Syk and Src are major pharmacological targets of a Cerbera manghas methanol extract with kaempferol-based anti-inflammatory activity

Marine algae: A treasure trove of bioactive anti-inflammatory compounds

This comprehensive review examines the diverse classes of pharmacologically active compounds found in marine algae and their promising anti-inflammatory effects. The review covers various classes of anti-inflammatory compounds sourced from marine algae, including phenolic compounds, flavonoids, terpenoids, caretenoids, alkaloids, phlorotannins, bromophenols, amino acids, peptides, proteins, polysaccharides, and fatty acids. The anti-inflammatory activities of marine algae-derived compounds have been extensively investigated using in vitro and in vivo models, demonstrating their ability to inhibit pro-inflammatory mediators, such as cytokines, chemokines, and enzymes involved in inflammation. Moreover, marine algae-derived compounds have exhibited immunomodulatory properties, regulating immune cell functions and attenuating inflammatory responses. Specific examples of compounds with notable anti-inflammatory activities are highlighted. This review provides valuable insights for researchers in the field of marine anti-inflammatory pharmacology and emphasizes the need for further research to harness the pharmacological benefits of marine algae-derived compounds for the development of effective and safe therapeutic agents.

Therapeutic role of kaempferol and myricetin in streptozotocin-induced diabetes synergistically via modulation in pancreatic amylase, glycogen storage and insulin secretion

Kaempferol and Myricetin alone have promising benefits on diabetes and related complications, yet the effectiveness of cotreating the two compounds on diabetes have not been studied. The existing investigation was to study the combined anti-diabetic effect of kaempferol and myricetin in Streptozotocin (STZ)-activated diabetes in rats. To evaluate the anti-diabetic activity, 36 Wistar rats were segregated into six groups; Normal, 50 mg/kg STZ-induced diabetes, and four (50 mg/kg kaempferol, 50 mg/kg myricetin, 25 mg/kg kaempferol + myricetin, and 5 mg/kg glibenclamide) compound-treated diabetic groups. The effects of co-treatment on parameters, glucose, insulin, lipid profile, liver enzymes, antioxidant biomarkers, and inflammatory cytokines were measured. The study revealed that combined treatment restored the assessed parameters including glucose levels, inflammatory cytokines, oxidative markers, and lipid and liver enzymes in diabetic rats. The results indicate that cotreatment of kaempferol and myricetin has a beneficial role against diabetes suggesting that cotreatment of these compounds can be used therapeutically in treating diabetes.

Bintaro (Cerbera odollam and Cerbera manghas): an overview of its eco-friendly use, pharmacology, and toxicology

Bintaro is a tropical mangrove plant often used as a shade tree found in Asia, Australia, Madagascar, and the Islands of the Western Pacific Ocean. The word Bintaro is also often pinned to its closest relative species, the Cerbera odollam. Flower color is one of the distinguishing features between these two species. Human poisoning with the cardiotoxic plant Bintaro is common in Southeast Asia because it bears a fruit that yields a powerful poison that has been used for suicide and homicide, hence it is also called the "Indian suicide tree". The seeds of Bintaro contain Cerberin, a cardiac glycoside toxin of the heart that blocks the calcium ion channels in heart muscles, resulting in disruption of the heartbeat most often fatally. The bio-active compound in the kernels of Bintaro varies due to which plant possesses other properties as well. The plant may also be used for medicinal purposes as it shows many pharmaceutical properties. The seeds of the plant have auspicious anticancer properties through apoptotic activity and the leaf extract of the plant was screened for its antioxidant activities. In addition, it is also used as an insecticide, pesticide, or antifungal agent. This review highlights the Pharmaceutical, toxicological, and environmentally friendly approaches of Bintaro.

Anti-Inflammatory Functions of Methanol Extract from Malus baccata (L.) Borkh. Leaves and Shoots by Targeting the NF-κB Pathway

Malus baccata (L.) Borkh. is a widely used medical plant in Asia. Since the anti-inflammatory mechanism of this plant is not fully understood, the aim of this study was to explore the anti-inflammatory function and mechanism of Malus baccata (L.) Borkh. methanol extract (Mb-ME). For in vitro experiments, nitric oxide production assay, PCR, overexpression strategy, immunoblotting, luciferase reporter assay, and immunoprecipitation were employed to explore the molecular mechanism and the target proteins of Mb-ME. For in vivo experiments, an HCl/EtOH-induced gastritis mouse model was used to confirm the anti-inflammatory function. Mb-ME showed a strong ability to inhibit the production of nitric oxide and the expression of inflammatory genes. Mb-ME decreased NF-κB luciferase activity mediated by MyD88 and TRIF. Moreover, Mb-ME blocked the activation of Src, Syk, p85, Akt, p50, p60, IKKα/β, and IκBα in LPS-induced RAW264.7 cells. Overexpression and immunoprecipitation analyses suggested Syk and Src as the target enzymes of Mb-ME. In vitro results showed that Mb-ME could alleviate gastritis and relieve the protein expression of p-Src, p-Syk, and COX-2, as well as the gene expression of COX-2 and TNF-α. In summary, this study implied that Mb-ME performs an anti-inflammatory role by suppressing Syk and Src in the NF-κB signaling pathway, both in vivo and in vitro.

