Cinobufagin enhances the protective efficacy of formalin-inactivated Salmonella typhimurium vaccine through Th1 immune response.

Cinobufagin (CBG), one active ingredient isolated from Venenum Bufonis, has been demonstrated to have immunoregulatory effect. The aim of this study was to investigate whether CBG can enhance the protective efficacy of formalin-inactivated Salmonella typhimurium (FIST) in mice. ICR mice were immunized with FIST (106 CFU/mouse) alone or mixed with CBG (10, 20, and 40 µg) or alum (200 µg) on day 1 and day 15. Two weeks after the second immunization, serum and spleen were sampled for measuring FIST-specific antibody levels, cytokine levels, and splenocyte proliferation. The results showed that CBG enhanced FIST-specific IgG and IgG2a, the levels of interferon-gamma (IFNγ) and nitric oxide (NO), and the splenocyte proliferation response induced by concanavalin A, lipopolysaccharide, and FIST. In vivo protection studies showed that CBG significantly decreased the bacterial burdens in the spleen and prolonged the survival time of FIST-immunized mice challenged with live Salmonella typhimurium. In vivo IFNγ neutralization led to a significant reduction in FIST-specific IgG2a and IFNγ levels, and in the protective efficacy in CBG/FIST-immunized mice. In conclusion, CBG enhances the protective efficacy of formalin-inactivated Salmonella typhimurium vaccine by promoting the Th1 immune response.

Ginsenoside Rh2-B1 stimulates cell proliferation and IFN-γ production by activating the p38 MAPK and ERK-dependent signaling pathways in CTLL-2 cells.

CONTEXT: Ginsenoside Rh2, an active component of ginseng, exhibits immunoregulatory and anti-inflammatory properties. Rh2-B1, a sulfated derivative, was prepared to enhance its water solubility. We studied the effect of Rh2-B1 on CTLL-2, a CD8⁺ cytotoxic T cell line that was known for protecting against viral infection. OBJECTIVE: We aimed to investigate the effect of Rh2-B1 on interferon (IFN)-γ production and cell proliferation and its possible mechanism. MATERIALS AND METHODS: Enzyme-linked immunosorbent assay (ELISA) was employed to analyze the IFN-γ concentration of the whole blood and the supernatant of CTLL-2 cell culture. Cell proliferation assay was conducted using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Western blots were used to evaluate changes in signal transduction pathways in CTLL-2 cells. RESULTS: Rh2-B1 was able to enhance IFN-γ production from whole blood culture of Balb/c mice. We then evaluated the effect of Rh2-B1 on a cytotoxic T cell line, CTLL-2 for cell proliferation, IFN-γ production and its molecular mechanism. Rh2-B1 promoted cell proliferation and IFN-γ production of CTLL-2 cells. It also induced activation of p38 mitogen-activated protein kinase (MAPK) and extracellular-signal-regulated kinases (ERK), but inhibited p56 Lck and transducer and activator of transcription 5 (STAT5) expression. The effect was blocked by the specific p38 MAPK inhibitor SB203580 and ERK inhibitor U0126. CONCLUSION: Rh2-B1 could stimulate cell proliferation and IFN-γ production by activating the p38 MAPK- and ERK-dependent signaling pathways in cytotoxic T cells. This may be a novel medicine for treatment of viral infections.

Xiang-Qi-Tang and its active components exhibit anti-inflammatory and anticoagulant properties by inhibiting MAPK and NF-κB signaling pathways in LPS-treated rat cardiac microvascular endothelial cells.

