Protective effect of taraxasterol on acute lung injury induced by lipopolysaccharide in mice

Taraxasterol, a pentacyclic-triterpene isolated from Taraxacum officinale, has been reported to have potent anti-inflammatory properties. However, the effect of taraxasterol on lipopolysaccharide (LPS)-induced mice acute lung injury has not been investigated. The aims of this study were to investigate whether taraxasterol could ameliorate the inflammation response in LPS-induced acute lung injury and to clarify the possible mechanism. Male BALB/c mice were pretreated with taraxasterol 1 h before intranasal instillation of LPS. 7 h after LPS administration, the myeloperoxidase (MPO) in lung tissues, lung wet/dry ratio and inflammatory cells in the bronchoalveolar lavage fluid (BALF) were detected. The levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β) in the BALF were measured by ELISA. The extent of phosphorylation of IκB-α, p65 NF-κB, p46–p54 JNK, p42–p44 ERK, and p38 were determined by western blotting. The results showed that taraxasterol attenuated the infiltration of inflammatory cells, the activity of myeloperoxidase (MPO), lung wet/dry ratio, and the expression of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) in a dose-dependent manner. Additionally, western blotting results showed that taraxasterol inhibited the phosphorylation of IκB-α, p65 NF-κB, p46–p54 JNK, p42–p44 ERK, and p38 caused by LPS. Our data suggest that anti-inflammatory effects of taraxasterol against the LPS-induced ALI may be due to its ability of inhibition of the NF-κB and MAPK signaling pathways.     

Genipin alleviates LPS-induced acute lung injury by inhibiting NF-κB and NLRP3 signaling pathways

Genipin has been reported to have anti-inflammatory effect. However, its role on lipopolysaccharide (LPS)-induced acute lung injury (ALI) has not been explored. This study aimed to evaluate the effect of genipin on murine model of acute lung injury induced by LPS. The mice were treated with genipin 1 h before LPS administration. 12 h later, the myeloperoxidase (MPO) in lung tissues and lung wet/dry ratio were detected. The levels of TNF-α, IL-1β and IL-6 in bronchoalveolar lavage fluid (BALF) were measured by ELISA. Apart from this, we use western blot to detect the protein expression in the NF-κB and NLRP3 signaling pathways. The results showed that the treatment of genipin markedly attenuated the lung wet/dry ratio and the MPO activity. Moreover, it also inhibited the levels of TNF-α, IL-1β, IL-6 in the BALF. In addition, genipin significantly inhibited LPS-induced NF-κB and NLRP3 activation. In conclusion, these results demonstrate that genipin protected against LPS-induced ALI through inhibiting NF-κB and NLRP3 signaling pathways.     

Protective effect of catalpol on lipopolysaccharide-induced acute lung injury in mice

Catalpol, an iridiod glucoside isolated from Rehmannia glutinosa, has been reported to have anti-inflammatory properties. Although anti-inflammatory activity of catalpol already reported, its involvement in lung protection has not been reported. Thus, we investigated the role of catalpol on lipopolysaccharide (LPS)-induced acute lung injury in this study. Mice acute lung injury model was induced by intranasal instillation of LPS. Catalpol was administrated 1 h prior to or after LPS exposure. The severity of pulmonary injury was evaluated 12 h after LPS administration. The results showed that catalpol inhibited lung W/D ratio, myeloperoxidase activity of lung samples, the amounts of inflammatory cells and TNF-α, IL-6, IL-4 and IL-1β in BALF induced by LPS. The production of IL-10 in BALF was up-regulated by catalpol. In vitro, catalpol inhibited TNF-α, IL-6, IL-4 and IL-1β production and up-regulated IL-10 expression in LPS-stimulated alveolar macrophages. Moreover, western blot analysis showed that the activation of NF-κB and MAPK signaling pathways was inhibited by catalpol. Furthermore, catalpol was found to inhibit TLR4 expression induced by LPS. In conclusion, catalpol potently protected against LPS-induced ALI. The protective effect may attribute to the inhibition of TLR4-mediated NF-κB and MAPK signaling pathways.     

