here, we review current knowledge on natural products and natural product-inspired small molecules reported to antagonize and/or inhibit the FPR1-mediated responses. Based on this literature, additional screening of selected commercially available natural compounds for their ability to inhibit fMLF-induced Ca(2+) mobilization in human neutrophils and FPR1 transfected HL-60 cells, and pharmacophore modeling, natural products with potential as FPR1 antagonists are considered and discussed in this review. The identification and characterization of natural products that antagonize FPR1 activity may have potential for the development of novel therapeutics to limit or alter the outcome of inflammatory processes.

Randainins A-D, Based on Unique Diterpenoid Architectures, from Callicarpa randaiensis

Four new compounds, randainins A-D (1-4), were isolated from the leaves and twigs of Callicarpa randaiensis, which is an endemic species in Taiwan. Compounds 1 and 2 are diterpenoids with an unusual trans-7/5 ring system, whereas compounds 3 and 4 are diterpenoids possessing a trans-5/7 ring scaffold. The structures of the new compounds were established based on NMR and MS data analyses. Anti-inflammatory activities and cytotoxicity were tested and evaluated for these compounds. Compound 4 exhibited moderate inhibition of superoxide-anion generation with an IC50 value of 21.5 ± 2.5 μM.

Effects of chalcone derivatives on players of the immune system

The immune system is the defense mechanism in living organisms that protects against the invasion of foreign materials, microorganisms, and pathogens. It involves multiple organs and tissues in human body, such as lymph nodes, spleen, and mucosa-associated lymphoid tissues. However, the execution of immune activities depends on a number of specific cell types, such as B cells, T cells, macrophages, and granulocytes, which provide various immune responses against pathogens. In addition to normal physiological functions, abnormal proliferation, migration, and differentiation of these cells (in response to various chemical stimuli produced by invading pathogens) have been associated with several pathological disorders. The unwanted conditions related to these cells have made them prominent targets in the development of new therapeutic interventions against various pathological implications, such as atherosclerosis and autoimmune diseases. Chalcone derivatives exhibit a broad spectrum of pharmacological activities, such as immunomodulation, as well as anti-inflammatory, anticancer, antiviral, and antimicrobial properties. Many studies have been conducted to determine their inhibitory or stimulatory activities in immune cells, and the findings are of significance to provide a new direction for subsequent research. This review highlights the effects of chalcone derivatives in different types of immune cells.

Biphenyl-Type Neolignan Derivatives from the Twigs of Magnolia denudata and Their Anti-Inflammatory Activity

Two new biphenyl-type neolignan derivatives, 2-[2-(hydroxymethyl)-1-benzofuran-5-yl]-4-(prop-2-en-1-yl)phenol (1) and 2'-ethoxy-5,5'-di(prop-2-en-1-yl)biphenyl-2-ol (2), were isolated from the twigs of Magnolia denudata, together with six known compounds (3-8). The structures of 1 and 2 were determined through extensive 1D- and 2D-NMR and mass-spectrometric analyses. Magnolol (6) and honokiol (7) exhibited potent inhibition (IC50 values=4.4±0.2 and 0.71±0.13 μg/ml, resp.) of O$\rm{{_{2}^{{^\cdot} -}}}$ generation by human nutrophils in response to N-formyl-L-methionyl-L-leucyl-L-phenylalanine/cytochalasin B (fMLP/CB). In addition, 2-[2-(hydroxymethyl)-1-benzofuran-5-yl]-4-(prop-2-en-1-yl)phenol (1), 2'-ethoxy-5,5'-di(prop-2-en-1-yl)biphenyl-2-ol (2), magnolol (6), and vanillic acid (8) inhibited fMLP/CB-induced elastase release with IC50 values=6.4±1.5, 2.4±0.4, 1.5±0.2, and 4.8±0.5 μg/ml, respectively.