Xiang-Qi-Tang (XQT) is a Chinese herbal formula containing Cyperus rotundus, Astragalus membranaceus and Andrographis paniculata. Alpha-Cyperone (CYP), astragaloside IV (AS-IV) and andrographolide (AND) are the three major active components in this formula. XQT may modulate the inflammatory or coagulant responses. We therefore assessed the effects of XQT on lipopolysaccharide (LPS)-induced inflammatory model of rat cardiac microvascular endothelial cells (RCMECs). XQT, CYP, AS-IV and AND inhibited the production of tumor necrosis factor alpha (TNF-α), intercellular cell adhesion molecule-1 (ICAM-1) and plasminogen activator inhibitor-1 (PAI-1), and up-regulated the mRNA expression of Kruppel-like factor 2 (KLF2). XQT and CYP inhibited the secretion of tissue factor (TF). To further explore the mechanism, we found that XQT, or its active components CYP, AS-IV and AND significantly inhibited extracellular signal-regulated kinase (ERK), c-jun NH2-terminal kinase (JNK) and p38 phosphorylation protein expression as well as decreased the phosphorylation levels of nuclear factor κB (NF-κB) p65 proteins in LPS-stimulated RCMECs. These results suggested that XQT and its active components inhibited the expression of inflammatory and coagulant mediators via mitogen-activated protein kinase (MAPKs) and NF-κB signaling pathways. These findings may contribute to future research on the action mechanisms of this formula, as well as therapy for inflammation- or coagulation-related diseases.

Peimine impairs pro-inflammatory cytokine secretion through the inhibition of the activation of NF-κB and MAPK in LPS-induced RAW264.7 macrophages.

In the previous study, we found that peimine has good anti-inflammatory effects in vivo. However, the anti-inflammatory mechanism of peimine remains unclear. We, therefore, assessed the effects of peimine on inflammatory cytokines in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. We found that peimine (0-25 mg/L) significantly inhibited tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1ß, and increased IL-10 production. Furthermore, peimine significantly inhibited the phosphorylation of p38, ERK and c-jun N-terminal kinase (JNK) as well as decreased p65 and IκB. The present results indicate that peimine inhibits the production of inflammatory cytokines induced by LPS through blocking MAPKs and NF-κB signaling pathways.

Protective effect of 13-methylberberine against mouse enteritis caused by MRSA.

ETHNOPHARMACOLOGICAL RELEVANCE: The emergence and spread of antibiotic resistance bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA), urgently need to develop alternative strategies or novel antibacterial drugs. Coptis chinensis Franch., one ancient Chinese herb, has been widely used for the treatment of intestine disease, such as diarrhea. Alkaloids are the major active compounds of Coptis chinensis Franch., and has anti-inflammatory, antioxidant, and antimicrobial effects. AIM OF THE STUDY: The aim of the study was tried to investigate the potential antibacterial effects of the alkaloids from Coptis chinensis Franch. and explore the mechanism. MATERIALS AND METHODS: A checkerboard assay, time-killing analysis, membrane functions assay, transcriptome analysis, and inducible resistance test showed the antibacterial effects and mechanisms of alkaloids from Coptis chinensis Franch. Hemolytic assay and MRSA-infected RAW264.7 cells were used to evaluate anti-virulence and anti-inflammatory activities of 13-methylberberine (13-MB). MRSA-infected Vero cells and mouse enteritis models were used to evaluate the anti-infectious effect of 13-MB against MRSA both in vitro and in vivo. RESULTS: 13-methylberberine (13-MB) displayed high bactericidal efficiency against methicillin-resistant S. aureus (MRSA). Mechanistic studies showed that 13-MB rapidly killed MRSA by interfering with the proton motive force, ROS generation and membrane fluidity via direct interaction with membrane phospholipids. 13-MB suppressed the virulence of MRSA, modulated the host immune response, and effectively eliminated MRSA in Vero cells. Importantly, 13-MB suppressed weight loss, inflammatory response, bacterial colonization and intestinal lesion in mouse enteritis caused by 13-MB susceptible and resistant S. aureus. CONCLUSION: These results supported the 13-MB has promising potential to be developed as natural drug with antibacterial activity, anti-virulence activity, and host modulation activity for the treatment of enteritis caused by MRSA.

Natural Antibacterial and Antivirulence Alkaloids From Macleaya cordata Against Methicillin-Resistant Staphylococcus aureus.