Anti-inflammatory effect of Yam Glycoprotein on lipopolysaccharide-induced acute lung injury via the NLRP3 and NF-κB/TLR4 signaling pathway

Acute lung injury (ALI) is a common lung disease accompanied by acute and persistent pulmonary inflammatory response syndrome, which leads to alveolar epithelial cells and capillary endothelial cell damage. Yam glycoprotein, separated from traditional Chinese yam, has been shown to have anti-inflammatory and immunomodulatory effects. In this experiment, we mainly studied the therapeutic effect and mechanism of a glycoprotein on the lipopolysaccharide (LPS)-induced ALI mice. An oral glycoprotein method was used to treat the mouse ALI model induced by LPS injection in the peritoneal cavity. Afterward, we measured the wet/dry (W/D) ratio, the activity of myeloperoxidase (MPO), the oxidative index superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase (GSH-PX) and the production of inflammatory cytokines interleukin-1β (IL-1β), tumour necrosis factor-α (TNF-α), and interleukin-6 (IL-6) to evaluate the effect of yam glycoprotein on lung tissue changes. We examined the protein expression of TLR4, ASC, NF-κBp65, p-NF-κBp65, Caspase-1, IκB, NLRP3, p-IκB, and β-actin by western blot analysis. Immunohistochemical analyses of NLRP3 and p-p65 in lung tissue were carried out to assess the mechanism of glycoprotein action. This result suggests that glycoprotein markedly depressed LPS-induced lung W/D ratio, MPO activity, MDA content SOD and GSH-Px depletion, and the contents of inflammatory cytokines IL-1β, IL-6, and TNF-α. Moreover, glycoprotein blocked TLR4/NF-κBp65 signaling activation and NLRP3inflammasome expression in LPS-induced ALI mice. As this particular study shows, glycoprotein has a safeguarding effects on LPS-induced ALI mice, possibly via activating NLRP3inflammasome and TLR4/NF-κB signaling pathways.     

Fibroblast Growth Factor 21 dependent TLR4/MYD88/NF-κB signaling activation is involved in lipopolysaccharide-induced acute lung injury

Fibroblast Growth Factor 21 (FGF21) has been reported to reduce inflammation and apoptosis. Inflammation and apoptosis are both the essential mechanisms during development of acute lung injury. This study evaluated whether pre-treatment of FGF21 could alleviate acute lung injury. Mice were pre-treated with FGF21 prior to lipopolysaccharide (LPS) treatment. 24 h later, the lung tissues and BALF were obtained to detect H&E pathology, W/D ratio, pro-inflammatory factors (TNF-α, IL-1β and IL-6) and apoptosis. In vitro, Human BEAS-2B and THP-1 cells were overexpressed with TLR4 or MYD88 or NF-κB plasmid to detect the inflammation or apoptosis. Data showed that FGF21 was proved to be beneficial for inhibiting inflammation and apoptosis in the LPS- induced Balb/c mice or LPS induced BEAS-2B or THP-1 cells. Furthermore, the data showed that FGF21 suppressed inflammation and apoptosis via inhibition of TLR4/MYD88/NF-κB signaling pathway. Therefore, FGF21 provides a possibility for the treatment of LPS induced acute lung injury.     

