OBJECTIVETo investigate the effect of toluene diisocyanate (TDI) on the expression of vascular endothelial growth factor (VEGF) in human bronchial epithelial (HBE) cells.

METHODSTDI-human serum albumin (TDI- HSA) conjugate was prepared using a modified Son's method. MTT assay was used to examine the viability of HBE135-E6E7 cells cultured in serum-free medium after treatment with HSA or TDI-HSA at different concentrations. VEGF mRNA expression of the HBE cells treated with HSA or TDI-HSA at 10, 20, 30 and 40 microg/ ml, respectively, was detected using semi-quantitative RT-PCR.

RESULTSTreatment with 40 microg/ml HSA and 40 microg/ml TDI-HSA did not result in significant changes in the viability of HBE135-E6E7 cells. RT-PCR revealed the constitutive expression of two VEGF isoforms, namely VEGF189 and VEGF165, in cultured HBE135-E6E7 cells. After exposure to TDI-HSA at the different concentrations (except for 10 microg/ml), a significant increase occurred in both VEGF189 and VEGF165 mRNA expressions in HBE135-E6E7 cells as compared with the expressions in the control group and the HSA-treated cells (P<0.05), and significant dose dependence was noted in the effect of TDI-HSA (P<0.05). No significant difference was found in the expressions between the control cells and the HAS-treated cells (P>0.05).

CONCLUSIONTDI induces significant increase in VEGF expression in HBE cells, and VEGF overexpression may play an important role in the pathogenesis of TDI-induced asthma.

Bronchi ; cytology ; Cell Line ; Cell Survival ; Epithelial Cells ; drug effects ; metabolism ; Humans ; Protein Isoforms ; metabolism ; RNA, Messenger ; metabolism ; Toluene 2,4-Diisocyanate ; pharmacology ; Vascular Endothelial Growth Factor A ; metabolism

Vascular endothelial growth factor (VEGF) is a multi-functional cytokine involved in inflammation, repair and angiogenesis in asthmatic airway. This study aimed to evaluate the role of VEGF in immediate bronchoconstriction induced by TDI inhalation, and in chronic TDI-asthma patients. 11 newly diagnosed TDI-asthma patients (group I), 12 chronic TDI-asthma patients with persistent asthma symptoms followed for >4 yr and 15 unexposed healthy controls were enrolled. In group I, induced sputum and serum were collected before and 7 hr after placebo- and TDI-bronchoprovocation test (BPT). In group II, induced sputum and serum were collected every 2 yr. VEGF levels were measured by ELISA. There were no significant differences in sputum and serum VEGF levels between patients and controls. Before and after placebo and TDI-BPT, no significant changes were noted in sputum and serum VEGF levels of group I. In group II patients, sputum VEGF showed variable changes at 1-yr, then decreased significantly at 2-yr (p<0.05), while serum VEGF showed variable changes at 2-yr, which decreased significantly at 4-yr (p<0.05). These results suggest that VEGF may play a minor role in immediate bronchoconstriction after TDI-BPT. In chronic TDI-asthma, VEGF may be involved to 2 yr after the diagnosis and the contribution may decrease after then.
Adult ; Asthma/*chemically induced/*metabolism ; Bronchi/pathology ; Enzyme-Linked Immunosorbent Assay ; Exercise ; Human ; Methacholine Chloride/pharmacology ; Middle Aged ; Placebos ; Sputum/*metabolism ; Support, Non-U.S. Gov't ; Time Factors ; Toluene 2,4-Diisocyanate/*pharmacology ; Vascular Endothelial Growth Factor A/*biosynthesis/metabolism

