LPS In RAW264 Research Articles

Inhibition of LPS-induced inflammatory response in RAW264.7 cells by natural Chlorogenic acid isomers involved with AKR1B1 inhibition

Inflammation is the physiological response of the immune system to injury or infection, typically manifested by local tissue congestion, swelling, heat, and pain. Prolonged or excessive inflammation can lead to tissue damage and the development of many diseases. The anti-inflammatory effects of natural ingredients have been extensively researched and confirmed. This study investigated the effects of Chlorogenic acid (CGA) isomers —— 3-Caffeolyquninic acid (3-CQA), 4-Caffeolyquninic acid (4-CQA), and 5-Caffeolyquninic acid (5-CQA) —— on the inflammatory response and oxidative stress reaction induced by LPS in RAW264.7 cells. Overall, 3-CQA exhibited the most significant reduction in levels of TNF-α, IL-6, NO, and ROS. 4-CQA showed superior inhibition of TNF-α compared to 5-CQA (p < 0.05), while no significant difference in other parameters. We further used DARTS and CETSA to demonstrate that CGA isomers have stable affinity with AKR1B1. As a positive control, the AKR1B1 antagonist epalrestat exhibited similar effects to the CGA isomers. 3-CQA having the smallest half-inhibitory concentration (IC50) for AKR1B1, while 4-CQA and 5-CQA have similar values. AutoDock simulations of the docking conformations revealed minimal differences in the average binding energies of the CGA isomers. The main differences were that VAL47 formed a hydrogen bond with 3-CQA, whereas GLN49 formed hydrogen bonds with 4-CQA and 5-CQA. Additionally, the number of hydrophobic bonds involving PHE122 and LEU300 varies. Our conclusion is that differences in non-covalent interactions result in the varying inhibitory abilities of CGA isomers on AKR1B1, which further affect the anti-inflammatory and antioxidant effects of CGA isomers.

Natural synergy: Oleanolic acid-curcumin co-assembled nanoparticles combat osteoarthritis

Curcumin (Cur) is a natural polyphenol that is one of the most valuable natural products. However, its use as a functional food is limited by low water solubility, chemical instability and poor bioavailability. In this study, a supramolecular co-assembly strategy was used to construct an oleanolic acid-curcumin (OLA-Cur) co-assembly composite nano-slow-release treatment system. As a co-assembled compound, OLA is a widely present pentacyclic triterpenoid compound with multiple biological activities in the plant kingdom, which is expected to jointly alleviate the damaging effects of papain-induced mouse osteoarthritis model. The OLA-Cur NPs shows the solid core-shell structure, which can effectively improve the water solubility of Cur and OLA, and has good stability and sustained release characteristics. The analysis results show that the two compounds are mainly assembled through hydrogen bonding interactions, hydrophobic interactions, and π - π stacking interactions. The OLA-Cur NPs can inhibit the release of pro-inflammatory cytokines TNF-α, IL-6, and IL-1β induced by LPS in RAW264.7 mouse macrophages, promote the secretion of anti-inflammatory cytokine IL-10, and improve the oxidative stress index of hydrogen peroxide induced human rheumatoid arthritis synovial fibroblasts. In addition, it has a certain improvement effect on cartilage and subchondral bone damage in mouse osteoarthritis models. These findings suggest that constructing co-assembled composite nanoparticles based on pure natural compounds may break through the limitations of a variety of important nutritional ingredients in functional foods.

