Linalool attenuates lung inflammation induced by Pasteurella multocida via activating Nrf-2 signaling pathway.

Pasteurellosis caused by Pasteurella multocida manifest often as respiratory infection in farmed small ruminants. Although the incidence of pasteurellosis due to P. multocida mainly takes the form of pneumonia, there is limited information on host factors that play a role in disease pathogenesis in the milieu of host-pathogen interactions. Nuclear factor-erythroid 2 related factor 2 (Nrf-2), a critical regulator for various inflammatory and immune responses by controlling oxidative stress, may play an important role in the processes of inflammation induced by P. multocida. In this study, linalool, a natural compound of the essential oils in several aromatic plant species, elevated nuclear Nrf-2 protein translocation in the A549 lung cell line and in vivo. The P. multocida-induced pro-inflammatory cytokines expression was abrogated by Nrf-2 siRNA. Postponed treatment with linalool decreased lung neutrophil accumulation and enhanced clearance of P. multocida. Furthermore, linalool significantly increased the expression of antioxidant enzymes regulated by Nrf-2 and diminished lung tissue levels of several pro-inflammatory cytokines, including tumor necrosis factor α (TNF-α) and interleukin (IL)-6. In addition, animals treated with linalool had a marked improvement in survival. These findings have uncovered that linalool acts as a novel Nrf-2 activator for a novel therapeutic strategy in pathogen-mediated lung inflammation.

p-Synephrine suppresses lipopolysaccharide-induced acute lung injury by inhibition of the NF-κB signaling pathway.

OBJECTIVE: We investigated whether p-synephrine exerts potent anti-inflammatory effects against acute lung injury (ALI) induced by lipopolysaccharide (LPS) in vivo, and we further investigated the inhibitory mechanism of p-synephrine in LPS-induced ALI. METHODS: Lipopolysaccharide (0.5 mg/kg) was instilled intranasally in phosphate-buffered saline to induce acute lung injury, and 6, 24, and 48 h after LPS was given, bronchoalveolar lavage fluid was obtained to measure pro-inflammatory mediator. We also evaluated the effects of p-synephrine on LPS-induced the severity of pulmonary injury. The phosphorylation of nuclear factor-κB (NF-κB) p65 protein was analyzed by Western blotting. RESULTS: Our data showed that p-synephrine significantly reduced the amount of inflammatory cells, the lung wet-to-dry weight (W/D) ratio, reactive oxygen species, myeloperoxidase activity and enhanced superoxide dismutase (SOD) in mice with LPS-induced ALI. Tumor necrosis factor α and interleukin (IL)-6 concentrations decreased significantly while the concentration of IL-10 was significantly increased after p-synephrine pretreatment. In addition, p-synephrine suppressed not only the phosphorylation of NF-κB but also the degradation of its inhibitor (IκBα). CONCLUSIONS: These results suggested that the inhibition of NF-κB activation and the regulation of SOD are involved in the mechanism of p-synephrine's protection against ALI.

Zingerone attenuates lipopolysaccharide-induced acute lung injury in mice.

Zingerone, one of the active components of ginger, is a phenolic alkanone with antioxidant and anti-inflammatory properties. In the present study, we analyzed the role of zingerone against RAW 264.7 cells and acute lung injury induced by lipopolysaccharide (LPS) in mice. RAW cells or BALB/c mice were pretreated with zingerone one hour before stimulated with LPS. We found that zingerone significantly inhibited the production of LPS-induced proinflammatory cytokines in vitro and in vivo. When pretreated with zingerone, pulmonary histopathologic changes, as well as alveolar hemorrhage and neutrophil infiltration were substantially suppressed in lung tissues, with evidence of reduced myeloperoxidase (MPO) activity in murine acute lung injury model. The lung wet-to-dry weight (W/D) ratios, as the index of pulmonary edema, were markedly decreased by zingerone pretreatment. Furthermore, we demonstrated that zingerone attenuates the mitogen-activated protein kinases (MAPK) and nuclear factor-kappaB (NF-κB) signaling pathways through blocking the phosphorylation of ERK, p38/MAPK and IκBα, NF-κB/P65. These results suggest that zingerone may provide protective effects against LPS-induced ALI.