This investigation was designed to confirm IL-8 production from human bronchial epithelial cells with toluene diisocyanate (TDI) exposure and to examine the effects of pro-inflammatory cytokine and dexamethasone. We cultured Beas-2B, a bronchial epithelial cell line with TDI-HSA conjugate and compared with those without conjugate. IL-8 in the supernatant was measured by ELISA. To evaluate the effect of proinflammatory cytokines, peripheral blood mononuclear cells (PBMC) were collected from TDI- and non-TDI asthma patients, and were added to the epithelial cell culture. Dexamethasone or antibodies to TNF-alpha and IL-1beta were pre-incubated with PBMC supernatant. There was a significant production of IL-8 from bronchial epithelial cells with addition of TDI-HSA conjugate in a dose-dependent manner, which was significantly augmented with addition of PBMC supernatant. Higher production of IL-8 was noted with addition of PBMC supernatant from TDI-asthma patients than in those from non-TDI asthma patients. IL-1beta and IL-1beta/TFNalpha antibodies were able to suppress the IL-8 productions. Pre-treatment of dexamethasone induced dose-dependent inhibition of the IL-8 production. These results suggest that the IL-8 production from bronchial epithelial cells contribute to neutrophil recruitment occurring in TDIinduced airway inflammation. IL-1beta released from PBMC of TDI-induced asthma patients may be one of the pro-inflammatory cytokines to enhance IL-8 production.
Asthma/immunology ; Bronchi/*cytology/metabolism ; Cell Line ; Dexamethasone/pharmacology ; Epithelial Cells/cytology/*drug effects/*metabolism ; Glucocorticoids/pharmacology ; Human ; Interleukin-8/*metabolism ; Leukocytes, Mononuclear/cytology/metabolism ; Support, Non-U.S. Gov't ; Toluene 2,4-Diisocyanate/*toxicity

OBJECTIVETo investigate the effect of toluene diisocyanate (TDI) on the production of reactive oxygen species (ROS) and the permeability of human bronchial epithelial (HBE) cells.

METHODSTDI-human serum albumin (TDI-HSA) conjugate was prepared using a modified Son's method. MTT assay was used to assess HBE cell viability after exposure to different concentrations of TDI-HSA. The level of intracellular ROS of HBE cells was detected by flow cytometry with an oxidation-sensitive fluorescent probe 2',7'-dichlorofluorescein diacetate (DCFH-DA) uploading, and the permeability of cell monolayer was assessed by detecting the transepithelial electrical resistance (TEER).

RESULTSThe exposure to 120 µg/ml TDI-HSA did not obviously affect the cell viability. Compared with the control group, the intracellular fluorescent intensity increased significantly in the cells exposed to 20, 60, and 100 µg/ml TDI-HSA (P<0.05). The intracellular ROS production increased significantly after 100 µg/ml TDI-HSA treatment (P<0.05), but the increment in ROS production was significantly suppressed by pretreatment of the cells with N-acetylcysteine (NAC) (P<0.05), which also enhanced the TEER decreased by TDI-HSA treatment (P<0.05).

CONCLUSIONSTDI enhances the permeability of HBE cell monolayer partially through a ROS-mediated pathway, suggesting the importance of oxidative stress in TDI-induced pulmonary diseases.

Bronchi ; cytology ; Cell Line ; Cell Membrane Permeability ; drug effects ; Epithelial Cells ; cytology ; metabolism ; Humans ; Oxidative Stress ; drug effects ; Reactive Oxygen Species ; metabolism ; Serum Albumin ; pharmacology ; Toluene 2,4-Diisocyanate ; pharmacology

OBJECTIVETo investigate the effect and mechanism of BSDW on the model of allergic rhinitis and the model of guinea pigs by histamine shocking in guinea pigs.

METHODUsing the model of allergic rhinitis in guinea pigs caused by 10% TDI, we observed the effect of BSDW on physiological and pathological symptoms of allergic rhinitis in guinea pigs, the effect of the levels of serum IgE and serum and nasal histamine. Using the model of guinea pigs by histamine shocking, we observed the effect of BSDW on physiological symptoms in guinea pigs.

RESULTBSDW significantly relieved the pathological symptoms of allergic rhinitis in guinea pigs, alleviated the hyperplasia of columnar epithelium, decreased the number of monocyte and eosinocyte compared with the model group. It also reduced the levels of serum IgE, and decreased the release of serum and nasal histamine. BSDW significantly prolonged the occurent time of gasping, eclampsia and death caused by shock, reduced the times of gasping in the model of guinea pigs by histamine shocking.