Anti-inflammatory activity of Staphylea bumalda leaves through inhibiting ERK1/2 and NF-κB signalling, and activating Nrf2/HO-1 signalling in LPS-stimulated RAW264.7 cells

ABSTRACT Staphylea bumalda leaves (SBL) are known to possess anti-inflammatory properties. However, there is a lack of clear study on the mechanisms underlying its anti-inflammatory activity. Therefore, this study aims to elucidate the mechanisms related to the anti-inflammatory effects of SBL. SBL70E effectively inhibited the production of NO, iNOS, COX-2, IL-1β, and IL-6 induced by LPS in RAW264.7 cells. SBL70E inhibited the phosphorylation of ERK1/2 and p65 in LPS-stimulated RAW264.7 cells. In addition, SBL70E suppressed LPS-mediated activation of NF-κB luciferase activity. SBL70E increased the levels of HO-1 and nuclear Nrf2. However, inhibition of p38, JNK and PI3K blocked SBL70E-mediated increase in HO-1 and nuclear Nrf2. These findings suggest that SBL70E suppresses the production of inflammatory mediators caused by LPS in RAW264.7 cells through the inhibition of ERK1/2 and NF-κB signalling and activation Nrf2/HO-1 signalling via the activation of p38, JNK, and PI3K. These findings imply that SBL70E exhibits anti-inflammatory activity.

A novel anti-inflammatory flavonoid from flowers of Hibiscus mutabilis L

Hibiscus mutabilis L. is a Traditional Chinese Medicinal plant of significant value. However, there has been limited research focusing specifically on its flowers. In this study, we report the isolation of one novel and nine known flavonoids from the flowers of H. mutabilis L. The structures of these compounds were elucidated using chemical and comprehensive spectral analysis, involving 1D, 2D NMR, and HRESIMS. The novel compound was further evaluated for its anti-inflammatory and cytotoxic activities using in vitro assays on RAW264.7 cells. Compound 1 at the concentration of 6.25 μM significantly inhibited the production of NO and TNF-α induced by LPS in RAW264.7 cells, exhibiting superior efficacy compared to the positive control dexamethasone, thus indicating its potential as an anti-inflammatory drug candidate.

Two new saponins from the rhizomes of Paris yunnanensis Franch

The phytochemical investigation on the rhizomes of Paris yunnanensis Franch. resulted in the discovery and characterisation of six compounds, including two new saponins named parisyunnanosides M-N (1–2), and four known ones (3–6). The structures of isolated compounds were determined by spectroscopic data analysis and chemical methods. Compound 2 is a pregnane-type saponin with a special α,β-unsaturated carboxylic acid moiety at C-17, which is first discovered in genus Paris. The anti-inflammatory activity of the isolated compounds was assessed in vitro. The results demonstrated that compounds 3 and 4 could significantly inhibit the production of NO which was induced by LPS in RAW 264.7 cells with IC50 values of 0.67 ± 0.17 μM and 0.85 ± 0.12 μM, respectively.

Rocaglamide regulates iron homeostasis by suppressing hepcidin expression

The anemia of inflammation (AI) is characterized by the presence of inflammation and abnormal elevation of hepcidin. Accumulating evidence has proved that Rocaglamide (RocA) was involved in inflammation regulation. Nevertheless, the role of RocA in AI, especially in iron metabolism, has not been investigated, and its underlying mechanism remains elusive. Here, we demonstrated that RocA dramatically suppressed the elevation of hepcidin and ferritin in LPS-treated mice cell line RAW264.7 and peritoneal macrophages. In vivo study showed that RocA can restrain the depletion of serum iron (SI) and transferrin (Tf) saturation caused by LPS. Further investigation showed that RocA suppressed the upregulation of hepcidin mRNA and downregulation of Fpn1 protein expression in the spleen and liver of LPS-treated mice. Mechanistically, this effect was attributed to RocA's ability to inhibit the IL-6/STAT3 pathway, resulting in the suppression of hepcidin mRNA and subsequent increase in Fpn1 and TfR1 expression in LPS-treated macrophages. Moreover, RocA inhibited the elevation of the cellular labile iron pool (LIP) and reactive oxygen species (ROS) induced by LPS in RAW264.7 cells. These findings reveal a pivotal mechanism underlying the roles of RocA in modulating iron homeostasis and also provide a candidate natural product on alleviating AI.

The Extracts Derived from Artemisia japonica Thunb. Leaves Mitigate Oxidative Stress and Inflammatory Response Induced by LPS in RAW264.7 Cells through Modulation of the Nrf2/HO-1 Signaling Pathway.