Protection of mice against lipopolysaccharide-induced endotoxic shock by pinocembrin is correlated with regulation of cytokine secretion.

Natural products have been used as potentially important sources of anti-inflammatory drugs. This study examined the effects of pinocembrin against lipopolysaccharide (LPS)-induced endotoxemia to ascertain whether pinocembrin could protect mice from ensuing death. Cytokine responses were also assessed in serum isolated from blood collected at 0, 2, 4, 6, 8, and 24 h after LPS administration of the mice (with or without drug treatment). The results showed that there was a lower production of TNFα, IL-6, and IL-1ß in the serum of LPS-challenged mice that had been pre-treated with pinocembrin. In addition, pre-treatment with pinocembrin improved host survival against the LPS-induced lethal endotoxemia. These results suggest that this new flavonoid could potentially be a novel candidate for preventing development/mitigation progression of septic shock.

Paeonol suppresses lipopolysaccharide-induced inflammatory cytokines in macrophage cells and protects mice from lethal endotoxin shock.

Paeonol (2'-hydroxy-4'-methoxyacetophenone) is the main phenolic compound of the radix of Paeonia suffruticosa which has been used as traditional Chinese medicine. In this study, we primarily investigated the anti-inflammatory effects and the underlying mechanisms of paeonol in RAW macrophage cells; and based on these effects, we assessed the protective effects of paeonol on lipopolysaccharide-induced endotoxemia in mice. The in vitro study showed that paeonol regulated the production of TNF-α, IL-1ß, IL-6, and IL-10 via inactivation of IκBα, ERK1/2, JNK, and p38 MAPK. In mouse model of lipopolysaccharide-induced endotoxemia, pro- and anti-inflammatory cytokines are significantly regulated, and thus the survival rates of lipolysaccharide-challenged mice are improved by paeonol (150, 200, or 250 mg/kg). Therefore, paeonol has a beneficial activity against lipopolysaccharide-induced inflammation in RAW 264.7 cell and mouse models.

Angelicin regulates LPS-induced inflammation via inhibiting MAPK/NF-κB pathways.

BACKGROUND: Angelicin is a furocoumarin found in Psoralea corylifolia L. fruit. The purpose of this study was to investigate the protective ability of angelicin against inflammation in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and LPS-induced in vivo acute lung injury model. MATERIALS AND METHODS: The concentrations of tumor necrosis factor alpha (TNF-α) and interleukin (IL)-6 in the culture supernatants of RAW 264.7 cells were determined 24 h after LPS administration. ALI was induced by intratracheal instillation of LPS. Six hours after LPS inhalation, bronchoalveolar lavage fluid and lung tissue samples were obtained for enzyme-linked immunosorbent assay, histologic, and Western blotting analyses. RESULTS: The results showed that pretreatment with angelicin markedly downregulated TNF-α and IL-6 levels in vitro and in vivo, and significantly decreased the amount of inflammatory cells, lung wet-to-dry weight ratio, and myeloperoxidase activity in LPS-induced ALI mice. Furthermore, Western blotting analysis results demonstrated that angelicin blocked the phosphorylation of IκBα, NF-κBp65, p38 MAPK, and JNK in LPS-induced ALI. CONCLUSIONS: These results suggest that angelicin was potentially advantageous to prevent inflammatory diseases by inhibiting NF-κB and MAPK pathways. Our data indicated that angelicin might be a potential new agent for prevention of inflammatory reactions and diseases in the clinic.

Tubeimoside-1 attenuates LPS-induced inflammation in RAW 264.7 macrophages and mouse models.

