In the present investigation, an attempt was made to formulate the oral sustained release matrix tablets of Ambroxol HCl in order to improve. DEVELOPMENT OF STABLE AMBROXOL HYDROCHLORIDE SYRUP AND. COMPARITIVE EVALUATION WITH MARKETED SAMPLES” is a bonafide. Expert Opin Drug Metab Toxicol. Aug;4(8) doi: / Ambroxol in the 21st century: pharmacological and clinical update.
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Ambroxol is used in COPD and asthma to increase mucociliary clearance and regulate surfactant levels, perhaps through anti-oxidant and anti-inflammatory activities. Airway hyperresponsiveness AHRlung cell composition and histology, and cytokine and protein carbonyl levels ambdoxol bronchoalveolar lavage BAL fluid were determined.
Ambroxol was administered either before the first OVA challenge or was begun after the last allergen challenge. Administration of ambroxol prior to challenge suppressed AHR, airway eosinophilia, goblet cell metaplasia, and reduced inflammation juranl subepithelial regions. When given after challenge, AHR was suppressed but without effects on eosinophil numbers.
Decreased levels of protein carbonyls were detected in BAL fluid following ambroxol treatment after challenge. Taken together, ambroxol was effective in preventing AHR and airway inflammation through upregulation of Th1 cytokines and protection from oxidative stress in the airways.
Asthma is the most prevalent chronic respiratory disease and the prevalence is still increasing 1. Outcomes of asthma treatments such as mortality rates were improved, but have stalled in the last decade 2.
Immunomodulatory Effects of Ambroxol on Airway Hyperresponsiveness and Inflammation
Excessive mucus production is a major component of many respiratory diseases, including bronchial asthma, chronic obstructive pulmonary disease COPDand cystic fibrosis 3. In asthma, airway mucus hypersecretion is thought to be a pathophysiological feature and contributor to morbidity and mortality 4. In particular, IL was shown to be a potent inducer of airway hyperresponsiveness AHRambroxpl airway inflammation, and goblet cell metaplasia 5.
Jurbal of MUC5AC, a mucin-inducing gene, was related to disease severity in asthmatics and in animal models 67. IL has been shown to be a major inducer of mucus production through goblet cell metaplasia in airway epithelial layers and to play a critical role jurrnal the development of AHR 8. Recent studies revealed that the epidermal growth factor receptor EGF-R appeared to be a convergent pathway for a number of mediator signals; EGF-R was upregulated in the airways of asthmatic patients 9.
These signaling molecules have been studied as potential targets of pharmacotherapy to inhibit airway mucus production in asthma 8.
On the other hand, appropriate levels of mucus production are essential for protection from airborne pathogens or allergens and probably for the clearance of inflammatory chemicals or dead cells. However, precise mechanisms and effects on mucus production and secretion in the pathogenesis of asthma are unclear. Accordingly, expectorants such as ambroxol have been widely used in these mucus-related respiratory diseases 1011 Ambroxol is a metabolite of bromhexine, which has been used in the therapy of airway diseases since the late s In asthmatics, ambroxol was shown to improve AHR and lung function 14 Ambroxol also maintains the airway surface environment by modulating surfactant protein levels in the amhroxol and increased mucociliary clearance 17 Based on these results, clinical trials with ambroxol to prevent or treat infant respiratory distress syndrome have been carried out 19 In basophils, ambroxol inhibited secretion of IL-4, IL, and histamine However, the underlying mechanisms whereby ambroxol exhibits anti-inflammatory effects in the airways such as in asthma remain to be defined.
The socioeconomic burden in the treatment of asthma has been of worldwide concern with increasing prevalence of the disease 12. Safe and cost-effective therapeutic alternatives are needed. Ambroxol has been in the clinic for many years, the drug is inexpensive and few adverse effects have been described.
Therefore, understanding the potential of the drug in the treatment of asthma is a valid concern. In this study, ambroxol was administrated jurbal mice in a model of allergen-induced AHR and airway inflammation. The drug was administered prior to and after allergen challenge and changes in airway inflammation and AHR were monitored. The animals were maintained on an ovalbumin OVA -free diet. Mice were sensitized by intraperitoneal i. In other experiments, as illustrated in Fig.
The dose of ambroxol was chosen based on previous studies 2123 and preliminary studies. Airway responsiveness was assessed as changes in airway function after challenge with aerosolized methacholine MCh Sigma. Mice were anesthetized, tracheostomized, mechanically ventilated, and lung function was assessed as described previously Ventilation was achieved at breaths per minute at a tidal volume of 0.
Aerosolized MCh jurnnal administered through bypass tubing via an ultrasonic nebulizer model D, DeVilbiss, Somerset, PA, USA placed between the expiratory port of the ventilator and the four-way connector.
Aerosolized MCh was administered for 8 seconds with a tidal volume of 0.
The data for RL were continuously collected for up to 3 minutes and maximum values were taken. Differential cell counts were performed by counting at least cells on cytocentrifuged preparations Shandon Cytosipin3, ThermoFisher Scientific, Waltham, MA.
Slides were stained with modified Wright-Giemsa and white blood cells were differentiated by standard hematological procedures in a blinded fashion. To determine the effects of ambroxol In vitrolung mononuclear cells MNCs were isolated and cultured with OVA and ambroxol under various conditions.
Briefly, lungs were taken from mice following exposure to OVA. Ambroxol was added to these cultures at concentrations of 0. After 24 hrs, supernatants were collected and stored smbroxol cytokine and protein carbonyl measurements as described below. Cytokine levels in the BAL fluid or supernatants from cultured cells were measured as previously described The limits of detection were 1.
