The role of antileukotrienes in the treatment of asthma

Soshiho-tang water extract inhibits ovalbumin-induced airway inflammation via the regulation of heme oxygenase-1

Background

Soshiho-tang, known as Xio-hai-Hu-Tang in Chinese and Sho-Saiko-to in Japanese, has been widely used as a therapeutic agent. Its pharmacological effects include anti-inflammatory, antioxidant, antihepatic fibrosis, antitumor and immunomodulating activities. However, little is known regarding its effects on allergic asthma. Therefore, the aim of the present study was to investigate whether the Soshiho-tang water extract (SSTW) has antiasthmatic effects on airway inflammation in an ovalbumin (OVA)-induced mouse model.

Methods

BALB/c mice were used as a model of asthma after induction by sensitization and challenge with OVA. We measured change in eosinophils, other inflammatory cells, and T helper 2 (Th2)-type cytokines, such as interleukin (IL)-4, IL-5, IL-13, IL-17, IL-33, and chemokine (eotaxin) in bronchoalveolar lavage fluid (BALF), presence of total and OVA-specific immunoglobulin (Ig)E in plasma, and expression of mucus production and heme oxygenase (HO)-1 protein in lung tissue.

Results

Our results show that SSTW had a suppressive effect on eosinophil influx into BALF and decreased the levels of Th2-type cytokines. Moreover, SSTW exhibited a marked decrease in mucus hypersecretion, total and OVA-specific IgE levels, and significantly induced HO-1 protein expression.

Conclusions

These results suggest that SSTW may be used as a valuable therapeutic agent for treating various inflammatory diseases including allergic asthma.

Samsoeum water extract attenuates allergic airway inflammation via modulation of Th1/Th2 cytokines and decrease of iNOS expression in asthmatic mice

Background

Samsoeum has long been used in Korea and other Asian countries as a traditional medicine to treat various diseases. In the present study, we investigated the antiasthma effect of the herbal medicine Samsoeum water extract (SSEW) using an in vivo ovalbumin (OVA)-induced asthmatic model.

Methods

Female BALB/c mice were sensitized by an intraperitoneal injection of OVA and subsequently challenged with nebulized OVA. We investigated the number of inflammatory cells, the production of Th1/Th2 cytokines and chemokine in bronchoalveolar lavage fluid (BALF), histological changes in lung tissue, the infiltration of inflammatory cells and hyperplasia of goblet cells in lung tissue, the levels of immunoglobulin E (IgE) in BALF and plasma, and the expression of inducible nitric oxide synthase (iNOS) in lung tissue.

Results

Our findings indicated that SSEW decreased the accumulation of inflammatory cells (particularly, eosinophil and neutrophil) and regulated the balance in the production of Th1/Th2 cytokines and chemokine in BALF. Moreover, SSEW suppressed the level of IgE in BALF and plasma, and inhibited the infiltration of inflammatory cells, hyperplasia of goblet cells, and the expression of iNOS in lung tissue.

Conclusions

Collectively, these results suggest that, because of its anti-inflammatory and antiasthma properties, SSEW may be useful in reducing airway inflammation in the treatment of allergic asthma.

Clinical effectiveness and safety of montelukast in asthma. What are the conclusions from clinical trials and meta-analyses?

Asthma is a common childhood atopic disease associated with chronicity and impaired quality of life. As there is no cure for this disease, treatment relies on avoidance of triggers such as food and aeroallergens, the use of inhaled bronchodilators/corticosteroids and antiallergic or immunomodulating therapies. Inhaled corticosteroids (ICSs) and bronchodilators have been the mainstay. However, in Asia, myths and fallacies regarding Western medicine and corticosteroids are prevalent and lead to nonadherence to treatment. Also, use of traditional and proprietary herbal medicines is popular. In the past decades, a novel class of nonsteroidal immunomodulating montelukasts has become available. This article reviews the evidence for the effectiveness and clinical efficacy of these medications. A number of randomized and controlled trials have been performed over the years. The majority of studies confirm the usefulness of montelukast as monotherapy and add-on therapy to ICS in mild to moderate childhood asthma across all age groups. ICSs are generally superior to montelukasts for asthma management. However, montelukast has a place in the treatment of young children with viral-triggered wheezing diseases, exercise-induced asthma, and in children whose parents are steroid-phobic and find ICS unacceptable.