CONTEXT: Acute lung injury (ALI), characterized by severe hypoxemia, pulmonary edema and neutrophil accumulation in the lung, is a common clinical problem associated with significant morbidity and mortality in shock, sepsis, ischemia reperfusion, etc. OBJECTIVE: In this study, we aimed at investigating the protective effect of tubeimoside-1 (TBMS1) on inflammation in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and a LPS-induced in vivo lung injury model. MATERIALS AND METHODS: We evaluated the effect of TBMS1 on LPS-induced production of tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-1ß in the culture supernatants of RAW 264.7 cells by enzyme-linked immunosorbent assay. LPS (0.5 mg/kg) was instilled intranasally in phosphate-buffered saline to induce ALI, and the severity of pulmonary injury was evaluated 6 h after LPS challenge. RESULTS: TBMS1 significantly inhibited the production of the pro-inflammatory cytokines, TNF-α, IL-6 and IL-1ß in vitro and in vivo. Pretreatment with TBMS1 markedly attenuated the development of pulmonary edema, histological severities and inflammatory cells infiltration in mice with ALI. In addition, we further demonstrated that TBMS1 exerts an anti-inflammatory effect in vivo model of ALI through suppression of IκB activation and p38/extracellular signal-regulated kinase mitogen-activated protein kinases signaling in a dose-dependent manner. DISCUSSION AND CONCLUSION: Overall, our data suggest that TBMS1 inhibits inflammation both in vitro and in vivo, and may be a potential therapeutic candidate for the prevention of inflammatory diseases.

Protective effect of esculentoside A on lipopolysaccharide-induced acute lung injury in mice.

BACKGROUND: Esculentoside A (EsA) is a saponin isolated from the Chinese herb Phytolacca esculenta. In our study, we sought to investigate the protective effects of EsA on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. MATERIALS AND METHODS: To determine the effects of EsA on the reduction of histopathologic changes in mice with ALI, inflammatory cell count in bronchoalveolar lavage fluid (BALF) and lung wet-to-dry weight ratio were measured in LPS-challenged mice, and lung histopathologic changes observed via paraffin section were assessed. Next, cytokine production induced by LPS in BALF was measured by enzyme-linked immunosorbent assay. To further study the mechanism of EsA protective effects on ALI, IκBa, p38, and extracellular signal receptor-activated kinase pathways were investigated in lung tissue of mice with ALI. RESULTS: In the present investigation, EsA showed marked effects by reducing inflammatory infiltration, thickening of the alveolar wall, and pulmonary congestion. Levels of tumor necrosis factor α and interleukin 6 elevated by LPS were significantly decreased in BALF in EsA-pretreated ALI model. Furthermore, EsA significantly suppressed phosphorylation of IκBa, p38, and extracellular signal receptor-activated kinase. CONCLUSIONS: Taken together, our results suggest that EsA suppressed inflammatory responses in LPS-induced ALI through inhibition of the nuclear factor kappa B and mitogen activated protein kinase signaling pathways. EsA may be a promising potential preventive agent for ALI treatment.

Phillyrin attenuates LPS-induced pulmonary inflammation via suppression of MAPK and NF-κB activation in acute lung injury mice.

Phillyrin (Phil) is one of the main chemical constituents of Forsythia suspensa (Thunb.), which has shown to be an important traditional Chinese medicine. We tested the hypothesis that Phil modulates pulmonary inflammation in an ALI model induced by LPS. Male BALB/c mice were pretreated with or without Phil before respiratory administration with LPS, and pretreated with dexamethasone as a control. Cytokine release (TNF-α, IL-1ß, and IL-6) and amounts of inflammatory cell in bronchoalveolar lavage fluid (BALF) were detected by ELISA and cell counting separately. Pathologic changes, including neutrophil infiltration, interstitial edema, hemorrhage, hyaline membrane formation, necrosis, and congestion during acute lung injury in mice were evaluated via pathological section with HE staining. To further investigate the mechanism of Phil anti-inflammatory effects, activation of MAPK and NF-κB pathways was tested by western blot assay. Phil pretreatment significantly attenuated LPS-induced pulmonary histopathologic changes, alveolar hemorrhage, and neutrophil infiltration. The lung wet-to-dry weight ratios, as the index of pulmonary edema, were markedly decreased by Phil pretreatment. In addition, Phil decreased the production of the proinflammatory cytokines including (TNF-α, IL-1ß, and IL-6) and the concentration of myeloperoxidase (MPO) in lung tissues. Phil pretreatment also significantly suppressed LPS-induced activation of MAPK and NF-κB pathways in lung tissues. Taken together, the results suggest that Phil may have a protective effect on LPS-induced ALI, and it potentially contributes to the suppression of the activation of MAPK and NF-κB pathways. Phil may be a new preventive agent of ALI in the clinical setting.