Fraxin ameliorates lipopolysaccharide-induced acute lung injury in mice by inhibiting the NF-κB and NLRP3 signalling pathways

Fraxin, the effective component of the Chinese traditional medicine Cortex Fraxini, is reported to have anti-inflammatory effects. This study assessed the anti-inflammatory effect of fraxin on the lipopolysaccharide (LPS)-induced inflammatory response in A549 cells and the protective efficacy on LPS-induced acute lung injury (ALI) in mice. Fraxin reduced LPS-induced TNF-α, IL-6 and IL-1β production in A549 cells and alleviated the LPS-induced wet/dry (W/D) weight ratio and the effects observed via histopathological examination of the lung in vivo. Furthermore, fraxin reduced the protein concentrations in the broncho-alveolar lavage (BAL) fluid and cytokine production in the sera. Fraxin also clearly attenuated the oxidation index, including the activity of myeloperoxidase (MPO), malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH). Immunohistochemistry analysis showed that fraxin suppressed LPS-induced inflammatory damage. The expression of proteins involved in the NF-κB and NLRP3 inflammatory corpuscle signalling pathways was consistent between the lung tissues and cell samples. Overall, fraxin played a protective role in LPS-induced lung injury by inhibiting the NF-κB and NLRP3 signalling pathways.     

Shikonin exerts anti-inflammatory effects in a murine model of lipopolysaccharide-induced acute lung injury by inhibiting the nuclear factor-kappaB signaling pathway

Shikonin, an analog of naphthoquinone pigments isolated from the root of Lithospermum erythrorhyzon, was recently reported to exert beneficial anti-inflammatory effects both in vivo and in vitro. The present study aimed to investigate the potential therapeutic effect of shikonin in a murine model of lipopolysaccharide (LPS)-induced acute lung injury (ALI). Dexamethasone was used as a positive control to evaluate the anti-inflammatory effect of shikonin in the study. Pretreatment with shikonin (intraperitoneal injection) significantly inhibited LPS-induced increases in the macrophage and neutrophil infiltration of lung tissues and markedly attenuated myeloperoxidase activity. Furthermore, shikonin significantly reduced the concentrations of TNF-α, IL-6 and IL-1β in bronchoalveolar lavage fluid induced by LPS. Compared with the LPS group, lung histopathologic changes were less pronounced in the shikonin-pretreated mice. Additionally, Western blotting results showed that shikonin efficiently decreased nuclear factor-kappaB (NF-κB) activation by inhibiting the degradation and phosphorylation of IκBα. These results suggest that shikonin exerts anti-inflammatory properties in LPS-mediated ALI, possibly through inhibition of the NF-κB signaling pathway, which mediates the expression of pro-inflammatory cytokines. Shikonin may be a potential agent for the prophylaxis of ALI.     

Geniposide,from Gardenia jasminoides Ellis,inhibits the inflammatory response in the primary mouse macrophages and mouse models

Geniposide, a main iridoid glucoside component of gardenia fruit, has been known to exhibit antibacterial, anti-inflammatory and other important therapeutic activities. The objective of this study was to investigate the protective effects of geniposide on inflammation in lipopolysaccharide (LPS) stimulated primary mouse macrophages in vitro and LPS induced lung injury model in vivo. The expression of pro-inflammatory cytokines was determined by enzyme-linked immunosorbent assay (ELISA). Nuclear factor-kappa B (NF-κB), inhibitory kappa B (IκBα) protein, p38, extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and Toll-like receptor 4 (TLR4) were determined by Western blot. Further analysis was carried out in mTLR4 and mMD-2 co-transfected HEK293 cells. The results showed that geniposide markedly inhibited the LPS-induced TNF-α, IL-6 and IL-1β production both in vitro and in vivo. Geniposide blocked the phosphorylation of IκBα, p65, p38, ERK and JNK in LPS stimulated primary mouse macrophages. Furthermore, geniposide inhibited the expression of TLR4 in LPS stimulated primary mouse macrophages and inhibited the LPS-induced IL-8 production in HEK293-mTLR4/MD-2 cells. In vivo study, it was also observed that geniposide attenuated lung histopathologic changes in the mouse models. These results suggest that geniposide exerts an anti-inflammatory property by down-regulating the expression of TLR4 up-regulated by LPS. Geniposide is highly effective in inhibiting acute lung injury and may be a promising potential therapeutic reagent for acute lung injury treatment.     