Artemisia japonica Thunb. has been used as a traditional Chinese medicine and a vegetable for thousands of years in China. However, there are few reports on the chemical composition and biological activity of its leaves. Thus, this study aimed to evaluate the chemical composition, antioxidant and anti-inflammatory effects of water extracts of A. japonica leaves and their underlying mechanisms. A total of 48 compounds were identified in the water extract using UPLC-QTOF-MS2 analysis, with phenolic acids, particularly chlorogenic acid compounds, being the predominant components. The ethyl acetate fraction (EAF) contained most of the total phenolic content (385.4217 mg GAE/g) and displayed superior antioxidant capacity with the IC50DPPH•, IC50ABTS•+, and OD0.5reducing power at 10.987 μg/mL, 43.630 μg/mL and 26.883 μg/mL, respectively. Furthermore, EAF demonstrated potent antioxidant and anti-inflammatory effects in LPS-induced RAW264.7 cells by upregulating the Nrf2/HO-1 signal pathway. These findings highlight that A. japonica leaves possess remarkable abilities to mitigate inflammation and oxidative stress, suggesting their potential utilization as medicinal agents and food additives for promoting human health.

Diterpenoids from Euphorbia peplus possessing cytotoxic and anti-inflammatory activities

Phytochemical investigation into the medium polar fraction of the ethanol extract of Euphorbia peplus led to the identification of 32 diterpenoids with five structural types. Compounds 1–5 and 7–11 are reported for the first time, while the configuration of 6,7-epoxy group of 6 was revised to be β-oriented. Compounds 1–5 feature a rare structural variation of the double bond at Δ1 migrating to Δ1(10) in the tigliane-type diterpenoid family. Biologically, compound 21 was found to be the only one to show moderate cytotoxic activity, associated with the presence of a benzoyloxy residue at C-16. Besides, compounds 4, 8, 12, 13, 16, and 19 show significant inhibitory activities against NO production induced by LPS in RAW264.7 macrophage cells, with IC50 values within 2–5 μM. Structure-activity relationship (SAR) analysis revealed that the ingenane-type diterpenoids have the best anti-inflammatory activity, and the esterification at 3-OH or 5-OH is crucial. Further biological researches demonstrated that 13, the predominant metabolite in this plant, exerts anti-inflammatory effects by blocking the activation of NF-κB and MAPK signaling pathways.

Suppression of Pro-Inflammatory M1 Polarization of LPS-Stimulated RAW 264.7 Macrophage Cells by Fucoxanthin-Rich Sargassum hemiphyllum.

Macrophages play an important role in managing the onset and progression of chronic inflammatory diseases. The primary objective of this study is to explore the antioxidant potential and anti-inflammatory properties of Sargassum hemiphyllum ethanol extract (SHE) and its fraction. SHE and its five constituent fractions were assessed for overall antioxidant capabilities and inhibitory effects on LPS-induced inflammation by modulating macrophages polarization in both RAW 264.7 macrophages and bone-marrow-derived macrophages (BMDM). Among the organic solvent fractions of SHE, the ethyl acetate fraction displayed the highest total phenolic content and total antioxidant capacity. Notably, the n-hexane (Hex) fraction showed the most substantial suppression of LPS-induced tumor necrosis factor α secretion in BMDM among the five fractions of SHE. The SHE and Hex fraction significantly reduced the heightened expression of pro-inflammatory cytokines and inflammation-inducible enzymes induced by LPS in RAW 264.7 macrophages. In particular, the SHE and Hex fraction inhibited M1 macrophage polarization by reducing the mRNA expression of M1 macrophage markers in macrophages that were polarized toward the M1 phenotype. Furthermore, the SHE and Hex fraction attenuated the induction in nuclear factor E2-related factor 2 and its target genes, which was accompanied by an alteration in antioxidant gene expression in M1-polarized BMDM. The findings suggest that both SHE and its Hex fraction exhibit inhibitory effects on LPS-triggered inflammation and oxidative stress by modulating the polarization of M1 macrophages within macrophage populations.