Herbs to curb cyclic nucleotide phosphodiesterase and their potential role in Alzheimer's disease

Cyclic nucleotides viz., cAMP/cGMP has been well known to play important role in cellular function and deficiency in their levels has been implicated in the pathogenesis of various neurodegenerative disorders including Alzheimer's disease (AD). Phosphodiesterases (PDE) are the enzymes involved in the metabolism of cyclic nucleotides and the inhibition of phosphodiesterases is considered to be viable strategy to restore the level of cyclic nucleotides and their functions in the brain. Various synthetic PDE inhibitors had been used clinically for various disorders and also suggested to be useful candidates for treating neurological disorders. However, side effects of these synthetic PDE inhibitors have limited their use in clinical practice. Natural plant extracts or their bio-active compounds are considered to be safe and are widely acceptable. During the last decade, many plant extracts or their bio-active compounds were tested pre-clinically for PDE inhibitory activity and are reported to be equally potent in inhibiting PDE's, as that of synthetic compounds. The present review is aimed to discuss the potential plant extract/compounds with PDE inhibitory activity and critically discuss their potential role in Alzheimer's disease.

Diversity-Oriented Approaches to Polycyclics and Bioinspired Molecules via the Diels-Alder Strategy: Green Chemistry, Synthetic Economy, and Beyond

We describe diverse approaches to various dienes and their utilization in the Diels-Alder reaction to produce a variety of polycycles. The dienes covered here are prepared by simple alkylation reaction or via the Claisen rearrangement or by enyne metathesis of alkyne or enyne building blocks. Here, we have also included the Diels-Alder chemistry of dendralenes, a higher analog of cross-conjugated dienes. The present article is inclusive of o-xylylene derivatives that are generated in situ starting with benzosultine or benzosulfone derivatives. The Diels-Alder reaction of these dienes with various dienophiles gave diverse polycyclic systems and biologically important targets.

Eunicellin-Based Diterpenoids, Hirsutalins S-V, from the Formosan Soft Coral Cladiella hirsuta

Four new eunicellin-type hirsutalins S–V (1–4), along with a known compound (–)-6α-hydroxy polyanthellin A (5), were isolated from the soft coral Cladiella hirsuta. The structures of the metabolites were determined by extensive spectroscopic analysis. Cytotoxity of compounds 1–5 against the proliferation of a limited panel of cancer cell lines was measured. Anti-inflammatory activity of compounds 1–5 was evaluated by measuring their ability in suppressing superoxide anion generation and elastase release in fMLP/CB-induced human neutrophils.

New Coumarin Derivatives and Other Constituents from the Stem Bark of Zanthoxylum avicennae: Effects on Neutrophil Pro-Inflammatory Responses

Three new coumarin derivatives, 8-formylalloxanthoxyletin (1), avicennone (2), and (Z)-avicennone (3), have been isolated from the stem bark of Zanthoxylum avicennae (Z. avicennae), together with 15 known compounds (4–18). The structures of these new compounds were determined through spectroscopic and MS analyses. Compounds 1, 4, 9, 12, and 15 exhibited inhibition (half maximal inhibitory concentration (IC₅₀) values ≤7.65 µg/mL) of superoxide anion generation by human neutrophils in response to formyl-l-methionyl-l-leucyl-l-phenylalanine/cytochalasin B (fMLP/CB). Compounds 1, 2, 4, 8 and 9 inhibited fMLP/CB-induced elastase release with IC₅₀ values ≤8.17 µg/mL. This investigation reveals bioactive isolates (especially 1, 2, 4, 8, 9, 12 and 15) could be further developed as potential candidates for the treatment or prevention of various inflammatory diseases.

Garcimultiflorone G, a novel benzoylphloroglucinol derivative from Garcinia multiflora with inhibitory activity on neutrophil pro-inflammatory responses

A novel benzoylphloroglucinol derivative, garcimultiflorone G (1), was isolated from the fruits of Garcinia multiflora. The structure of 1 was determined through extensive 1D- and 2D-NMR, and MS analyses. Garcimultiflorone G (1) showed inhibitory effects against superoxide anion (O·2(-) generation and elastase release by human neutrophils in response to formyl-L-methionyl-L-leucyl-L-phenylalanine/cytochalasin B (fMLP/CB), with IC50 values of 6.97 ± 1.56 and 11.70 ± 1.58 μM, respectively.

Epigenetic mechanisms in COPD: implications for pathogenesis and drug discovery

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death worldwide. The growing burden of COPD is due to continuous tobacco use, which is the most important risk factor of the disease, indoor fumes, occupational exposures and also aging of the world's population. Epigenetic mechanisms significantly contribute to COPD pathophysiology.