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 1 h before LPS challenge. We found that the levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) 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 8 h 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.     

β-Patchoulene from patchouli oil protects against LPS-induced acute lung injury via suppressing NF-κB and activating Nrf2 pathways

β-Patchoulene (β-PAE), a tricyclic sesquiterpene isolated from the essential oil of the leaves and stems of Pogostemon cablin (Blanco) Benth., has been reported to have potent anti-inflammatory activity. The aim of this study was to evaluate the potential protective effect of β-PAE on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice and to illuminate the underlying mechanisms. ALI was induced by intracheal instillation of LPS into lung, and dexamethasone (DEX) was used as a positive control. Results indicated that pretreatment with β-PAE significantly decreased the mortality rate of mice and lung W/D weight ratio, ameliorated lung pathological changes as compared to model group. Meanwhile, β-PAE pretreatment markedly inhibited the increase of TNF-α, IL-6 and IL-1β secretions in the bronchoalveolar lavage fluid, and prevented LPS-induced elevations of MPO activity and MDA level in the lung. Additionally, β-PAE pretreatment significantly elevated miR-146a expression and suppressed the LPS-induced activation of NF-κB and expression of its mediated genes (TNF-α, IL-6 and IL-1β). β-PAE was also observed to markedly upregulate the Nrf2 and HO-1 expression and activate the antioxidant genes (NQO-1, GCLC and HO-1). Taken together, β-PAE possessed protective effect against LPS-induced ALI, which might be associated with its differential regulation of NF-κB and Nrf2 activities and up-regulation of expression of miR-146a. The results rendered β-PAE a promising anti-inflammatory agent worthy of further development into a pharmaceutical drug for the treatment of ALI.     

Protective effects of morin on lipopolysaccharide/d-galactosamine-induced acute liver injury by inhibiting TLR4/NF-κB and activating Nrf2/HO-1 signaling pathways

Morin, a bioactive flavonoid extracted from the bark of Moraceae plants and many medicinal herbs, has anti-inflammatory and antioxidative effects. In this research, we explored the protective effects of morin against lipopolysaccharide (LPS) and d-galactosamine (D-GalN) induced acute liver injury in mice. Mice were given an intraperitoneal injection of morin before LPS and D-GalN treatment and the HepG2 cells were only given morin to investigate its effects. The results showed that morin markedly inhibited the production of serum alanine transaminase (ALT), aspartate aminotransferase (AST), interleukin-6 (IL-6), tumor necrosis factor (TNF-α) and hepatic TNF-α, IL-6, and myeloperoxidase (MPO) induced by LPS/D-GalN. In order to evaluate morin effect in the future, we investigated the expression of nuclear factor E2 related factor 2 (Nrf2), nuclear factor-kappaB (NF-κB), toll like receptor 4 (TLR4) on liver injury. Taken together, these results suggested that morin could exert the anti-inflammatory and anti-oxidative effects against LPS/D-GalN-induced acute liver injury by activating Nrf2 signal pathways and inhibiting NF-κB activation.     

