The regulatory effect of oxymatrine on the TLR4/MyD88/NF-κB signaling pathway in lipopolysaccharide-induced MS1 cells

Exploring the Neuroprotective Potential of N-Methylpyridinium against LPS-Induced Neuroinflammation: Insights from Molecular Mechanisms

N-methylpyridinium (NMP) is produced through the pyrolysis of trigonelline during the coffee bean roasting process. Preliminary studies suggest that NMP may have health benefits, thanks to its antioxidant properties. Based on this background, the aim of this study was to evaluate whether NMP could have a protective effect against LPS-induced neuroinflammation in human glioblastoma cells (U87MG). With this aim, U87MG cells were pre-treated with NMP (0.5 μM) for 1 h and then exposed to LPS (1 μg/mL) for 24 h. Our findings show that NMP attenuates LPS-induced neuroinflammation by reducing the expression of pro-inflammatory cytokines, such as IL-1β, TNF-α and IL-6, through the inhibition of the NF-κB signaling pathway, which is critical in regulating inflammatory responses. NMP is able to suppress the activation of the NF-κB signaling pathway, suggesting its potential in preventing neuroinflammatory conditions. These outcomes support the notion that regular consumption of NMP, possibly through coffee consumption, may offer protection against neuroinflammatory states implicated in neurological disorders.

Acteoside and isoacteoside alleviate renal dysfunction and inflammation in lipopolysaccharide-induced acute kidney injuries through inhibition of NF-κB signaling pathway

Acute kidney injury (AKI) is a sudden loss of renal function with a high mortality rate and inflammation is thought to be the underlying cause. The phenylpropanoid components acteoside (ACT) and isoacteoside (ISO), which were isolated from Cistanche deserticola Y.C.Ma, have been reported to have preventive effects against kidney disorders. This study aimed to investigate the anti-inflammatory properties and protective mechanisms of ACT and ISO. In this investigation, kidney function was assessed using a semi-automatic biochemical analyzer, histopathology was examined using Hematoxylin-Eosin staining and immunohistochemistry, and the concentration of inflammatory cytokines was assessed using an enzyme-linked immunosorbent assay (ELISA) test. In addition, using Western blot and q-PCR, the expression of proteins and genes connected to the NF-κB signaling pathway in mice with lipopolysaccharide (LPS)-induced AKI was found. The findings showed that under AKI intervention in LPS group, ACT group and ISO group, the expression of Rela (Rela gene is responsible for the expression of NFκB p65 protein) and Tlr4 mRNA was considerably elevated (P<0.01), which led to a significant improvement in the expression of MyD88, TLR4, Iκ-Bɑ and NF-κB p65 protein (P<0.001). The levels of Alb, Crea and BUN (P<0.001) increased along with the release of downstream inflammatory factors such as IL-1β, IL-6, Cys-C, SOD1 and TNF-α (P<0.001). More importantly, the study showed that ISO had a more favorable impact on LPS-induced AKI mice than ACT. In conclusion, by inhibiting NF-κB signaling pathway, ACT and ISO could relieve renal failure and inflammation in AKI, offering a fresh possibility for the therapeutic management of the condition.

The inflammatory profiles of pulmonary alveolar macrophages and alveolar type 2 cells in SCD

The lung microenvironment plays a crucial role in maintaining lung homeostasis as well as the initiation and resolution of both acute and chronic lung injury. Acute chest syndrome (ACS) is a complication of sickle cell disease (SCD) like acute lung injury. Both the endothelial cells and peripheral blood mononuclear cells are known to secrete proinflammatory cytokines elevated during ACS episodes. However, in SCD, the lung microenvironment that may favor excessive production of proinflammatory cytokines and the contribution of other lung resident cells, such as alveolar macrophages and alveolar type 2 epithelial (AT-2) cells, to ACS pathogenesis is not completely understood. Here, we sought to understand the pulmonary microenvironment and the proinflammatory profile of lung alveolar macrophages (LAMs) and AT-2 cells at steady state in Townes sickle cell (SS) mice compared to control mice (AA). In addition, we examined lung function and micromechanics molecules essential for pulmonary epithelial barrier function in these mice. Our results showed that bronchoalveolar lavage (BAL) fluid in SS mice had elevated protein levels of pro-inflammatory cytokines interleukin (IL)-1β and IL-12 (p ⩽ 0.05) compared to AA controls. We showed for the first time, significantly increased protein levels of inflammatory mediators (Human antigen R (HuR), Toll-like receptor 4 (TLR4), MyD88, and PU.1) in AT-2 cells (1.4 to 2.2-fold) and LAM (17-21%) isolated from SS mice compared to AA control mice at steady state. There were also low levels of anti-inflammatory transcription factors (Nrf2 and PPARy) in SS mice compared to AA controls (p ⩽ 0.05). Finally, we found impaired lung function and a dysregulated composition of surfactant proteins (B and C). Our results demonstrate that SS mice at steady state had a compromised lung microenvironment with elevated expression of proinflammatory cytokines by AT-2 cells and LAM, as well as dysregulated expression of surfactant proteins necessary for maintaining the alveolar barrier integrity and lung function.

A Focused Review on Molecular Signalling Mechanisms of Ginsenosides Anti-Lung Cancer and Anti-inflammatory Activities

BACKGROUND

Ginseng (Panax ginseng Meyer) is a cultivated medicinal herb that has been widely available in the Asian region since the last century. Ginseng root is used worldwide in Oriental medicine. Currently, the global mortality and infection rates for lung cancer and inflammation are significantly increasing. Therefore, various preventative methods related to the activity of ginsenosides have been used for lung cancer as well as inflammation.