The emergence and spread of antibiotic-resistant bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA), underly the urgent need to develop novel antibacterial drugs. Macleaya cordata, a traditional medicinal plant, has been widely used in livestock animals, plants, and humans. Alkaloids are the primary bioactive compounds of Macleaya cordata and exhibit antibacterial, antiinflammatory, and antioxidant activities. Nevertheless, the antibacterial compounds and mode of action of Macleaya cordata remain unclear. In the present study, we investigated the antibacterial activity and mode of action of alkaloids from Macleaya cordata. Sanguinarine, 6-ethoxysanguinarine (6-ES), 6-methoxydihydrosanguinarine (6-MS), chelerythrine (CH), and dihydrochelerythrine (DICH) exhibited good antibacterial activity against Gram-positive bacteria, including MRSA. 6-ES rapidly killed MRSA, possibly by interfering with membrane and metabolic functions including ROS production by targeting the membrane and FtsZ in S. aureus. Additionally, 6-ES directly suppressed the hemolytic activity of α-hemolysin, alleviated inflammatory responses, and eliminated intracellular MRSA, as well as displayed low development of drug resistance, in vitro. Finally, a 6-ES-loaded thermosensitive hydrogel promoted wound healing in mice infected with MRSA. These results supported 6-ES as a novel potential candidate or leading compound with antibacterial, antivirulence, and host immunomodulatory activities in fighting against bacterial infections.

Tanshinone IIA protected against lipopolysaccharide-induced brain injury through the protective effect of the blood-brain barrier and the suppression of oxidant stress and inflammatory response.

Brain microvascular endothelial cells are essential components of the blood-brain barrier (BBB) that acts as a selective physical barrier and plays protective roles in maintaining brain homeostasis. Tanshinone IIA (Tan IIA), isolated from Salvia miltiorrhiza Bunge, exhibited healthy effects such as antioxidant effects, anti-inflammatory effects, and cardiovascular protective effects. Here, we tried to investigate the positive effect and the potential mechanism of Tan IIA on the lipopolysaccharide (LPS)-induced brain injury in mice and brain microvascular endothelial cells in vitro. In vivo, Tan IIA inhibited the brain injury, and the enhancement of blood-brain barrier permeability in the LPS-induced brain injury in mice. Moreover, Tan IIA suppressed inflammatory response and oxidant response in LPS-treated mice evidenced by low levels of serum TNF-α and IL-1ß, high superoxide dismutase (SOD) activity and low malondialdehyde (MDA) in the brain. In vitro, Tan IIA suppressed the generation of reactive oxygen species (ROS) and MDA, and promoted SOD activity in LPS-stimulated brain microvascular endothelial cells. Moreover, Tan IIA promoted the expression of Claudin5, ZO-1, Nrf2, HO-1 and NQO1 in LPS-stimulated brain microvascular endothelial cells. In conclusion, Tan IIA protected against the LPS-induced brain injury via the suppression of oxidant stress and inflammatory response and protective effect of the BBB through activating Nrf2 signaling pathways and rescue of the tight junction proteins in microvascular endothelial cells, supporting the application of Tan IIA and Salvia miltiorrhiza Bunge as food supplements for the treatment of brain disease.

Xiang-qi-tang increases avian pathogenic Escherichia coli-induced survival rate and regulates serum levels of tumor necrosis factor alpha, interleukin-1 and soluble endothelial protein C receptor in chicken.

Xiang-qi-tang (XQT) is a Chinese herbal formula containing rhizoma Cyperi, Andrographis paniculata and Astragalus membranaceus. The present study investigated the effects of XQT on the mortality and inflammatory mediators in a chicken model challenged with avian pathogenic Escherichia coli (APEC). To detect the effect of XQT, the chickens were pretreated with the formula 12 h before being challenged with 10(8) colony forming unit (CFU) of APEC. The results showed that 0.6 g/kg XQT significantly elevated the survival rate of infected chickens. To further investigate the mechanism of decreasing mortality of XQT, we examined plasma inflammatory mediator levels. The levels of tumor necrosis factor alpha (TNF-α), interleukin-1 (IL-1) and soluble endothelial protein C receptor (sEPCR) were significantly increased in chickens challenged with APEC alone, whereas chickens pretreated with 0.6 g/kg XQT showed marked decrease of these inflammatory mediator levels during the death peak. Taken together, this study demonstrates that XQT has protective effects in APEC-treated chickens. The action mechanisms of XQT involve anti-inflammation and antithrombotic activity. These findings may contribute to future research on the action mechanisms of this formula, as well as prevention of or therapy for avian colibacillosis.