Anti-inflammatory effect of Barringtonia angusta methanol extract is mediated by targeting of Src in the NF-κB signalling pathway

CONTEXT

Among the plants in the genus Barringtonia (Lecythidaceae) used as traditional medicines to treat arthralgia, chest pain, and haemorrhoids in Indonesia, Barringtonia racemosa L. and Barringtonia acutangula (L.) Gaertn. have demonstrated anti-inflammatory activity in systemic inflammatory models.

OBJECTIVE

The anti-inflammatory activity of Barringtonia angusta Kurz has not been investigated. We prepared a methanol extract of the leaves and stems of B. angusta (Ba-ME) and systemically evaluated its anti-inflammatory effects in vitro and in vivo.

MATERIALS AND METHODS

RAW264.7 cells stimulated with LPS or Pam3CSK4 for 24 h were treated with Ba-ME (12.5, 25, 50, 100, and 150 µg/mL), and NO production and mRNA levels of inflammatory genes were evaluated. Luciferase reporter gene assay, western blot analysis, overexpression experiments, and cellular thermal shift assay were conducted to explore the mechanism of Ba-ME. In addition, the anti-gastritis activity of Ba-ME (50 and 100 mg/kg, administered twice per day for two days) was evaluated using an HCl/EtOH-induced gastritis mouse model.

RESULTS

Ba-ME dose-dependently suppressed NO production [IC₅₀ = 123.33 µg/mL (LPS) and 46.89 µg/mL (Pam3CSK4)] without affecting cell viability. Transcriptional expression of iNOS, IL-1β, COX-2, IL-6, and TNF-α and phosphorylation of Src, IκBα, p50/105, and p65 were inhibited by Ba-ME. The extract specifically targeted the Src protein by binding to its SH2 domain. Moreover, Ba-ME significantly ameliorated inflammatory lesions in the HCl/EtOH-induced gastritis model.

DISCUSSION AND CONCLUSIONS

The anti-inflammatory activity of Ba-ME is mediated by targeting of the Src/NF-κB signalling pathway, and B. angusta has potential as an anti-inflammatory drug.

Protective effect of (+)-catechin against lipopolysaccharide-induced inflammatory response in RAW 264.7 cells through downregulation of NF-κB and p38 MAPK

Catechin, a flavonol belonging to the flavonoid group of polyphenols is present in many plant foods. The present study was done to evaluate the effect of catechin on various inflammatory mediators using lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. The effect of catechin on total cyclooxygenase (COX) activity, 5-lipoxygenase (5-LOX), myeloperoxidase, nitrite and inducible nitric oxide synthase (iNOS) level, secretion of tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10) were assessed in LPS-stimulated RAW 264.7 cells. The expression of COX-2, iNOS, TNF-α, nuclear factor-ĸB (NF-κB) and p38 mitogen-activated protein kinase (MAPK) genes were also investigated. The effect was further analyzed using human PBMCs by assessing the level of TNF-α and IL-10. The study demonstrated that the inflammatory mediators such as COX, 5-LOX, nitrite, iNOS, and TNF-α were significantly inhibited by catechin in a concentration-dependent manner whereas IL-10 production was up-regulated in RAW 264.7 cells. Moreover, catechin down-regulated the mRNA level expression of COX-2, iNOS, TNF-α, NF-κB and p38 MAPK. The current study ratifies the beneficial effect of catechin as a dietary component in plant foods to provide protection against inflammatory diseases.

Syk/NF-κB-targeted anti-inflammatory activity of Melicope accedens (Blume) T.G. Hartley methanol extract

ETHNOPHARMACOLOGICAL RELEVANCE

Melicope accedens (Blume) Thomas G. Hartley is a plant included in the family Rutaceae and genus Melicope. It is a native plant from Vietnam that has been used for ethnopharmacology. In Indonesia and Malaysia, the leaves of M. accedens are applied externally to decrease fever.

