LPS-induced Production Of Inflammatory Mediators Research Articles

The Antioxidant and Anti-Inflammatory Properties of Bee Pollen from Acorn (Quercus acutissima Carr.) and Darae (Actinidia arguta).

Aging is a complex biological process characterized by a progressive decline in physical function and an increased risk of age-related chronic diseases. Additionally, oxidative stress is known to cause severe tissue damage and inflammation. Pollens from acorn and darae are extensively produced in Korea. However, the underlying molecular mechanisms of these components under the conditions of inflammation and oxidative stress remain largely unknown. This study aimed to investigate the effect of bee pollen components on lipopolysaccharide (LPS)-induced RAW 264.7 mouse macrophages. This study demonstrates that acorn and darae significantly inhibit the LPS-induced production of inflammatory mediators, such as nitric oxide (NO) and prostaglandin E2 (PGE2), in RAW 264.7 cells. Specifically, bee pollen from acorn reduces NO production by 69.23 ± 0.04% and PGE2 production by 44.16 ± 0.08%, while bee pollen from darae decreases NO production by 78.21 ± 0.06% and PGE2 production by 66.23 ± 0.1%. Furthermore, bee pollen from acorn and darae reduced active oxygen species (ROS) production by 47.01 ± 0.5% and 60 ± 0.9%, respectively. It increased the nuclear potential of nuclear factor erythroid 2-related factor 2 (Nrf2) in LPS-stimulated RAW 264.7 cells. Moreover, treatment with acorn and darae abolished the nuclear potential of nuclear factor κB (NF-κB) and reduced the expression of extracellular signal-associated kinase (ERK) and c-Jun N-terminal kinase (JNK) phosphorylation in LPS-stimulated RAW 264.7 cells. Specifically, acorn decreased NF-κB nuclear potential by 90.01 ± 0.3%, ERK phosphorylation by 76.19 ± 1.1%, and JNK phosphorylation by 57.14 ± 1.2%. Similarly, darae reduced NF-κB nuclear potential by 92.21 ± 0.5%, ERK phosphorylation by 61.11 ± 0.8%, and JNK phosphorylation by 59.72 ± 1.12%. These results suggest that acorn and darae could be potential antioxidants and anti-inflammatory agents.

Mutanolysin-Digested Peptidoglycan of Lactobacillus reuteri Promotes the Inhibition of Porphyromonas gingivalis Lipopolysaccharide-Induced Inflammatory Responses through the Regulation of Signaling Cascades via TLR4 Suppression.

Periodontitis is an oral infectious disease caused by various pathogenic bacteria, such as Porphyromonas gingivalis. Although probiotics and their cellular components have demonstrated positive effects on periodontitis, the beneficial impact of peptidoglycan (PGN) from probiotic Lactobacillus remains unclear. Therefore, our study sought to investigate the inhibitory effect of PGN isolated from L. reuteri (LrPGN) on P. gingivalis-induced inflammatory responses. Pretreatment with LrPGN significantly inhibited the production of interleukin (IL)-1β, IL-6, and CCL20 in RAW 264.7 cells induced by P. gingivalis lipopolysaccharide (LPS). LrPGN reduced the phosphorylation of PI3K/Akt and MAPKs, as well as NF-κB activation, which were induced by P. gingivalis LPS. Furthermore, LrPGN dose-dependently reduced the expression of Toll-like receptor 4 (TLR4), indicating that LrPGN inhibits periodontal inflammation by regulating cellular signaling cascades through TLR4 suppression. Notably, LrPGN exhibited stronger inhibition of P. gingivalis LPS-induced production of inflammatory mediators compared to insoluble LrPGN and proteinase K-treated LrPGN. Moreover, MDP, a minimal bioactive PGN motif, also dose-dependently inhibited P. gingivalis LPS-induced inflammatory mediators, suggesting that MDP-like molecules present in the LrPGN structure may play a crucial role in the inhibition of inflammatory responses. Collectively, these findings suggest that LrPGN can mitigate periodontal inflammation and could be a useful agent for the prevention and treatment of periodontitis.