Prime-O-glucosylcimifugin attenuates lipopolysaccharide-induced acute lung injury in mice.

Prime-O-glucosylcimifugin is an active chromone isolated from Saposhnikovia root which has been reported to have various activities, such as anti-convulsant, anticancer, anti-inflammatory properties. The purpose of this study was to evaluate the effect of prime-O-glucosylcimifugin on acute lung injury (ALI) induced by lipopolysaccharide in mice. BALB/c mice received intraperitoneal injection of Prime-O-glucosylcimifugin 1h before intranasal instillation (i.n.) of lipopolysaccharide (LPS). Concentrations of tumor necrosis factor (TNF)-α, interleukin (IL)-1ß and interleukin (IL)-6 in bronchoalveolar lavage fluid (BALF) were measured by enzyme-linked immunosorbent assay (ELISA). Pulmonary histological changes were evaluated by hematoxylin-eosin, myeloperoxidase (MPO) activity in the lung tissue and lung wet/dry weight ratios were observed. Furthermore, the mitogen-activated protein kinases (MAPK) signaling pathway activation and the phosphorylation of IκBα protein were determined by Western blot analysis. Prime-O-glucosylcimifugin showed promising anti-inflammatory effect by inhibiting the activation of MAPK and NF-κB signaling pathway.

Suppression of LPS-induced inflammatory responses by gossypol in RAW 264.7 cells and mouse models.

Gossypol, a yellowish polyphenolic compound originally from cotton plant, has been known to exert a potential for anti-cancer, anti-inflammatory and other important therapeutic activities. The purpose of this investigation was to determine the protection of gossypol on inflammation in Lipopolysaccharide (LPS) stimulated RAW 264.7 cells and LPS induced in vivo lung injury model. The effects of gossypol on pro-inflammatory cytokines and signaling pathways were evaluated by enzyme-linked immunosorbent assay and Western blot. The results showed that gossypol significantly inhibited the production of LPS-induced TNF-α, IL-6 and IL-1ß both in vitro and vivo. Furthermore, gossypol blocked the phosphorylation of IκBα protein, p65, p38, c-Junterminal kinase (JNK) and extracellular signal-regulated kinase (ERK) in LPS stimulated RAW 264.7 cells. From the in vivo study, it was observed that gossypol attenuated lung histopathologic changes in mouse models. The present data suggest that gossypol suppresses the inflammation in vitro and vivo, and may be a potential therapeutic candidate for the treatment of inflammatory disorders.

p-Cymene modulates in vitro and in vivo cytokine production by inhibiting MAPK and NF-κB activation.

The present study was designed to investigate the effects of p-cymene on lipopolysaccharide (LPS)-induced inflammatory cytokine production both in vitro and in vivo. The production of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and interleukin-10 (IL-10) in LPS-stimulated RAW 264.7 cells and C57BL/6 mice was evaluated by sandwich ELISA. Meanwhile, the mRNA levels of cytokine genes were examined in vitro by semiquantitative RT-PCR. In a further study, we analyzed the activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways by western blotting. We found that p-cymene significantly regulated TNF-α, IL-1ß, and IL-6 production in LPS-stimulated RAW 264.7 cells. Furthermore, the levels of relative mRNAs were also found to be downregulated. In in vivo trail, p-cymene markedly suppressed the production of TNF-α and IL-1ß and increased IL-10 secretion. We also found that p-cymene inhibited LPS-induced activation of extracellular signal receptor-activated kinase 1/2, p38, c-Jun N-terminal kinase, and IκBα. These results suggest that p-cymene may have a potential anti-inflammatory action on cytokine production by blocking NF-κB and MAPK signaling pathways.

Anti-inflammatory effects of linalool in RAW 264.7 macrophages and lipopolysaccharide-induced lung injury model.

