Clarithromycin prevents human respiratory syncytial virus-induced airway epithelial responses by modulating activation of interferon regulatory factor-3.

Macrolide antibiotics exert immunomodulatory activity by reducing pro-inflammatory cytokine production by airway epithelial cells, fibroblasts, vascular endothelial cells, and immune cells. However, the underlying mechanism of action remains unclear. Here, we examined the effect of clarithromycin (CAM) on pro-inflammatory cytokine production, including interferons (IFNs), by primary human nasal epithelial cells and lung epithelial cell lines (A549 and BEAS-2B cells) after stimulation by Toll-like receptor (TLR) and RIG-I-like receptor (RLR) agonists and after infection by human respiratory syncytial virus (RSV). CAM treatment led to a significant reduction in poly I:C- and RSV-mediated IL-8, CCL5, IFN-ß and -λ production. Furthermore, IFN-ß promoter activity (activated by poly I:C and RSV infection) was significantly reduced after treatment with CAM. CAM also inhibited IRF-3 dimerization and subsequent translocation to the nucleus. We conclude that CAM acts a crucial modulator of the innate immune response, particularly IFN production, by modulating IRF-3 dimerization and subsequent translocation to the nucleus of airway epithelial cells. This newly identified immunomodulatory action of CAM will facilitate the discovery of new macrolides with an anti-inflammatory role.

Clarithromycin ameliorates pulmonary inflammation induced by short term cigarette smoke exposure in mice.

BACKGROUND: Cigarette smoking is considered to be one of major causes of acute worsening of asthma as well as chronic obstructive pulmonary disease (COPD). Macrolide antibiotics have been reported to reduce the risk of exacerbations of COPD, and possibly neutrophilic asthma. However, the effect of clarithromycin (CAM) on pulmonary inflammation caused by short term exposure to cigarette smoke still remains to be investigated. METHODS: C57BL/6J female mice were daily exposed to tobacco smoke using a tobacco smoke exposure system, or clean air for 8 days, while simultaneously treated with either oral CAM or vehicles. Twenty four hours after the last exposure, mice were anaesthetized and sacrificed, and bronchoalveolar lavage (BAL) fluids were collected. Cellular responses in BAL fluids were evaluated. Levels of cytokine mRNA in the lung tissues were measured by quantitative RT-PCR. Paraffin-embedded lung tissues were evaluated to quantitate degree of neutrophil infiltration. RESULTS: The numbers of total cells, macrophages and neutrophils in the BAL fluid of smoke-exposed mice were significantly increased as compared to clean air group. These changes were significantly ameliorated in CAM-treated mice. The lung morphological analysis confirmed decrease of neutrophils by CAM treatment. Studies by quantitative PCR demonstrated CAM treatment significantly reduced lung expression levels of IL-17A, keratinocyte-derived chemokine (KC), granulocyte-macrophage colony stimulating factor (GM-CSF) and MMP-9 induced by cigarette smoke. CONCLUSION: We demonstrate that CAM administration resolves enhanced pulmonary inflammation induced by short term cigarette smoke exposure in mice.

Gastroprotective effects of Hwanglyeonhaedok-tang against Helicobacter pylori-induced gastric cell injury.

