Potent Anti-inflammatory Compound Research Articles

Therapeutic Efficacy of Silymarin from Nigerian Medicinal Plants in NDEAInduced Hepatocellular Carcinoma: Impact on NF-κB, IL-6, IL-10, MDA, and LDH

Liver cancer, particularly hepatocellular carcinoma (HCC), is a rising global health concern, driven by risk factors such as HBV, HCV, and NASH. Key biomarkers like malondialdehyde (MDA), lactate dehydrogenase (LDH), NF-kB, and cytokines are indicative of oxidative stress and inflammation associated with HCC progression. Phytochemicals from Nigerian medicinal plants, especially silymarin a potent antioxidant and anti-inflammatory compound derived from milk thistle have shown promising therapeutic potential in mitigating liver damage. These bioactive compound target oxidative damage and immune modulation pathways, offering hope for innovative treatments against HCC. This study investigates the hepatoprotective effects of silymarin on biochemical markers in Nnitrosodiethylamine (NDEA)-induced hepatocellular carcinoma (HCC) in rats, focusing on lactate dehydrogenase (LDH), malondialdehyde (MDA), nuclear factor-kappa B (NF-kB), and cytokine levels. Results indicate that NDEA exposure significantly elevated LDH, MDA, and NF-kB levels in serum and liver tissues, correlating with tissue damage and oxidative stress. Silymarin treatment markedly reduced LDH levels (p < 0.001), suggesting their role in mitigating HCC progression. Elevated MDA levels indicated enhanced lipid peroxidation, with silymarin reducing MDA significantly (p < 0.001), implicating their antioxidative properties. NF-kB levels, an early marker of neoplastic changes, were notably decreased following silymarin administration, particularly with 75 mg of silymarin, which showed a stronger effect than sorafenib a reference drug. NDEA also increased pro-inflammatory cytokine IL-6, which was dose dependently downregulated by silymarin, whereas IL-10 levels, an anti-inflammatory cytokine, were upregulated in treated groups, aiding in inflammation modulation. This study underscores the therapeutic potential of silymarin, supporting its efficacy in HCC management by reducing oxidative damage, inflammation, and cell proliferation markers

Synthesis of a Small Library of Glycoderivative Putative Ligands of SGLT1 and Preliminary Biological Evaluation.

Sodium-glucose co-transporter 1 (SGLT1) is primarily expressed on the membrane of enterocytes, a type of epithelial cell found in the intestines, where it mediates the unidirectional absorption of glucose and galactose. Beyond its well-established role in nutrient absorption, SGLT1 also plays a protective role in maintaining the integrity of the intestinal barrier. Specifically, the natural ligand of SGLT1 (d-glucose) and a synthetic C-glucoside developed by our group can induce a protective anti-inflammatory effect on the intestinal epithelium. In this paper, we report the creation of a small library of C-glycoside, putative ligands for SGLT1, to gain further insights into its unclear mechanism of action. Preliminary biological experiments performed on an in vitro model of doxorubicin-induced mucositis, a severe intestinal inflammatory condition, indicate that the aromatic moiety present in all the compounds of the library is crucial for biological activity, while the sugar component appears to have less influence. These findings will be exploited to develop new, more potent anti-inflammatory compounds and to better understand and rationalize the protective mechanism of action.

Synthesis, characterization, computational studies and anti-inflammatory activity evaluation of some new indole substituted aryl ethers