BACKGROUND: Inflammation, characterized by redness, swelling, pain and a sensation of heat, is one of the body's self-defense systems. Although the inflammation response has an important role in host survival, it also leads to chronic inflammatory diseases. Linalool is a natural compound of the essential oils in several aromatic plants species. It possesses anti-inflammatory, antinociceptive, and other bioactive properties. In the present study, we investigated the protective effects of linalool on inflammation in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and an LPS-induced in vivo lung injury model. METHODS: We evaluated the effects of linalool on LPS-induced production of inflammatory mediators in Raw 264.7 murine macrophages by enzyme-linked immunosorbent assay and Western blot. To confirm the anti-inflammatory activity of linalool in vivo, we induced an acute lung injury in an LPS-induced mouse model. RESULTS: Linalool attenuated the production of LPS-induced tumor necrosis-α and interleukin-6 both in vitro and in vivo. Furthermore, phosphorylation of IκBα protein, p38, c-Jun terminal kinase, and extracellular signal-regulated kinase in LPS-stimulated RAW 264.7 cells was blocked by linalool. Our in vivo study also found that linalool attenuated lung histopathologic changes in mouse models. CONCLUSIONS: The results suggest that linalool inhibits inflammation both in vitro and in vivo, and may be a potential therapeutic candidate for the treatment of inflammatory diseases.

Preventive effect of Imperatorin on acute lung injury induced by lipopolysaccharide in mice.

Imperatorin, a linear furanocoumarin, has many pharmacological effects such as antibacterial, anti-inflammatory and antiviral effects. The purpose of this study was to investigate the effect of Imperatorin on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. BALB/c mice were pretreated with Imperatorin 1h before LPS challenge. We found that the levels of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß) and interleukin-6 (IL-6) in the bronchoalveolar lavage fluid (BALF) were decreased significantly, and the level of interleukin-10 (IL-10) was up-regulated 8h after Imperatorin treatment. Pretreatment with Imperatorin (15 or 30 mg/kg) decreased lung wet-to-dry weight (W/D) ratio, the number of inflammatory cells and myeloperoxidase (MPO) activities. Additionally, Imperatorin attenuated lung histopathological changes and significantly inhibited the phosphorylation of IκB, JNK, ERK and p38/MAPK. These findings demonstrate that Imperatorin protects against LPS-induced ALI in mice.

p-Cymene protects mice against lipopolysaccharide-induced acute lung injury by inhibiting inflammatory cell activation.

The objective of this study was to test the hypothesis that p-cymene can attenuate acute lung injury induced by lipopolysaccharide (LPS) in vivo. In the mouse model of LPS-induced acute lung injury, intraperitoneal preconditioning with p-cymene resulted in a significant reduction of pro-inflammatory cytokines (TNF-α, IL-1ß and IL-6), lung water gain, inflammatory cell infiltration, lung tissue myeloperoxidase activity. In addition, p-cymene blocked the phosphorylation of IκBα protein and mitogen-activated protein kinases (MAPK) signaling pathway activation. Histopathologic examination of lung tissue indicated that p-cymene treatment markedly decreased focal thickening, congestion, pulmonary edema, and inflammatory cells infiltration. The results showed that p-cymene had a protective effect on LPS-induced ALI in mice.

In vitro and in vivo protection provided by pinocembrin against lipopolysaccharide-induced inflammatory responses.

Pinocembrin or 5, 7-dihydroxyflavanone is a flavanone, a type of flavonoid. In the present study, we first assessed the anti-inflammatory effects of pinocembrin in RAW macrophage cells; and based on these effects, we investigated the therapeutic effects of pinocembrin in murine model of endotoxin-induced acute lung injury. We found that in vitro pretreatment with pinocembrin remarkably regulated the production of TNF-α, IL-1ß, IL-6 and IL-10 via inhibiting the phosphorylation of IκBα, ERK1/2, JNK and p38MAPK. In the mouse model of LPS-induced acute lung injury, pinocembrin (20 or 50 mg/kg, i.p.) attenuated the development of pulmonary edema, histological severities, as well as neutrophil, lymphocyte and macrophage infiltration, which were increased by LPS administration. Additionally, TNF-α, IL-1ß and IL-6 concentrations decreased significantly while the concentration of IL-10 was significantly increased after pinocembrin pretreatment. Our results also showed that pinocembrin attenuated LPS-induced lung injury through suppression of IκBα, JNK and p38MAPK activation. These findings suggest that pinocembrin may represent a novel candidate for the modulation of inflammatory responses.