AIM OF THE STUDY

The molecular mechanisms of the anti-inflammatory properties of M. accedens are not yet understood. Therefore, we examined those mechanisms using a methanol extract of M. accedens (Ma-ME) and determined the target molecule in macrophages.

MATERIALS AND METHODS

We evaluated the anti-inflammatory effects of Ma-ME in lipopolysaccharide (LPS)-stimulated RAW264.7 cells and in an HCl/EtOH-triggered gastritis model in mice. To investigate the anti-inflammatory activity, we performed a nitric oxide (NO) production assay and ELISA assay for prostaglandin E2 (PGE₂). RT-PCR, luciferase gene reporter assays, western blotting analyses, and a cellular thermal shift assay (CETSA) were conducted to identify the mechanism and target molecule of Ma-ME. The phytochemical composition of Ma-ME was analyzed by HPLC and LC-MS/MS.

RESULTS

Ma-ME suppressed the production of NO and PGE₂ and the mRNA expression of proinflammatory genes (iNOS, IL-1β, and COX-2) in LPS-stimulated RAW264.7 cells without cytotoxicity. Ma-ME inhibited NF-κB activation by suppressing signaling molecules such as IκBα, Akt, Src, and Syk. Moreover, the CETSA assay revealed that Ma-ME binds to Syk, the most upstream molecule in the NF-κB signal pathway. Oral administration of Ma-ME not only alleviated inflammatory lesions, but also reduced the gene expression of IL-1β and p-Syk in mice with HCl/EtOH-induced gastritis. HPLC and LC-MS/MS analyses confirmed that Ma-ME contains various anti-inflammatory flavonoids, including quercetin, daidzein, and nevadensin.

CONCLUSIONS

Ma-ME exhibited anti-inflammatory activities in vitro and in vivo by targeting Syk in the NF-κB signaling pathway. Therefore, we propose that Ma-ME could be used to treat inflammatory diseases such as gastritis.

In vitro antibacterial activity of extracts from Samoan medicinal plants and their effect on proliferation and migration of human fibroblasts

ETHNOPHARMACOLOGICAL RELEVANCE

The prevalence of different types of chronic wounds, due to the ageing population and increase incidence of diseases, is becoming a worldwide problem. Various medicinal plants used in folk medicine have demonstrated wound healing and antimicrobial properties, and some of these species are currently used in commercial preparations. Despite the well-documented and rich tradition of the use of local herbs for the treatment of skin injuries in Samoan folk medicine, their wound healing potential has not yet been systematically studied.

AIM OF THE STUDY

Investigation into the in vitro antibacterial activity of ethanol extracts from 14 medicinal plants used in Samoan traditional medicine for the healing of wounds, burns and sores, and their effects on the proliferation and migration of human fibroblasts.

MATERIALS AND METHODS

The antibacterial activity of these extracts was tested against pathogens associated with infected skin injuries, using the broth microdilution method. The effect on migration, proliferation and viability of human dermal fibroblasts was evaluated using wound healing scratch assay, cell proliferation assay, and thiazolyl blue tetrazolium bromide cytotoxicity test.

RESULTS

The extracts from Cerbera manghas, Commelina diffusa, Kleinhovia hospita, Mikania micrantha, Omalanthus nutans, Peperomia pellucida, Phymatosorus scolopendria, Piper graeffei, Psychotria insularum, and Schizostachyum glaucifolium inhibited the growth of Staphylococcus aureus at the minimum inhibitory concentration (MIC) of ≥4 μg/mL, whereas C. manghas and P. pellucida produced the same MIC against both Escherichia coli and Pseudomonas aeruginosa. Among the antibacterially active species, C. diffusa, K. hospita, P. scolopendria, P. insularum, and S. glaucifolium did not produce toxicity towards the standard line of normal adult human dermal fibroblasts (IC₈₀ > 128 μg/mL). In addition, extracts from Barringtonia asiatica, C. manghas, M. micrantha, O. nutans, P. insularum, and Piper graeffei stimulated significant migration of dermal fibroblasts, while M. micrantha, O. nutans, and P. insularum did not affect cell proliferation at a concentration of 32 μg/mL.

CONCLUSIONS

The results suggest that the above-mentioned species of Samoan medicinal plants can be used for the development of new wound healing agents. However, further phytochemical and pharmacological research is needed regarding the isolation and identification of their active constituents.