Treatment with pyranopyran-1, 8-dione attenuates airway responses in cockroach allergen sensitized asthma in mice

Chronic allergic asthma is characterized by Th2-typed inflammation, and contributes to airway remodeling and the deterioration of lung function. Viticis Fructus (VF) has long been used in China and Korea as a traditional herbal remedy for treating various inflammatory diseases. Previously, we have isolated a novel phytochemical, pyranopyran-1, 8-dione (PPY), from VF. This study was conducted to evaluate the ability of PPY to prevent airway inflammation and to attenuate airway responses in a cockroach allergen-induced asthma model in mice. The mice sensitized to and challenged with cockroach allergen were treated with oral administration of PPY. The infiltration of total cells, eosinophils and lymphocytes into the BAL fluid was significantly inhibited in cockroach allergen-induced asthma mice treated with PPY (1, 2, or 10 mg/kg). Th2 cytokines and chemokine, such as IL-4, IL-5, IL-13 and eotaxin in BAL fluid were also reduced to normal levels following treatment with PPY. In addition, the levels of IgE were also markedly suppressed after PPY treatment. Histopathological examination demonstrated that PPY substantially inhibited eosinophil infiltration into the airway, goblet cell hyperplasia and smooth muscle hypertrophy. Taken together, these results demonstrate that PPY possesses a potent efficacy on controlling allergic asthma response such as airway inflammation and remodeling.

Inhibitory effects of Pycnogenol® (French maritime pine bark extract) on airway inflammation in ovalbumin-induced allergic asthma

Pycnogenol® (PYC) is a standardized extracts from the bark of the French maritime pine (Pinus maritime) and used as a herbal remedy for various diseases. In this study, we evaluated the effects of PYC on airway inflammation using a model of ovalbumin (OVA)-induced allergic asthma and RAW264.7 cells. PYC decreased nitric oxide production and reduced the interleukine (IL)-1β and IL-6 levels in LPS-stimulated RAW264.7 cells. PYC also reduced the expression of inducible nitric oxide synthase (iNOS) and matrix metalloproteinase (MMP)-9 and enhanced the expression of hemeoxygenase (HO)-1. In the in vivo experiment, PYC decreased the inflammatory cell count and the levels of IL-4, IL-5, IL-13, and immunoglobulin (Ig) E in BALF or serum. These results are consistent with the histological analysis findings, which showed that PYC attenuated the airway inflammation and mucus hypersecretion induced by OVA challenge. In addition, PYC enhanced the expression of HO-1. In contrast, PYC inhibited the elevated expression of iNOS and MMP-9 proteins induced by OVA challenge. In conclusion, PYC exhibits protective effects against OVA-induced asthma and LPS-stimulated RAW264.7 cells. These results suggest that PYC has potential as a therapeutic agent for the treatment of allergic asthma.

Diallyl-disulfide, an organosulfur compound of garlic, attenuates airway inflammation via activation of the Nrf-2/HO-1 pathway and NF-kappaB suppression

Diallyl disulfide (DADS) is a major organosulfur compound found in garlic oil that is widely used as a flavoring agent. In this study, we evaluated the effects of DADS on airway inflammation using an ovalbumin-induced model of allergic asthma and RAW264.7 cells. DADS decreased nitric oxide production with a reduction in the levels of interleukins (IL)-1β and IL-6 in RAW264.7 cells stimulated with LPS. DADS also reduced the expression of proinflammatory proteins including inducible nitric oxide synthase (iNOS), nuclear factor (NF)-κB, and matrix metalloproteinase (MMP)-9, and it enhanced the expression of antioxidant proteins including Nrf-2 and hemeoxygenase (HO)-1. In in vivo experiments, DADS decreased the inflammatory cell count in the bronchoalveolar lavage fluid (BALF) with IL-4, IL-5, IL-13, and immunoglobulin (Ig) E. These results were consistent with the histological analysis. DADS attenuated the airway inflammation and mucus hypersecretion induced by OVA challenge. In addition, DADS induced the activation of Nrf-2 and the expression of HO-1. In contrast, DADS reduced the activation of NF-κB, iNOS and MMP-9. In conclusion, DADS reduced the airway inflammation via regulation of Nrf-2/HO-1 and NF-κB. These results suggest that DADS might represent a useful new oral therapy to treat allergic asthma.