Attenuated memory impairment and neuroinflammation in Alzheimer’s disease by aucubin via the inhibition of ERK-FOS axis

Alzheimer's disease (AD) is a degenerative illness accompanied by cognitive and memory loss. In addition to the widely accepted, convincing amyloid cascade hypothesis, the activation of glial cells and neuroinflammation, especially the microglia-mediated neuroinflammation, has an essential role in the development and progression of AD. Therefore, the anti-inflammatory treatment is becoming a promising therapeutic strategy. Aucubin (Au) is a natural product derived from many plants with anti-inflammatory and antioxidant activities. Up to now, no research has been conducted to investigate the anti-inflammatory effects of Au and its neuroprotective quality on AD and the potential molecular mechanisms of its medical roles. In our study, the results of network pharmacology revealed the potential therapeutic effect of Au on AD. The results of studies in vivo showed that Au improved the behaviors, counteracted cognitive and memory deficits, and ameliorated AD-like pathological features of the mouse brain, e.g., the deposition of Aβ plaques, neuronal damage, and inflammatory responses induced by glial cell overactivation, in APP/PS1 mice. The transcriptome sequencing further confirmed that the pathological symptoms of AD could be reversed by inhibiting the ERK/FOS axis to alleviate the inflammatory response. The in vitro experiments revealed that Au suppressed the BV2 cell activation, inhibited the phosphorylation of ERK1/2 and the expression of c-FOS, and reduced the LPS-induced inflammatory mediator production by BV2 cells and primary astrocytes. Our study suggested that Au exerted its neuroprotective effects by inhibiting the inflammatory responses, which could be a promising treatment of AD.

Standardized extract of Glehnia Littoralis abrogates memory impairment and neuroinflammation by regulation of CREB/BDNF and NF-κB/MAPK signaling in scopolamine-induced amnesic mice model

Mild cognitive impairment is a typical symptom of early Alzheimer’s disease (AD). Glehnia littoralis (G. littoralis), a medicinal halophyte plant commonly used to treat strokes, has been shown to possess some therapeutic qualities. In this study, we investigated the neuroprotective and anti-neuroinflammatory effects of a 50% ethanol extract of G. littoralis (GLE) on lipopolysccharide (LPS)-stimulated BV-2 cells and scopolamine-induced amnesic mice. In the in vitro study, GLE treatment (100, 200, and 400 µg/mL) markedly attenuated the translocation of NF-κB to the nucleus concomitantly with the significant mitigation of the LPS-induced production of inflammatory mediators, including NO, iNOS, COX-2, IL-6, and TNF-α. In addition, the GLE treatment suppressed the phosphorylation of MAPK signaling in the LPS-stimulated BV-2 cells. In the in vivo study, mice were orally administered with the GLE (50, 100, and 200 mg/kg) for 14 days, and cognitive loss was induced via the intraperitoneal injection of scopolamine (1 mg/kg) from 8 to 14 days. We found that GLE treatment ameliorated memory impairment and simultaneously improved memory function in the scopolamine-induced amnesic mice. Correspondingly, GLE treatment significantly decreased the AChE level and upregulated the protein expression of neuroprotective markers, such as BDNF and CREB, as well as Nrf2/HO-1 and decreased the levels of iNOS and COX-2 in the hippocampus and cortex. Furthermore, GLE treatment attenuated the increased phosphorylation of NF-κB/MAPK signaling in the hippocampus and cortex. These results suggest that GLE has a potential neuroprotective activity that may ameliorate learning and memory impairment by regulating AChE activity, promoting CREB/BDNF signaling, and inhibiting NF-κB/MAPK signaling and neuroinflammation.

TDAG51 promotes transcription factor FoxO1 activity during LPS-induced inflammatory responses.