Health Benefits of Silybum marianum: Phytochemistry, Pharmacology, and Applications.

Silybum marianum (SM), a well-known plant used as both a medicine and a food, has been widely used to treat various diseases, especially hepatic diseases. The seeds and fruits of SM contain a flavonolignan complex called silymarin, the active compounds of which include silybin, isosilybin, silychristin, dihydrosilybin, silydianin, and so on. In this review, we thoroughly summarize high-quality publications related to the pharmacological effects and underlying mechanisms of SM. SM has antimicrobial, anticancer, hepatoprotective, cardiovascular-protective, neuroprotective, skin-protective, antidiabetic, and other effects. Importantly, SM also counteracts the toxicities of antibiotics, metals, and pesticides. The diverse pharmacological activities of SM provide scientific evidence supporting its use in both humans and animals. Multiple signaling pathways associated with oxidative stress and inflammation are the common molecular targets of SM. Moreover, the flavonolignans of SM are potential agonists of PPARγ and ABCA1, PTP1B inhibitors, and metal chelators. At the end of the review, the potential and perspectives of SM are discussed, and these insights are expected to facilitate the application of SM and the discovery and development of new drugs. We conclude that SM is an interesting dietary medicine for health enhancement and drug discovery and warrants further investigation.

Schizandrin attenuates inflammation induced by avian pathogenic Escherichia coli in chicken type II pneumocytes.

Avian pathogenic Escherichia coli (APEC) is a kind of highly pathogenic parenteral bacteria, which adheres to chicken type II pneumocytes through pili, causing inflammatory damage of chicken type II pneumocytes. Without affecting the growth of bacteria, anti-adhesion to achieve anti-inflammatory effect is considered to be a new method for the treatment of multi-drug-resistant bacterial infections. In this study, the anti-APEC activity of schizandrin was studied in vitro. By establishing the model of chicken type II pneumocytes infected with APEC-O78, the adhesion number, the expression of virulence genes, the release of lactate dehydrogenase (LDH), levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-6, IL-8 and activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways were detected. The results showed that schizandrin reduced the release of LDH and the adherence of APEC on chicken type II pneumocytes. Moreover, schizandrin markedly decreased the levels of IL-1ß, IL-8, IL-6, and TNF-α, the mechanism responsible for these effects was attributed to the inhibitory effect of schizandrin on NF-κB and MAPK signaling activation. In conclusion, our findings revealed that schizandrin could reduce the inflammatory injury of chicken type II pneumocytes by reducing the adhesion of APEC-O78 to chicken type II pneumocytes. The results indicate that schizandrin can be a potential agent to treat inflammation caused by avian colibacillosis.

Natural Products That Target Virulence Factors in Antibiotic-Resistant Staphylococcus aureus.

The increase in the incidence of antibiotic-resistant Staphylococcus aureus (S. aureus) associated infections necessitates the urgent development of novel therapeutic strategies and antibacterial drugs. Antivirulence strategy is an especially compelling alternative strategy due to its low selective pressure for the development of drug resistance in bacteria. Plants and microorganisms are not only important food and medicinal resources but also serve as sources for the discovery of natural products that target bacterial virulence factors. This review discusses the mechanisms of the major virulence factors of S. aureus, including the accessory gene regulator quorum-sensing system, bacterial biofilm formation, α-hemolysin, sortase A, and staphyloxanthin. We also provide an overview of natural products isolated from plants and microorganisms with activity against the major virulence factors of S. aureus and their adjuvant effects on existing antibiotics to overcome antibiotic-resistant S. aureus. Finally, the limitations and solutions of these antivirulence compounds are discussed, which will help in the development of novel antibacterial drugs against antibiotic-resistant S. aureus.

Natural Flavones from Morus alba against Methicillin-Resistant Staphylococcus aureus via Targeting the Proton Motive Force and Membrane Permeability.