Epigynumgenane-type pregnane glycosides from Epigynum cochinchinensis and their immunosuppressive activity

Five undescribed C₂₁ pregnane glycosides, epigycosides D-H, together with four known analogues, two lignans, and a flavonoid have been isolated from the stems of Epigynum cochinchinensis. The structures of pregnane glycosides were elucidated using spectroscopic techniques and acid hydrolysis. The in vitro immunological activities were assessed against Con A-stimulated proliferation of mice splenocytes. The C₂₁ pregnane glycosides showed immunosuppressive activity in a concentration-dependent manner. Moreover, epigycoside E exhibited a potent immunosuppressive effect, and the IC₅₀ value on Con A-stimulated mice splenocytes was 22.1 ± 6.4 μM. Epigycoside E also caused G₀/G₁ arrest, and inhibited TNF-α and IL-2 production.

Acute and subacute toxicity evaluation of ethanol extract from aerial parts of Epigynum auritum in mice

Acute and subacute toxicities of the ethanol extract from Epigynum auritum (EAE) wereperformed by oral administration in pathogen-free mice. Acute toxicity study was performed at a single dose of 5000 mg/kg for 14 consecutive days, while subacute toxicity test was conducted by daily oral administration of EAE at doses of 312, 625, 1250, and 2500 mg/kg for 28 days. Acute toxicity study showed that LD₅₀ of EAE was over 5000 mg/kg. The results of subacute toxicity showed no significant adverse effect of EAE at 312 mg/kg. Moreover, EAE exhibited toxicities to liver, spleen and kidney in mice determined by hematological, serum biochemical and histological analyses during daily oral administration of 1250 mg/kg and 2500 mg/kg EAE. The results revealed that the dose of EAE lower than 625 mg/kg can be regarded as safe.

Mycetia cauliflora methanol extract exerts anti-inflammatory activity by directly targeting PDK1 in the NF-κB pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Mycetia cauliflora Reinw. (Rubiaceae) has been used as a traditional remedy to ameliorate clinical signs of inflammatory diseases, including pain, inflammation, ulcers, and wounds. Among the Mycetia subfamilies, the molecular and cellular mechanisms of Mycetia longifolia (Rubiaceae) have been studied. However, those of Mycetia cauliflora are not clearly understood. Comprehensive investigation of this plant is necessary to evaluate its potential for ethnopharmacological use.

MATERIALS

and methods: The activities of Mycetia cauliflora methanol extract (Mc-ME) on the secretion of inflammatory mediators, the mRNA expression of proinflammatory cytokines, and identification of its molecular targets were elucidated using lipopolysaccharide (LPS)-induced macrophage-like cells. Moreover, the suppressive actions of Mc-ME were examined in an LPS-induced peritonitis mouse model.

RESULTS

At nontoxic concentrations, Mc-ME downregulated the release of nitric oxide (NO), the mRNA expression of inducible nitric oxide synthase (iNOS), and the mRNA expression of interleukin (IL)-1β from LPS-activated RAW264.7 cells. This extract also inhibited the nuclear translocation of p65 and p50 and the phosphorylation of IκBα, IKK, and AKT. Western blot analysis and in vitro kinase assays confirmed that phosphoinositide-dependent kinase-1 (PDK1) is the direct immunopharmacological target of Mc-ME effect. In addition, Mc-ME significantly reduced inflammatory signs in an animal model of acute peritonitis. These effects were associated with decreased NO production and decreased AKT phosphorylation.

CONCLUSION

Our results suggest that Mc-ME displays anti-inflammatory actions in LPS-treated macrophage-like cells and in an animal model of acute inflammatory disease. These actions are preferentially managed by targeting PDK1 in the nuclear factor (NF)-κB signaling pathway.

Chemo-preventive and therapeutic effect of the dietary flavonoid kaempferol: A comprehensive review

Kaempferol, a natural flavonoid present in several plants, possesses a wide range of therapeutic properties such as antioxidant, anticancer, and anti-inflammatory. It has a significant role in reducing cancer and can act as a therapeutic agent in the treatment of diseases and ailments such as diabetes, obesity, cardiovascular diseases, oxidative stress, asthma, and microbial contamination disorders. Kaempferol acts through different mechanisms: It induces apoptosis (HeLa cervical cancer cells), decreases cell viability (G2/M phase), downregulates phosphoinositide 3-kinase (PI3K)/AKT (protein kinase B) and human T-cell leukemia/lymphoma virus-I (HTLV-I) signaling pathways, suppresses protein expression of epithelial-mesenchymal transition (EMT)-related markers including N-cadherin, E-cadherin, Slug, and Snail, and metastasis-related markers such as matrix metallopeptidase 2 (MMP-2). Accordingly, the aim of the present review is to collect information pertaining to the effective role of kaempferol against various degenerative disorders, summarize the antioxidant, anti-inflammatory, anticancer, antidiabetic, and antiaging effects of kaempferol and to review the progress of recent research and available data on kaempferol as a protective and chemotherapeutic agent against several ailments.