Tight regulation of Toll-like receptor (TLR)-mediated inflammatory responses is important for innate immunity. Here, we show that T-cell death-associated gene 51 (TDAG51/PHLDA1) is a novel regulator of the transcription factor FoxO1, regulating inflammatory mediator production in the lipopolysaccharide (LPS)-induced inflammatory response. TDAG51 induction by LPS stimulation was mediated by the TLR2/4 signaling pathway in bone marrow-derived macrophages (BMMs). LPS-induced inflammatory mediator production was significantly decreased in TDAG51-deficient BMMs. In TDAG51-deficient mice, LPS- or pathogenic Escherichia coli infection-induced lethal shock was reduced by decreasing serum proinflammatory cytokine levels. The recruitment of 14-3-3ζ to FoxO1 was competitively inhibited by the TDAG51-FoxO1 interaction, leading to blockade of FoxO1 cytoplasmic translocation and thereby strengthening FoxO1 nuclear accumulation. TDAG51/FoxO1 double-deficient BMMs showed significantly reduced inflammatory mediator production compared with TDAG51- or FoxO1-deficient BMMs. TDAG51/FoxO1 double deficiency protected mice against LPS- or pathogenic E. coli infection-induced lethal shock by weakening the systemic inflammatory response. Thus, these results indicate that TDAG51 acts as a regulator of the transcription factor FoxO1, leading to strengthened FoxO1 activity in the LPS-induced inflammatory response.

Effect of Baicalin on the LPS-Induced Production of Inflammatory Mediators in Low-Dose Corticosterone Pretreated RAW 267.4 cells and Hepa1c1c-7 Cells

Low-dose glucocorticoids (GCs) are known to induce inflammation and immunosuppression. However, whether preconditioning with a low dose of GCs induces hepatic inflammation remains unclear. Although baicalin has beneficial therapeutic activity against liver damage, 100 μM baicalin enhances the lipopolysaccharide (LPS)-induced production of inflammatory acute-phase proteins in Hepa1c1c-7 cells. This study was performed to investigate the effect of 100 μM baicalin on the LPS-induced production of inflammatory mediators in liver cells, including Kupffer cells and hepatocytes, pre-conditioned with a low dose of GCs. RAW 267.4 cells and Hepa1c1c-7 cells were pretreated with 50 (cort 50) or 100 ng/mL (cort 100) corticosterone for 24 h and then cultured with 100 μM baicalin in fresh complete medium in the presence of LPS. Our results demonstrated that baicalin markedly decreased the LPS-induced production of TNF-α, IL-6, IL-1β, and nitric oxide in RAW 267.4 cells. Baicalin also strongly attenuated the LPS-induced production of TNF-α in cort 50- and cort 100-pretreated RAW 267.4 cells. Baicalin significantly upregulated the production of IL-6 induced by LPS and the production of VEGF decreased by LPS, but decreased the LPS-induced production of CRP in cort 100- pretreated Hepa1c1c-7 cells compared to untreated Hepa1c1c-7 cells. In conclusion, these findings suggest that 100 μM baicalin may enhance the LPS-induced production of inflammatory acute-phase proteins in hepatocytes, whereas it may downregulate these protein levels in macrophages and Kupffer cells. Moreover, preconditioning with a low dose of corticosterone may prime the effects of 100 μM baicalin on the LPS-induced production of IL-6 in hepatocytes, leading to hepatic insulin resistance or fatty liver disease.

Ethanol extract of Chondracanthus tenellus (Harvey) Hommersand attenuates lipopolysaccharide-induced inflammatory and oxidative response by blocking the NF-κB, MAPKs, and PI3K/Akt signaling pathways

Objective: To investigate whether the ethanol extract of Chondracanthus tenellus (Harvey) Hommersand, a type of red algae, could exhibit anti-inflammatory potential in lipopolysaccharide (LPS)-stimulated macrophages. Methods: The ethanol extract of Chondracanthus tenellus was applied to 100 ng/mL LPS-stimulated RAW 264.7 cells, and cell viability, phagocytic ability, levels of pro-inflammatory factors, and the production of reactive oxygen species were measured. To identify the underlying mechanism of the ethanol extract of Chondracanthus tenellus, the expression of inflammation-regulated genes was estimated. Results: The ethanol extract of Chondracanthus tenellus had no cytotoxic effect at concentrations below 300 μg/mL, and reduced the LPS-induced production of inflammatory mediators including nitric oxide (NO) and prostaglandin E2. Furthermore, the extract markedly suppressed the expression of inducible NO synthase and cyclooxygenase-2, as well as the production of reactive oxygen species. The LPS-induced up-regulation of pro-inflammatory cytokines was attenuated by treatment with the ethanol extract of Chondracanthus tenellus, reducing their extracellular secretion. The Chondracanthus tenellus extract also inhibited LPS-mediated activation of nuclear factor-kappa B (NF-κB). In addition, the phosphorylation of mitogen activated protein kinases (MAPKs) and phosphatidylinositol 3 kinase (PI3K)/Akt was markedly increased by LPS, which was significantly abolished by the Chondracanthus tenellus extract. Conclusions: Our findings indicate that the ethanol extract of Chondracanthus tenellus exhibited potential anti-inflammatory and antioxidant effects through downregulating the NF-κB, MAPKs, and PI3K/Akt signaling pathways in LPS stimulated RAW 264.7 macrophages.