A number of anti-inflammatory drugs with an aryl-ether part, such as Nimesulide and Rofecoxibs, have been shown to damage cells and kill liver cells. Keeping in view this rationale, the present work was aimed at synthesising new indole-substituted aryl ethers and evaluating their anti-inflammatory effects, which have minimal side effects. New indole substituted aryl ethers were synthesised. Spectral characterisation of these newly synthesised compounds was done using infrared (IR), proton nuclear magnetic resonance (1H NMR), and carbon-13 nuclear magnetic resonance (13C NMR) spectroscopy techniques. Further, In-silico studies were performed with an aim to evaluate the suitability of synthesised compounds as potential bioactive candidates for anti-inflammatory activity. The synthesised compounds were subjected to anti-inflammatory activity evaluation using the carrageenan-induced rat paw edema model. Primarily, the chemical reaction completion was ensured using TLC and M.P. Further, the structures of all synthesised compounds were confirmed by the results of spectra characterization. Results of in-silico study exhibited the docking of compounds on target proteins. On the basis of experimental findings, it was concluded that compound AG-1 (N-(1H-indol-3yl) methylene)-4-phenoxyaniline) is the most potent anti-inflammatory compound amongst all the newly synthesised compounds. Findings of the present study concluded that AG-1 could be used as a viable new lead bioactive compound to serve as a potent candidate for a new anti-inflammatory drug. The novelty of the present work resides in the simplest way of synthesis, a good docking score, and excellent anti-inflammatory potential when evaluated in vivo.

Recent Advances in Anti-Inflammatory Compounds from Marine Microorganisms.

Marine microbial secondary metabolites with diversified structures have been found as promising sources of anti-inflammatory lead compounds. This review summarizes the sources, chemical structures, and pharmacological properties of anti-inflammatory natural products reported from marine microorganisms in the past three years (2021-2023). Approximately 252 anti-inflammatory compounds, including 129 new ones, were predominantly obtained from marine fungi and they are structurally divided into polyketides (51.2%), terpenoids (21.0%), alkaloids (18.7%), amides or peptides (4.8%), and steroids (4.3%). This review will shed light on the development of marine microbial secondary metabolites as potential anti-inflammatory lead compounds with promising clinical applications in human health.

Medicinal Plants and Bioactive Compounds with Potential Anti-inflammatory and Antidiabetic Activities: A Review

Background: Inflammation is a complex process. Persistent and uncontrolled inflammation may act as an etiologic factor for many chronic disorders like diabetes. Objective: This review aims to classify the anti-inflammatory and antidiabetic medicinal plants, their traditional uses, and their active compounds that have been tested for their anti-inflammatory and antidiabetic effects. Methods: We checked scientific publications in various electronic databases from 1981 to 2021. All the molecular structures were provided in ADC/ChemSketch. Results: We reviewed 58 species, belonging to 39 families. These species have long been used in traditional medicine to cure a variety of ailments, including, dysentery, typhoid fever, anemia, digestive and cardiac disorders, as well as diabetes and inflammation. Asteraceae represents the dominant family. The most potent anti-inflammatory and antidiabetic active compounds were reviewed including myricetin, quercetin, hesperetin, rutin, luteolin, chlorogenic acid, vanillic acid, gallic acid, ferulic acid, benzoic acid, cinnamic acid, gentisic acid, camphor, 1,8-cineol, p-cymene, limonene, linalool, thymoquinone, carvacrol, aromadendrine, α-pinene, lycopene, phytol, imperatorin, chalepin, hexadecanoic acid, linoleic acid, tellimagrandin I, and trigalloyl glucose. Conclusion: This review indicates that medicinal plants have many therapeutic dynamics against inflammation and diabetes that could be exploited for the discovery of therapeutic preparation or agent for treating the two illnesses at the same time.

Total Syntheses and Anti-Inflammatory Studies of Three Natural Coumarins: Glycycoumarin, Glycyrin, and 3-O-Methylglycyrol.

Licorice (Glycyrrhiza uralensis Fisch), a significant traditional Chinese herbal medicine, has been extensively utilized in China to treat various ailments. Natural bioactive coumarins, glycycoumarin, glycyrin, and 3-O-methylglycyrol, were isolated from licorice, and they exhibited various pharmacological properties. In this report, we have accomplished the total synthesis of glycycoumarin, glycyrin, and 3-O-methylglycyrol in 5-7 linear steps from commercially available 2,4,6-trihydroxybenzaldehyde with yields of 12.3-21.2%. Additionally, their anti-inflammatory activities were studied and compared. Glycycoumarin, glycyrin, and 3-O-methylglycyrol exhibited different levels of anti-inflammatory activities, with glycyrin being the most potent. Mechanistic studies indicated that glycyrin exerted its anti-inflammatory properties by inhibiting the activation of TNF-α, IL-6, and IL-1β, making it a potential anti-inflammatory lead compound for further optimization and discovery of new agents.