Lung type 2 innate lymphoid cells express cysteinyl leukotriene receptor 1, which regulates TH2 cytokine production

BACKGROUND

Cysteinyl leukotrienes (CysLTs) contribute to asthma pathogenesis, in part through cysteinyl leukotriene receptor 1 (CysLT1R). Recently discovered lineage-negative type 2 innate lymphoid cells (ILC2s) potently produce IL-5 and IL-13.

OBJECTIVES

We hypothesized that lung ILC2s might be activated by leukotrienes through CysLT1R.

METHODS

ILC2s (Thy1.2(+) lineage-negative lymphocytes) and CysLT1R were detected in the lungs of wild-type, signal transducer and activator of transcription 6-deficient (STAT6(-/-)), and recombination-activating gene 2-deficient (RAG2(-/-)) mice by means of flow cytometry. T(H)2 cytokine levels were measured in purified lung ILC2s stimulated with leukotriene D₄ (LTD₄) in the presence or absence of the CysLT1R antagonist montelukast. Calcium influx was measured by using Fluo-4 intensity. Intranasal leukotriene C₄, D₄, and E₄ were administered to naive mice, and levels of ILC2 IL-5 production were determined. Finally, LTD₄ was coadministered with Alternaria species repetitively to RAG2(-/-) mice (with ILC2s) and IL-7 receptor-deficient mice (lack ILC2s), and total ILC2 numbers, proliferation (Ki-67(+)), and bronchoalveolar lavage fluid eosinophil numbers were measured.

RESULTS

CysLT1R was expressed on lung ILC2s from wild-type, RAG2(-/-), and STAT6(-/-) naive and Alternaria species-challenged mice. In vitro LTD₄ induced ILC2s to rapidly generate high levels of IL-5 and IL-13 within 6 hours of stimulation. Interestingly, LTD4, but not IL-33, induced high levels of IL-4 by ILC2s. LTD₄ administered in vivo rapidly induced ILC2 IL-5 production that was significantly reduced by montelukast before treatment. Finally, LTD₄ potentiated Alternaria species-induced eosinophilia, as well as ILC2 accumulation and proliferation.

CONCLUSIONS

We present novel data that CysLT1R is expressed on ILC2s and LTD₄ potently induces CysLT1R-dependent ILC2 production of IL-4, IL-5, and IL-13. Additionally, LTD₄ potentiates Alternaria species-induced eosinophilia and ILC2 proliferation and accumulation.

EBM84 attenuates airway inflammation and mucus hypersecretion in an ovalbumin-induced murine model of asthma

EBM84 is a traditional herbal medicine and a combination of extracts obtained from Pinellia ternata and Zingiber officinale. It is traditionally used to treat vomiting, nausea, sputum and gastrointestinal disorders, and functions is an effective expectorant. In this study, we evaluated the protective effects of EBM84 on asthmatic responses, particularly mucus hypersecretion in an ovalbumin (OVA)-induced murine model of asthma. We also analyzed EBM84 composition using high performance liquid chromatography. Animals were sensitized on days 0 and 14 via intraperitoneal injection using 20 µg OVA. On days 21, 22 and 23 after initial sensitization, the mice received an airway challenge with OVA (1% w/v in PBS) for 1 h using an ultrasonic nebulizer (NE-U12). EBM84 was administered by gavage to the mice at doses of 16.9, 33.8 and 67.5 mg/kg once daily from days 18 to 23. EBM84 administration significantly lowered elevated levels of interleukin (IL)-4, IL-13, eotaxin and immunoglobulin (Ig)E in the bronchoalveolar lavage fluid or plasma. Airway inflammation and mucus hypersecretion were attenuated following EBM84 administration. EBM84 also inhibited the overexpression of mucin 5AC (MUC5AC) induced by OVA challenge in lung tissue. This result was consistent with the immunohistochemistry results. Our results indicate that EBM84 effectively inhibited airway inflammation and mucus hypersecretion via the downregulation of T helper 2 (Th2) cytokines, which reduced MUC5AC expression. Therefore, EBM84 has potential as a useful medicine for the treatment of allergic asthma.