Histatin-1 Attenuates LPS-Induced Inflammatory Signaling in RAW264.7 Macrophages.

Macrophages play a critical role in the inflammatory response to environmental triggers, such as lipopolysaccharide (LPS). Inflammatory signaling through macrophages and the innate immune system are increasingly recognized as important contributors to multiple acute and chronic disease processes. Nitric oxide (NO) is a free radical that plays an important role in immune and inflammatory responses as an important intercellular messenger. In addition, NO has an important role in inflammatory responses in mucosal environments such as the ocular surface. Histatin peptides are well-established antimicrobial and wound healing agents. These peptides are important in multiple biological systems, playing roles in responses to the environment and immunomodulation. Given the importance of macrophages in responses to environmental triggers and pathogens, we investigated the effect of histatin-1 (Hst1) on LPS-induced inflammatory responses and the underlying molecular mechanisms in RAW264.7 (RAW) macrophages. LPS-induced inflammatory signaling, NO production and cytokine production in macrophages were tested in response to treatment with Hst1. Hst1 application significantly reduced LPS-induced NO production, inflammatory cytokine production, and inflammatory signaling through the JNK and NF-kB pathways in RAW cells. These results demonstrate that Hst1 can inhibit LPS-induced inflammatory mediator production and MAPK signaling pathways in macrophages.

Anti-Inflammatory Activity of Kurarinone Involves Induction of HO-1 via the KEAP1/Nrf2 Pathway.

Kurarinone, a flavonoid isolated from the roots of Sophora flavescens, was suggested to exert potent antioxidant and immunosuppressive effects. However, the underlying mechanisms remain unclear. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a key transcription factor that regulates the antioxidant defense system with anti-inflammatory activity. In the present study, we demonstrated that kurarinone activated Nrf2 and increased the expression of antioxidant enzymes, including heme oxygenase-1 (HO-1). Mechanistically, kurarinone downregulated the expression of kelch-like ECH-associated protein 1 (KEAP1), subsequently leading to the activation of Nrf2. Kurarinone also inhibited the expression of the inflammatory cytokine, interleukin (IL)-1β, and inducible nitric oxide synthase (iNos) in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. The overexpression of HO-1 suppressed the LPS-induced production of inflammatory mediators in RAW264.7 cells, and the immunosuppressive effects of kurarinone were partially inhibited by a treatment with Tin Protomorphyrin IX (TinPPIX), an inhibitor of HO-1. These results indicate that kurarinone activates the KEAP1/Nrf2 pathway to induce HO-1 expression, thereby exerting immunosuppressive effects.

Effects of the Hydrogen Sulfide Donor GYY4137 and HSP70 Protein on the Activation of SH-SY5Y Cells by Lipopolysaccharide

The effects of exogenous recombinant human heat shock protein Hsp70 and hydrogen sulfide donor GYY4137 on the mechanisms of endocytosis of lipopolysaccharide (LPS) by human neuroblastoma cells SH-SY5Ywas studied. Hsp70 and GYY4137 have been shown to significantly reduce LPS-induced production of inflammatory mediators by SH-SY5Y cells, including reactive oxygen species, nitric oxide, TNFα, IL-1β, and IL-6. Both the recombinant protein Hsp70 and the hydrogen sulfide donor GYY4137 exhibited significant protective effects; however, the combined use of these agents did not lead to a cumulative effect. It has been shown that pinocytosis, as well as clathrin-, caveolin-, tubulin- and receptor-dependent endocytosis were involved in protecting the cells by both the hydrogen sulfide donor and Hsp70 from LPS-induced production of reactive oxygen species and NO.

Extract from Bougainvillea xbuttiana (Variety Orange) Inhibits Production of LPS-Induced Inflammatory Mediators in Macrophages and Exerts a Protective Effect In Vivo.