A New Immunosuppressive Pregnane Glycoside and Two Known Analogues from Epigynum cochinchinensis

Phytochemical investigation of the ethyl acetate soluble fraction from the leaves of Epigynum cochinchinensis led to the isolation of one new C21 pregnane glycoside, epigycoside C (1), along with two known analogues epigycoside A (2) and epigynoside G (3). Their structures were elucidated on the basis of extensive spectroscopic techniques. The in vitro immunosuppressive activity of compound 1 was evaluated against concanavalin A (Con A)- and lipopolysaccharides (LPS)-stimulated proliferation of mice splenocytes. Compound 1 displayed significant immunosuppressive activities in a dose-dependent manner.

Natural agents mediated autophagic signal networks in cancer

Recent studies suggested that natural compounds are important in finding targets for cancer treatments. Autophagy (“self-eating”) plays important roles in multiple diseases and acts as a tumor suppressor in cancer. Here, we examined the molecular mechanism by which natural agents regulate autophagic signals. Understanding the relationship between natural agents and cellular autophagy may provide more information for cancer diagnosis and chemoprevention.

Syk - GTP RAC-1 mediated immune-stimulatory effect of Cuscuta epithymum, Ipomoea batata and Euphorbia hirta plant extracts

Polymorphonuclear neutrophils (PMNn) are the pivotal mediators of phagocytosis. In addition to neutropenia, impaired neutrophilic function is associated with pathological conditions and immuno-deficiencies. Henceforth, Immuno-stimulatory strategies targeting neutrophilic function are indeed powerful tools in combating obstinate infections. In appreciation towards the usefulness of herbal medicines in therapeutic scenario, the present study was carried out to analyse the immuno-stimulatory effect of Cuscuta epithymum, Ipomoea batata and Euphorbia hirta using in-vitro and in-vivo rodent experimental models. Throughout the experimentation, phagocytosis was studied and expressed as phagocytotic index and percentage phagocytosis. Different extracts of these plants were initially screened for their potency to induce phagocytosis in PMNn and the methanolic fractions, which are effective, were considered for further experimentation.The phagocytosis stimulation by the methanolic extracts was compared with the standard Granulocyte Macrophage - Colony Stimulating Factor (GM-CSF) at a dose of 65ng/ml. Immunoblotting analysis shown that the methanolic extracts induce the phosphorylation of Syk which in turn phosphorylates GDP-RAC-1, hinting the possible mechanism of action. Following these in vitro investigations, the potency of methanolic extracts was assessed using rat model by performing carbon clearance assay, Delayed Type Hypersensitivity and antibody titre.The phosphorylation status of Syk and GDP-RAC-1 was also assessed in the edematous fluid collected from the right hind paw. In vivo findings were in agreement with the in vitro findings by presenting an improved immune response and increased phosphorylation of Syk and GDP-RAC-1. Conclusively, this study provides the initial insights into the therapeutic implications of the tropical plants in inducing phagocytosis.

JS-III-49, a hydroquinone derivative, exerts anti-inflammatory activity by targeting Akt and p38

Since previous studies have reported that hydroquinone (HQ) exerted immunosuppressive and anti-inflammatory activity, various HQ derivatives have been synthesized and their biological activities investigated. In this study, we explored the anti-inflammatory activity of JS-III-49, a novel HQ derivative, in macrophage-mediated inflammatory responses. JS-III-49 suppressed the production of the inflammatory mediators nitric oxide (NO) and prostaglandin E₂ (PGE₂) and down-regulated the mRNA expression of the inflammatory enzymes cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) as well as the expression of the pro-inflammatory cytokines interleukin-6 (IL-6) and IL-1b without cytotoxicity in LPS-stimulated RAW264.7 cells. JS-III-49 inhibited nuclear translocation of the NF-kB transcription factors p65 and p50 by directly targeting Akt, an upstream kinase of the NF-kB pathway, in LPS-stimulated RAW264.7 cells. However, JS-III-49 did not directly inhibit the kinase activities of Src and Syk, which are upstream kinases of Akt, in LPS-stimulated RAW264.7 cells. Moreover, JS-III-49 suppressed the nuclear translocation of c-Fos, one of the components of AP-1, by specifically targeting p38, an upstream mitogen-activated protein kinase (MAPK) in the AP-1 pathway in LPS-stimulated RAW264.7 cells. These results suggest that JS-III-49 plays an anti-inflammatory role in LPS-stimulated macrophages by targeting Akt and p38 in the NF-kB and AP-1 pathways, respectively.