METHODS

Web-based searches were performed on Web of Science, Springer, PubMed, and Scopus. A cancer statistical analysis was also conducted to show the current ratio of affected cases and death from lung cancer around the world.

RESULTS

Ginsenosides regulate the enzymes that participate in tumor growth and migration, such as nuclear factor kappa B (NF-κB), mitogen-activated protein kinase (p38 MAPK), c-Jun N-terminal kinase (JNK), extracellular signalregulated kinases 1/2 (ERK1/2), the gelatinase network metalloproteinase-2 (MMP-2/9) and activator protein 1 (AP-1). In addition, ginsenosides also possess anti-inflammatory effects by inhibiting the formation of proinflammatory cytokines (tumor necrosis factor-α) (TNF-α) and interleukin-1β (IL-1β) and controlling the activities of inflammatory signalling pathways, such as NF-κB, Janus kinase2/signal transducer, and activator of transcription 3 (Jak2/Stat3).

CONCLUSION

In several in vitro and in vivo models, P. ginseng showed potential beneficial effects in lung cancer and inflammation treatment. In this review, we provide a detailed and up-to-date summary of research evidence for antilung cancer and anti-inflammatory protective effects of ginsenosides and their potential molecular mechanisms.

The biological activities of quinolizidine alkaloids

Quinolizidine alkaloids isolated from various marine and terrestrial animals and plants are primarily composed of lupinine-, matrine-, and sparteine-type alkaloids. Matrine, phenanthroquinolizidines, bis-quinolizidines, and small molecules from amphibian skins are representative compounds of such alkaloids. Quinolizidine alkaloids harbor anticancer, antibacterial, antiinflammatory, antifibrosis, antiviral, and anti-arrhythmia. In this chapter, we comprehensively outline the biological activity and pharmacological action of quinolizidine alkaloids and discuss new avenues toward the discovery of novel and more efficient drugs based on these naturally occurring compounds. It is urgent for basic research and clinical practice to conduct more targeted comprehensive research based on the lead drugs of quinolizidine alkaloids with significant pharmacological activity.

Anti-Inflammatory Effects and Molecular Mechanisms of Shenmai Injection in Treating Acute Pancreatitis: Network Pharmacology Analysis and Experimental Verification

Background

Acute pancreatitis (AP) is an inflammatory disorder of the exocrine pancreas without specific treatment. Shenmai injection (SMI) was reported to eliminate the severity of experimental AP. This study aimed to explore the mechanisms underlying the synergistic protective effects of SMI on AP based on network pharmacology and experimental validation.

Methods

Network pharmacology analysis and molecular docking based on identified components were performed to construct the potential therapeutic targets and pathways. The principal components of SMI were detected via ultra-high-performance liquid chromatography-coupled with quadrupole time-of-flight mass spectrometry (UHPLC-QTOF/MS). Effect of SMI and the identified components on cellular injury and IL6/STAT3 signaling was assessed on mouse pancreatic acinar cell line 266–6 cells. Finally, 4% sodium taurocholate (NaT) was used to induce AP model to assess the effects of SMI in treating AP and validate the potential molecular mechanisms.

Results

By searching the TCMSP and ETCM databases, 119 candidate components of SMI were obtained. UHPLC-QTOF/MS analysis successfully determined the representative components of SMI: ginsenoside Rb1, ginsenoside Rg1, ginsenoside Re, and ophiopogonin D. Fifteen hub targets and eight related pathways were obtained to establish the main pharmacology network. Subnetwork analysis and molecular docking indicated that the effects of these four main SMI components were mostly related to the interleukin (IL) 6/STAT3 pathway. In vitro, SMI, ginsenoside Rb1, ginsenoside Rg1, ginsenoside Re, and ophiopogonin D increased the cell viability of NaT-stimulated mouse pancreatic acinar 266–6 cells and decreased IL6 and STAT3 expression. In vivo, 10 mL/kg SMI significantly alleviated the pancreatic histopathological changes and the expression of IL6 and STAT3 in the AP mice.

Conclusion

This study demonstrated SMI may exert anti-inflammatory effects against AP by suppressing IL6/STAT3 activation, thus providing a basis for its potential use in clinical practice and further study in treating AP.

Effect of Tea Tree Oil on the Expression of Genes Involved in the Innate Immune System in Goat Rumen Epithelial Cells

Simple Summary

Subacute rumen acidosis (SARA) often causes significant losses on commercial farms. SARA is mainly caused by endotoxin (LPS) produced by the lysis of Gram-negative bacteria, which causes an inflammatory response. To alleviate the inflammatory response mediated by LPS, it is important to improve animal production performance. Tea tree oil (TTO) is a plant extract that possesses good bactericidal and anti-inflammatory effects. According to this study, LPS can significantly induce inflammatory responses in goat rumen epithelial cells (GRECs), while the addition of TTO could markedly mitigate inflammatory responses mediated by LPS in GRECs. Therefore, it may be useful for the treatment of SARA.