Anti-inflammatory Effect of Dictyopteis undulata in RAW 264.7 Cells

Purpose: This study aimed to analyze the anti-inflammatory effects of <i>Dictyopteris undulata</i> extract on skin using RAW 264.7 cells.Methods: Its anti-inflammatory effects on RAW 264.7 cells were evaluated by measuring the cell viability, gene expression levels (<i>IL-1α/IL-1β/IL-6</i> and <i>TNF-α</i>), and nitric oxide (NO)/prostaglandin E2 (PGE<sub>2</sub>) production.Results: Quantitative real-time polymerase chain reaction showed that the <i>D. undulata</i> extract decreased the mRNA levels of <i>IL-1α/IL-1β/IL-6</i> and <i>TNF-α</i>. Additionally, PGE<sub>2</sub>/NO detection revealed that <i>D. undulata</i> extract exhibited anti-inflammatory properties.Conclusion: <i>D. undulata</i> extract is a potential anti-inflammatory compound. Further study on the anti-inflammatory mechanisms of <i>D. undulata</i> extract would facilitate the development of cosmeceutics and pharmacological treatments.

Fisetin is a selective adenosine triphosphate-competitive inhibitor for mitogen-activated protein kinase kinase 4 to inhibit lipopolysaccharide-stimulated inflammation.

The mitogen-activated protein kinase kinase 4 (MKK4), a member of the MAP kinase kinase family, directly phosphorylates and activates the c-Jun NH2-terminal kinases (JNK), in response to proinflammatory cytokines and cellular stresses. Regulation of the MKK4 activity is considered to be a novel approach for the prevention and treatment of inflammation. The aim of this study was to identify whether fisetin, a potential anti-inflammatory compound, targets MKK4-JNK cascade to inhibit lipopolysaccharide (LPS)-stimulated inflammatory response. RAW264 macrophage pretreated with fisetin following LPS stimulation was used as a cell model to investigate the transactivation and expression of related-inflammatory genes by transient transfection assay, electrophoretic mobility shift assay (EMSA), or enzyme-linked immunosorbent assay (ELISA), and cellular signaling as well as binding of related-signal proteins by Western blot, pull-down assay and kinase assay, and molecular modeling. The transactivation and expression of cyclooxygenase-2 (COX-2) gene as well as prostaglandin E2 (PGE2) secretion induced by LPS were inhibited by fisetin in a dose-dependent manner. Signaling transduction analysis demonstrated that fisetin selectively inhibited MKK4-JNK1/2 signaling to suppress the phosphorylation of transcription factor AP-1 without affecting the NF-κB and Jak2-Stat3 signaling as well as the phosphorylation of Src, Syk, and TAK1. Furthermore, in vitro and ex vivo pull-down assay using cell lysate or purified protein demonstrated that fisetin could bind directly to MKK4. Molecular modeling using the Molecular Operating Environment™ software indicated that fisetin docked into the ATP-binding pocket of MKK4 with a binding energy of -71.75 kcal/mol and formed a 1.70 Å hydrogen bound with Asp247 residue of MKK4. The IC50 of fisetin against MKK4 was estimated as 2.899 μM in the kinase assay, and the ATP-competitive effect was confirmed by ATP titration. Taken together, our data revealed that fisetin is a potent selective ATP-competitive MKK4 inhibitor to suppress MKK4-JNK1/2-AP-1 cascade for inhibiting LPS-induced inflammation.

Taming the storm: potential anti-inflammatory compounds targeting SARS-CoV-2 MPro.