Ponciretin attenuates ethanol-induced gastric damage in mice by inhibiting inflammatory responses

BACKGROUND

Poncirin (PO) and isosakuranetin (or ponciretin [PT]) are compounds found in fruits of the genus Citrus. They are frequently used in traditional Chinese medicine for the treatment of inflammation and asthma. Therefore, we examined their anti-gastritis effects in vitro and in vivo.

METHODS

The anti-inflammatory effects of PO and PT were examined using ethanol- or LPS-stimulated KATO III cells. Gastritis was induced in ICR mice via intragastric injection of absolute ethanol. Levels of inflammatory markers were measured by enzyme-linked immunosorbent assay, immunoblotting, and quantitative polymerase chain reaction.

RESULTS

Treatment with PT or PO inhibited the secretion of interleukin (IL)-8 and tumor necrosis factor (TNF) in ethanol- or LPS-stimulated KATO III cells. They also reduced the activation of nuclear factor kappa B (NF-κB). Pre-treatment with PT or PO significantly protected against ethanol-induced hemorrhagic gastritis, characterized by edema, tissue erosions, and mucosal friability in mice. Treatment with PT or PO suppressed ethanol-induced NF-κB activation and the release of TNF, IL-8, and IFN-γ. The protective effect of PT was greater than that of PO and comparable to ranitidine, a positive control.

CONCLUSION

PT may attenuate ethanol-induced gastritis by inhibiting the infiltration of immune cells, including neutrophils, via the regulation of CXCL4 (or IL-8) secretion and the activation NF-κB.

Cerbera manghas methanol extract exerts anti-inflammatory activity by targeting c-Jun N-terminal kinase in the AP-1 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Cerbera manghas L. (Apocynaceae) is a medicinal plant traditionally used to ameliorate the clinical signs of inflammatory diseases and hypertension.

AIM OF STUDY

Although C. manghas L. has long been used as a traditional remedy for various diseases, the underlying molecular and cellular mechanisms are poorly understood. A detailed investigation of these mechanisms is necessary to demonstrate the ethnopharmaceutical utility of this plant.

MATERIALS AND METHODS

The effects of C. manghas methanol extract (Cm-ME) on the production of inflammatory mediators and the expression of proinflammatory cytokines and identification of molecular targets were investigated using lipopolysaccharide (LPS)-treated macrophages in vitro. In addition, the inhibitory effects of Cm-ME orally administered were tested by LPS/D-galactosamine (D-GalN)-induced hepatitis and LPS-induced peritonitis mouse models in vivo.

RESULTS

Cm-ME downregulated the production of prostaglandin (PG)E₂ and the mRNA expression of cyclooxygenase (COX)-2, tumor necrosis factor (TNF)-α, and interleukin (IL)-1β in LPS-stimulated RAW264.7 cells under non-toxic concentration of Cm-ME. This extract inhibited the nuclear translocation of c-Jun and p-ATF2, the phosphorylation of JNK and p38, and AP-1 activity. Western blot analysis and in vitro kinase assay confirmed that JNK is a direct pharmacological target of Cm-ME action. In addition, Cm-ME significantly ameliorated the clinical signs of LPS/D-GalN-induced hepatitis and lowered the production of nitric oxide (NO) and the phosphorylation of JNK in LPS-induced peritonitis conditions.

CONCLUSION

Cm-ME exerts anti-inflammatory actions on LPS-stimulated macrophages and in mouse models of acute inflammatory disease. These actions are predominantly mediated by targeting JNK in the AP-1 signaling pathway.

Functional Role of Milk Fat Globule-Epidermal Growth Factor VIII in Macrophage-Mediated Inflammatory Responses and Inflammatory/Autoimmune Diseases

Inflammation involves a series of complex biological processes mediated by innate immunity for host defense against pathogen infection. Chronic inflammation is considered to be one of the major causes of serious diseases, including a number of autoimmune/inflammatory diseases, cancers, cardiovascular diseases, and neurological diseases. Milk fat globule-epidermal growth factor 8 (MFG-E8) is a secreted protein found in vertebrates and was initially discovered as a critical component of the milk fat globule. Previously, a number of studies have reported that MFG-E8 contributes to various biological functions including the phagocytic removal of damaged and apoptotic cells from tissues, the induction of VEGF-mediated neovascularization, the maintenance of intestinal epithelial homeostasis, and the promotion of mucosal healing. Recently, emerging studies have reported that MFG-E8 plays a role in inflammatory responses and inflammatory/autoimmune diseases. This review describes the characteristics of MFG-E8-mediated signaling pathways, summarizes recent findings supporting the roles of MFG-E8 in inflammatory responses and inflammatory/autoimmune diseases, and discusses MFG-E8 targeting as a potential therapeutic strategy for the development of anti-inflammatory/autoimmune disease drugs.