To investigate junral role of ambroxol as an anti-oxidant agent, we determined protein carbonyl levels in BAL fluid as an index of oxidative stress in the lung Four different judnal per slide in 8 samples from each group of mice were examined in a blinded manner.
The Tukey-Kramer test was used for comparisons between multiple groups. Since measured values may not be normally distributed on account of the small sample sizes, nonparametric analysis, Mann-Whitney U test, was also used to confirm that the statistical differences remained significant.
The p values for significance were set to 0. Ambroxol treatment of sham-sensitized mice did not show any effects. As shown in Fig.
In mice which received ambroxol prior to the OVA challenges, reduced levels of both inflammatory cells and PAS-staining goblet cell metaplasia were observed in lung tissue sections. Levels of protein carbonyls in BAL fluid were not altered by ambroxol treatment initiated prior to the allergen challenge data not shown. When ambroxol treatment was initiated following OVA challenge of sensitized mice, the development of AHR was significantly decreased compared to the control group Fig. However, ambroxol treatment initiated after completion of the OVA challenges showed no effect on the number of eosinophils in the BAL fluid Fig.
Ambroxol treatment in sham-sensitized mice showed no effect on cytokine levels or cell composition in BAL fluid or AHR. In contrast to ambroxol treatment begun prior to OVA challenge, histological analysis revealed that ambroxol treatment initiated following OVA challenge did not alter inflammatory cell infiltration or goblet cell metaplasia in the airways of OVA-sensitized and challenged mice Fig.
Levels of protein carbonyls in BAL fluid were assayed to determine the degree of oxidative damage in the airways. These levels were decreased when ambroxol treatment was jurnwl after the completion of OVA challenge compared to vehicle-treated mice. Lung MNCs were collected and purified from mice after sensitization and challenge to OVA and cytokine levels in the supernatants of cultured ambrxol were determined.
IL was increased following addition of OVA and was increased further in the presence of ambroxol in a dose-dependent manner. Cytokine secretion levels from alveolar macrophages were analyzed following culture with OVA and ambroxol Fig. Ambroxol has been widely used since the late s in various respiratory diseases with the goal of improving mucus clearance, facilitating expectoration, easing of productive cough, and providing local anesthetic effects 13 Ambroxol has been used to treat asthmatics The data, albeit limited, suggest some effects in improving airway responsiveness and inflammation However, the mechanisms underlying these effects are not well understood.
When ambroxol treatment was initiated prior to OVA challenge of sensitized mice, decreased levels of airway responsiveness, eosinophilia, and goblet cell metaplasia along the airways were observed, accompanied by decreases in the levels of the Th2-type cytokines, IL-5, and IL in BAL fluid.
Immunomodulatory Effects of Ambroxol on Airway Hyperresponsiveness and Inflammation
Asthma is a complex disease in which numerous factors contribute to the characteristic features of the disease, persistent airway dysfunction including AHR and allergic airway inflammation Among these factors, Th2 cells and related cytokines, IL-4, IL-5, and IL are thought to play a central role in the pathogenesis of the disease Therefore, reduction of Th2 cytokines in the airways by ambroxol may be a cause of the reductions in AHR and airway inflammation induced by allergen.
The levels of protein carbonyls as a marker of oxidative stress were also significantly reduced. However, the numbers of eosinophils and levels of Th2 cytokines in BAL fluid, and goblet cell metaplasia were not altered under this delayed treatment regimen. Thus, ambroxol appeared to act at two different levels: A second effect of the drug may lie in the anti-oxidant activity. Oxidative stress can be induced in any organ of the body when the balance of anti-oxidant versus reactive oxygen species is altered Oxidative stress causes damage in the airways and exaggerates airway diseases including asthma or in animal models of airway allergic inflammation 35 Ambroxol has been shown to have anti-oxidant properties and reduce oxidant production from inflammatory cells In vitrosuch as polymorphonuclear cells, alveolar macrophages, or human bronchial epithelial cells 16404142and inhibited AHR induced by ozone in dogs In the present study, we demonstrated that ambroxol treatment begun after OVA challenge of sensitized mice decreased the levels of protein carbonyls in BAL fluid, a biomarker of oxidative stress In parallel, airway responsiveness in response to inhaled MCh was decreased while eosinophil numbers were not altered.
This may indicate that the anti-oxidant properties of ambroxol target airway function with little to no effect on airway inflammation. The assumption was that the anti-oxidant effects of ambroxol were transient and decreased levels of protein carbonyls in BAL fluid were not observed 2 days after cessation of ambroxol treatment.
Recent studies have revealed regulatory effects of oxidative stress on cytokine production. These findings may explain some of the results seen in this study; the antioxidant properties of ambroxol may be ambrooxl to the increased levels of IL in the mice with established airway inflammation but was protective against Th2 differentiation detected as decreased levels of IL-5 and IL In summary, administration of ambroxol was shown to normalize AHR when given either prior to or after completion of allergen challenge in previously sensitized mice.
Ambroxol treatment prior to allergen challenge reduced BAL eosinophils and Th2 cytokines, while the same treatment begun after completion of the allergen challenges also impacted cytokine levels and levels of protein carbonyls in BAL fluid. Taken together, ambroxol exhibits potent therapeutic benefits through its antioxidant and immunomodulatory properties in these animal models and may prove beneficial in asthmatics.
Ambroxol in the 21st century: pharmacological and clinical update.
The authors thank Diana Nabighian for assistance in preparing the manuscript. The authors have no financial conflict of interest. National Center for Biotechnology InformationU. Journal List Immune Netw v. Published online Jun Find articles by Katsuyuki Takeda. Find articles by Nobuaki Jurnql. Find articles by Shigeki Matsubara.