In severe COVID-19 cases, an exacerbated inflammatory response triggers a cytokine storm that can worsen the prognosis. Compounds with both antiviral and anti-inflammatory activities show promise as candidates for COVID-19 therapy, as they potentially act against the SARS-CoV-2 infection regardless of the disease stage. One of the most attractive drug targets among coronaviruses is the main protease (MPro). This enzyme is crucial for cleaving polyproteins into non-structural proteins required for viral replication. The aim of this review was to identify SARS-CoV-2 MPro inhibitors with both antiviral and anti-inflammatory properties. The interactions of the compounds within the SARS-CoV-2 MPro binding site were analyzed through molecular docking when data from crystallographic structures were unavailable. 18 compounds were selected and classified into five different superclasses. Five of them exhibit high potency against MPro: GC-376, baicalein, naringenin, heparin, and carmofur, with IC50 values below 0.2μM. The MPro inhibitors selected have the potential to alleviate lung edema and decrease cytokine release. These molecules mainly target three critical inflammatory pathways: NF-κB, JAK/STAT, and MAPK, all previously associated with COVID-19 pathogenesis. The structures of the compounds occupy the S1/S2 substrate binding subsite of the MPro. They interact with residues from the catalytic dyad (His41 and Cys145) and/or with the oxyanion hole (Gly143, Ser144, and Cys145), which are pivotal for substrate recognition. The MPro SARS-CoV-2 inhibitors with potential anti-inflammatory activities present here could be optimized for maximum efficacy and safety and be explored as potential treatment of both mild and severe COVID-19.

Inhibition of angiogenesis and metastasis in colorectal cancer cell lines through KRAS-associated signaling pathways by 2-methoxy-6-undecyl-1,4-benzoquinone

Colorectal cancer (CRC), the third most prevalent cancer globally, presents formidable hurdles in treatment owing to factors such as therapeutic resistance and genetic mutations affecting primary drug targets. 2-methoxy-6-undecyl-1,4-benzoquinone (BQ), derived from Ardisia crispa roots, has emerged as a potent anti-inflammatory and anti-angiogenic compound with substantial potential, as evidenced by previous studies. This study aimed to explore the potential of BQ in suppressing angiogenesis and metastasis in the human CRC cell lines LoVo and HCT116. Various in vitro and in silico studies have been conducted to elucidate the potential pathway(s) of BQ. BQ was highly cytotoxic, with an IC50 of 7.01 ± 0.6 μM in HCT116 and 9.58 ± 0.8 μM in LoVo cells. Moreover, BQ induced notable apoptotic activity and suppressed migration, invasion, and adhesion in both cell lines. The inhibition of MMP-2 suggests the potential of BQ to impede extracellular matrix degradation and CRC cell metastasis. BQ inhibits the expression of key proteins involved in angiogenesis and metastasis, including VEGF-A, VEGF-C, BRAF, ERK, KRAS, PI3K, and AKT. Molecular docking simulations illustrated the robust binding of BQ to CRC protein receptors. BQ holds promise in impeding CRC progression by targeting angiogenesis and metastasis, particularly through inhibition of the KRAS/BRAF/ERK and KRAS/PI3K/AKT signaling pathways.

Triethylene Glycol Squalene Improves Hair Regeneration by Maintaining the Inductive Capacity of Human Dermal Papilla Cells and Preventing Premature Aging.

De novo hair follicle (HF) regeneration, achieved through the replenishment of the dermal papilla (DP), acknowledged as the principal orchestrator of the hair growth cycle, is emerging as a prospective therapeutic intervention for alopecia. Nonetheless, multiple attempts have shown that these cells lose key inductive properties when cultured in a two-dimensional (2D) monolayer, leading to precocious senescence engendered by oxidative stress and inflammatory processes. Consequently, the three-dimensional (3D) spheroid technique is presently widely employed for DP cell culture. Nevertheless, substantiating the regenerative potential of these cells within the hair follicle (HF) milieu remains a challenge. In this current study, we aim to find a new approach to activate the inductive properties of DP cells. This involves the application of hair-growth-stimulating agents that not only exhibit concurrent protective efficacy against the aging process but also induce HF regeneration. To achieve this objective, we initially synthesized a novel highly amphiphilic derivative derived from squalene (SQ), named triethylene glycol squalene (Tri-SQ). Squalene itself is a potent antioxidant and anti-inflammatory compound traditionally employed as a drug carrier for alopecia treatment. However, its application is limited due to its low solubility. Subsequently, we applied this newly synthesized derivative to DP cells. The data obtained demonstrated that the derivative exhibits robust antioxidant and anti-inflammatory activities while concurrently promoting the expression of genes associated with hair growth. Moreover, to further assess the hair regrowth inductive properties of DP cells, we cultured the cells and treated them with Tri-SQ within a 3D spheroid system. Subsequently, these treated cells were injected into the previously depilated dorsal area of six-week-old male C57BL/6 mice. Results revealed that 20 days postinjection, a complete regrowth of hair in the previously hairless area, particularly evident in the case of 3D spheroids treated with the derivative, was observed. Additionally, histological and molecular analyses demonstrated an upregulation of markers associated with hair growth and a concurrent decrease in aging hallmarks, specifically in the 3D spheroids treated with the compound. In summary, our approach, which involves the treatment of Tri-SQ combined with a 3D spheroid system, exhibited a notably robust stimulating effect. This effect was observed in the induction of inductive properties in DP cells, leading to HF regeneration, and concurrently, it demonstrated an inhibitory effect on cellular and follicular aging.