Triterpenoid and Coumarin Isolated from Astilbe grandis with Anti-Inflammatory Effects through Inhibiting the NF-κB Pathway in LPS-Induced RAW264.7 Cells.

The roots of Astilbe grandis, known as "Ma sang gou bang", are used as a Miao traditional medicine with anti-inflammatory and analgesic properties. However, the active components and mechanism of action of this plant remain mostly uncharacterized. The aim of this study was to identify its active components and verify their pharmacological activity. The extract of A. grandis root was separated using various chromatographic methods. As a result, we obtained one novel triterpenoid, named astigranlactone (1), which has an unusual lactone moiety formed between C-7 and C-27. Additionally, a known coumarin compound, 11-O-galloyl bergenin (2) was isolated from this plant. The structures of these two compounds were elucidated by extensive NMR experiments in conjunction with HR-ESI-MS data. To the best of our knowledge, both compounds were isolated from this species for the first time. Moreover, we tested the anti-inflammation effect of the two compounds by establishing a cellular inflammation model induced by LPS in RAW264.7 cells. The effect of different concentrations of these compounds on the activity of RAW264.7 cells was assessed using a CCK8 assay. The levels of nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) in the supernatant of each group were evaluated using the Griess method and an enzyme-linked immunosorbent assay (ELISA). Western blot and quantitative real-time PCR (qRT-RCR) were used to measure the levels of cyclooxygenase 2 (COX-2) and nitric oxide synthase (iNOS) gene expression. Our findings revealed that these two compounds inhibited the high levels of NO, TNF-α, IL-6, IL-1β, COX-2, and iNOS (induced by LPS). Mechanistic studies demonstrated that these two compounds reduced the activation of the nuclear transcription factor-B (NF-κB) signaling pathway by inhibiting the phosphorylation of p65. Therefore, our study indicates that compounds 1 and 2 can exert a definite anti-inflammatory effect by inhibiting the NF-κB signaling pathway.

Olive mill wastewater and hydroxytyrosol inhibits atherogenesis in apolipoprotein E-deficient mice.

The Mediterranean diet, which is characterized by high consumption of olive oil, prevents cardiovascular disease. Meanwhile, olive mill wastewater (OMWW), which is obtained as a byproduct during olive oil production, contains various promising bioactive components such as water-soluble polyphenols. Hydroxytyrosol (HT), the major polyphenol in OMWW, has anti-oxidative and anti-inflammatory properties; however, the atheroprotective effects of OMWW and HT remain to be fully understood. Here, we investigated the effect of OMWW and HT on atherogenesis. Male 8-week-old apolipoprotein E-deficient mice were fed a western-type diet supplemented with OMWW (0.30%w/w) or HT (0.02%w/w) for 20weeks. The control group was fed a non-supplemented diet. OMWW and HT attenuated the development of atherosclerosis in the aortic arch as determined by Sudan IV staining (P < 0.01, respectively) without alteration of body weight, plasma lipid levels, and blood pressure. OMWW and HT also decreased the production of oxidative stress (P < 0.01, respectively) and the expression of NADPH oxidase subunits (e.g., NOX2 and p22phox) and inflammatory molecules (e.g. IL-1β and MCP-1) in the aorta. The results of in vitro experiments demonstrated that HT inhibited the expression of these molecules that were stimulated with LPS in RAW264.7 cells, murine macrophage-like cells. OMWW and HT similarly attenuated atherogenesis. HT is a major component of water-soluble polyphenols in OMWW, and it inhibited inflammatory activation of macrophages. Therefore, our results suggest that the atheroprotective effects of OMWW are at least partially attributable to the anti-inflammatory effects of HT.

Involvement of extracellular vesicles in the progression, diagnosis, treatment, and prevention of whole-body ionizing radiation-induced immune dysfunction.

