Identification of pyrogallol from Awa-tea as an anti-allergic compound that suppresses nasal symptoms and IL-9 gene expression.

As the expression level of allergic disease sensitive genes are correlated with the severity of allergic symptoms, suppression of these gene expressions could be promising therapeutics. We demonstrated that protein kinase Cδ / heat shock protein 90-mediated H1R gene expression signaling and nuclear factor of activated T-cells (NFAT)-mediated IL-9 gene expression signaling are responsible for the pathogenesis of pollinosis. Treatment with Awa-tea combined with wild grape hot water extract suppressed these signaling and alleviated nasal symptoms in toluene-2,4-diisocyanate (TDI)-sensitized rats. However, the underlying mechanism of its anti-allergic activity is not elucidated yet. Here, we sought to identify an anti-allergic compound from Awa-tea and pyrogallol was identified as an active compound. Pyrogallol strongly suppressed ionomycin-induced up-regulation of IL-9 gene expression in RBL-2H3 cells. Treatment with pyrogallol in combination with epinastine alleviated nasal symptoms and suppressed up-regulation of IL-9 gene expression in TDI-sensitized rats. Pyrogallol itself did not inhibit calcineurin phosphatase activity. However, pyrogallol suppressed ionomycin-induced dephosphorylation and nuclear translocation of NFAT. These data suggest pyrogallol is an anti-allergic compound in Awa-tea and it suppressed NFAT-mediated IL-9 gene expression through the inhibition of dephosphorylation of NFAT. This might be the underlying mechanism of the therapeutic effects of combined therapy of pyrogallol with antihistamine. J. Med. Invest. 67 : 289-297, August, 2020.

Xinqin exhibits the anti-allergic effect through the JAK2/STAT5 signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Xinqin, a polyherbal medicine, is an important traditional Chinese herbal formula used in traditional oriental medicine for treatment of allergic rhinitis (AR). The formula is based on the Chinese Pharmacopoeia AIM OF THE STUDY: Previously, Xinqin exhibited potent anti-allergic effect in a guinea pig model of AR. In this study, we explored the molecular mechanism of the anti-allergic effect mediated by Xinqin. MATERIALS AND METHODS: AR was induced in guinea pigs (Hartley) with toluene-2, 4-diisocyanate (TDI) in vivo and in HMC-1 mast cells with A23187/phorbol 12-myristate-13-acetate (PMA) in vitro. The releases of allergic inflammatory mediators such as histamine, leukotriene (LT) D4, immunoglobulin (Ig) E, TNF-α, and IL-6 were analyzed for allergy. The mast cell degranulation was displayed in HMC-1 mast cells. The activities of janus protein kinase 2 (JAK2), signal transduction and activator of transcription 5 (STAT5) and suppressor of cytokine signaling 3 (SOCS3) were evaluated by Western blot. RESULTS: Treatment with Xinqin resulted in AR symptoms and decreases in levels of histamine, LTD4, IgE, TNF-α, and IL-6 in serum of guinea pig model of AR and in A23187/PMA-stimulated HMC-1 mast cells. Treatment with Xinqin also inhibited cell degranulation in A23187/PMA-stimulated HMC-1 mast cells. The JAK2/STAT5 signaling pathway could play an important role in the anti-allergic activity mediated by Xinqin. CONCLUSIONS: Xinqin exerts the anti-allergic effect by modulating mast cell-mediated allergic responses by down-regulating JAK2/STAT5 signaling pathway. Results from this study provide a mechanistic basis for the application of Xinqin in the treatment of AR.

Suppression of neuropeptide production by quercetin in allergic rhinitis model rats.