Is there a role for essential fatty acids in osteoporosis?

Inflammatory markers are inversely associated with bone density, geometry, and strength in postmenopausal women, and elderly subjects suggesting that osteoporosis is a low-grade systemic inflammatory condition. But glucocorticoids that are potent anti-inflammatory compounds instead of arresting/preventing osteoporosis induce osteoporosis. These results indicate that IL-6 and TNF-α, post-menopausal state, and steroids produce osteoporosis by an unidentified mechanism. Pro-inflammatory cytokines, estrogen, and steroids bring about their actions by influencing the metabolism of essential fatty acids (EFAs). I propose that EFAs and their metabolites act as second messengers of actions of corticosteroids, cytokines, and estrogen. This implies that EFAs are of benefit in the prevention and management of osteoporosis. This argument is supported by the observation that plasma phospholipid content of unsaturated fatty acids is decreased in those with osteoporosis. The reports that long-chain metabolites of EFAs including arachidonic acid, docosahexaenoic acid and eicosapentaenoic acid, and lipoxin A4 are of benefit in the prevention and management of osteoporosis lends further support to this proposal.

Rotundifuran Induces Ferroptotic Cell Death and Mitochondria Permeability Transition in Lung Cancer Cells.

Rotundifuran (RF), a potent anti-inflammatory and anti-cancer compound, is a natural compound predominantly present in Vitex Rotundifolia. Herein, we investigated the effects of RF on the growth of lung cancer cells. Our findings suggested that RF inhibits cell growth, highlighting its potential as a therapeutic agent for cancer treatment. Interestingly, we observed that cell growth inhibition was not due to apoptosis, as caspases were not activated and DNA fragmentation did not occur. Furthermore, we found that intracellular vacuoles and autophagy were induced, but RF-induced cell death was not affected when autophagy was inhibited. This prompted us to investigate other possible mechanisms underlying cell growth inhibition. Through a cDNA chip analysis, we confirmed changes in the expression of ferroptosis-related genes and observed lipid peroxidation. We further examined the effect of ferroptosis inhibitors and found that they alleviated cell growth inhibition induced by RF. We also observed the involvement of calcium signaling, ROS accumulation, and JNK signaling in the induction of ferroptosis. Our findings suggested that RF is a potent anti-cancer drug and further studies are needed to validate its clinal use.

Effect of n-Hexane Extract from Tanacetum argenteum (Lam.) Willd. subsp. argenteum on the Secretion of Proinflammatory Cytokines in THP-1 Cell Line

Inflammation is an initial biological process that involves the activation of the immune system in response to injury, infection or exposure to toxic agents. During this process, cytokines, small proteins produced by immune cells, play a vital role in regulating the immune response. Inflammatory cytokines, including interleukins, tumor necrosis factor-α, nitric oxide, and interferon-gamma, initiate the immune response and promote inflammation. Natural products are frequently a source of potential anti-inflammatory compounds, and screening natural products can lead to the discovery of novel bioactive compounds. The present study aimed to investigate the effects of n-hexane extract from Tanacetum argenteum subsp. argenteum on the lipopolysaccharide-induced inflammatory response in human macrophages THP-1 cell. Cells were incubated with different concentrations of n-hexane extract, and the inhibitor effects of the extract exposure on various cytokine secretions were determined. The findings demonstrated that n-hexane extract dramatically decreased the levels of interleukin‑6, interleukin‑1β, and tumor necrosis factor‑α in differentiated THP-1 cells, indicating the remarkable anti-inflammatory potential of the extract. Furthermore, in silico analysis of toxicogenomic data revealed the interactions between the active component of the n-hexane extract and interleukin-6, interleukin-1β, and tumor necrosis factor.