Acute radiation syndrome (ARS) develops after exposure to high doses of ionizing radiation and features immune suppression and organ failure. Currently, there are no diagnostics to identify the occurrence or severity of exposure and there are limited treatments and preventative strategies to mitigate ARS. Extracellular vesicles (EVs) are mediators of intercellular communication that contribute to immune dysfunction across many diseases. We investigated if EV cargo can identify whole body irradiation (WBIR) exposure and if EVs promote ARS immune dysfunction. We hypothesized that beneficial EVs derived from mesenchymal stem cells (MSC-EVs) would blunt ARS immune dysfunction and might serve as prophylactic radioprotectants. Mice received WBIR (2 or 9 Gy) with assessment of EVs at 3 and 7 days after exposure. LC-MS/MS proteomic analysis of WBIR-EVs found dose-related changes as well as candidate proteins that were increased with both doses and timepoints (34 total) such as Thromboxane-A Synthase and lymphocyte cytosolic protein 2. Suprabasin and Sarcalumenin were increased only after 9 Gy suggesting these proteins may indicate high dose/lethal exposure. Analysis of EV miRNAs identified miR-376 and miR-136, which were increased up to 200- and 60-fold respectively by both doses of WBIR and select miRNAs such as miR-1839 and miR-664 were increased only with 9 Gy. WBIR-EVs (9 Gy) were biologically active and blunted immune responses to LPS in RAW264.7 macrophages, inhibiting canonical signaling pathways associated with wound healing and phagosome formation. When given 3 days after exposure, MSC-EVs slightly modified immune gene expression changes in the spleens of mice in response to WBIR and in a combined radiation plus burn injury exposure (RCI). MSC-EVs normalized the expression of certain key immune genes such as NFκBia and Cxcr4 (WBIR), Map4k1, Ccr9 and Cxcl12 (RCI) and lowered plasma TNFα cytokine levels after RCI. When given prophylactically (24 and 3 hours before exposure), MSC-EVs prolonged survival to the 9 Gy lethal exposure. Thus, EVs are important participants in ARS. EV cargo might be used to diagnose WBIR exposure, and MSC-EVs might serve as radioprotectants to blunt the impact of toxic radiation exposure.

Bactericidal and anti-inflammatory effects of Moquilea tomentosa Benth. flavonoid-rich leaf extract

BackgroundNatural products are an important source of bioproducts with pharmacological properties. Here we investigate the components of leaves from M. tomentosa Benth. (Fritsch) (Chrysobalanaceae) and its effects on bacterial cell growth, biofilm production and macrophage activity.MethodsThe effect of the different leaf extracts against bacterial cell growth was performed using the microdilution method. The most active extract was analyzed by mass spectrometry, and its effect on bacterial biofilm production was evaluated on polystyrene plates. The extract effect on macrophage activity was tested in the RAW264.7 cell line, which was stimulated with different concentrations of the extract in the presence or absence of LPS.ResultsWe show that the ethyl acetate (EtOAc) extract was the most effective against bacterial cell growth. EtOAc extract DI-ESI (-)MSn analysis showed the presence of a glycosylated flavonoid tentatively assigned as myricetin 3-O-xylosyl-rhamnoside (MW 596). Also, the EtOAc extract increased biofilm formation by S. aureus and inhibited cytokine and NO production induced by LPS in RAW macrophages.ConclusionM. tomentosa flavonoid-enriched EtOAc extract presented a bactericidal and anti-inflammatory pharmacological potential.

(+)/(-)-Yanhusamides A-C, three pairs of unprecedented benzylisoquinoline-pyrrole hetero-dimeric alkaloid enantiomers from Corydalis yanhusuo.