Abstract

In subacute rumen acidosis (SARA), the rumen epithelium is frequently attacked by endotoxin (LPS), which is caused by the lysis of dead Gram-negative bacteria. However, the rumen epithelium innate immune system can actively respond to the infection. Previous studies have demonstrated that tea tree oil (TTO) has good bactericidal and anti-inflammatory effects. Therefore, the aim of this study was to investigate the effect of TTO on the expression of genes involved in the inflammatory cytokines in goat rumen epithelial cells (GRECs) triggered by LPS. Our study shows that rumen epithelial cells isolated from goat rumen tissue can be cultured in vitro in 0.25% trypsin for a long time. These cells were identified as epithelial cells by the expression of cytokeratin 18, monocarboxylate transporter 4 (MCT4), Na[+]/H[+] hydrogen exchanger 1 (NHE1), putative anion transporter 1 (PAT1), vH⁺ ATPase B subunit (vH⁺ ATPase), and anion exchanger 2 (AE2). The mRNA expression of IL-1β, IL-6, TNF-α, TLR-2, NF-κB, CXCL6 and CXCL8 genes was significantly increased when LPS was used compared to untreated controls. In addition, mRNA expression of IL-1β, IL-6, TNF-α, TLR-2, NF-κB, CXCL8, CXCL6 and interferon-induced protein with tetratricopeptide repeats 3 (IFIT3) genes was also significantly higher in the LPS group compared to the 0.05% TTO group. However, the expression of IL-1β, IL-6, TNF-α, TLR-2, CXCL6 and IFIT3 genes was significantly lower in the LPS and 0.05% TTO group compared to the 1 μg/mL LPS group. These results suggest that TTO can inhibit LPS-induced inflammatory cytokines expression in GRECs.

Oleuropein Attenuates Lipopolysaccharide-Induced Acute Kidney Injury In Vitro and In Vivo by Regulating Toll-Like Receptor 4 Dimerization

Acute kidney injury (AKI) is a common critical illness that involves multiple systems and multiple organs with a rapid decline in kidney function over short period. It has a high mortality rate and presents a great treatment challenge for physicians. Oleuropein, the main active constituent of Ilex pubescens Hook. et Arn. var. kwangsiensis Hand.-Mazz. displays significant anti-inflammatory activity, although oleuropein’s therapeutic effect and mechanism of action in AKI remain to be elucidated. The present study aimed to further clarify the mechanism by which oleuropein exerts effects on inflammation in vitro and in vivo. In vitro, the inflammatory effect and mechanism were investigated through ELISA, Western blotting, the thermal shift assay, co-immunoprecipitation, and immunofluorescence staining. Lipopolysaccharide (LPS) induced acute kidney injury was employed in an animal model to investigate oleuropein’s therapeutic effect on AKI and mechanism in vivo. The underlying mechanisms were investigated by Western blot analysis of kidney tissue. In LPS-stimulated macrophages, our data demonstrated that oleuropein significantly reduced the expression of inflammatory mediators like NO, IL-6, TNF-α, iNOS, and COX-2. Moreover, oleuropein inhibited NF-κB/p65 translocation, and had a negative regulatory effect on key proteins in the NF-κB and MAPK pathways. In addition, the thermal shift and co-immunoprecipitation assays revealed that oleuropein played an essential role in binding to the active sites of TLR4, as well as inhibiting TLR4 dimerization and suppressing the binding of TLR4 to MyD88. Oleuropein markedly alleviated LPS induced acute kidney injury, decreased serum creatinine and blood urea nitrogen (BUN) levels and proinflammatory cytokines. More importantly, the TLR4-MyD88-NF-κB/MAPK pathways were confirmed to play an important role in the oleuropein treatment of AKI. In this study, oleuropein exhibited excellent anti-inflammatory effects by regulating TLR4-MyD88-NF-κB/MAPK axis in vitro and in vivo, suggesting oleuropein as a candidate molecule for treating AKI.

Low molecular weight-PAHs induced inflammation in A549 cells by activating PI3K/AKT and NF-κB signaling pathways

Our previous study has demonstrated that two low molecular weight-polycyclic aromatic hydrocarbons (LMW-PAHs), phenanthrene (Phe) and fluorene (Flu), alone and as a mixture could induce oxidative damage and inflammation in A549 cells. However, the associated mechanisms have not been well discussed. The aim of this study was to further investigate the roles of PI3K/AKT and NF-κB signaling pathways in the inflammatory effects in A549 cells induced by Phe, Flu and their mixture. The results indicated that Phe, Flu and their mixture significantly activated PI3K/AKT and NF-κB signaling pathways by increasing the phosphorylation levels of PI3K, AKT, IκBα and NF-κB p65. In addition, pro-inflammatory cytokine expressions of TNF-α and IL-6 induced by the binary mixture of Phe and Flu were all alleviated by co-treatment with PI3K/AKT and NF-κB specific inhibitors (LY294002 and BAY11-7082). The results suggested that PI3K/AKT and NF-κB signaling pathways played an important role in LMW-PAHs induced inflammation in A549 cells.

TLR4-MyD88-NF-κB signaling pathway contributes to the progression of secondary hepatic injury and fibrosis in hepatolithiasis