The emergence and rapid spread of methicillin-resistant Staphylococcus aureus (MRSA) critically requires alternative therapeutic options. New antibacterial drugs and strategies are urgently needed to combat MRSA-associated infections. Here, we investigated the antibacterial activity of flavones from Morus alba and the potential mode of action against MRSA. Kuwanon G, kuwanon H, mulberrin, and morusin displayed high efficiency in killing diverse MRSA isolates. On the basis of structure-activity analysis, the cyclohexene-phenyl ketones and isopentenyl groups were critical to increase the membrane permeability and to dissipate the proton motive force. Meanwhile, mechanistic studies further showed that kuwanon G displayed rapid bactericidal activity in vitrowith difficulty in developing drug resistance. Kuwanon G targeted phosphatidylglycerol and cardiolipin in the cytoplasmic membrane through the formation of hydrogen bonds and electrostatic interactions. Additionally, kuwanon G promoted wound healing in a mouse model of MRSA skin infection. In summary, these results indicate that flavones are promising lead compounds to treat MRSA-associated infections through disrupting the proton motive force and membrane permeability.

Antibacterial Effect and Mode of Action of Flavonoids From Licorice Against Methicillin-Resistant Staphylococcus aureus.

Staphylococcus aureus is a bacterial pathogen that causes food poisoning, various infections, and sepsis. Effective strategies and new drugs are needed to control S. aureus associated infections due to the emergence and rapid dissemination of antibiotic resistance. In the present study, the antibacterial activity, potential mode of action, and applications of flavonoids from licorice were investigated. Here, we showed that glabrol, licochalcone A, licochalcone C, and licochalcone E displayed high efficiency against methicillin-resistant Staphylococcus aureus (MRSA). Glabrol, licochalcone A, licochalcone C, and licochalcone E exhibited low cytotoxicity without hemolytic activity based on safety evaluation. Glabrol displayed rapid bactericidal activity with low levels of resistance development in vitro. Meanwhile, glabrol rapidly increased bacterial membrane permeability and dissipated the proton move force. Furthermore, we found that peptidoglycan, phosphatidylglycerol, and cardiolipin inhibited the antibacterial activity of glabrol. Molecular docking showed that glabrol binds to phosphatidylglycerol and cardiolipin through the formation of hydrogen bonds. Lastly, glabrol showed antibacterial activity against MRSA in both in vivo and in vitro models. Altogether, these results suggest that glabrol is a promising lead compound for the design of membrane-active antibacterial agents against MRSA and can be used as a disinfectant candidate as well.

Baicalin protects mice against Salmonella typhimurium infection via the modulation of both bacterial virulence and host response.

BACKGROUND: The worsening problems of antibiotic resistance prompt the need for alternative strategies. Baicalin, which is isolated from Scutellaria baicalensisi, has been demonstrated to exhibit anti-inflammatory, anti-virulence and antimicrobial effects. Salmonella typhimurium is an important foodborne pathogenic bacteriaum that causes gastrointestinal disease in humans and many animals. PURPOSE: The aim of this study was to investigate the effects of baicalin on S. typhimurium infection in mice and its possible mechanism in vitro. STUDY DESIGN: To evaluate the effect of baicalin in vivo, mice were orally administered of baicalin, and then were infected by an intragastric administration of S. typhimurium. The minimal inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of baicalin, baicalein, and oroxylin A against S. typhimurium were detected under the guides of the Clinical and Laboratory Standards Institute. In vitro, Caco-2 cells were infected with S. typhimurium in the presence or absence of baicalin, baicalein, and oroxylin A at sub-MICs. METHODS: In the in vivo experiment, the body weight loss, the serum levels of TNFα,  IL-6, and lactic dehydrogenase (LDH), the pathological changes of the caecum and the caecum bacterial burdens were examined. The MICs and MBCs of baicalin, baicalein, and oroxylin A against S. typhimurium were detected by two-fold serial dilutions. In vitro, Caco-2 cells were infected with S. typhimurium, and the invasion capacity, TNFα, nitrate, and LDH were analysed. The transcription levels of Salmonella pathogenicity island 1 virulence associated genes (sopB, sopE, sopE2) of S. typhimurium in the presence of baicalin, baicalein, and oroxylin A were detected by qRT-PCR. RESULTS: Our results showed that baicalin significantly decreased the body weight loss, the serum levels of TNFα,  IL-6, and LDH, and the caecum bacterial burdens of mice challenged with S. typhimurium. Histological examination showed that baicalin decreased the lesion in the caecum of S. typhimurium-infected mice. MICs and MBCs of baicalin, and oroxylin A. against S. typhimurium were > 128 µg/ml. MICs and MBCs of baicalein against S. typhimurium were 64 µg/ml, and > 128 µg/ml, respectively. Pretreatment of Caco-2 cells or S. typhimurium with baicalin, baicalein, and oroxylin A significantly inhibited the invasion of Caco-2 cells by S. typhimurium in a dose-dependent manner. Sub-MICs of baicalin, baicalein, and oroxylin A also significantly decreased the levels of TNFα, nitrate, and LDH from S. typhimurium-infected Caco-2 cells. Moreover, the transcription levels of sopB, sopE, and sopE2 were significantly suppressed by baicalin, baicalein, and oroxylin A. CONCLUSIONS: These results demonstrated that baicalin is a promising agent for the prevention of S. typhimurium infection via the modulation of both bacterial virulence and host response.