ETHNOPHARMACOLOGICAL RELEVANCE: Helicobacter pylori, which is found in the stomachs of approximately half of the world's population, has been associated with the development of chronic gastritis and gastric cancer. Hwanglyeonhaedok-tang (HHT) is a popular traditional medicine for the therapies of gastric ulcers and gastritis. AIM OF THE STUDY: The emerging resistance of H. pylori to antibiotics arouses requirement on alternative nonantibiotic-based therapies. In the present study, we investigated the anti-inflammatory activity and anti-microbial activity of HHT against H. pylori in vitro and in an H. pylori-infected mouse model. MATERIALS AND METHODS: H. pylori were treated with various concentrations of HHT and then incubated with human gastric carcinoma AGS cells. For the in vivo study, mice were orally infected with H. pylori three times over the course of 1 week, and then subjected to daily administration of HHT (120 or 600 mg/kg) for 4 weeks or standard triple therapy for 1 week. At the scheduled termination of the experiment, all mice were killed and their stomachs were collected for histological examination, quantitative real-time PCR, and Western blot analysis. RESULTS: Our in vitro studies showed that HHT treatment inhibited the adhesion of H. pylori to AGS cells and suppressed the H. pylori-induced increases of inflammatory regulators, such as interleukin (IL)-8, cyclooxygenase 2 (COX-2), and inducible nitric oxide synthase (iNOS). In the mouse model, HHT treatment significantly reduced H. pylori colonization, inflammation, and the levels of IL-1ß, IL-6, C-X-C motif chemokine ligand 1 (CXCL1), tumor necrosis factor alpha (TNF-α), COX-2, and iNOS in gastric mucosa. Further investigation showed that HHT treatment reduced the H. pylori-induced phosphorylations of p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinases 1/2 (ERK1/2), c-Jun N-terminal protein kinase (JNK), and nuclear factor-kappa B (NF-κB). CONCLUSIONS: Our findings collectively suggest that HHT has anti-inflammatory activity and antibacterial activity against H. pylori and could be an alternative to antibiotics for preventing H. pylori infection.

Gastroprotective activity of the hydroethanolic extract and isolated compounds from the leaves of Solanum cernuum Vell.

ETHNOPHARMACOLOGICAL RELEVANCE: Solanum cernuum Vell. (Solanaceae) is a Brazilian medicinal plant, traditionally known as "panaceia". Its folk name is probably due to its wide range of applications in traditional medicine including the treatment of ulcers. AIM OF THE STUDY: To evaluate the gastroprotective activities of the hydroethanolic extract (ESC) of S. cernuum and its major isolated compounds using in vivo gastric ulcer models. MATERIAL AND METHODS: The ESC extract was obtained by maceration followed by percolation of the dried and powdered leaves of S. cernuum in ethanol:water (7:3). The major compounds in the extract were isolated by applying various preparative chromatographic techniques. The gastroprotective activity was evaluated in mice using different gastric ulcer-induced models. The anti-Helicobacter pylori activity was performed using the agar-well diffusion and broth microdilution methods. RESULTS: The ESC extract showed gastroprotective effects in the assay of acute gastric ulcer-induced by HCl/EtOH, nonsteroidal anti-inflammatory drug, and acetic acid-induced chronic ulcer protocols. The results also demonstrated that the gastroprotection induced by ESC extract is related to the activity of nitric oxide and endogenous sulfhydryls, which are important gastroprotective factors. The ESC extract and the alkaloid cernumidine did not show activity against H. pylori in the concentrations tested. CONCLUSIONS: The present study showed that the crude extract of S. cernuum possessed gastroprotective activity which corroborating the traditional use of this plant for the treatment of gastric ulcers. The isolated flavonoids, quercitrin and afzelin as well as the phenylpropanoid, isoferulic acid are suggested to be the compounds responsible for the gastroprotective activity of S. cernuum extract.

Lectin-conjugated microspheres for eradication of Helicobacter pylori infection and interaction with mucus.

Using second generation mucoadhesives may enhance targeting antibiotics for eradication of Helicobacter pylori from the stomach for the treatment of peptic ulcer. The aim of this research was to prepare and characterise ethylcellulose/chitosan microspheres containing clarithromycin with their surfaces functionalised with concanavalin A to produce a floating-mucoadhesive formulation. The microspheres were prepared using an emulsification-solvent evaporation method. Particle size, surface morphology, in vitro buoyancy profile, zeta potential, drug entrapment efficiency, in vitro drug release and release kinetics of the particles were determined. Lectin was conjugated to the microsphere surface using two-stage carbodiimide activation and confirmed using FTIR, fluorescence studies and zeta potential measurements. Conjugation ranged from 11 to 15 µg Con A/mg microspheres which represents over 56% efficiency although there was some drug loss during the conjugation process. Conjugation did not have a significant effect on the buoyancy and release of drug from the microspheres using a mucus diffusion model with 53% and 40% of drug released from unconjugated and conjugated microspheres within 12h. Conjugation improved mucoadhesion and interaction with porcine gastric mucin compared to unconjugated microspheres. The buoyancy and improved mucoadhesion of the microspheres provides potential for delivery of clarithromycin and other drugs to the stomach.