This paper focused on evaluating the effect of TLR4-MyD88-NF-κB signaling pathway in the progression of secondary hepatic injury and fibrosis in hepatolithiasis. The levels of inflammatory factors (IL-1β, IL-6, TNF-α) and serum biochemical values (ALT, AST, Tbil, Dbil, ALP, GGT) were detected by ELISA. IHC was used to detected the expression level of TLR4 in liver tissues of hepatolithiasis patients and mice. The pathological changes of liver tissue were observed by HE staining. The levels of MyD88, NF-κB, IκB, Laminin (LN), and chitosan enzyme 3-like protein 1 (CHI3L1) were detected by western blotting. In hepatolithiasis patients, the levels of TNF-α, IL-1β, and IL-6 were distinctly raised and proteins associated with TLR4-MyD88-NF-κB signaling pathway (such as TLR4, MyD88, NF-κB, and IκB) in liver tissues were significantly up-regulated. In Bile duct ligation (BDL) model of mice, the results showed that in addition to the significant increase of inflammatory factors, liver function indexes, and fibrosis indexes in BDL mice were also significantly up-regulated. Additionally, TLR4-MyD88-NF-κB signaling pathway was activated in BDL mice. After TLR4 knockdown in BDL mice, inflammatory factors, liver function indexes, and fibrosis indexes were significantly down-regulated. TLR4-MyD88-NF-κB signaling pathway proteins were restrained. TLR4-MyD88-NF-κB signaling pathway took part in the progression of secondary hepatic injury and fibrosis in hepatolithiasis. Inhibition of TLR4-MyD88-NF-κB signaling pathway can reduce the progression of secondary hepatic injury and fibrosis in hepatolithiasis.

Ganoderma lucidum Rhodiola compound preparation prevent D-galactose-induced immune impairment and oxidative stress in aging rat model

Aging is an irreversible process. This research aims to study the anti-aging effects of GRCP, a compound preparation made by Ganoderma lucidum and Rhodiola rosen, in aging rats. Rats were subcutaneously injected with 400 mg/kg of D-galactose daily, and aging could be induced after 8 weeks. The aging rats were treated with GRCP. This experiment was divided into 6 groups. Rats were randomly divided into the model group, positive control group, low-dose GRCP group (25 mg/kg body weight), medium-dose GRCP group (50 mg/kg body weight), and high-dose GRCP group (100 mg/kg body weight), healthy and normal rats were used as blank controls. After the end, the results show that the use of GRCP at a dose of 100 mg/kg is the best treatment for improving aging rats. Rats gained weight, spleen and thymus indexes, and splenocyte proliferation improved, and inflammatory cytokine levels decreased. Besides, biochemical indicators show that GRCP can improve the antioxidant enzyme activity and reduce the content of lipofuscin and TGF-β in aging rats (P < 0.05). GRCP can also inhibit the activation of the MyD88/NF-κB pathway in rat hippocampus. These results seem to suggest that GRCP can be used as a potential natural supplement or functional food to prevent aging.

Suppression of inflammatory cascades via novel cinnamic acid nanoparticles in acute hepatitis rat model

Hepatitis was characterized by extreme inflammation and hepatocellular damage. Therefore, the current study aimed to gain insights into the modulation role of Cinnamic acid nanoparticles (CANPs) against acute hepatitis induced by d-Galactosamine and gamma radiation exposure (D-Gal/radiation) in the rat model and to suggest the implied molecular mechanism of CANPs. Acute hepatitis seriousness and the serum enzyme activities of ALT, AST, and ALP have been diminished upon oral administration of CANPs. Besides, the hepatic tissue levels of malondialdehyde (MDA) and nitric oxide (NO) have been significantly decreased, and the total antioxidant activity (TAO) depletion was extremely restored. Furthermore, the reduction of hepatic damage caused by pretreatment with CANPs was accompanied by significant suppression in the levels of hepatic proinflammatory cytokines (TNF-α, IL-1β, and IL-18), NF-κB, NLRP3, caspase-1 and proapoptotic protein BAX whereas anti-apoptotic protein Bcl-2 level significantly elevated as compared with D-Gal/radiation-induced acute hepatitis (AH) group. Also, CANPs suppress the D-Gal/radiation-induced IL-1β, IL-18, and ASK1 mRNA gene expression and the protein expression of TLR4 and MyD88 in the hepatic tissue. These biochemical parameters are confirmed by histological examination of the liver tissues. The present results indicated that CANPs can protect the hepatic cells from damage by both its anti-inflammatory and antioxidant influence as well as by modulating oxidation cellular pathways that have contributed to the acute severity of hepatitis. Also, CANPs is capable of suppressing apoptosis. Consequently, Nanoparticles of Cinnamic acid have the medicinal ability to protect the liver from acute hepatitis.

LncRNA-AK149641 regulates the secretion of tumor necrosis factor-α in P815 mast cells by targeting the nuclear factor-kappa B signaling pathway

Long noncoding RNAs play important roles in various biological processes. However, not much is known about their roles in inflammatory response. Mast cells, involved in innate and adaptive immunity, are one of the major effector cells in allergic inflammatory reactions and contribute to the pathogenesis of disorders, including asthma. In the present study, we aimed to verify and elucidate the function and possible role of a novel lncRNA, called lncRNA-AK149641, in the mechanism of lipopolysaccharide (LPS)-induced inflammatory response in P815 mast cells. The results showed that downregulating lncRNA-AK149641 decreased secretion of tumor necrosis factor-α into the supernatants of LPS-stimulated mast cells. Mechanistically, the activity of nuclear factor-kappa B (NF-κB) decreased after downregulating lncRNA-AK149641, as shown by western blot and electrophoretic mobility shift assays. Moreover, RNA binding protein immunoprecipitation (RIP) verified that lncRNA-AK149641 was able to bind to NF-κB in the nucleus. In conclusion, we demonstrated that lncRNA-AK149641 regulated LPS-induced inflammatory response in mast cells through the NF-κB signaling pathway.