BACKGROUND: Quercetin, a dietary flavonoid found in many fruits, red wine and onion, among others, has been reported to have potent anti-oxidant, anti-viral and anti-cancer effects. Although quercetin is also reported to have anti-inflammatory and anti-allergic effects, the precise mechanisms by which quercetin favorably modify the clinical conditions of allergic diseases such as allergic rhinitis (AR). The present study was designed to examine the influence of quercetin on the development of AR by using AR model rats. METHODS: Sprague-Dawley (SD) rats were sensitized with toluene 2,4-diisocyanate (TDI) by intranasal instillation of a 10 % TDI in ethyl acetate in a volume of 5 µl once a day for 5 consecutive days. This sensitization procedure was repeated after a 2-day interval. After 5 days of the second sensitization, rats were treated with various doses of quercetin once a day for 2 to 7 days. Nasal allergy-like symptoms, which were induced by bilateral application of 5 µl of 10 % TDI in ethyl acetate, were assessed by counting sneezing and nasal rubbing behaviors for 10 min just after TDI nasal challenge. The levels of substance P (SP), calcitonin gene-related peptide (CGRP) and nerve growth factor (NGF) in nasal lavage fluids obtained 6 h after TDI nasal challenge was examined by ELISA. RESULTS: Oral administration of quercetin for 5 and 7 days, but not 2 and 3 days, could inhibit sneezing and nasal rubbing movements, which were increased by TDI nasal challenge. The minimum dose that caused significant inhibition was 25 mg/kg. Oral administration of quercetin at more than 25 mg/kg for 5 days significantly inhibited the increase in SP, CGRP and NGF contents in nasal lavage fluids induced by TDI nasal challenge. CONCLUSION: The present results strongly suggested that quercetin will be a good candidate for the supplement on the management and treatment of allergic diseases, especially AR.

Evaluation of anti-asthmatic and antioxidant potential of Boerhavia procumbens in toluene diisocyanate (TDI) treated rats.

AIM OF THE STUDY: Asthma is an ailment of airways characterized by activation of the T helper (Th) 2 lymphocytes and subsequent movement of inflammatory cells. Boerhavia procumbens of family Nyctaginaceae is locally used for the treatment of asthma, cough, hemorrhoids, dropsy, cardiac, eyes and kidney problems. We have evaluated its methanol extract (BPM) as a therapeutic candidate for asthma against toluene diisocyanate (TDI) allergic model in rat. The BPM extract was obtained from the whole plant of B. procumbens in methanol. Sprague-Dawley male 36 rats (200-250 g) were categorized into 6 groups having six rats in each category. The animals were provoked (10%) and sensitized (5%) by TDI. Animals of groups I-III were vehicle control (ethyl acetate), diseased control (TDI) and reference control (TDI+dexamethasone {2.5mg/kg bw}), respectively. Animals of group IV (TDI+200mg/kg bw) and group V (TDI+400mg/kg bw) were administered with BPM whereas group VI was administered with 400mg/kg bw alone of BPM. Protective effects of BPM were determined by counting the number of leucocytes and estimation of interleukines in blood, bronchoalveolar lavage (BAL) and in in vitro culture of spleen cells. Estimation of antioxidant enzymes, lipid peroxides and H2O2 and histopathology of lungs were carried out for antioxidant potential of plant extract used. RESULTS: Methanol extract of B. procumbens suppressed the asthmatic symptoms and inhibited the infiltration of eosinophils and lymphocytes in lungs of TDI provoked rats. Administration of BPM to TDI provoked rats, dose dependently, inhibited the release of interleukins (IL)-2 in serum and IL-4, IL-6 interferon gamma (IFN-γ) in bronchoalveolar lavage (BAL) and in in vitro culture of spleen cells, and ameliorated the oxidative stress in lung tissues. Quantitative scoring of the lung histopathology exhibited protective effects of BPM and the inflammation, mucus, thickening of peribronchial smooth muscle layer and subepithelial deposition of collagen induced with TDI were ameliorated. The BPM has the anti-inflammatory properties that may be used to treat the asthma and inflammatory related ailments.

Effect of Ipomea carnea Jacq. flowers on hematological changes in toluene diisocyanate-induced inflammation in Wistar rats.