基于TLR4/NF-κB/NLRP3信号通路研究三叶香茶菜含药血清对枯否细胞活化的影响

目的 研究三叶香茶菜含药血清(isodon ternifolius-containing serum,ITS)通过Toll样受体4(TLR4)/核因子κB(NF-κB)/NOD样受体蛋白3(NLRP3)信号通路对脂多糖(lipopolysaccharide,LPS)诱导的大鼠原代肝枯否细胞(Kupffer cell,KC)活化的影响。方法 分离培养大鼠原代KC,将LPS诱导的大鼠原代KC分为空白对照组、模型对照组、空白血清组、阳性对照组(秋水仙碱含药血清组)、ITS组、TLR4阻断剂组、TLR4阻断剂+ITS组。MTT法检测不同浓度ITS对KC增殖活性的影响;ELISA法检测KC细胞上清液白介素-1β(IL-1β)、白细胞介素-18(IL-18)、肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)含量;荧光定量聚合应(PCR)、Western blotting和免疫荧光检测KC中TLR4/NF-κB/NLRP3信号通路中TLR4、核因子κB抑制蛋白α(IκBα)、半胱肽氨酸蛋白酶-1(Caspase-1)、NLRP3 mRNA和TLR4、IκBα、磷酸化IκBα(p-IκBα)、Caspase-1、NLRP3、NF-κBp65蛋白表达情况。结果 与模型对照组相比,各药物组KC上清液中IL-1β、IL-18、TNF-α和IL-6含量,以及细胞中TLR4、IκBα、Caspase-1、NLRP3 mRNA和TLR4、IκBα、p-IκBα、Caspase-1、NLRP3、NF-κBp65蛋白的表达均下调或降低(P<0.05或P<0.01);与TLR4阻断剂组比较,TLR4阻断剂+ITS组上述多数指标的改善更加明显。结论 三叶香茶菜可能通过下调TLR4/NF-κB/NLRP3信号通路抑制KC活化,减少炎性因子的表达和释放,从而减轻肝脏炎症损伤。     

Sclareol ameliorate lipopolysaccharide-induced acute lung injury through inhibition of MAPK and induction of HO-1 signaling

Sclareol is a natural fragrance compound that is used widely in the cosmetic and food industries. This study examined the effect of sclareol on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. Mice were treated with sclareol 1 h before an intratracheal (I.T.) LPS challenge to induce an ALI model. The effects on lung tissue and lung injury were evaluated 6 h after LPS induction. Pretreatment with sclareol noticeably improved the LPS-induced histological alterations and edema in lung tissue. Sclareol also inhibited the release of pro-inflammatory mediators. Differences in nitric oxide (NO), tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), IL-6, and IL-10 were found in the bronchoalveolar lavage fluid (BALF) 6 h after LPS-induced lung injury. This study also found a reduced number of total cells and reduced protein concentrations in the BALF. There were also changes in the pulmonary wet/dry (W/D) weight ratio, antioxidant enzyme activity, and myeloperoxidase activity in lung tissues. Sclareol effectively blocked the phosphorylation of mitogen-activated protein kinases (MAPKs) and impeded the protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). The compound boosted the expression of heme oxygenase-1 (HO-1) and inhibited the breakdown of nuclear factor-kappa B (NF-κB) and inhibitor of kappa B (IκBα). To the best of the authors' knowledge, this study is the first to demonstrate that sclareol effectively inhibits acute lung edema, and the results suggest that sclareol may be a potential agent for the treatment of ALI. The potential therapeutic benefits may include the attenuation of LPS-induced pulmonary inflammation due to sclareol's effects on several pathways, including NF-κB, MAPKs and HO-1, as well as the regulation of antioxidant enzyme activity.     

DATS通过NF-κB抑制LPS诱导小鼠肺泡巨噬细胞促炎细胞因子表达

目的探讨二烯丙基三硫(DATS)抑制脂多糖(LPS)诱导小鼠肺泡巨噬细胞肿瘤坏死因子-α(TNF-α)及白介素-1β表达的信号转导机制。方法体外培养MH-S细胞,用DATS和(或)LPS进行干预。反转录PCR检测细胞中TNF-α、IL-1β mRNA表达,电泳迁移率改变分析(EMSA)检测细胞核因子-κB(NF-κB)活性,Western blot检测细胞磷酸化(p-IκB)及非磷酸化IκB的表达。结果LPS刺激MH-S细胞可导致TNF-α、IL-1β mRNA、p-IκB表达增加及NF-κB活性升高。用DATS(0.1、0.5、2.5、5.0mg.L-1)预处理细胞30min后再给予LPS刺激,可使TNF-α、IL-1β mRNA表达降低,并呈剂量依赖性;升高的NF-κB活性及p-IκB表达均显不同程度的抑制。单独DATS对TNF-α、IL-1β mRNA表达及NF-κB活性无影响。结论DATS可通过抑制IκB磷酸化及NF-κB活化,进而下调LPS诱导小鼠肺泡巨噬细胞TNF-α、IL-1β mRNA表达。     