Prospect and clinical value of oxymatrine in prevention and treatment of pancreatic fibrosis

Studies have confirmed that pancreatic stellate cell activation is the central event in the initiation and development of pancreatic fibrosis (PF), but the specific mechanism of PF is still unknown, and there is no specific treatment for PF. Some basic studies have confirmed that oxymatrine (OMT) has a certain therapeutic effect on PF, but further research is needed. It can be predicted that OMT has a far-reaching research prospect and good clinical application value for the prevention and treatment of PF, and is also conducive to the better development and utilization of traditional Chinese herbal medicine radix sophorae flavescentis.

Chaiqin chengqi decoction alleviates severity of acute pancreatitis via inhibition of TLR4 and NLRP3 inflammasome: Identification of bioactive ingredients via pharmacological sub-network analysis and experimental validation

BACKGROUND

Chaiqin chengqi decoction (CQCQD) is a Chinese herbal formula derived from dachengqi decoction. CQCQD has been used for the management of acute pancreatitis (AP) in the West China Hospital for more than 30 years. Although CQCQD has a well-established clinical efficacy, little is known about its bioactive ingredients, how they interact with different therapeutic targets and the pathways to produce anti-inflammatory effects.

PURPOSE

Toll-like receptor 4 (TLR4) and the nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome-mediated pro-inflammatory signaling pathways, play a central role in AP in determining the extent of pancreatic injury and systemic inflammation. In this study, we screened the bioactive ingredients using a pharmacological sub-network analysis based on the TLR4/NLRP3 signaling pathways followed by experimental validation.

METHODS

The main CQCQD bioactive compounds were identified by UPLC-QTOF/MS. The TLR4/NLRP3 targets in AP for CQCQD active ingredients were confirmed through a pharmacological sub-network analysis. Mice received 7 intraperitoneal injections of cerulein (50 μg/kg; hourly) to induce AP (CER-AP), while oral gavage of CQCQD (5, 10, 15 and 20 g/kg; 3 doses, 2 hourly) was commenced at the 3rd injection of cerulein. Histopathology and biochemical indices were used for assessing AP severity, while polymerase chain reaction, Western blot and immunohistochemistry analyses were used to study the mechanisms. Identified active CQCQD compounds were further validated in freshly isolated mouse pancreatic acinar cells and cultured RAW264.7 macrophages.

RESULTS

The main compounds from CQCQD belonged to flavonoids, iridoids, phenols, lignans, anthraquinones and corresponding glycosides. The sub-network analysis revealed that emodin, rhein, baicalin and chrysin were the compounds most relevant for directly regulating the TLR4/NLRP3-related proteins TLR4, RelA, NF-κB and TNF-α. In vivo, CQCQD attenuated the pancreatic injury and systemic inflammation of CER-AP and was associated with reduced expression of TLR4/NLRP3-related mRNAs and proteins. Emodin, rhein, baicalin and chrysin significantly diminished pancreatic acinar cell necrosis with varied effects on suppressing the expression of TLR4/NLRP3-related mRNAs. Emodin, rhein and chrysin also decreased nitric oxide production in macrophages and their combination had synergistic effects on alleviating cell death as well as expression of TLR4/NLRP3-related proteins.

CONCLUSIONS

CQCQD attenuated the severity of AP at least in part by inhibiting the TLR4/NLRP3 pro-inflammatory pathways. Its active ingredients, emodin, baicalin, rhein and chrysin contributed to these beneficial effects.

Ginsenoside Rb1 exerts anti-inflammatory effects in vitro and in vivo by modulating toll-like receptor 4 dimerization and NF-kB/MAPKs signaling pathways

BACKGOUND

Ginsenoside Rb1, the main active constituent of Panax ginseng, displays significant anti-inflammatory activity, although the mechanism has not been clearly unraveled. In this study, Rb1's mechanism of anti-inflammatory effects were investigated.

METHODS

The flow cytometry and enzyme-linked immunosorbent assay (ELISA) were empolyed to detect pro-inflammatory cytokines release. The related protein and gene expression was investigated by western blotting and qRT-PCR. The dimerization of TLR4 was measured by co-immunoprecipitation and molecular docking assays. Cellular thermal shift assay was used for the determination of the binding of Rb1 and TLR4. For animal moldels, LPS- or cantharidin-induced acute kidney injury, LPS-induced septic death, and dimethyl benzene-induced ear edema were employed to investigate Rb1's anti-inflammatory activity in vivo.

RESULTS

Rb1 significantly decreased inflammatory cytokines release in LPS-stimulated RAW264.7 cells and BMDMs, as well as COX-2 and iNOS amounts. Rb1 reduced LPS-associated calcium influx, ROS production, and NO generation. The NF-κB and MAPK axes participated in Rb1's anti-inflammatory effects. Molecular docking simulation indicated Rb1 bound to TLR4 to prevent TLR4 dimerization, as confirmed by co-immunoprecipitation and cellular thermal shift assay. Furthermore, MyD88 recruitment and TAK1 expression were altered by reduced TLR4 dimerization, indicating the TLR4-MyD88-NF-κB/MAPK pathways contributed to Rb1's anti-inflammatory process. In animal models, Rb1 markedly alleviated LPS- or cantharidin-induced acute kidney injury, rescued LPS-induced septic mice from death, and inhibited dimethyl benzene-induced mouse ear edema.

CONCLUSION

Overall, these findings demonstrate Rb1 exhibits marked anti-inflammatory effects, suggesting Rb1 represents an optimal molecule for treating inflammatory diseases.