Background Different pharmacological properties, such as antioxidant, antiproliferative, and anti-inflammatory properties, have been described among natural products. We previously described that the Bougainvillea xbuttiana (Variety Orange) ethanolic extract (BxbO) has an anti-inflammatory effect; however, this action is not fully understood. In this study, the action of the BxbO extract on the secretion of inflammatory mediators in two experimental models, in vitro and in vivo, after LPS challenge was evaluated. Methods Peritoneal macrophages were obtained from female BALB/c mice and LPS-challenged with or without the BxbO extract. For the evaluation of mediators, the supernatants at 0, 12, 24, 36, and 48 hours were collected. For in vivo estimation, groups of female BALB/c mice were first intraperitoneously injected with different amounts of LPS and later administered the oral BxbO extract (v.o.) for 144 hours. To understand the mechanism of action, sera obtained from mice were collected at 0, 2, 4, 8, 12, and 24 hours after LPS challenge (with or without BxbO) for the detection of mediators. Results The results showed that, in both peritoneal macrophages and sera of mice treated with the BxbO extract 1 hour before or together with LPS challenge, proinflammatory cytokines and nitric oxide release were unquestionably repressed. In contrast, in both systems studied here, the IL-10 levels were elevated to 5 to 9 times. At lethal doses of LPS, the BxbO extract treatment was found to protect animals from death. Conclusions The results revealed that the inhibitory, protective, and benign effects of the BxbO extract were due to its capacity to balance the secretion of mediators.

Sesquiterpene lactones from Artemisia austroyunnanensis suppresses ROS production and reduces cytokines, iNOS and COX-2 levels via NF-KB pathway in vitro

The inhibitory effects of six sesquiterpene lactones (1–6) isolated from Artemisia austroyunnanensis Ling & Y. R. Ling were studied on the LPS-induced inflammatory mediator production in RAW264.7 cells. The results showed they can decrease the level of ROS in a concentration-dependent response. The compounds down-regulate the expression of iNOS and COX-2 and a series of classical inflammatory factors, including TNF-α, IL-1β, IL-6 and IL-10. These effects can be partially explained by the supression of the phosphorylation of NF-κB. Additionally, the relationship between their structures and inflammatory factors was analyzed and discussed.

Chelidonine suppresses LPS-Induced production of inflammatory mediators through the inhibitory of the TLR4/NF-κB signaling pathway in RAW264.7 macrophages

Chelidonine is one of the alkaloids of Chelidonium majus, which has broad pharmacological activities, including anti-inflammatory. Despite chelidonine has been shown to exhibit anti-inflammatory activity, the molecular mechanisms are not yet fully elucidated. In this paper, we used RAW264.7 macrophages and mice to investigate the anti-inflammatory effects of chelidonine. Firstly, we found that chelidonine significantly suppressed LPS-induced the production of NO and PGE2, as well as iNOS and COX-2 mRNA and protein expression. In addition, pro-inflammatory cytokines induced by LPS, such as TNFα and IL-6 were also attenuated by chelidonine. What’s more, LPS-induced activation and degradation of IκBα followed by translocation of the p65 from the cytoplasm to the nucleus were attenuated by chelidonine. Furthermore, chelidonine even significantly inhibited TLR4 expression induced by LPS. Finally, we verified that chelidonine striking ly decreased serum TNFα, IL-6 and PGE2 levels in LPS stimulated mice. Taken together, this study demonstrated that chelidonine may suppressed the LPS-induced inflammatory response both in vitro and in vivo, which was relating to TLR4/NF-κB signaling pathway disturbed by chelidonine.

Effect of Low Dose Corticosterone Pretreatment on the Production of LPS-Induced Inflammatory Mediators in Endotoxin-Preexposed Cells

Effect of Low Dose Corticosterone Pretreatment on the Production of LPS-Induced Inflammatory Mediators in Endotoxin-Preexposed Cells

Glycyrrhizin inhibits LPS-induced inflammatory mediator production in endometrial epithelial cells.