Astragaloside IV Inhibits the Inflammatory Injury of Chicken Type II Pneumocytes Induced by Avian Pathogenic Escherichia coli.

Avian pathogenic Escherichia coli (APEC) induces septicemia in chickens by invading type II pneumocytes after breaching the blood-air barrier. Type II pneumocytes play an important role in maintaining the function of the blood-air barrier. Astragaloside IV has been shown in previous studies to have an anti-inflammatory effect. To explore whether astragaloside IV can inhibit APEC-induced injury in chicken type II pneumocytes, cells were infected with APEC-O78. The results showed that astragaloside IV significantly reduced cell damage in chicken type II pneumocytes induced by APEC-O78 by downregulating the production of TNF-α and IL-1ß, upregulating the secretion of IL-4 and IL-10, suppressing the mRNA levels of TLR-4, TLR-5, ERK, and p38 of chicken type II pneumocytes as well as inhibiting bacterial adhesion and F-actin cytoskeleton polymerization. These results suggest that astragaloside IV may be useful in novel pharmaco-therapeutic approaches to the treatment of chicken colibacillosis.

Telocinobufagin enhances the Th1 immune response and protects against Salmonella typhimurium infection.

Ideal potential vaccine adjuvants to stimulate a Th1 immune response are urgently needed to control intracellular infections in clinical applications. Telocinobufagin (TBG), an active component of Venenum bufonis, exhibits immunomodulatory activity. Therefore, we investigated whether TBG enhances the Th1 immune response to ovalbumin (OVA) and formalin-inactivated Salmonella typhimurium (FIST) in mice. TBG augmented serum OVA- and FIST-specific IgG and IgG2a and the production of IFNγ by antigen-restimulated splenocytes. TBG also dramatically enhanced splenocyte proliferative responses to concanavalin A, lipopolysaccharide, and OVA and substantially increased T-bet mRNA levels and the CD3(+)/CD3(+)CD4(+)/CD3(+)CD8(+) phenotype in splenocytes from OVA-immunized mice. In in vivo protection studies, TBG significantly decreased the bacterial burdens in the spleen and prolonged the survival time of FIST-immunized mice challenged with live S. typhimurium. In vivo neutralization of IFNγ with anti-IFNγ mAbs led to a significant reduction in FIST-specific IgG2a and IFNγ levels and in anti-Salmonella effect in TBG/FIST-immunized mice. In conclusion, these results suggest that TBG enhances a Th1 immune response to control intracellular infections.

Andrographolide interferes quorum sensing to reduce cell damage caused by avian pathogenic Escherichia coli.

Avian pathogenic Escherichia coli (APEC) induce septicemia in chickens by invading type II pneumocytes to breach the blood-air barrier. The virulence of APEC can be regulated by quorum sensing (QS). Andrographolide is a QS inhibitor of Pseudomonas aeruginosa (P. aeruginosa). Therefore, we investigate whether andrographolide inhibits the injury of chicken type II pneumocytes by avian pathogenic E. coli O78 (APEC-O78) by disrupting the bacterial QS system. The results showed that sub-MIC of andrographolide significantly reduced the release of lactate dehydrogenase (LDH), F-actin cytoskeleton polymerization, and the degree of the adherence to chicken type II pneumocytes induced by APEC-O78. Further, we found that andrographolide significantly decreased the autoinducer-2 (AI-2) activity and the expression of virulence factors of APEC-O78. These results suggest that andrographolide reduce the pathogenicity of APEC-O78 in chicken type II pneumocytes by interfering QS and decreasing virulence. These results provide new evidence for colibacillosis prevention methods in chickens.