Anisodamine alleviates lipopolysaccharide-induced pancreatic acinar cell injury through NLRP3 inflammasome and NF-κB signaling pathway

Purpose: Anisodamine (An) has anti-inflammatory effects, but its role in acute pancreatitis is still unknown. This study aimed to explore the action mechanism of An pretreatment in lipopolysaccharide (LPS)-induced pancreatic acinar cells, hoping to provide a research basis for the disease treatment.Materials and methods: Pancreatic acinar cells were pretreated with An at different concentrations and then induced by LPS. The viability and apoptosis of the treated cells were measured by Cell Counting Kit-8 and flow cytometry. The releases of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-18 were measured by enzyme-linked immunosorbent assay. The expressions of thioredoxin-interacting protein (TXNIP), apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), NOD-like receptor protein 3 (NLRP3), Caspase-1, p65, and inhibitor of kappa B alpha (IκBα) in the treated cells were detected by Western blot and quantitative real-time polymerase chain reaction assay.Results: LPS promoted apoptosis of pancreatic acinar cells, suppressed cell viability, increased TNF-α, IL-1β, and IL-18 releases and the expression levels of TXNIP, ASC, NLRP3, Caspase-1, p-p65, and p-IκBα, however, such effects of LPS could be alleviated by An pretreatment with the strongest effect when the concentration of An was set at 100 μg/mL. Moreover, overexpressed NLRP3 aggravated the effects of LPS in pancreatic acinar cells, which could be reversed by pretreatment of 100 μg/mL An.Conclusion: An pretreatment attenuated LPS-induced apoptosis and inflammatory response of pancreatic acinar cells through suppressing NLRP3 and inactivating NF-κB signaling pathway, thus, it could be explored as a potential therapy for treating acute pancreatitis.

Lipoxin suppresses inflammation via the TLR4/MyD88/NF-κB pathway in periodontal ligament cells

Objective

The objective of the present study was to evaluate the anti‐inflammatory effects of lipoxin A4 (LXA4) for the treatment of periodontitis in an in vitro model.

Methods

Human PDLCs were challenged with Escherichia coli (E. coli) lipopolysaccharide (LPS) to evoke an inflammatory response. This was done either in monoculture or in coculture with THP‐1, a monocytic cell line. Thereafter, cytokine expression was measured by ELISA, with or without LXA4. In addition, the effects of LXA4 were analyzed on the TLR‐MyD88‐NF‐κB (TMN)‐mediated intracellular signal pathway using immunocytochemistry.

Results

In response to LPS, the level of the pro‐inflammatory cytokine tumor necrosis factor alpha increased, whereas the anti‐inflammatory cytokine interleukin‐4 decreased significantly (p < .05). These effects were consistently reversed when LPS‐challenged PDLCs were also treated with LXA4. The results in the coculture system were comparable to the monoculture. Immunohistochemistry and quantitative assessment confirmed the importance of the TMN signal pathway in these processes.

Conclusion

These results corroborate earlier findings that PDLCs play an important role in inflammation. Moreover, LXA4 might offer new approaches for the therapeutic treatment of periodontal disease.

Oxymatrine protects against l-arginine-induced acute pancreatitis and intestine injury involving Th1/Th17 cytokines and MAPK/NF-κB signalling

Context: Oxymatrine (OMT) has various pharmacological effects, including immune reaction regulation, anti-inflammation and anti-hypersensitive reaction. Objective: This is the first report to investigate the molecular mechanism of OMT function in l-arginine (Arg)-induced acute pancreatitis (AP) involving intestinal injury. Materials and methods: Rat pancreatic AR42J and small intestinal IEC-6 cells were treated with Arg (200-800 µM) for 48 h plus OMT (4 mg/mL) treatment. Thirty adult Wistar rats were randomly assigned to control (saline), AP (i.p. of 250 mg/100 g body weight Arg) and OMT (i.p. injection of 50 mg/kg b.w. OMT every 6 h following Arg). Both cells and rats were harvested at 48 h. Results: Arg-induced cell proliferation in both rats AR42J (EC₅₀ 633.9 ± 31.4 µM) and IEC-6 cells (EC₅₀ 571.3 ± 40.4 µM) in a dose-dependent manner, which was significantly inhibited by OMT (4 mg/mL). Meanwhile, Arg (600 µM) induced expression of proinflammatory cytokines (TNF-α, IL-6, IL-1β, NF-κB, IL-17A/IL-17F and IFN-γ) and activation of p-p38/p-ERK in vitro, which was reversed by OMT. In vivo, OMT (50 mg/kg) inhibited 250 mg/100 g of Arg-induced AP involving intestinal injury, including inhibiting Arg-induced inflammatory in pancreas and intestine, inhibiting Arg-induced increase of TNF-α, IL-6, IL-1β, NF-κB and p-p38/p-ERK-MAPK signalling, and inhibiting Arg-induced increase of IL-17A/IL-17F, IFN-γ, ROR-γt and T-bet. Meanwhile, OMT inhibited Arg-induced expression of CD44 and CD55 in intestinal injury. Discussion and conclusions: OMT protects against Arg-induced AP involving intestinal injury via regulating Th1/Th17 cytokines and MAPK/NF-κB signalling, which is a promising therapeutic agent in clinics.

Essential oil from Fructus Alpinia zerumbet (fruit of Alpinia zerumbet (Pers.) Burtt.et Smith) protected against aortic endothelial cell injury and inflammation in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Fructus Alpinia zerumbet (FAZ), a dry and ripe fruit of Alpinia zerumbet (Pers.) Burtt. et Smith, is widely used as a spice to treat cardiovascular diseases in clinic as a miao folk medicine in Guizhou Province of China. Essential oil extracted from FAZ (EOFAZ) is the key bioactive ingredients.