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-3ß-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.

Effect of Ipomea carnea Jacq. flowers on hematological changes in toluene diisocyanate-induced inflammation in Wistar rats / 中国天然药物

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.

Albizia lebbeck suppresses histamine signaling by the inhibition of histamine H1 receptor and histidine decarboxylase gene transcriptions.

Histamine plays major roles in allergic diseases and its action is mediated mainly by histamine H(1) receptor (H1R). We have demonstrated that histamine signaling-related H1R and histidine decarboxylase (HDC) genes are allergic diseases sensitive genes and their expression level affects severity of the allergic symptoms. Therefore, compounds that suppress histamine signaling should be promising candidates as anti-allergic drugs. Here, we investigated the effect of the extract from the bark of Albizia lebbeck (AL), one of the ingredients of Ayruvedic medicines, on H1R and HDC gene expression using toluene-2,4-diisocyanate (TDI) sensitized allergy model rats and HeLa cells expressing endogenous H1R. Administration of the AL extract significantly decreased the numbers of sneezing and nasal rubbing. Pretreatment with the AL extract suppressed TDI-induced H1R and HDC mRNA elevations as well as [(3)H]mepyramine binding, HDC activity, and histamine content in the nasal mucosa. AL extract also suppressed TDI-induced up-regulation of IL-4, IL-5, and IL-13 mRNA. In HeLa cells, AL extract suppressed phorbol-12-myristate-13-acetate- or histamine-induced up-regulation of H1R mRNA. Our data suggest that AL alleviated nasal symptoms by inhibiting histamine signaling in TDI-sensitized rats through suppression of H1R and HDC gene transcriptions. Suppression of Th2-cytokine signaling by AL also suggests that it could affect the histamine-cytokine network.

Transcriptional microarray analysis reveals suppression of histamine signaling by Kujin alleviates allergic symptoms through down-regulation of FAT10 expression.

Previously, we have shown that hot water extract from Kujin, the dried roots of Sophora flavescens alleviates allergic symptoms by suppressing histamine signaling at the transcription level in toluene 2,4-diisocyanate (TDI)-sensitized rats. To know more insights into the mechanism of the anti-allergic action of Kujin, we carried out the microarray analysis to explore genes that were up-regulated by treatment with TDI and also were suppressed these up-regulated gene expression by Kujin. Microarray analysis revealed the substantial up-regulation of FAT10 (also called UbD) mRNA due to TDI sensitization and Kujin extract significantly suppressed this up-regulation. FAT10 is an ubiquitin like protein having an active role in the immune system and is induced by proinflammatory cytokines. Activation of NF-κB by FAT10 also has been reported. However, the role of FAT10 in allergic pathogenesis remains unknown. Here we investigated the correlation of FAT10-NF-κB signaling with histamine signaling in TDI-sensitized rats. Real time RT-PCR analysis confirmed that treatment with TDI up-regulated FAT10 mRNA expression in the nasal mucosa of TDI-sensitized rats and Kujin extract suppressed this elevation. Treatment with H(1)-antihistamines suppressed the TDI-induced up-regulation of FAT10 mRNA expression in TDI-sensitized rats. Direct administration of histamine into the nasal cavity of non-TDI-treated normal rats up-regulated the expression of FAT10 mRNA. Our data suggest that Kujin might alleviate allergic symptoms by inhibition of NF-κB activation through suppression of histamine-induced up-regulation of FAT10 mRNA expression.

Pathway analysis of gene expression in local lymph nodes draining skin exposed to three different sensitizers.