4-Isopropyl-2,6-bis(1-phenylethyl)aniline 1, an Analogue of KTH-13 Isolated from Cordyceps bassiana, Inhibits the NF-κB-Mediated Inflammatory Response

The Cordyceps species has been a good source of compounds with anticancer and anti-inflammatory activities. Recently, we reported a novel compound (4-isopropyl-2,6-bis(1-phenylethyl)phenol, KTH-13) with anticancer activity isolated from Cordyceps bassiana and created several derivatives to increase its pharmacological activity. In this study, we tested one of the KTH-013 derivatives, 4-isopropyl-2,6-bis(1-phenylethyl)aniline 1 (KTH-13-AD1), with regard to anti-inflammatory activity under macrophage-mediated inflammatory conditions. KTH-13-AD1 clearly suppressed the production of nitric oxide (NO) and reactive oxygen species (ROS) in lipopolysaccharide (LPS) and sodium nitroprusside- (SNP-) treated macrophage-like cells (RAW264.7 cells). Similarly, this compound also reduced mRNA expression of inducible NO synthase (iNOS) and tumor necrosis factor-α (TNF-α), as analyzed by RT-PCR and real-time PCR. Interestingly, KTH-13-AD1 strongly diminished NF-κB-mediated luciferase activities and nuclear translocation of NF-κB family proteins. In accordance, KTH-13-AD1 suppressed the upstream signaling pathway of NF-κB activation, including IκBα, IKKα/β, AKT, p85/PI3K, and Src in a time- and dose-dependent manner. The autophosphorylation of Src and NF-κB observed during the overexpression of Src was also suppressed by KTH-13-AD1. These results strongly suggest that KTH-13-AD1 has strong anti-inflammatory features mediated by suppression of the Src/NF-κB regulatory loop.

Fisetin Suppresses Macrophage-Mediated Inflammatory Responses by Blockade of Src and Syk

Flavonoids, such as fisetin (3,7,3′,4′-tetrahydroxyflavone), are plant secondary metabolites. It has been reported that fisetin is able to perform numerous pharmacological roles including anti-inflammatory, anti-microbial, and anti-cancer activities; however, the exact anti-inflammatory mechanism of fisetin is not understood. In this study, the pharmacological action modes of fisetin in lipopolysaccharide (LPS)-stimulated macrophage-like cells were elucidated by using immunoblotting analysis, kinase assays, and an overexpression strategy. Fisetin diminished the release of nitric oxide (NO) and reduced the mRNA levels of inducible NO synthase (iNOS), tumor necrosis factor (TNF)-α, and cyclooxygenase (COX)-2 in LPS-stimulated RAW264.7 cells without displaying cytotoxicity. This compound also blocked the nuclear translocation of p65/nuclear factor (NF)-κB. In agreement, the upstream phosphorylation events for NF-κB activation, composed of Src, Syk, and IκBα, were also reduced by fisetin. The phospho-Src level, triggered by overexpression of wild-type Src, was also inhibited by fisetin. Therefore, these results strongly suggest that fisetin can be considered a bioactive immunomodulatory compound with anti-inflammatory properties through suppression of Src and Syk activities.

The dietary flavonoid Kaempferol mediates anti-inflammatory responses via the Src, Syk, IRAK1, and IRAK4 molecular targets

Even though a lot of reports have suggested the anti-inflammatory activity of kaempferol (KF) in macrophages, little is known about its exact anti-inflammatory mode of action and its immunopharmacological target molecules. In this study, we explored anti-inflammatory activity of KF in LPS-treated macrophages. In particular, molecular targets for KF action were identified by using biochemical and molecular biological analyses. KF suppressed the release of nitric oxide (NO) and prostaglandin E2 (PGE2), downregulated the cellular adhesion of U937 cells to fibronectin (FN), neutralized the generation of radicals, and diminished mRNA expression levels of inflammatory genes encoding inducible NO synthase (iNOS), TNF-α, and cyclooxygenase- (COX-) 2 in lipopolysaccharide- (LPS-) and sodium nitroprusside- (SNP-) treated RAW264.7 cells and peritoneal macrophages. KF reduced NF-κB (p65 and p50) and AP-1 (c-Jun and c-Fos) levels in the nucleus and their transcriptional activity. Interestingly, it was found that Src, Syk, IRAK1, and IRAK4 responsible for NF-κB and AP-1 activation were identified as the direct molecular targets of KF by kinase enzyme assays and by measuring their phosphorylation patterns. KF was revealed to have in vitro and in vivo anti-inflammatory activity by the direct suppression of Src, Syk, IRAK1, and IRAK4, involved in the activation of NF-κB and AP-1.