A chemical investigation on the aqueous extract of Corydalis yanhusuo tubers led to the isolation and structural elucidation of three pairs of trace enantiomeric hetero-dimeric alkaloids, (+)/(-)-yanhusamides A-C (1-3), featuring an unprecedented 3,8-diazatricylco[5.2.2.02,6]undecane-8,10-diene bridged system. Their structures were exhaustively characterized by X-ray diffraction, comprehensive spectroscopic data analysis, and computational methods. Guided by the hypothetical biosynthetic pathway for 1-3, a gram-scale biomimetic synthesis of (±)-1 was achieved in 3 steps using photoenolization/Diels-Alder (PEDA) [4+2] cycloaddition. Compounds 1‒3 exhibited potent inhibition of NO production induced by LPS in RAW264.7 macrophages. The invivo assay showed that oral administration of 30mg/kg of (±)-1 attenuated the severity of rat adjuvant-induced arthritis (AIA). Additionally, (±)-1 induced a dose-dependent antinociceptive effect in the acetic acid-induced mice writhing assay.

Ochrathinols A and B, two pairs of sulfur-containing racemates from an Antarctic fungus Aspergillus ochraceopetaliformis SCSIO 05702 inhibit LPS-induced pro-inflammatory cytokines and NO production

Ochrathinols A and B ((±)-1 and (±)-2), two undescribed sulfur-containing racemates, and ochracids A and B (3 and 4), two unprecedented pyrrolizidine alkaloids, were isolated from an Antarctic soil-derived fungus Aspergillus ochraceopetaliformis SCSIO 05702. Their structures including absolute configurations were determined through extensive spectroscopic analysis, chiral-phase HPLC analysis, quantum ECD calculations, and X-ray single-crystal diffraction. Ochrathinols A and B are unprecedented sulfur natural products featuring a novel 3-methylhexahydro-2H-cyclopenta [b]thiophene core. Interestingly, ochrathinol A ((±)-1) outstandingly suppressed the release of LPS-induced IL-1β, IL-6, and TNF-α inflammatory cytokines with concentration of 10 μM and alleviated the unbalanced NAD+/NADH ratio caused by LPS in RAW264.7 macrophages.

Low-intensity pulsed ultrasound promotes skeletal muscle regeneration via modulating the inflammatory immune microenvironment.

Background: Low-intensity pulsed ultrasound (LIPUS, a form of mechanical stimulation) can promote skeletal muscle functional repair, but a lack of mechanistic understanding of its relationship and tissue regeneration limits progress in this field. We investigated the hypothesis that specific energy levels of LIPUS mediates skeletal muscle regeneration by modulating the inflammatory microenvironment. Methods: To address these gaps, LIPUS irritation was applied in vivo for 5 min at two different intensities (30mW/cm2 and 60mW/cm2) in next 7 consecutive days, and the treatment begun at 24h after air drop-induced contusion injury. In vitro experiments, LIPUS irritation was applied at three different intensities (30mW/cm2, 45mW/cm2, and 60mW/cm2) for 2 times 24h after introduction of LPS in RAW264.7. Then, we comprehensively assessed the functional and histological parameters of skeletal muscle injury in mice and the phenotype shifting in macrophages through molecular biological methods and immunofluorescence analysis both in vivo and in vitro. Results: We reported that LIPUS therapy at intensity of 60mW/cm2 exhibited the most significant differences in functional recovery of contusion-injured muscle in mice. The comprehensive functional tests and histological analysis in vivo indirectly and directly proved the effectiveness of LIPUS for muscle recovery. Through biological methods and immunofluorescence analysis both in vivo and in vitro, we found that this improvement was attributable in part to the clearance of M1 macrophages populations and the increase in M2 subtypes with the change of macrophage-mediated factors. Depletion of macrophages in vivo eliminated the therapeutic effects of LIPUS, indicating that improvement in muscle function was the result of M2-shifted macrophage polarization. Moreover, the M2-inducing effects of LIPUS were proved partially through the WNT pathway by upregulating FZD5 expression and enhancing β-catenin nuclear translocation in macrophages both in vitro and in vivo. The inhibition and augment of WNT pathway in vitro further verified our results. Conclusion: LIPUS at intensity of 60mW/cm2 could significantly promoted skeletal muscle regeneration through shifting macrophage phenotype from M1 to M2. The ability of LIPUS to direct macrophage polarization may be a beneficial target in the clinical treatment of many injuries and inflammatory diseases.