Genomic analysis in the local lymph node assays (LLNAs) is useful for assessing skin sensitization of chemicals and providing insights into mechanisms of sensitization. In this study, we collected 1406 genes from previous microarray findings, validated changes in their expression by RT-PCR analysis in local lymph nodes draining skin exposed to different sensitizers, and interpreted their biological function through pathway-based genomic analysis, in which 468 genes were identified as being in the KEGG pathway database. The top-ranked functions (P < 0.01) identified as being affected by the sensitizers were associated with aspects of cell growth, such as DNA replication, cell cycle regulation and pyrimidine metabolism. All the sensitizers tested (DNCB, OXA and TDI) induced significant up-regulation of Psme4, which is associated with DNA replication; Tfdp1, which is related to cell cycle regulation; and Dut, which is involved in pyrimidine metabolism. Specific changes were also shown in functional categories related to the immune response, including cytokines and their receptors. Genes identified in these functional categories, such as Ccl21c, Cxcl9, Cxcl10, Ifng and Il12rb1, were found to have functional relevance. These findings may enhance our understanding and assessment of chemical sensitizers, and enable us to distinguish sensitizers from irritants and to classify chemicals as contact sensitizers.

Sho-seiryu-to suppresses histamine signaling at the transcriptional level in TDI-sensitized nasal allergy model rats.

BACKGROUND: The therapeutic use of Kampo medicine, Sho-seiryu-to (SST) in allergic disorders is well known. As histamine plays a central role in allergic diseases, it is possible that SST affects the allergy-related histamine signaling. In this study, we investigated the effect of SST on allergy-related histamine signaling in the nasal mucosa of toluene 2, 4-diisocyanate (TDI)-sensitized nasal allergy model rats. METHODS: Six-week-old male, Brown Norway rats were sensitized for 2 weeks with 10 microl of 10% TDI, and after a 1 week interval, provocation was initiated with the same amount of TDI. SST (0.6g/rat) was given orally 1 hour before TDI treatment began for a period of 3 weeks. Nasal symptoms were scored for 10 minutes immediately after TDI-provocation. The genes expression in nasal mucosa was determined using real-time quantitative RT-PCR. RESULTS: SST significantly suppressed TDI-induced nasal allergy-like symptoms. TDI provocation showed a significant up-regulation of histamine H(1) receptor (H1R) and histidine decarboxylase (HDC) gene expressions. Prolonged pre-treatment of SST significantly suppressed the mRNA levels of H1R and HDC that was up-regulated by TDI. SST also suppressed TDI-induced interleukin (IL)-4 and IL-5 mRNA elevation. However, SST showed no significant effect for TDI-induced mRNA elevation of IL-13. CONCLUSIONS: These results demonstrate that SST alleviates nasal symptoms by the inhibition of histamine signaling through suppression of TDI-induced H1R and HDC gene up-regulation. SST also suppresses cytokine signaling through suppression of IL-4 and IL-5 gene expression. Suppression of histamine signaling may be a novel mechanism of SST in preventing allergic diseases.

Transport behavior of n-alkane penetrants into castor oil based polyurethane-polyester nonwoven fabric composites.

Castor oil based polyurethane (PU)-polyester nonwoven fabric composites were fabricated by impregnating the polyester nonwoven fabric in a composition containing castor oil and diisocyanate. Composites were fabricated with two different isocyanates such as toluene-2,4-diisocyanate (TDI) and hexamethylene diisocyanate (HMDI). Transport behavior of n-alkane penetrants (pentane, hexane and heptane) into both PUs and PU-polyester nonwoven fabric composites were studied. Sorption studies were carried out at different temperatures. From the sorption results, the diffusion (D) and permeation (P) coefficients of penetrants have been calculated. Significant increase in the diffusion and permeation coefficients was observed with increase in the temperature of sorption experiments. Drastical reduction in diffusion and permeation coefficients was noticed in the composites compared to neat PUs. Attempts were made to estimate the empirical parameters like n, which suggests the mode of transport and K is a constant depends on the structural characteristics of the composite in addition to its interaction with penetrants. The temperature dependence of the transport coefficients has been used to estimate the activation energy parameter for diffusion (E(D)) and permeation (E(P)) processes from Arrhenius plots. Furthermore, the sorption results have been interpreted in terms of the thermodynamic parameters such as enthalpy (DeltaH) and entropy (DeltaS).