Pinellia ternata Breitenbach attenuates ovalbumin-induced allergic airway inflammation and mucus secretion in a murine model of asthma

OBJECTIVE

Pinellia ternata is an important plant in traditional Chinese medicine. This study describes the anti-inflammatory effects of a water extract of P. ternata (PTE) in allergic airway inflammation in a model of asthma in mice.

MATERIALS AND METHODS

BALB/c mice were sensitized with ovalbumin (OVA) and, upon an OVA aerosol challenge, developed airway eosinophilia, mucus hypersecretion, elevations in cytokine, chemokine, and immunoglobulin levels and overexpression of inducible nitric oxide (iNOS).

RESULTS

Intragastric administration of PTE significantly attenuated OVA-induced influx of total leukocytes, eosinophils, neutrophils, macrophages and lymphocytes into lungs, and attenuated levels of interleukin (IL)-4, IL-13 and tumor necrosis factor-α (TNF-α), in a dose-dependent manner. PTE also significantly reduced the plasma levels of total and OVA-specific immunoglobulin (Ig)E release into the airspace. Histological studies showed that PTE inhibited OVA-induced lung tissue eosinophilia and airway mucus production. Moreover, in whole lung tissue lysates, immunohistology showed that PTE markedly attenuated the OVA-induced increase in mucin 5AC and iNOS expression.

CONCLUSIONS

These results indicate that PTE has protective effects against allergic airway inflammation.

Dianthus superbus fructus suppresses airway inflammation by downregulating of inducible nitric oxide synthase in an ovalbumin-induced murine model of asthma

Background

Dianthus superbus has long been used as a herbal medicine in Asia and as an anti-inflammatory agent. In this study, we evaluated the anti-inflammatory effects of Dianthus superbus fructus ethanolic extract (DSE) on Th2-type cytokines, eosinophil infiltration, and other factors in an ovalbumin (OVA)-induced murine asthma model. To study the possible mechanism of the anti-inflammatory effect of DSE, we also evaluated the expression of inducible nitric oxide synthase (iNOS) in the respiratory tract.

Methods

Mice were sensitized on days 0 and 14 by intraperitoneal injection of OVA. On days 21, 22 and 23 after initial sensitization, mice received an airway challenge with OVA for 1 h using an ultrasonic nebulizer. DSE was applied 1 h prior to OVA challenge. Mice were administered DSE orally at doses of 100 mg/kg or 200 mg/kg once daily from day 18 to 23. Bronchoalveolar lavage fluid (BALF) was collected 48 h after the final OVA challenge. Levels of interleukin (IL)-4, IL-13 and eotaxin in BALF were measured using enzyme-linked immunosorbent assays (ELISAs). Lung tissue sections were stained with hematoxylin and eosin for assessment of cell infiltration and mucus production with periodic acid shift staining, in conjunction with ELISA and western blot analyses for iNOS expression.

Results

DSE significantly reduced the levels of IL-4, IL-13, eotaxin, and immunoglobulin (Ig) E, number of inflammatory cells in BALF, and inflammatory cell infiltration and mucus production in the respiratory tract. DSE also attenuated the overexpression of iNOS protein induced by OVA challenge.

Conclusion

Our results suggest that DSE effectively protects against allergic airway inflammation by downregulating of iNOS expression and that DSE has potential as a therapeutic agent for allergic asthma.

An extract of Crataegus pinnatifida fruit attenuates airway inflammation by modulation of matrix metalloproteinase-9 in ovalbumin induced asthma

BACKGROUND

Crataegus pinnatifida (Chinese hawthorn) has long been used as a herbal medicine in Asia and Europe. It has been used for the treatment of various cardiovascular diseases such as myocardial weakness, tachycardia, hypertension and arteriosclerosis. In this study, we investigated the anti-inflammatory effects of Crataegus pinnatifida ethanolic extracts (CPEE) on Th2-type cytokines, eosinophil infiltration, expression of matrix metalloproteinase (MMP)-9, and other factors, using an ovalbumin (OVA)-induced murine asthma model.