AREAS COVERED

This review focuses on disease-relevant changes in DNA modification, histone modification and non-coding RNA expression in COPD, and provides insight into novel therapeutic approaches modulating epigenetic mechanisms. Recent findings revealed, among others, globally changed DNA methylation patterns, decreased levels of histone deacetylases and reduced microRNAs levels in COPD. The authors also discuss a potential role of the chromatin silencing Polycomb group of proteins in COPD.

EXPERT OPINION

COPD is a highly complex disease and therapy development is complicated by the fact that many smokers develop both COPD and lung cancer. Of interest, combination therapies involving DNA methyltransferase inhibitors and anti-inflammatory drugs provide a promising approach, as they might be therapeutic for both COPD and cancer. Although the field of epigenetic research has virtually exploded over the last 10 years, particular efforts are required to enhance our knowledge of the COPD epigenome in order to successfully establish epigenetic-based therapies for this widespread disease.

Steroidal and α-tocopherylhydroquinone glycosides from two soft corals Cladiella hirsuta and Sinularia nanolobata

Cytotoxic and anti-inflammatory glycosides were isolated from two soft corals,Cladiella hirsutaandSinularia nanolobata. Compounds3and4represent the first example of tocopheryl xyloside derivatives.

New bioactive steroids from the soft coral Klyxum flaccidum

The structures, cytotoxic and anti-inflammatory activities of steroids isolated from the soft coral Klyxum flaccidum are reported.

Capsisteroids A–F, withanolides from the leaves of Solanum capsicoides

A known withanolide steroid cilistol G (1) and six new withanolides, capsisteroids A–F (2–7), were isolated from the EtOAc extract of the leaves of Solanum capsicoides.

Bioactive chemical constituents from the brown alga Homoeostrichus formosana

A new chromene derivative, 2-(4',8'-dimethylnona-3'E,7'-dienyl)-8-hydroxy-2,6-dimethyl-2H-chromene (1) together with four known natural products, methylfarnesylquinone (2), isololiolide (3), pheophytin a (4), and β-carotene (5) were isolated from the brown alga Homoeostrichus formosana. The structure of 1 was determined by extensive 1D and 2D spectroscopic analyses. Acetylation of 1 yielded the monoacetylated derivative 2-(4',8'-dimethylnona-3'E,7'-dienyl)-8-acetyl-2,6-dimethyl-2H-chromene (6). Compounds 1-6 exhibited various levels of cytotoxic, antibacterial, and anti-inflammatory activities. Compound 2 was found to display potent in vitro anti-inflammatory activity by inhibiting the generation of superoxide anion (IC50 0.22 ± 0.03 μg/mL) and elastase release (IC50 0.48 ± 0.11 μg/mL) in FMLP/CB-induced human neutrophils.

Lasiodiplodia sp. ME4-2, an endophytic fungus from the floral parts of Viscum coloratum, produces indole-3-carboxylic acid and other aromatic metabolites

Background

Studies on endophytes, a relatively under-explored group of microorganisms, are currently popular amongst biologists and natural product researchers. A fungal strain (ME4-2) was isolated from flower samples of mistletoe (Viscum coloratum) during a screening program for endophytes. As limited information on floral endophytes is available, the aim of the present study is to characterise fungal endophytes using their secondary metabolites.

Results

ME4-2 grew well in both natural and basic synthetic media but produced no conidia. Sequence analysis of its internal transcribed spacer rDNA demonstrated that ME4-2 forms a distinct branch within the genus Lasiodiplodia and is closely related to L. pseudotheobromae. This floral endophyte was thus identified as Lasiodiplodia sp. based on its molecular biological characteristics. Five aromatic compounds, including cyclo-(Trp-Ala), indole-3-carboxylic acid (ICA), indole-3-carbaldehyde, mellein and 2-phenylethanol, were found in the culture. The structures of these compounds were determined using spectroscopic methods combined with gas chromatography. To the best of our knowledge, our work is the first to report isolation of these aromatic metabolites from a floral endophyte. Interestingly, ICA, a major secondary metabolite produced by ME4-2, seemed to be biosynthesized via an unusual pathway. Furthermore, our results indicate that the fungus ME4-2 is a potent producer of 2-phenylethanol, which is a common component of floral essential oils.

Conclusions

This study introduces a fungal strain producing several important aromatic metabolites with pharmaceutical or food applications and suggests that endophytic fungi isolated from plant flowers are promising natural sources of aromatic compounds.