Endometriosis is a continuous inflammation of uterine endometrium that usually affects women of reproductive age. Glycyrrhizin, a triterpene isolated from the roots and rhizomes of licorice (Glycyrrhiza glabra), has been known to have anti-inflammatory effect. The purpose of this study was to investigate the anti-inflammatory effect of glycyrrhizin on LPS-stimulated mouse endometrial epithelial cells (MEEC). The levels of TNF-α, IL-1β, and PGE2 were measured by ELISA. The expression of COX-2, iNOS, TLR4, and NF-ĸB were detected by western blot analysis. The results showed that glycyrrhizin significantly suppressed LPS-induced TNF-α, IL-1β, NO, and PGE2 production. Also, LPS-induced iNOS and COX-2 expression were attenuated by glycyrrhizin. Furthermore, glycyrrhizin significantly attenuated TLR4 expression and NF-κB activation induced by LPS in MEEC. In conclusion, the present study demonstrated that glycyrrhizin inhibited LPS-induced inflammatory response by inhibiting TLR4 signaling pathway in MEEC. Glycyrrhizin may be used as a potential agent for the treatment of endometriosis.

Ferulic acid suppresses expression of tryptophan metabolic key enzyme indoleamine 2, 3-dioxygenase via NFκB and p38 MAPK in lipopolysaccharide-stimulated microglial cells.

Ferulic acid (FA) is a phenol compound found in plants that has anti-inflammatory properties. Indoleamine 2, 3-dioxygenase (IDO) is a tryptophan catabolic enzyme induced in immune cells, including glial cells, during inflammation. Enhanced IDO expression leads to reduced tryptophan levels and increased levels of toxic metabolites, including quinolinic acid. Therefore, inhibition of IDO expression may be effective in suppressing progression of neurodegenerative diseases. In this study, we examined the effect of FA in microglial cells on IDO expression levels and related inflammatory signal molecules. FA suppressed LPS-induced IDO mRNA expression and also suppressed nuclear translocation of NF-κB and phosphorylation of p38 MAPK. However, FA did not affect the production of LPS-induced inflammatory mediators and phosphorylation of JNK. Our results indicate that FA suppresses LPS-induced IDO mRNA expression, which may be mediated by inhibition of the NF-κB and p38 MAPK pathways in microglial cells.

Essential oil of Artemisia argyi suppresses inflammatory responses by inhibiting JAK/STATs activation

Ethnopharmacological relevanceArtemisia argyi is a herbal medicine traditionally used in Asia for the treatment of bronchitis, dermatitis and arthritis. Recent studies revealed the anti-inflammatory effect of essential oil in this plant. However, the mechanisms underlying the therapeutic potential have not been well elucidated. The present study is aimed to verify its anti-inflammatory effect and investigate the probable mechanisms. Materials and methodsThe essential oil from Artemisia argyi (AAEO) was initially tested against LPS-induced production of inflammatory mediators and cytokines in RAW264.7 macrophages. Protein and mRNA expressions of iNOS and COX-2 were determined by Western blotting and RT-PCR analysis, respectively. The effects on the activation of MAPK/NF-κB/AP-1 and JAK/STATs pathway were also investigated by western blot. Meanwhile, in vivo anti-inflammatory effect was examined by histologic and immunohistochemical analysis in TPA-induced mouse ear edema model. ResultsThe results of in vitro experiments showed that AAEO dose-dependently suppressed the release of pro-inflammatory mediators (NO, PGE2 and ROS) and cytokines (TNF-α, IL-6, IFN-β and MCP-1) in LPS-induced RAW264.7 macrophages. It down-regulated iNOS and COX-2 protein and mRNA expression but did not affect the activity of these two enzymes. AAEO significantly inhibited the phosphorylation of JAK2 and STAT1/3, but not the activation of MAPK and NF-κB cascades. In animal model, oral administration of AAEO significantly attenuated TPA-induced mouse ear edema and decreased the protein level of COX-2. ConclusionAAEO suppresses inflammatory responses via down-regulation of the JAK/STATs signaling and ROS scavenging, which could contribute, at least in part, to the anti-inflammatory effect of AAEO.

6-Shogaol attenuates LPS-induced inflammation in BV2 microglia cells by activating PPAR-γ.