METHODS/PRINCIPAL FINDING

Airways of OVA-sensitized mice exposed to OVA challenge developed eosinophilia, mucus hypersecretion and increased cytokine levels. CPEE was applied 1 h prior to OVA challenge. Mice were administered CPEE orally at doses of 100 and 200 mg/kg once daily on days 18-23. Bronchoalveolar lavage fluid (BALF) was collected 48 h after the final OVA challenge. Levels of interleukin (IL)-4 and IL-5 in BALF were measured using enzyme-linked immunosorbent (ELISA) assays. Lung tissue sections 4 µm in thickness were stained with Mayer's hematoxylin and eosin for assessment of cell infiltration and mucus production with PAS staining, in conjunction with ELISA, and Western blot analyses for the expression of MMP-9, intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 protein expression. CPEE significantly decreased the Th2 cytokines including IL-4 and IL-5 levels, reduced the number of inflammatory cells in BALF and airway hyperresponsiveness, suppressed the infiltration of eosinophil-rich inflammatory cells and mucus hypersecretion and reduced the expression of ICAM-1, VCAM-1 and MMP-9 and the activity of MMP-9 in lung tissue of OVA-challenged mice.

CONCLUSIONS

These results showed that CPEE can protect against allergic airway inflammation and can act as an MMP-9 modulator to induce a reduction in ICAM-1 and VCAM-1 expression. In conclusion, we strongly suggest the feasibility of CPEE as a therapeutic drug for allergic asthma.

Kochia scoparia fruit attenuates allergic airway inflammation in ovalbumin (OVA)-induced murine asthma model

Kochia scoparia fruit has been used in Asia for a long time. It possesses anti-inflammatory, antiallergic, and antipruritic actions. We investigated the role of a K. scoparia fruit ethanolic extract (KSEE) in allergic airway inflammation in a mouse asthma model. BALB/c mice were sensitized with ovalbumin (OVA) and, upon OVA aerosol challenge, developed airway eosinophilia, mucus hypersecretion, elevations in cytokine, chemokine, and immunoglobulin levels, and upregulation of MMP-9, intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) expression. Intragastric administration of KSEE significantly attenuated OVA-induced influx of total leukocytes, eosinophils, neutrophils, macrophages, and lymphocytes into lungs, as well as attenuating levels of interleukin (IL)-4 and IL-5 in a dose-dependent manner. KSEE also significantly reduced the serum levels of total and OVA-specific immunoglobulin (Ig)E and OVA-specific IgG1 release into the airspace. Histological studies showed that KSEE inhibited OVA-induced lung tissue eosinophilia and airway mucus production. Moreover, in whole lung tissue lysates, immunoreactivity showed that KSEE markedly attenuated the OVA-induced increase in expression of ICAM-1, VCAM-1, and MMP-9. These results show that KSEE possesses protective effects against allergic airway inflammation, acts as an MMP-9 inhibitor, and induces a reduction in ICAM-1 and VCAM-1 expression.

Tiarellic acid attenuates airway hyperresponsiveness and inflammation in a murine model of allergic asthma

Asthma is a persistent inflammatory disease characterized by airway obstruction and hyperresponsiveness in association with airway inflammation. In the current research, we studied the anti-inflammatory and anti-asthmatic effects of tiarellic acid (TA) isolated from Tiarella polyphylla, based on asthmatic parameters, such as immunoglobulin E (IgE) level, cytokine release, eosinophilia, airway hyperresponsiveness (AHR), reactive oxygen species (ROS) and mucus hypersecretion, in an ovalbumin (OVA)-sensitized/challenged mouse model. TA significantly inhibited increases in IgE, levels of ROS and T helper cytokines, such as interleukin (IL)-4, IL-5, TNF-α, and IL-13, in bronchoalveolar lavage fluid (BALF), and effectively suppressed airway hyperresponsiveness, eosinophilia, and mucus hypersecretion in the asthmatic mouse model. In addition, we found that administration of TA attenuated ovalbumin-induced increases in NF-κB activity in lungs. The efficacy of TA was comparable to that of montelukast, a currently available anti-asthmatic drug. Our results support the utility of TA as a herbal medicine for asthma treatment and may have application in the development of anti-inflammatory and anti-asthmatic drugs.