AIM OF THE STUDY

This study aimed to examine the effects and mechanisms of EOFAZ on lipopolysaccharide (LPS)-induced endothelial cell injury, inflammation and apoptosis in vitro and in vivo.

MATERIALS AND METHODS

For the in vitro study, LPS-treated human aortic endothelial cells were used to perform PCR, western blot analysis and immunofluorescence. For the in vivo study, male mouse were divided into four groups, vehicle control group and LPS group received 0.5% Tween-80 in saline; and two EOFAZ groups receive different dose of EOFAZ (90 mg kg ^-1·day^-1, 180 mg kg ^-1·day^-1) respectively. Each group was fed for 7 days by intragastrical administration at daily base. Then, except vehicle control group received saline, mice in other three groups were administered with LPS (1 mg kg ^-1, dissolved in saline) by intraperitoneal injection. 24 h later, Aorta tissue was collected and frozen immediately in liquid N₂, stored at -80 °C for western blot analysis.

RESULTS

We found that EOFAZ completely prevented LPS-induced HAEC activation and inflammation in vitro and in vivo, as assessed by expression of endothelial adhesion molecules, ICAM-1 and VCAM-1. Similarly, EOFAZ significantly blunted LPS-induced endothelial injury, as tested by MTT assay, LDH release and caspase-3 activation. We further demonstrated that TLR4-dependent NF-κB signaling may be involved in the process.

CONCLUSION

EOFAZ protected against LPS-induced endothelial cell injury and inflammation likely via inhibition of TLR4-dependent NF-κB signaling.

Standardized extract of Zingiber zerumbet suppresses LPS-induced pro-inflammatory responses through NF-κB, MAPK and PI3K-Akt signaling pathways in U937 macrophages

BACKGROUND

Zingiber zerumbet rhizome has been used as spices and in traditional medicine to heal various immune-inflammatory related ailments. Although the plant was reported to have potent anti-inflammatory and immunosuppressive properties by several studies, the molecular mechanisms underlying the effects have not been well justified.

PURPOSE

The study was carried out to investigate the molecular mechanisms underlying the anti-inflammatory properties of the standardized 80% ethanol extract of Z. zerumbet through its effect on mitogen-activated protein kinase (MyD88)-dependent nuclear factor-kappa B (NF-кB), mitogen activated protein kinase (MAPK) and phosphatidylinositol 3-kinase/Akt (PI3K-Akt) signaling pathways in lipopolysaccharide (LPS)-induced U937 human macrophages.

METHODS

Standardization of the 80% ethanol extract of Z. zerumbet was performed by using a validated reversed-phase HPLC method, while LC-MS/MS was used to profile the secondary metabolites. The release of pro-inflammatory markers, tumor necrosis factor (TNF)-α, interleukin (IL)-1β and prostaglandin E₂ (PGE₂) was evaluated by enzyme-linked immunosorbent assay (ELISA), while the Western blot technique was executed to elucidate the expression of mediators linked to MyD88-dependent respective signaling pathways. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) assay was carried out to quantify the relative gene expression of cyclooxygenase (COX)-2 and pro-inflammatory mediators at the transcriptional level.

RESULTS

The quantitative and qualitative analyses of Z. zerumbet extract showed the presence of several compounds including the major chemical marker zerumbone. Z. zerumbet extract suppressed the release of pro-inflammatory mediators, COX-2 protein expression and downregulated the mRNA expression of pro-inflammatory markers. Z. zerumbet-treatment also blocked NF-κB activation by preventing the phosphorylation of IKKα/β and NF-κB (p65) as well as the phosphorylation and degradation of IκBα. Z. zerumbet extract concentration-dependently inhibited the phosphorylation of respective MAPKs (JNK, ERK, and p38) as well as Akt. Correspondingly, Z. zerumbet extract suppressed the upstream signaling adaptor molecules, TLR4 and MyD88 prerequisite for the NF-κB, MAPKs, and PI3K-Akt activation.

CONCLUSION

The findings suggest that Z. zerumbet has impressive role in suppressing inflammation and related immune disorders by inhibition of various pro-inflammatory markers through the imperative MyD88-dependent NF-κB, MAPKs, and PI3K-Akt activation.

The effects of SIRT1/FoxO1 on LPS induced INS-1 cells dysfunction

Oxidative stress is one of the key mechanisms of sepsis related organ dysfunction including stress hyperglycemia. Silent mating type information regulation 2 homolog 1 (SIRT1) could regulate glucose metabolism through its deacetylase activity. In this study, we aimed to investigate the role of SIRT1/forkhead box protein 1 (FoxO1) pathway on lipopolysaccharide (LPS) induced INS-1 cells dysfunction from aspects of oxidative stress and apoptosis. After being treated with 1 mg/L LPS together with or without SIRT1 activator resveratrol (RSV) or SIRT1 inhibitor EX527, cell viability, ROS generation, malondialdehyde (MDA), superoxide, insulin secretion, and activity of superoxide dismutase (SOD) in INS-1 cells were measured by specific assays. Protein expression of SIRT1, FoxO1, toll-like receptor 4 (TLR4), and acetylated FoxO1 (ac-FoxO1) were detected by western blot analysis. Nuclear and cytoplasmic protein was extracted respectively to analyze SIRT1 and FoxO1 redistribution. Mitochondrial potentials and apoptosis were detected by flow cytometry or observed under fluorescence microscope. Results showed that LPS decreased cell viability and insulin secretion, increased ROS, MDA, and superoxide generation, whereas inhibited SOD activity and FoxO1 nuclear transportation. Activation of SIRT1 by RSV down-regulated TLR4 expression, SIRT1 and FoxO1 nuclear protein expression increased after RSV pretreatment. Additionally, LPS induced decreased mitochondrial membrane potentials and structural abnormalities, which could be partially reversed by RSV. SIRT1/FoxO1 may be one of potential targets which could resist against LPS-induced INS-1 cells from oxidative stress damage and mitochondrial dysfunction.