Accumulation of kaempferitrin and expression of phenyl-propanoid biosynthetic genes in kenaf (Hibiscus cannabinus)

Kenaf (Hibiscus cannabinus) is cultivated worldwide for its fiber; however, the medicinal properties of this plant are currently attracting increasing attention. In this study, we investigated the expression levels of genes involved in the biosynthesis of kaempferitrin, a compound with many biological functions, in different kenaf organs. We found that phenylalanine ammonia lyase (HcPAL) was more highly expressed in stems than in other organs. Expression levels of cinnamate 4-hydroxylase (HcC4H) and 4-coumarate-CoA ligase (Hc4CL) were highest in mature leaves, followed by stems and young leaves, and lowest in roots and mature flowers. The expression of chalcone synthase (HcCHS), chalcone isomerase (HcCHI), and flavone 3-hydroxylase (HcF3H) was highest in young flowers, whereas that of flavone synthase (HcFLS) was highest in leaves. An analysis of kaempferitrin accumulation in the different organs of kenaf revealed that the accumulation of this compound was considerably higher (>10-fold) in leaves than in other organs. On the basis of a comparison of kaempferitrin contents with the expression levels of different genes in different organs, we speculate that HcFLS plays an important regulatory role in the kaempferitrin biosynthetic pathway in kenaf.

Flavonoids Affect Host-Microbiota Crosstalk through TLR Modulation

Interaction between host cells and microbes is known as crosstalk. Among other mechanisms, this takes place when certain molecules of the micro-organisms are recognized by the toll-like receptors (TLRs) in the body cells, mainly in the intestinal epithelial cells and in the immune cells. TLRs belong to the pattern-recognition receptors and represent the first line of defense against pathogens, playing a pivotal role in both innate and adaptive immunity. Dysregulation in the activity of such receptors can lead to the development of chronic and severe inflammation as well as immunological disorders. Among components present in the diet, flavonoids have been suggested as antioxidant dietary factors able to modulate TLR-mediated signaling pathways. This review focuses on the molecular targets involved in the modulatory action of flavonoids on TLR-mediated signaling pathways, providing an overview of the mechanisms involved in such action. Particular flavonoids have been able to modify the composition of the microbiota, to modulate TLR gene and protein expression, and to regulate the downstream signaling molecules involved in the TLR pathway. These synergistic mechanisms suggest the role of some flavonoids in the preventive effect on certain chronic diseases.

Pharmacological and Ethnomedicinal Overview of Heritiera fomes: Future Prospects

Mangrove plants are specialized woody plants growing in the swamps of tidal-coastal areas and river deltas of tropical and subtropical parts of the world. They have been utilized for medicinal and other purposes by the coastal people over the years. Heritiera fomes Buch. Ham. (family: Sterculiaceae) commonly known as Sundari (Bengali) is a preeminent mangrove plant occurring in the Sundarbans forest located in the southern part of Bangladesh and adjoining West Bengal province of India. The plant has applications in traditional folk medicine as evidenced by its extensive use for treating diabetes, hepatic disorders, gastrointestinal disorders, goiter, and skin diseases by the local people and traditional health practitioners. A number of investigations indicated that the plant possesses significant antioxidant, antinociceptive, antihyperglycemic, antimicrobial, and anticancer activities. Phytochemical analyses have revealed the presence of important chemical constituents like saponins, alkaloids, glycosides, tannins, steroids, flavonoids, gums, phytosterols, and reducing sugars. The present study is aimed at compiling information on phytochemical, biological, pharmacological, and ethnobotanical properties of this important medicinal plant, with a view to critically assess the legitimacy of the use of this plant in the aforementioned disorders as well as providing directions for further research.

Functional roles of Syk in macrophage-mediated inflammatory responses

Inflammation is a series of complex biological responses to protect the host from pathogen invasion. Chronic inflammation is considered a major cause of diseases, such as various types of inflammatory/autoimmune diseases and cancers. Spleen tyrosine kinase (Syk) was initially found to be highly expressed in hematopoietic cells and has been known to play crucial roles in adaptive immune responses. However, recent studies have reported that Syk is also involved in other biological functions, especially in innate immune responses. Although Syk has been extensively studied in adaptive immune responses, numerous studies have recently presented evidence that Syk has critical functions in macrophage-mediated inflammatory responses and is closely related to innate immune response. This review describes the characteristics of Syk-mediated signaling pathways, summarizes the recent findings supporting the crucial roles of Syk in macrophage-mediated inflammatory responses and diseases, and discusses Syk-targeted drug development for the therapy of inflammatory diseases.