Epigallocatechin-3-gallate protects toluene diisocyanate-induced airway inflammation in a murine model of asthma.

Epigallocatechin-3-gallate (EGCG), a major form of tea catechin, has anti-allergic properties. To elucidate the anti-allergic mechanisms of EGCG, we investigated its regulation of matrix metalloproteinase (MMP-9) expression in toluene diisocyanate (TDI)-inhalation lung tissues as well as TNF-alpha and Th2 cytokine (IL-5) production in BAL fluid. Compared with untreated asthmatic mice those administrated with EGCG had significantly reduced asthmatic reaction. Also, increased reactive oxygen species (ROS) generation by TDI inhalation was diminished by administration of EGCG in BAL fluid. These results suggest that EGCG regulates inflammatory cell migration possibly by suppressing MMP-9 production and ROS generation, and indicate that EGCG may be useful as an adjuvant therapy for bronchial asthma.

[Influence of Xinqin tablets on guinea-pig nasal hypersensitivity].

OBJECTIVE: To study the influence of Xinqin tablets on guinea-pig nasal hypersensitivity. METHOD: 2,4-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. RESULT: Xinqin 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. CONCLUSION: Xinqin tablets have significant effect on nasal hypersensitivity, and prevent the occurrence of allergic rhinitis.

Influence of Xinqin tablets on guinea-pig nasal hypersensitivity / 中国中药杂志

<p><b>OBJECTIVE</b>To study the influence of Xinqin tablets on guinea-pig nasal hypersensitivity.</p><p><b>METHOD</b>2,4-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.</p><p><b>RESULT</b>Xinqin 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.</p><p><b>CONCLUSION</b>Xinqin tablets have significant effect on nasal hypersensitivity, and prevent the occurrence of allergic rhinitis.</p>

Toluene diisocyanate exposure induces laryngo-tracheal eosinophilia, which can be ameliorated by supplementation with antioxidant vitamins in guinea pigs.

OBJECTIVE: Toluene diisocyanate (TDI)-induced asthma is a common cause of occupational lung disease. In addition, a sore throat is one of the complaints of TDI-exposed workers. The aim of the present study was to determine whether TDI exposure induces laryngeal and/or tracheal lesions in experimental animals. MATERIAL AND METHODS: Guinea pigs underwent naris application of TDI three times, and their respiratory tracts were then examined using light and electron microscopy. Some animals simultaneously received vitamins C and E. which function as antioxidant agents. RESULTS: When TDI-treated animals showed the clinical sign of labored breathing, many eosinophils had appeared in the lamina propria and mucosa of both the larynx and trachea, which finally infiltrated the tract lumen through the ruptured epithelium. Laryngo-tracheal inflammation was more severe than that observed in the lungs. However, supplementation with antioxidant vitamins in TDI-treated animals ameliorated the respiratory eosinophilia. CONCLUSION: Naris application of TDI induced laryngotracheitis. which was significantly suppressed by the antioxidant vitamins, This implies a preventive effect of the vitamins on this occupational disease.

[Effect and mechanism of bishudiwan(BSDW) against allergy].

OBJECTIVE: To 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. METHOD: Using 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. RESULT: BSDW 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. CONCLUSION: BSDW 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.

Effect and mechanism of bishudiwan(BSDW) against allergy / 中国中药杂志

<p><b>OBJECTIVE</b>To 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.</p><p><b>METHOD</b>Using 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.</p><p><b>RESULT</b>BSDW 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.</p><p><b>CONCLUSION</b>BSDW 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.</p>

Increase in airway hyperresponsiveness among workers exposed to methylene diphenyldiisocyanate compared to workers exposed to toluene diisocyanate at a petrochemical plant in Korea.

