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ABSTRACT: Recently, nicotine administration has been shown to be a potent inhibitor of a variety of innate immune responses, including endotoxin-induced sepsis.
It was the aim of this study to evaluate the effect of nicotine on attenuating lung injury and improving the survival in mice with lipopolysaccharide (LPS)-induced acute lung injury (ALI).
ALI was induced in mice by intratracheal instillation of LPS (3 mg/ml). The mice received intratracheal instillation of nicotine (50, 250 and 500 μg/kg) before or after LPS administration. Pulmonary histological changes were evaluated by hematoxylin-eosin stain, and lung wet/dry weight ratios were observed. Concentrations of tumor necrosis factor (TNF)-α, interleukin (IL)-1β and high mobility group box (HMGB)-1, as well as myeloperoxidase (MPO) activity were measured by enzyme-linked immunosorbent assay. The mortality rate was recorded and analyzed by the Kaplan-Meier method.
Nicotine pretreatment significantly attenuated the severity of lung injury and inhibited the production of TNF-α, IL-1β and HMGB-1 in mice with ALI. After LPS administration, the lung wet/dry weight ratios, as an index of lung edema, and MPO activity were also markedly reduced by nicotine pretreatment. Early treatment with a high dose of nicotine (500 μg/kg) after LPS administration decreased the mortality in mice with ALI, even when treatment was started 24 h after LPS administration.
Nicotine attenuated the lung injury and reduced mortality in mice with LPS-induced ALI.
Respiration 01/2011; 81(1):39-46. · 2.26 Impact Factor
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Yun-Feng Ni,
Jian-Ke Kuai,
Zi-Fan Lu, Guo-Dong Yang,
Hai-Yan Fu,
Jian Wang,
Feng Tian,
Xiao-Long Yan,
Ya-Chao Zhao,
Yun-Jie Wang,
Tao Jiang
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ABSTRACT: Glycyrrhizin (GL), a major active constituent of licorice root, has been attributed numerous pharmacologic effects, including anti-inflammatory, anti-viral, anti-tumor, and hepatoprotective activities. In this study, we investigated the anti-inflammatory effect of GL on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. ALI was induced in Balb/c mice by intratracheal instillation of LPS (1 mg/kg). Before 1 h of LPS administration, the mice received intraperitoneal injection of GL at varied doses (10, 25, and 50 mg/kg). The severity of pulmonary injury was evaluated 12 h after LPS administration. GL pretreatment led to significant attenuation of LPS induced evident lung histopathologic changes, alveolar hemorrhage, and neutrophil infiltration with evidence of reduced myeloperoxidase (MPO) activity. The lung wet/dry weight ratios, as an index of lung edema, were markedly reduced by GL pretreatment. The concentrations of pro-inflammatory cytokines interleukin (IL)-1β and tumor necrosis factor (TNF)-α were elevated in bronchoalveolar lavage fluid (BALF) after LPS administration, which were significantly inhibited by GL pretreatment. GL pretreatment also reduced the concentrations of nitric oxide (NO) in lung tissues. Furthermore, the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) was suppressed by GL pretreatment. In conclusion, GL potently protected against LPS-induced ALI, and the protective effects of GL may attribute partly to the suppression of COX-2 and iNOS expression.
Journal of Surgical Research 11/2010; 165(1):e29-35. · 2.25 Impact Factor
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ABSTRACT: 1. The scaffolding protein Homer 1a is constitutively expressed in the myocardium, although its function in cardiomyocytes remains poorly understood. The aim of the present study was to investigate Homer 1a expression in hypertrophic cardiac cells and its role in angiotensin (Ang) II-induced cardiac hypertrophy. 2. After serum starvation for 24 h, cells were treated with 1 micromol/L simvastatin, 100 nmol/L angiotensin (Ang) II or their combination added to Dulbecco's modified Eagle's medium containing 0.5% serum. For combination treatment with AngII plus simvastatin, cells were exposed to simvastatin 12 h before the addition of AngII to the medium and cells were then incubated in the presence of both drugs for a further 24 h. Western blotting was used to determine Homer 1a protein expression. Hypertrophy was evaluated by determining the protein content per cell. 3. Homer 1a protein levels were upregulated following AngII-induced hypertrophy in H9C2 cells and neonatal rat cardiomyocytes, and these increases were augmented by simvastatin pretreatment. Concomitantly, simvastatin pretreatment inhibited extracellular signal-regulated kinase (ERK) 1/2 phosphorylation and AngII-induced hypertrophy. 4. The inhibitory effects of simvastatin against AngII-induced hypertrophy were attenuated by Homer 1a silencing, suggesting that simvastatin suppresses cardiac hypertrophy in a Homer 1a-dependent manner. Furthermore, AngII-induced hypertrophy and ERK1/2 phosphorylation in neonatal rat cardiomyocytes were significantly inhibited following the overexpression of Homer 1a using an adenovirus. 5. These results suggest a possible role for Homer 1a in inhibiting cardiac hypertrophy perhaps in part through inhibition of ERK1/2 activation.
Clinical and Experimental Pharmacology and Physiology 07/2009; 37(1):40-5. · 1.85 Impact Factor