Cyanidin-3-O-β-glucoside ameliorates lipopolysaccharide-induced acute lung injury by reducing TLR4 recruitment into lipid rafts

Cyanidin-3-O-β-glucoside (C3G), a typical anthocyanin pigment that exists in the human diet, has been reported to have anti-inflammatory properties. The aim of this study was to detect the effect of C3G on LPS-induced acute lung injury and to investigate the molecular mechanisms. Acute lung injury was induced by intratracheal administration of LPS in mice. Alveolar macrophages from mice were stimulated with LPS and were treated with C3G. Our results showed that C3G attenuated lung histopathologic changes, myeloperoxidase (MPO) activity, TNF-α, IL-1β and IL-6 production in LPS-induced acute lung injury model. In vitro, C3G dose-dependently inhibited TNF-α, IL-1β, IL-6, IL-10 and IFN-β production, as well as NF-κB and IRF3 activation in LPS-stimulated alveolar macrophages. Furthermore, C3G disrupted the formation of lipid rafts by depleting cholesterol and inhibited TLR4 translocation into lipid rafts. Moreover, C3G activated LXRα-ABCG1-dependent cholesterol efflux. Knockout of LXRα abrogated the anti-inflammatory effects of C3G. In conclusion, C3G has a protective effect on LPS-induced acute lung injury. The promising anti-inflammatory mechanisms of C3G is associated with up-regulation of the LXRα-ABCG1 pathway which result in disrupting lipid rafts by depleting cholesterol and reducing translocation of TLR4 to lipid rafts, thereby suppressing TLR4 mediated inflammatory response.     

脂质微泡介导转染MIF siRNA对小鼠急性肺损伤的保护作用

目的：通过探讨超声微泡基因转染系统转染MIF siRNA对小鼠急性肺损伤的保护作用,评价超声微泡基因转染系统的有效性。方法：以脂多糖（LPS）诱导小鼠建立急性肺损伤动物模型,随机分成4组：正常对照组（Con）、LPS刺激组（LPS）、LPS＋PC＋MIF siRNA治疗组（PC＋MIF siRNA）、LPS＋WP＋MIF siRNA治疗组（WP＋MIF siRNA）;通过超声微泡基因转染系统转染MIF siRNA,运用EMSA、Western-Blot、ELISA和相关病理检测技术,观察小鼠肺组织NF-κB/IκB-α表达、炎症介质TNF-α、IL-1β、IL-6水平,及肺组织湿干重比和炎症病理病变,探讨MIF siRNA对小鼠急性肺损伤的保护作用。结果：WP＋MIF siRNA治疗组通过上调肺组织细胞浆中IκB-α表达,对LPS刺激激活的细胞核NF-κB有明显抑制作用、从而抑制炎症介质TNF-α、IL-1β、IL-6释放,减轻小鼠肺组织病理损伤。但PC＋MIF siRNA治疗组对LPS刺激导致的小鼠肺损伤无任何改善的治疗作用。结论：脂质微泡/PEI-Chol介导的基因转染系统能有效转染MIF siRNA,对LPS介导的小鼠急性肺损伤具有一定的保护作用。     

Ginsenoside Rg3 ameliorates lipopolysaccharide-induced acute lung injury in mice through inactivating the nuclear factor-κB (NF-κB) signaling pathway