Screening of anti-inflammatory activities components of Angelica dahurica root based on spectrum-effect relationship analysis and NF-κB pathway.

Angelica dahurica root (ADR), a commonly utilized herbal medicine in China and other Asian nations, which has anti-inflammatory effects on diverse inflammatory ailments. However, the bioactive components and underlying mechanism responsible for the anti-inflammatory effect of ADR are still unclear. This work attempted to discover the anti-inflammatory bioactive compounds and explore their underlying mechanism in ADR based on spectrum-effect relationship analysis and NF-κB signaling pathway. Chromatographic fingerprints of ADR samples were established by high performance liquid chromatography with diode array detection (HPLC-DAD), and a total of eleven common peaks were selected. Then, high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (HPLC-Q/TOF-MS) was employed for identification of eleven common peaks in ADR Meanwhile, the anti-inflammatory activities of ADR samples were assessed by inhibition of NO, interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) production in LPS-induced RAW264.7 cells. The spectrum-effect relationships between the eleven common peaks in HPLC fingerprints and anti-inflammatory effects of ADR samples were investigated to identify the potential anti-inflammatory bioactive compounds by grey relational analysis (GRA) and partial least squares regression (PLSR). The spectrum-effect relationship analysis results indicated that six coumarin compounds, including bergapten, xanthotoxin, phellopterin, isoimperatorin, xanthotoxol and imperatorin could be potential anti-inflammatory bioactive compounds in ADR. The further validation experiments also showed that these six coumarins demonstrated significant inhibition of NO, IL-1β, IL-6, and TNF-α production in LPS-induced RAW264.7 cells. In addition, western blot analysis was conducted to explore the mechanisms of two potential anti-inflammatory bioactive compounds (phellopterin and isoimperatorin) by assessing the protein levels in the NF-κB signaling pathway. The western blot results illustrated that phellopterin and isoimperatorin could significantly down-regulate the phosphorylated NF-κB p65 (p-p65), phosphorylated IκBα (p-IκBα) and iNOS, and depress the pro-portion of p-p65/p65 and p-IκBα/IκBα, which indicated that these two coumarins in ADR could potentially exert anti-inflammatory effects by suppressing of NF-κB pathway.

Intrarectal Administration of Adelmidrol plus Hyaluronic Acid Gel Ameliorates Experimental Colitis in Mice and Inhibits Pro-Inflammatory Response in Ex Vivo Cultured Biopsies Derived from Ulcerative Colitis-Affected Patients.

Improving clinical outcomes and delaying disease recrudescence in Ulcerative Colitis (UC) patients is crucial for clinicians. In addition to traditional and new pharmacological therapies that utilize biological drugs, the development of medical devices that can ameliorate UC and facilitate the remission phase should not be overlooked. Drug-based therapy requires time to be personalized and to evaluate the benefit/risk ratio. However, the increasing number of diagnosed UC cases worldwide necessitates the exploration of new strategies to enhance clinical outcomes. By incorporating medical devices alongside pharmacological treatments, clinicians can provide additional support to UC patients, potentially improving their condition and slowing down the recurrence of symptoms. Chemically identified as an azelaic acid derivative and palmitoylethanolamide (PEA) analog, adelmidrol is a potent anti-inflammatory and antioxidant compound. In this study, we aimed to evaluate the effect of an intrarectal administration of 2% adelmidrol (Ade) and 0.1% hyaluronic acid (HA) gel formulation in both the acute and resolution phase of a mouse model of colitis induced via DNBS enema. We also investigated its activity in cultured human colon biopsies isolated from UC patients in the remission phase at follow-up when exposed in vitro to a cytomix challenge. Simultaneously, with its capacity to effectively alleviate chronic painful inflammatory cystitis when administered intravesically to urological patients such as Vessilen, the intrarectal administration of Ade/HA gel has shown remarkable potential in improving the course of colitis. This treatment approach has demonstrated a reduction in the histological damage score and an increase in the expression of ZO-1 and occludin tight junctions in both in vivo studies and human specimens. By acting independently on endogenous PEA levels and without any noticeable systemic absorption, the effectiveness of Ade/HA gel is reliant on a local antioxidant mechanism that functions as a "barrier effect" in the inflamed gut. Building on the findings of this preliminary study, we are confident that the Ade/HA gel medical device holds promise as a valuable adjunct in supporting traditional anti-UC therapies.