Astilbin Inhibits High Glucose-Induced Inflammation and Extracellular Matrix Accumulation by Suppressing the TLR4/MyD88/NF-κB Pathway in Rat Glomerular Mesangial Cells

Diabetic nephropathy (DN) is characterized by inflammatory responses and extracellular matrix (ECM) accumulation. Astilbin is an active natural compound and possesses anti-inflammatory activity. The aim of this study was to evaluate the anti-inflammatory effect of astilbin on high glucose (HG)-induced glomerular mesangial cells and the potential mechanisms. The results showed that HG induced cell proliferation of HBZY-1 cells in a time-dependent manner, and astilbin inhibited HG-induced cell proliferation. The expression and secretion of inflammatory cytokines, including interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α), and ECM components, including collagen IV (Col IV) and fibronectin (FN), were induced by HG. Moreover, TGF-β1 and CTGF were also induced by HG. The induction by HG on inflammatory response and ECM accumulation was inhibited after astilbin treatment. Astilbin treatment also attenuated HG-induced decrease in expression of matrix metalloproteinase (MMP)-2 and MMP-9. The TLR4/MyD88/NF-κB pathway was activated by HG, and the inhibitor of TLR4 exhibited the same effect to astilbin on reversing the induction of HG. TLR4 overexpression attenuated the effect of astilbin on HG-induced inflammatory cytokine production and ECM accumulation. The results suggested that astilbin attenuated inflammation and ECM accumulation in HG-induced rat glomerular mesangial cells via inhibiting the TLR4/MyD88/NF-κB pathway. This work provided evidence that astilbin can be considered as a potential candidate for DN therapy.

Oxymatrine exerts protective effects on osteoarthritis via modulating chondrocyte homoeostasis and suppressing osteoclastogenesis

Osteoarthritis (OA) is a common degenerative disease characterized by the progressive destruction both articular cartilage and the subchondral bone. The agents that can effectively suppress chondrocyte degradation and subchondral bone loss are crucial for the prevention and treatment of OA. Oxymatrine (OMT) is a natural compound with anti‐inflammatory and antitumour properties. We found that OMT exhibited a strong inhibitory effect on LPS‐induced chondrocyte inflammation and catabolism. To further support our results, fresh human cartilage explants were treated with LPS to establish an ex vivo degradation model, and the results revealed that OMT inhibited the catabolic events of LPS‐stimulated human cartilage and substantially attenuated the degradation of articular cartilage ex vivo. As subchondral bone remodelling is involved in OA progression, and osteoclasts are a unique cell type in bone resorption, we investigated the effects of OMT on osteoclastogenesis, and the results demonstrated that OMT suppresses RANKL‐induced osteoclastogenesis by suppressing the RANKL‐induced NFATc1 and c‐fos signalling pathway in vitro. Further, we found that the anti‐inflammatory and anti‐osteoclastic effects of oxymatrine are mediated via the inhibition of the NF‐κB and MAPK pathways. In animal studies, OMT suppressed the ACLT‐induced cartilage degradation, and TUNEL assays further confirmed the protective effect of OMT on chondrocyte apoptosis. MicroCT analysis revealed that OMT had an attenuating effect on ACLT‐induced subchondral bone loss in vivo. Taken together, these results show that OMT interferes with the vicious cycle associated with OA and may be a potential therapeutic agent for abnormal subchondral bone loss and cartilage degradation in osteoarthritis.

Vitamin A-coupled liposomes carrying TLR4-silencing shRNA induce apoptosis of pancreatic stellate cells and resolution of pancreatic fibrosis

Chronic pancreatitis leads to irreversible damage in pancreatic endocrine and exocrine functions. However, there is no clinically available antifibrotic drug. Pancreatic stellate cells (PSCs) can be activated by Toll-like receptor 4 (TLR4) responses to its ligands and they contribute to the formation of pancreatic fibrosis. Silencing the expression of TLR4 in PSCs by RNAi may be a novel therapeutic strategy for the treatment of pancreatic fibrosis. In addition, PSCs have a remarkable capacity for vitamin A uptake most likely through cellular retinol binding protein (CRBP). In our study, to ensure the efficient delivery of RNAi therapeutic agents to PSCs, VitA-coupled liposomes (VA-lips) were used as drug carriers to deliver plasmids expressing TLR4-specific short hairpin RNA (shRNA) to treat pancreatic fibrosis. Our study demonstrated that silencing the expression of TLR4 could induce mitochondrial apoptosis in aPSCs and might be an effective therapeutic strategy for the treatment of pancreatic fibrosis.

KEY MESSAGES

VA-lip-shRNA-TLR4 recovers pancreatic tissue damage. VA-lip-shRNA-TLR4 resolution of pancreatic fibrosis. VA-lip-shRNA-TLR4 accelerates ECM degradation and inhibits ECM synthesis. Silencing TLR4 induces aPSCs mitochondrial apoptosis. Silencing TLR4 inhibits the activation of NF-κB.