Optimization of enzymatic extraction, characterization and bioactivities of Se-polysaccharides from Se-enriched Lentinus edodes

Selenium (Se) is a necessary micronutrient, while Se-deficiency is common in most areas worldwide. Developing dietary Se-supplements can address this issue. Se-enriched Lentinus edodes are good sources of natural Se-polysaccharides that are promising dietary Se-supplements. However, Se-polysaccharides from Se-enriched Lentinus edodes (Se–P-LE) fruit body via enzymatic-extraction (EE) have only been sparsely studied. Thus, the EE of Se–P-LE was optimized via Box-Behnken and uniform test, and the physicochemical and bio-functional properties of Se–P-LE were investigated herein. The results showed that the optimized EE conditions were: extracting temperature of 45 °C, pH of 4.5, time of 85 min and a liquid-solid ratio of 20:1 mL/g. The addition amount of cellulase, papain and pectinase were 0.80, 0.65 and 0.8 g/100 g samples, respectively. Under this condition, Se–P-LE yield was 18.16 ± 0.10%, and the Se content of Se–P-LE was 29.51 ± 0.23 μg/100 g. Characterization of Se–P-LE showed that Se–P-LE were Se-conjugated polysaccharides with pyranoglycan and β-glycosidic linkages. Se–P-LE were composed of 8 monosaccharides with shear-thinning properties and microcrystalline/amorphous structures. The bioactivities assays showed that Se–P-LE displayed a higher DPPH and hydroxyl radical scavenging rate than ordinary polysaccharides. Besides, Se–P-LE significantly reduced mRNA expression and levels of pro-inflammation factors (NO, IL-6/1β and TNF-α) caused by LPS in RAW264.7 cell line.

Antimicrobial peptide HI-3 from Hermetia illucens alleviates inflammation in lipopolysaccharide-stimulated RAW264.7 cells via suppression of the nuclear factor kappa-B signaling pathway.

Hermetia illucens-3 (HI-3), an active insect antimicrobial peptide extracted from H. illucens larvae, exerts antibacterial and anticancer activity. However, the inflammatory effects and their relative molecular mechanisms remain unclear. To explore the inflammatory effects of HI-3, an inflammatory model was induced using 1 ng/mL LPS in RAW264.7 cells. The cell viability and phagocytosis of LPS-stimulated RAW264.7 cells were then detected after HI-3 treatment. Furthermore, the antioxidant activity, the levels of proinflammatory cytokines, and the expression levels of both p65 and inhibitor of nuclear factor kappa B (IκB) were measured. Results showed that HI-3 could inhibit the differentiation, proliferation, phagocytosis, and antioxidant ability, as well as the secretion and messenger RNA expression levels of IL-6, TNF-α, and IL-1β of LPS-induced RAW264.7 cells in a dose-dependent manner. At the same time, the level of the anti-inflammatory cytokine IL-10 was increased after HI-3 treatment. Western blotting results showed that HI-3 suppressed LPS-induced p65 and IκB activation in a dose-dependent manner. Therefore, HI-3 exerts its anti-inflammatory effect by inhibiting the expression of proinflammatory cytokines and the activation of p65 and IκB, which indicated that HI-3 could be a promising therapeutic medicine for inflammation.

Sinomenine inhibits macrophage M1 polarization by downregulating α7nAChR via a feedback pathway of α7nAChR/ERK/Egr-1