Regulation of inflammatory cytokines in lipopolysaccharide-stimulated RAW 264.7 murine macrophage by 7-O-methyl-naringenin.

7-O-Methylnaringenin, extracted from Rhododendron speciferum, belongs to the flavanone class of polyphenols. In the present study, we investigated the anti-inflammatory effects of 7-O-methylnaringenin on cytokine production by lipopoly-saccharide (LPS)-stimulated RAW 264.7 macrophages in vitro. The results showed that pretreatment with 10, 20 or 40 µg/mL of 7-O-methylnaringenin could downregulate tumour necrosis factor (TNF-α), interleukin (IL-6) and interleukin (IL-1ß) in a dose-dependent manner. Furthermore, we investigated the signal transduction mechanisms to determine how 7-O-methylnaringenin affects RAW 264.7 macrophages. The activation of mitogen-activated protein kinases (MAPK) and IκBα were measured by Western blotting. The data showed that 7-O-methylnaringenin could downregulate LPS-induced levels of phosphorylation of ERK1/2, JNK and IκBα. These observations indicated that 7-O-methylnaringenin modulated inflammatory cytokine responses by blocking NF-қB, ERK1/2 and JNK/MAPKs activation.

Astragalin attenuates lipopolysaccharide-induced inflammatory responses by down-regulating NF-κB signaling pathway.

Astragalin (AG), a flavonoid from many traditional herbs and medicinal plants, has been described to exhibit in vitro anti-inflammatory activity. The present study aimed to determine the protective effects and the underlying mechanisms of astragalin on lipopolysaccharide-induced endotoxemia and lung injury in mice. Mice were injected intraperitoneally (i.p.) with lipopolysaccharide (LPS) (dose range: 5-40 mg/kg). We observed mice on mortality for 7 days twice a day and recorded survival rates. In drug testing, we examined the therapeutic effects of astragalin (25, 50 or 75 mg/kg) on LPS- induced endotoxemia by dosing orally astragalin 1 hour before LPS challenge. Using an experimental model of LPS-induced acute lung injury (ALI), we examined the effect of astragalin in resolving lung injury. The investigations revealed that pretreatment with astragalin can improve survival during lethal endotoxemia and attenuate inflammatory responses in a murine model of lipopolysaccharide-induced acute lung injury. The mechanisms by which Astragalin exerts its anti-inflammatory effect are correlated with inhibition of tumor necrosis factor-α (TNF-α), interleukin-1 (IL-1), and interleukin-6 (IL-6) production via inactivation of NF-κB.

Traditional medicine alpinetin inhibits the inflammatory response in Raw 264.7 cells and mouse models.

Alpinetin, one of the main constituents of the seeds of Alpinia katsumadai Hayata, belonging to flavonoids, has been known to exhibit antibacterial, anti-inflammatory and other important therapeutic activities. The purpose of this study was to investigate the protection of alpinetin on inflammation in Lipopolysaccharide (LPS) stimulated Raw 264.7 cells and LPS induced vivo lung injury model. The effects of alpinetin on pro-inflammatory cytokines and signaling pathways were analyzed by enzyme-linked immunosorbent assay and Western blot. The results showed that alpinetin markedly inhibited the LPS- induced TNF-α, IL-6 and IL-1ß production both in vitro and vivo. Furthermore, alpinetin blocked the phosphorylation of IκBα protein, p65, p38 and extracellular signal-regulated kinase (ERK) in LPS stimulated RAW 264.7 cells. From in vivo study, it was also observed that alpinetin attenuated lung histopathologic changes in mouse models. These results suggest that alpinetin potentially decreases the inflammation in vitro and vivo, and might be a therapeutic agent against inflammatory diseases.