6-Shogaol, a pungent agent isolated from Zingiber officinale Roscoe, has been known to have anti-tumor and anti-inflammatory effects. However, the anti-inflammatory effects and biological mechanism of 6-Shogaol in LPS-activated BV2 microglia remains largely unknown. In this study, we evaluated the anti-inflammatory effects of 6-Shogaol in LPS-activated BV2 microglia. 6-Shogaol was administrated 1 h before LPS treatment. The production of inflammatory mediators were detected by ELISA. The expression of NF-κB and PPAR-γ were detected by western blot analysis. Our results revealed that 6-Shogaol inhibited LPS-induced TNF-α, IL-1β, IL-6, and PGE2 production in a concentration dependent manner. Furthermore, 6-Shogaol inhibited LPS-induced NF-κB activation by inhibiting phosphorylation and nuclear translocation of NF-κB p65. In addition, 6-Shogaol could increase the expression of PPAR-γ. Moreover, inhibition of PPAR-γ by GW9662 could prevent the inhibition of 6-Shogaol on LPS-induced inflammatory mediator production. In conclusion, 6-Shogaol inhibits LPS-induced inflammation by activating PPAR-γ.

Effects of aqueous extracts of Taraxacum Officinale on expression of tumor necrosis factor-alpha and intracellular adhesion molecule 1 in LPS-stimulated RMMVECs

BackgroundMastitis gives rise to big financial burden to farm industry (mainly dairy production) and public health. Its incidence is currently high and therefore, highly effective treatments for therapy, especially with natural products are required. Taraxacum officinale has been reported to use for anti-inflammation. However, its effect on endothelium during mastitis has not been reported.MethodsWe firstly established inflammation experimental model of rat mammary microvascular endothelial cells (RMMVECs). We evaluated the effects of dandelion leaf aqueous extracts (DAE) on LPS-induced production of inflammatory mediators in RMMVECs by enzyme-linked immunosorbent assay and Western blot. We treated RMMVECs with 1 μg/ml LPS for 4 h and then incubated with 10, 100 and 200 μg/mL DAE for 4, 8, 12 and 24 h. The expression (mRNA and protein level) of targets (tumor necrosis factor-alpha (TNF- α) and Intracellular Adhesion Molecule 1 (ICAM1) was analyzed by employing real-time PCR and Western blots. The in vivo anti-inflammatory effect of DAE on mastitis within an Staphylococcus aureus-induced mouse model was also determined.ResultsThe obtained results showed that dandelion extracts at the concentration of 100 and 200 μg/mL could significantly inhibit both TNF-α and ICAM-1 expression in all time points checked while 10 μg/mL of dandelion only suppress both expression at 8 and 12 h post-treatment. The in vivo tests showed that the DAE inhibited the expression of TNF-α and ICAM-1 in a time-dependent manner.ConclusionsAll results suggest that the endothelium may use as as a possible target of dandelion for anti-inflammation.

GYF-17, a chloride substituted 2-(2-phenethyl)-chromone, suppresses LPS-induced inflammatory mediator production in RAW264.7 cells by inhibiting STAT1/3 and ERK1/2 signaling pathways

GYF-17, a 2-(2-phenethyl)-chromone derivative, was isolated from agarwood and showed superior activity of inhibiting NO production of RAW264.7 cells induced by LPS in our preliminary pharmacodynamic screening. In order to develop novel therapeutic drug for acute and chronic inflammatory disorders, the anti-inflammatory activity and underlying mechanism of GYF-17 were investigated in LPS-induced RAW264.7 cells. The results showed that GYF-17 could reduce LPS-induced expression of iNOS and then result in the decrement of NO production. More meaningful, the expression and secretion of key pro-inflammatory factors, including TNF-α, IL-6 and IL-1β, were intensively inhibited by GYF-17. Furthermore, GYF-17 also down regulated the expression of COX2 and the production of PGE2 which plays important role in causing algesthesia during inflammatory response. In mechanism study, GYF-17 selectively suppressed phosphorylation of STAT1/3 and ERK1/2 during the activation of NF-κB, MAPK and STAT signaling pathways induced by LPS. Collectively, GYF-17 can intensively suppress the production of LPS-induced inflammatory mediators in RAW264.7 cells by inhibiting STAT1/3 and ERK1/2 signaling pathways and thereby shows great potential to be developed into therapeutic drug for inflammatory diseases.