Arteannuin B, a sesquiterpene lactone from Artemisia annua, attenuates inflammatory response by inhibiting the ubiquitin-conjugating enzyme UBE2D3-mediated NF-κB activation

BackgroundAnomalous activation of NF-κB signaling is associated with many inflammatory disorders, such as ulcerative colitis (UC) and acute lung injury (ALI). NF-κB activation requires the ubiquitination of receptor-interacting protein 1 (RIP1) and NF-κB essential modulator (NEMO). Therefore, inhibition of ubiquitation of RIP1 and NEMO may serve as a potential approach for inhibiting NF-κB activation and alleviating inflammatory disorders. PurposeHere, we identified arteannuin B (ATB), a sesquiterpene lactone found in the traditional Chinese medicine Artemisia annua that is used to treat malaria and inflammatory diseases, as a potent anti-inflammatory compound, and then characterized the putative mechanisms of its anti-inflammatory action. MethodsDetections of inflammatory mediators and cytokines in LPS- or TNF-α-stimulated murine macrophages using RT-qPCR, ELISA, and western blotting, respectively. Western blotting, CETSA, DARTS, MST, gene knockdown, LC-MS/MS, and molecular docking were used to determine the potential target and molecular mechanism of ATB. The pharmacological effects of ATB were further evaluated in DSS-induced colitis and LPS-induced ALI in vivo. ResultsATB effectively diminished the generation of NO and PGE2 by down-regulating iNOS and COX2 expression, and decreased the mRNA expression and release of IL-1β, IL-6, and TNF-α in LPS-exposed RAW264.7 macrophages. The anti-inflammatory effect of ATB was further demonstrated in LPS-treated BMDMs and TNF-α-activated RAW264.7 cells. We further found that ATB obviously inhibited NF-κB activation induced by LPS or TNF-α in vitro. Moreover, compared with ATB, dihydroarteannuin B (DATB) which lost the unsaturated double bond, completely failed to repress LPS-induced NO release and NF-κB activation in vitro. Furthermore, UBE2D3, a ubiquitin-conjugating enzyme, was identified as the functional target of ATB, but not DATB. UBE2D3 knockdown significantly abolished ATB-mediated inhibition on LPS-induced NO production. Mechanistically, ATB could covalently bind to the catalytic cysteine 85 of UBE2D3, thereby inhibiting the function of UBE2D3 and preventing ubiquitination of RIP1 and NEMO. In vivo, ATB treatment exhibited robust protective effects against DSS-induced UC and LPS-induced ALI. ConclusionOur findings first demonstrated that ATB exerted anti-inflammatory functions by repression of NF-κB pathway via covalently binding to UBE2D3, and raised the possibility that ATB could be effective in the treatment of inflammatory diseases and other diseases associated with abnormal NF-κB activation.

Forsythia velutina Nakai extract: A promising therapeutic option for atopic dermatitis through multiple cell type modulation.