BACKGROUND: The purpose of this study was to investigate the prevalence of airway hyperresponsiveness induced by methylene diphenyldiisocyanate (MDI) and toluene diisocyanate (TDI) at a petrochemical industry complex in Korea. METHODS: Questionnaires, allergic skin test, and nonspecific airway hyperresponsiveness (AHR) were studied in 64 exposed workers and 27 control subjects. Questionnaires included questions about symptoms of cough, wheezing, chest tightness, dyspnea, rhinorrhea, sneezing, itching, stuffiness, tearing, urticaria, sore throat, and exacerbating time. Methacholine challenge tests were done. Bronchial responsiveness (BRindex) defined as log (% fall in FEV(1))/log (last concentration of methacholine +10). RESULTS: Prevalence of AHR (PC20 FEV(1) < 16.0 mg/mL of methacholine) was higher in MDI-exposed workers than in TDI-exposed workers [4/20 (20%) vs. 2/42 (4.7%), P<0.05]. Twenty-three workers (36%) of all subjects had respiratory symptoms. MDI-exposed workers, in comparison with control subjects, had higher BRindex (0.73+/-0.04 vs. 0.62+/-0.02, P<0.05). Workers exposed to TDI or MDI who had respiratory symptoms (n = 23), in comparison to workers exposed to TDI or MDI without respiratory symptoms (n = 41), had significantly higher BRindex (0.82+/-0.06 vs. 0.60+/-0.02, P<0.05). FEV(1) was significantly negatively correlated with BRindex (r = -0.253, P<0.05). BRindex was not correlated with atopy, smoking status, and exposure duration. CONCLUSIONS: These findings suggest that workers exposed to MDI are at a higher risk of asthma in comparison with TDI-exposed workers and control subjects at a petrochemical plant in Korea.

Effect of dietary vitamin E supplementation on murine nasal allergy.

BACKGROUND: Although many studies have reported the effects of dietary vitamin E on the immune response, none so far has assessed its role in nasal allergy. METHODS: Female BALB/c mice were randomized into two groups and fed a 20% casein diet (control group, 50 mg vitamin E/kg diet) or this diet supplemented with 535 mg vitamin E/kg diet (vitamin E group, 585 mg vitamin E/kg diet) for 4 weeks. During the fifth week, the mice in each group were divided into two subgroups to form a total of four treatment groups: group A (control), group B [control + toluene diisocyanate (TDI) sensitization], group C (vitamin E supplementation), and group D (vitamin E supplementation + TDI sensitization). Groups B and D were treated with two courses of intranasal application of 5% TDI in ethyl acetate, whereas groups A and C were treated with ethyl acetate alone. A week after second sensitization all groups were provoked by applying 2.5% of TDI in the vehicle and nasal allergic responses were observed for 10 minutes. Splenic lymphoproliferation, splenic cell cytokines, and the total serum IgE were measured. RESULTS: Members of group D had lower (P < 0.01) scores of nasal response and sneezed less frequently (P < 0.01) than those of group B. Similarly, splenic lymphoproliferation and production of IL-4 and IL-5 as well as the total serum IgE levels were lower (P < 0.01) in group D than in group B. CONCLUSIONS: The results indicate that higher doses of vitamin E supplementation may suppress nasal allergic responses.

[The effect of granule-rhinitis on allergic nasal mucosa].

OBJECTIVE: To investigate the effect of granule-rhinitis on allergic rhinitis. METHOD: Experimental guinea pigs with allergic rhinitis were treated with granule-rhinitis. During the total course of treatment, sneezing and nasal itching were observed and recorded and then compared quantitatively with those of the control groups. Histological changes of the nasal mucosa were observed. RESULT: The various symptoms of allergic rhinitis were obviously relieved in the treatment group. Granule-rhinitis reduced inflammatory cell infiltration, particularly decreased the number of mast cells and eosinophils in the superficial layers of the nasal mucosa, and reduced the release of mediators from mast cells. It diminished the vasodilatation in nasal mucosa. CONCLUSION: Granule-rhinitis is effective in the treatment of allergic rhinitis.