Ginsenoside Rg3 (GRg3), one of the major active saponins isolated from ginseng (the root of Panax ginseng C.A. Meyer, Araliaceae), has been reported with many health benefits. Currently, the protective effect of GRg3 on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice was investigated. The results indicated that GRg3 treatment could greatly attenuate LPS-induced histopathological alterations in the lung in a concentration-dependent manner. LPS-induced increase of lung wet-to-dry weight ratio (W/D ratio) was also dose-dependently reduced by GRg3 treatment. LPS-induced increases of the total cells, neutrophils and macrophages in the bronchoalveolar lavage fluids (BALFs) were significantly inhibited by GRg3 treatment in a dose-dependent fashion. The levels of pro-inflammatory cytokines including TNF-α, IL-1β and IL-6 in BALFs increased after LPS-induced ALI, which was inhibited by GRg3. Western blot results showed that during ALI LPS activated NF-κB pathway in the lung tissues by upregulating NF-κB p65 phosphorylation and its downstream COX-2 expression; however, these effects of LPS were inhibited by GRg3 treatment. Taken together, these findings in present study suggested that GRg3 provided protective effects against LPS-induced ALI in animal model and might harbor the potential to be considered as drug for the treatment of ALI in clinic.     

Naringin attenuates acute lung injury in LPS-treated mice by inhibiting NF-κB pathway

Naringin has been reported as an effective anti-inflammatory compound. We previously showed that naringin had antitussive effect on experimentally induced cough in guinea pigs. However, the effects and mechanism of naringin on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice are not fully understood. In this study, our aim was to evaluate the anti-inflammatory activities of naringin on LPS-induced ALI in mice and clarify its underlying mechanisms of action. We found that in vivo pretreatment with naringin markedly decreased the lung wet weight to dry weight ratio, and led to significant attenuation of LPS-induced evident lung histopathological changes. Meanwhile, naringin significantly reduced bronchoalveolar lavage fluid (BALF) total cell and neutrophil (PMN) counts after LPS challenge. Furthermore, naringin inhibited myeloperoxidase (MPO: a marker enzyme of neutrophil granule) and inducible nitric oxide synthase (iNOS) activities in lung tissue and alleviated LPS-induced tumor neurosis factor-α (TNF-α) secretion in BALF in a dose-dependent manner. Additionally, Western blotting showed that naringin efficiently blunt NF-κB activation by inhibiting the degradation of I?B-α and the translocation of p65. Taken together, these results suggest that naringin shows anti-inflammatory effects through inhibiting lung edema, MPO and iNOS activities, TNF-α secretion and pulmonary neutrophil infiltration by blockade of NF-κB in LPS-induced ALI.     

丹参酮II-A通过调控TLR4/IκBα/NFκB信号通路抑制LPS诱导的细胞炎症

目的建立脂多糖(LPS)诱导的小鼠单核巨噬细胞(RAW264.7)炎症模型,探究丹参酮II-A(Tan IIA)的抗炎活性及其机制。方法CCK-8法测定Tan IIA对细胞活力的影响;迁移小室测定Tan IIA对LPS诱导细胞迁移能力作用;ELISA法测定细胞上清液中小鼠肿瘤坏死因子α(tumor necrosis factoralpha,TNF-α)、白介素6(interleukin 6,IL-6)、IL^-1β、单核细胞趋化蛋白-1(monocyte chemoattractant protein,MCP-1)的含量;Western blot法检测基质金属蛋白酶2(matrix metalloproteinases,MMP-2)、MMP-9、Toll样受体-4(TLR4)、IκB-α、p-IκB-α、NFκB和p-NFκB蛋白的表达。结果Tan IIA对LPS诱导的RAW264.7细胞培养液中炎症因子TNF-α、IL-6、IL^-1β和MCP-1的分泌有明显的抑制作用;明显下调MMP-2、MMP-9、TLR4、p-IκB-α和p-NFκB的蛋白的表达,抑制IκB-α磷酸化和NFκB的入核和活化。结论Tan IIA可通过抑制MMP-2和MMP-9的表达以及TLR4/κB-α/NF-κB信号通路,调控TNF-α、IL-6、IL^-1β等炎症因子的释放而发挥抗炎活性。