Antiasthmatic effects of Gleditsia sinensis in an ovalbumin-induced murine model of asthma

This study evaluated the antiasthmatic effects of Gleditsia sinensis ethanolic extract (GSEE) and its underlying mechanisms, using an in vivo murine model of asthma. Female BALB/c mice were sensitized, challenged with ovalbumin, and then examined for asthmatic reactions. The results showed that GSEE exerted profound inhibitory effects on the accumulation of eosinophils in the airways and reduced the levels of interleukin (IL)-4 and IL-5 in bronchoalveolar lavage fluid (BALF) and immunoglobulin E (IgE) in BALF and plasma. Gleditsia sinensis ethanolic extract also suppressed the production of reactive oxygen species in BALF and inflammatory infiltration, in a dose-dependent manner, and it inhibited goblet-cell hyperplasia in lung tissue. Thus, GSEE shows antiasthmatic effects in a murine model of allergic asthma, which appeared to be mediated partially by the reduction of oxidative stress and airway inflammation. These results indicate that GSEE could be an effective novel therapeutic agent for the treatment of allergic asthma.

Effects of astilbic acid on airway hyperresponsiveness and inflammation in a mouse model of allergic asthma

Bronchial asthma is characterized by chronic lung inflammation, airway hyperresponsiveness (AHR), and airway remodeling. Astilbic acid, extracted from the medicinal herb Astilbe chinensis, is used as a headache remedy in traditional medicine and has anti-pyretic and analgesic effects. However, the effect of astilbic acid on asthma remains to be established. In the present study, we therefore examined the effect of astilbic acid in a mouse model in which asthma was established by sensitization and challenge with ovalbumin (OVA). Astilbic acid inhibited OVA-induced AHR to inhaled methacholine and significantly suppressed the levels of T-helper 2-type cytokines (including IL [interleukin]-4, IL-5, and IL-13) and inflammatory cells (including eosinophils) in bronchoalveolar lavage (BAL) fluid. Histochemical analysis revealed reduced goblet cell hyperplasia and mucus production, as well as attenuated eosinophil-rich leukocyte infiltration, in the astilbic acid-treated group, compared with OVA-challenged mice. Moreover, the compound significantly inhibited synthesis of IL-4-, IL-5-, IL-13-, IL-17-, and eotaxin-encoding mRNA following asthma induction in lung tissue, in addition to suppressing the immunoglobulin E (IgE) response to asthma in both BAL fluid and serum. Our results indicate that astilbic acid has great potential as a therapeutic candidate for the treatment of asthma.

Anti-asthmatic effect of schizandrin on OVA-induced airway inflammation in a murine asthma model

Asthma comprises a triad of reversible airway obstruction, bronchial smooth muscle cell hyperreactivity to bronchoconstrictors, and chronic bronchial inflammation. Clinical and experimental findings have established eosinophilia as a sign of allergic disorders. In the present investigation, we evaluated the anti-asthmatic effects of schizandrin and its underlying mechanisms in an in vivo murine asthmatic model. To accomplish this, female BALB/c mice were sensitized and challenged with ovalbumin (OVA), and examined for the following typical asthmatic reactions: increased numbers of eosinophils and other inflammatory cells in bronchoalveolar lavage fluid (BALF); production of Th1 cytokines (such as tumor necrosis factor (TNF)-α in BALF); production of Th2 cytokines (such as interleukin IL-4 and IL-5) in BALF; presence of total and OVA-specific immunoglobulins (Ig)E in serum; presence of oxidative stress; hyperplasia of goblet cells in the lung; and marked influx of inflammatory cells into the lung. Our results collectively show that schizandrin exerts profound inhibitory effects on accumulation of eosinophils into the airways and reduces the levels of IL-4, IL-5, IFN-γ, and TNF-α in BALF. Additionally, schizandrin suppresses the production of reactive oxygen species (ROS) in a dose-dependent manner, and inhibits goblet cell hyperplasia and inflammatory cell infiltration in lung tissue. Thus, schizandrin has anti-asthmatic effects, which seem to be partially mediated by reduction of oxidative stress and airway inflammation, in a murine allergic asthma model. These results indicate that schizandrin may be an effective novel therapeutic agent for the treatment of allergic asthma.