BackgroundSinomenine (SIN) is an anti-inflammatory drug that has been used for decades in China to treat arthritis. In a previous study, SIN acted on α7 nicotinic acetylcholine receptor (α7nAChR) to inhibit inflammatory responses in macrophages, which indicates a new anti-inflammatory mechanism of SIN. However, the level of α7nAChR was increased in the inflammatory responses and was downregulated by SIN in vitro, so the underlying mechanisms of SIN acting on α7nAChR remain unclear. PurposeTo analyze the role of α7nAChR in inflammation and the effect and mechanism of SIN regulation of α7nAChR. MethodsThe effects of SIN on α7nAChR in endotoxemic mice and LPS-stimulated macrophages were observed. Nicotine (Nic) was used as a positive control, and berberine (Ber) was used as a negative control targeting α7nAChR. The antagonists of α7nAChR, α-bungarotoxin (BTX) and mecamylamine (Me), were used to block α7nAChR. In RAW264.7 macrophage cells in vitro, α7nAChR short hairpin RNA (shRNA) was used to knock down α7nAChR. Macrophage polarization was analyzed by the detection of TNF-α, IL-6, iNOS, IL-10, Arg-1, and Fizz1. U0126 was used to block ERK phosphorylation. The cytokines α7nAChR, ERK1/2, p-ERK1/2 and Egr-1 were detected. ResultsSIN decreased the levels of TNF-α, IL-6 and the expression of α7nAChR increased by LPS in endotoxemic mice. The above effects of SIN were attenuated by BTX. In the α7nAChR shRNA transfected RAW264.7 cells, compared with the control, α7nAChR was knocked down, and M1 phenotype markers (including TNF-α, IL-6, and iNOS) were significantly downregulated, whereas M2 phenotype markers (including IL-10, Arg-1, and Fizz1) were significantly upregulated when stimulated by LPS. SIN inhibited the expression of p-ERK1/2 and the transcription factor Egr-1 induced by LPS in RAW264.7 cells, and the above effects of SIN were attenuated by BTX. The expression of α7nAChR was suppressed by U0126, which lessened the expression of p-ERK1/2 and Egr-1. ConclusionsSIN acts on α7nAChR to inhibit inflammatory responses and downregulates high expression of α7nAChR in vivo and in vitro. The increase of α7nAChR expression is correlated with inflammatory responses and participates in macrophage M1 polarization. SIN downregulates α7nAChR via a feedback pathway of α7nAChR/ERK/Egr-1, which contributes to inhibiting macrophage M1 polarization and inflammatory responses.

Chemical investigation and anti-inflammatory activities of the aerial part of Filipendula palmata

Ethnopharmacological relevanceFilipendula palmata Maxim. as an ethnic herb is commonly used by Oroqen minority people in the treatment of rheumatism in China and as a wild vegetable is eaten by Russian in the Far East area. However, so far, the chemical constituents and bioactivity of this edible herb are still unclear, especially the anti-inflammatory constituents and action have not been elucidated despite the traditional folk use. Aim of study: The current study was conducted to investigate the main chemical components of the aerial part of F. palmata and evaluate the anti-inflammatory and antioxidant and cytotoxic activities of the extract and the isolated constituents. Materials and methods: Various chromatographic techniques including silica gel, ODS, HPLC were used to isolate the components and several spectroscopic methods such as UV, IR, MS and NMR were adopted to characterize the structures of the compounds. The inhibitory action of the extract and components on the production of nitric oxide stimulated by LPS in RAW264.7 cells was applied to evaluate the anti-inflammatory activity and the MTT method was used to investigate the cytotoxicity. In addition, the antioxidant capacity of F. palmata was measured in three in vitro assays including DPPH and hydroxyl radicals scavenging and FRAP experiments. Results: The bioactivity research demonstrated that the EtOAc fraction and n-BuOH fraction of this ethnic herb possessed potent anti-inflammation activity in RAW264.7 macrophages and antioxidant activity in three in vitro assays. The chemical study on the EtOAc fraction led to a new dihydrophenanthrene derivative, filipendutin A (1), together with 9 known compounds from the herb, in which compound 4 could significantly inhibit the production of nitric oxide in RAW264.7 cells, while compounds 1 and 9 exhibited obvious cytotoxicity in cells. Conclusions: These results demonstrated that F. palmata had significant anti-inflammatory and antioxidant activities and could be used in the treatment of inflammatory diseases. Meanwhile, the cytotoxic activity of EtOAc fraction and its components also indicated the potential application in antitumor which remained the further study in the future.