Atopic dermatitis (AD) is a complex condition characterized by impaired epithelial barriers and dysregulated immune cells. In this study, we demonstrated Forsythia velutina Nakai extract (FVE) simultaneously inhibits basophils, macrophages, keratinocytes, and T cells that are closely interrelated in AD development. We analyzed the effect of FVE on nitric oxide and reactive oxygen species (ROS) production in macrophages, basophil degranulation, T cell activation, and tight junctions in damaged keratinocytes. Expression of cell-type-specific inflammatory mediators was analyzed, and the underlying signaling pathways for anti-inflammatory effects of FVE were investigated. The anti-inflammatory effects of FVE were validated using a DNCB-induced mouse model of AD. Anti-inflammatory activity of compounds isolated from FVE was validated in each immune cell type. FVE downregulated the expression of inflammatory mediators and ROS production in macrophages through TLR4 and NRF2 pathways modulation. It significantly reduced basophil degranulation and expression of type 2 (T2) and pro-inflammatory cytokines by perturbing FcεRI signaling. Forsythia velutina Nakai extract also robustly inhibited the expression of T2 cytokines in activated T cells. Furthermore, FVE upregulated the expression of tight junction molecules in damaged keratinocytes and downregulated leukocyte attractants, as well as IL-33, an inducer of T2 inflammation. In the AD mouse model, FVE showed superior improvement in inflammatory cell infiltration and skin structure integrity compared to dexamethasone. Dimatairesinol, a lignan dimer, was identified as the most potent anti-inflammatory FVE compound. Forsythia velutina Nakai extract and its constituent compounds demonstrate promising efficacy as a therapeutic option for prolonged AD treatment by independently inhibiting various cell types associated with AD and disrupting the deleterious link between them.

Baicalin exerts neuroprotective actions by regulating the Nrf2-NLRP3 axis in toxin-induced models of Parkinson's disease

Baicalin, a potent anti-oxidative and anti-inflammatory flavonoid compound derived from Scutellaria baicalensis, has emerged as a neuroprotective agent. However, the mechanisms by which baicalin is neuroprotective in Parkinson's disease (PD) remain unclear. In this research, α-syn/MPP+ and MPTP were used to establish PD models in BV2 cells and C57BL/6 mice, respectively. The effect and mechanism of action of baicalin in PD were investigated by Western blotting, RT-qPCR, ELISA, Immunohistochemistry (IHC) staining, Immunofluorescence (IF) staining, HPLC and methods. Results demonstrate that baicalin mitigates oxidative stress, microglia activation and inflammatory response caused by α-syn/MPP+ and MPTP. It protects against dopaminergic neuron loss and relieves motor deficits. Meanwhile, baicalin not only significantly up-regulates the expression of Nrf2 and its downstream antioxidant enzyme, but also suppresses the activation of NLRP3 inflammasome simultaneously. Notably, the beneficial effects of baicalin in PD treatment are blocked by Nrf2 knockdown. This research reveals that baicalin may exert neuroprotective effects in PD treatment by suppressing the activation of NLRP3 inflammasome and it is dependent on the Nrf2-mediated antioxidative response.

Design and synthesis of novel hederagonic acid analogs as potent anti-inflammatory compounds capable of protecting against LPS-induced acute lung injury

Acute lung injury (ALI) presents a significant clinical challenge due to its high mortality rates and the lack of effective treatment strategies. The most effective approaches to treating ALI include disrupting inflammatory cascades and associated inflammatory damage within the lung. Hederagenin was utilized as a core skeleton to design and synthesize 33 hederagonic acid derivatives. Among these derivatives, compound 29 demonstrated potent anti-inflammatory activity without inducing cytotoxicity, inhibiting nitric oxide (NO) release by 78–86 %. Detailed structure-activity relationship studies and the reverse virtual screening of ALI-related targets revealed that compound 29 exhibits a high affinity for the STING protein. Mechanistic studies revealed that compound 29 suppresses macrophage activation, inhibits the nuclear translocation of IRF3 and p65, and disrupts the STING/IRF3/NF-κB signaling pathway, thereby attenuating the inflammatory response. The in vivo administration of compound 29 was sufficient to protect against lipopolysaccharide (LPS)-induced ALI by suppressing the production of inflammatory mediators, including IL-6, TNF-α, and IFN-β, thereby preserving lung tissue integrity. These results substantiate the anti-inflammatory efficacy of compound 29, both in vitro and in vivo, indicating its potential as a promising lead compound in ALI treatment strategies.