Montelukast in the treatment of allergic rhinitis: an evidence-based review

Cysteinyl-leukotrienes (CysLTs) are endogenous mediators of inflammation and play an important role in allergic airway disease by stimulating bronchoconstriction, mucus production, mucosal oedema and inflammation, airway infiltration by eosinophils, and dendritic cell maturation that prepares for future allergic response. Montelukast inhibits these actions by blocking type 1 CysLT receptors found on immunocytes, smooth muscle and endothelium in the respiratory mucosa. Initially developed as a treatment for asthma, montelukast has more recently found use in the treatment of allergic rhinitis (AR). We conducted a systematic review of studies that have evaluated montelukast in the treatment of seasonal AR (SAR) and perennial AR (PAR), with and without concomitant asthma. Primary consideration was given to large, randomised, placebo-controlled, double-blind clinical trials in which AR endpoints were assessed and the use of concurrent treatments for AR was excluded. Eight such studies were found in the literature. The primary endpoint in these was daytime nasal symptom severity represented by a composite score derived from individual self-ratings of nasal congestion, rhinorrhoea, nasal pruritus and sneezing. Secondary endpoints have included these individual nasal symptom scores, additional scores for eye, ear and throat symptoms, the impact of rhinitis on quality of sleep, global evaluations of outcome by patients and physicians, and measures of the severity of concomitant asthma. A general outcome was that patients treated with montelukast had significantly greater improvements in their symptoms of SAR and PAR than did patients who were given a placebo. As monotherapy, montelukast exhibited efficacy similar to that of loratadine, but less than that of the intranasally administered corticosteroid fluticasone propionate. The use of montelukast in combination with antihistamines such as loratadine or cetirizine has generally resulted in greater efficacy than when these agents were used alone, and in some studies has produced results comparable with intranasally applied corticosteroids. In patients with AR comorbid with asthma, montelukast treatment has resulted in significant improvements in both, compared with placebo. Montelukast is well tolerated and has a favourable safety profile; adverse events have occurred at similar frequencies in patients taking either montelukast or placebo. Montelukast provides an effective and well tolerated oral treatment for allergic airway inflammation in patients with SAR or PAR without asthma, and in patients in whom AR is comorbid with asthma.

Suppressive effect of verproside isolated from Pseudolysimachion longifolium on airway inflammation in a mouse model of allergic asthma

Allergic inflammation of the airways has a critical role in asthma development. We investigated a suppressive effect of verproside (3,4-dihydroxy catalpol) isolated from the extract of Pseudolysimachion longifolium on asthmatic parameters--such as immunoglobulin E (IgE) level, cytokine release, eosinophilia, airway hyperresponsiveness and mucus hypersecretion--in an OVA-sensitized/challenged mouse model. Verproside significantly inhibited the increase of total IgE and the cytokines IL-4 and IL-13 in plasma and bronchoalveolar lavage fluid, and also effectively suppressed airway hyperresponsiveness, eosinophilia and mucus hypersecretion in OVA-induced asthmatic mice. The efficacy of verproside was comparable to montelukast, an anti-asthmatic drug that is currently available. These results suggest that verproside could be a major marker in herbal medicines that are used for asthma treatment, and could also act as a lead for anti-asthmatic drugs.

Asthma controller therapy during pregnancy

OBJECTIVE

This study was undertaken to educate physicians on the safety of asthma controller use during pregnancy.

STUDY DESIGN

A comprehensive literature search using MEDLINE, the Cochrane Controlled Trials Register and Database of Systematic Reviews, EMBASE, and selected bibliographies identified human gestational studies of asthma controller medications from which maternal and fetal outcomes were obtained. The US Food and Drug Administration (FDA) pregnancy category ratings were identified from product package inserts.

RESULTS

Human gestational studies were identified for the inhaled corticosteroids (ICSs) beclomethasone, budesonide, and triamcinolone and for cromolyn sodium, theophylline, and salmeterol. Human pregnancy data support an FDA Pregnancy Category B rating for budesonide. Pregnancy Category B ratings for cromolyn, nedocromil, montelukast, and zafirlukast are based primarily on safety in animal reproduction studies. ICSs other than budesonide, theophylline, zileuton, and long-acting beta 2 -adrenergic agonists are Pregnancy Category C.