Inhibitory effects of α-cyperone on adherence and invasion of avian pathogenic Escherichia coli O78 to chicken type II pneumocytes.

Avian pathogenic Escherichia coli (APEC) are extra-intestinal pathogenic E. coli, and usually cause avian septicemia through breaching the blood-gas barrier. Type II pneumocytes play an important role of maintaining the function of the blood-gas barrier. However, the mechanism of APEC injuring type II pneumocytes remains unclear. α-cyperone can inhibit lung cell injury induced by Staphylococcus aureus. In order to explore whether α-cyperone regulates the adherence and invasion of APEC-O78 to chicken type II pneumocytes, we successfully cultured chicken type II pneumocytes. The results showed that α-cyperone significantly decreased the adherence of APEC-O78 to chicken type II pneumocytes. In addition, α-cyperone inhibited actin cytoskeleton polymerization induced by APEC-O78 through down regulating the expression of Nck-2, Cdc42 and Rac1. These results provide new evidence for the prevention of colibacillosis in chicken.

Inhibitory effects of sulfated 20(S)-ginsenoside Rh2 on the release of pro-inflammatory mediators in LPS-induced RAW 264.7 cells.

Ginsenoside Rh2 is one of the most important ginsenosides in ginseng with anti-inflammatory and antitumor effects. However, the extremely poor oral bioavailability induced by its low water solubility greatly limits the potency of Rh2 in vivo. In the previous study, we sulfated 20(S)-ginsenoside Rh2 with chlorosulfonic acid and pyridine method, and got one novel derivative, Rh2-B1, with higher water solubility and greater immunologic enhancement than Rh2. However, the anti-inflammatory effect of Rh2-B1 remains unclear. We therefore investigated the effects of Rh2-B1 on lipopolysaccharide (LPS)-induced proinflammatory mediators in RAW 264.7 macrophages. We found that Rh2-B1 dramatically inhibited LPS-induced overproduction of nitric oxide, prostaglandin E2, tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6. Consistently, the protein and mRNA expression levels of inducible nitric oxide synthase and cyclooxygenase-2 were remarkably decreased by Rh2-B1. In addition, Rh2-B1 significantly suppressed the phosphorylations of p38, c-Jun N-terminal kinase, and extracellular signal receptor-activated kinase 1/2 induced by LPS. Rh2-B1 was further shown to inhibit NF-κB p65 translocation into the nucleus by suppressing IκBα degradation. In conclusion, we demonstrate that Rh2-B1 inhibits the release of LPS-induced pro-inflammatory mediators through blocking mitogen-activated protein kinases and NF-κB signaling pathways, suggesting that sulfated ginsenosides could be potential agents for anti-inflammatory therapies.

Sulfated derivative of 20(S)-ginsenoside Rh2 inhibits inflammatory cytokines through MAPKs and NF-kappa B pathways in LPS-induced RAW264.7 macrophages.

In the previous study, we found that sulfated derivative B2 of ginsenoside Rh2 (Rh2-B2) has greater anti-inflammatory effects than 20(S)-ginsenoside Rh2. However, the anti-inflammatory mechanism of Rh2-B2 remains unclear. We therefore assessed the effects of Rh2-B2 on inflammatory cytokines in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. We found that Rh2-B2 (1-5 mg/L) significantly inhibited tumor necrosis factor alpha, interleukin (IL)-6, IL-1ß, and increased IL-10 production from protein and mRNA levels. Furthermore, Rh2-B2 significantly inhibited the phosphorylation of p38 and c-Jun N-terminal kinase as well as decreased p65 nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) translocation into the nucleus by nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha degradation. The present results indicate that Rh2-B2 inhibits the production of inflammatory cytokines induced by LPS through blocking mitogen-activated protein kinases and NF-κB signaling pathways.