CONCLUSIONBSDW has significant effect against allergy. The mechanism relates to its effects of decreasing the levels of serum IgE and inhibiting the release of serum and nasal histamine.

Administration, Intranasal ; Animals ; Anti-Allergic Agents ; pharmacology ; Asarum ; chemistry ; Drug Combinations ; Drugs, Chinese Herbal ; pharmacology ; Female ; Guinea Pigs ; Histamine ; blood ; Immunoglobulin E ; blood ; Lamiaceae ; chemistry ; Male ; Nasal Mucosa ; immunology ; Plants, Medicinal ; chemistry ; Rhinitis, Allergic, Perennial ; immunology ; Scutellaria ; chemistry ; Toluene 2,4-Diisocyanate

AIM: To investigate the active chloroform fraction of the ethanol extract of Ipomoea carnea flowers on hematological changes in toluene diisocyanate-induced inflammation in Wistar rats. METHOD: Except for the control group, all of the rats were sensitized with intranasal application of 5 μL of 10% toluene diisocyanate (TDI) for 7 days. One week after second sensitization, all of the rats were provoked with 5 μL of 5% TDI to induce airway hypersensitivity. After the last challenge, blood and bronchoalvelor lavage (BAL) fluid were collected and subjected to total and differential leucocytes count. Flash chromatography was performed on the most active chloroform fraction to isolate an individual component. RESULTS: Treatment with the ethanolic extract and its chloroform fraction at an oral dose of 200 mg·kg⁻¹ showed a significant decrease in circulating neutrophil and eosinophil in blood and BAL as compared with standard dexamethasone (DEXA). The structure of the compound obtained from chloroform fraction of Ipomea carnea was elucidated as stigmast-5, 22-dien-3β-ol on the basis of spectral data analysis. CONCLUSION The chloroform fraction was found to be more effective to suppress airway hyper reactivity symptoms, and decreased count of both total and differential inflammatory cells.
Animals ; Asthma ; blood ; chemically induced ; drug therapy ; metabolism ; Bronchoalveolar Lavage Fluid ; Eosinophils ; metabolism ; Female ; Flowers ; chemistry ; Hematology ; Inflammation ; blood ; chemically induced ; drug therapy ; metabolism ; Ipomoea ; chemistry ; Leukocyte Count ; Male ; Molecular Structure ; Neutrophils ; metabolism ; Phytotherapy ; Plant Extracts ; chemistry ; pharmacology ; therapeutic use ; Rats ; Rats, Wistar ; Stigmasterol ; analogs & derivatives ; chemistry ; isolation & purification ; pharmacology ; therapeutic use ; Toluene 2,4-Diisocyanate

OBJECTIVETo study the influence of Xinqin tablets on guinea-pig nasal hypersensitivity.

METHOD2,4-Toluene Diisocyanate (TDI) was selected as antigen and used in nose to establish guinea-pig allergic rhinitis. The effects of Xinqin tablets on symptoms of nasal hypersensitivity in guinea-pigs, histamine content of nasal mucosa and activity of nitric oxide synthase (NOS) were examined.

RESULTXinqin tablets could significantly relieve the pathological symptoms of nasal hypersensitivity in guinea-pig, reduce histamine content of nasal mucosa and inhibit the activity of nitric oxide synthase.

CONCLUSIONXinqin tablets have significant effect on nasal hypersensitivity, and prevent the occurrence of allergic rhinitis.

Animals ; Asarum ; chemistry ; Drugs, Chinese Herbal ; administration & dosage ; isolation & purification ; pharmacology ; Guinea Pigs ; Histamine ; metabolism ; Male ; Nasal Mucosa ; drug effects ; metabolism ; pathology ; Nitric Oxide Synthase ; metabolism ; Phytotherapy ; Plants, Medicinal ; chemistry ; Rhinitis, Allergic, Perennial ; chemically induced ; metabolism ; pathology ; Scutellaria ; chemistry ; Toluene 2,4-Diisocyanate