CONCLUSION

Human pregnancy data for many asthma controllers are lacking; nonetheless, data support a range of choices among medications rated Pregnancy Category B.

Inhibition of human eosinophil activation by a cysteinyl leukotriene receptor antagonist (pranlukast; ONO-1078)

Eosinophils produce cysteinyl leukotrienes such as leukotriene C4 and D4 upon stimulation by platelet-activating factor or other mediators, and these cells themselves express cysteinyl leukotriene receptors. Pranlukast, a compound developed in Japan, antagonizes cysteinyl leukotriene receptors and inhibits contraction of airway smooth muscle, microvascular leakage into airways, and eosinophil infiltration. This agent can decrease symptoms of bronchial asthma, but its specific influences on effector functions of eosinophils important to the pathogenesis and exacerbation of asthma remain unknown. In the present study, we investigated the effect of pranlukast on human eosinophil functions. Eosinophils obtained from peripheral blood of normal volunteers were stimulated by platelet-activating factor, leukotriene D4, or phorbol ester. Superoxide anion generation was measured by reduction of cytochrome c. Expression of alphaMbeta2 was analyzed by flow cytometry. To evaluate eosinophil degranulation, eosinophil protein X, a toxic granule constituent, was measured by radioimmunoassay in sample supernatants. Pranlukast partially inhibited major eosinophil effector functions of superoxide anion generation and degranulation induced by platelet-activating factor, although at concentrations tested pranlukast failed to significantly reduce platelet-activating factor-induced alphaMbeta2 expression. Pranlukast completely inhibited leukotriene D4-induced superoxide generation and alphaMbeta2 expression. In contrast, pranlukast at 10(-6)M did not affect phorbol ester-induced superoxide generation at 120 minutes, degranulation, or alphaMbeta2 expression. The results suggested that inhibition by pranlukast of platelet-activating, factor-induced eosinophil effector functions such as superoxide generation and degranulation might result at least partly from antagonism of autocrine mechanisms involving cysteinyl leukotrienes produced in response to platelet-activating factor.

The role of antileukotrienes in the treatment of asthma

Cysteinyl leukotrienes (Cys-LTs) are mediators released in asthma and are both direct bronchoconstrictors and proinflammatory substances that mediated several steps in the pathophysiology of chronic asthma, including inflammatory cells recruitment, vascular leakage, and possibly airway remodelling. Available evidence from clinical trials and real world experience derived from managing patients with asthma justifies a broader role for antiLTRAs in asthma management than that recommended in the National Asthma Education and Prevention Programm (NAEPP) and National Health Lung and Blood Institute (NHLBI) treatment guidelines. Leukotriene-receptor antagonist drugs (LTRAs) seem to be effective alternatives to inhaled corticosteroids (ICS) either as monotherapy or as adjunctive therapy that reduces the need for higher doses of ICS in patients with mild-to-moderate persistent asthma. LTRAs may be used as adjunctive therapy for al levels of disease severity because they are effective in combination with ICS during long-term maintenance therapy. The agents seem especially effective in preventing aspirin-induced asthma, exercise-induced asthma (EIA) and they may provide an additional advantage of reducing nasal congestion in patients with both asthma and rhinitis.

Capillary zone electrophoresis with electrochemical detection--a simple and effective method to analyze oxygen-consuming and peroxide-forming processes

Numerous biological, chemical and photochemical processes consume molecular oxygen, thereby forming peroxides, hydroperoxides and even hydrogen peroxide. This paper describes a new system for monitoring quasi simultaneously oxygen uptake and peroxide formation. For this purpose capillary electrophoresis with electrochemical detection was connected to a new automated injector that periodically injects a sample of the reaction mixture into the capillary electrophoresis system without any contact with the atmosphere. The device was tested with some pharmacologically relevant reactions such as enzymatic oxidation of glucose catalyzed by glucose oxidase, enzymatic lipid oxidation by lipoxygenase and the photodynamic reaction of the anti-inflammatory drug ketoprofen.