Ambroxol - Resurgence of an old molecule as an anti-inflammatory agent in chronic obstructive airway diseases

A brief review on critical analytical aspects for quantification of ambroxol in biological samples

Ambroxol (AMB) is a member of the expectorant class, widely used as a secreolytic agent in patients to break up secretions. AMB is rapidly and effectively distributed from blood to tissue. The lungs have the highest concentration of AMB; accumulation of AMB in human lung tissue was detected at concentrations 15- to 20-fold greater than those reported in the circulation. Because of its wide range of actions and therapeutic applications may be worth looking into, particularly for respiratory symptoms, antioxidant, anti-inflammatory, influenza, and rhinovirus infections. Though several analytical methodologies have been established and confirmed for the AMB analysis in matrices of pharmaceutical and biological origins, novel sustainable, and economical methods are still to be choice of protocol to increase its sensitivity, reliability, and repeatability. Therefore, the present review offers an overview of critical analytical aspects regarding the HPLC, LC-MS/MS, HPTLC, capillary electrophoresis, spectrophotometry, and electrochemical methods for quantifying AMB in pharmaceutical and biological samples. Furthermore, this review will thoroughly discuss the physicochemical properties, stability, extraction conditions, instrumentation, and operational parameters of the targeted analyte. As a result, for the first time, this review complies with vital background information and an up-to-date interpretation of research undertaken by anticipated methodologies examined and implemented for the pharmaceutical analysis AMB.

Inhibition of Clostridioides difficile Toxins TcdA and TcdB by Ambroxol

Clostridioides (C.) difficile produces the exotoxins TcdA and TcdB, which are the predominant virulence factors causing C. difficile associated disease (CDAD). TcdA and TcdB bind to target cells and are internalized via receptor-mediated endocytosis. Translocation of the toxins’ enzyme subunits from early endosomes into the cytosol depends on acidification of endosomal vesicles, which is a prerequisite for the formation of transmembrane channels. The enzyme subunits of the toxins translocate into the cytosol via these channels where they are released after auto-proteolytic cleavage. Once in the cytosol, both toxins target small GTPases of the Rho/Ras-family and inactivate them by mono-glucosylation. This in turn interferes with actin-dependent processes and ultimately leads to the breakdown of the intestinal epithelial barrier and inflammation. So far, therapeutic approaches to treat CDAD are insufficient, since conventional antibiotic therapy does not target the bacterial protein toxins, which are the causative agents for the clinical symptoms. Thus, directly targeting the exotoxins represents a promising approach for the treatment of CDAD. Lately, it was shown that ambroxol (Ax) prevents acidification of intracellular organelles. Therefore, we investigated the effect of Ax on the cytotoxic activities of TcdA and TcdB. Ax significantly reduced toxin-induced morphological changes as well as the glucosylation of Rac1 upon intoxication with TcdA and TcdB. Most surprisingly, Ax, independent of its effects on endosomal acidification, decreased the toxins’ intracellular enzyme activity, which is mediated by a catalytic glucosyltransferase domain. Considering its undoubted safety profile, Ax might be taken into account as therapeutic option in the context of CDAD.

Respiratory RNA Viruses: How to Be Prepared for an Encounter with New Pandemic Virus Strains

The characteristics of the biology of influenza viruses and coronavirus that determine the implementation of the infectious process are presented. With provision for pathogenesis of infection possible effects of serine proteinase inhibitors, heparin, and inhibitors of heparan sulfate receptors in the prevention of cell contamination by viruses are examined. It has been determined that chelators of metals of variable valency and antioxidants should be used for the reduction of replicative activity of viruses and anti-inflammatory therapy. The possibility of a pH-dependent impairment of glycosylation of cellular and viral proteins was traced for chloroquine and its derivatives. The use of low-toxicity drugs as part of adjunct therapy increases the effectiveness of synthetic antiviral drugs and interferons and ensures the safety of baseline therapy.

Targeting Crucial Host Factors of SARS-CoV-2

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread worldwide since its first incidence in Wuhan, China, in December 2019. Although the case fatality rate of COVID-19 appears to be lower than that of SARS and Middle East respiratory syndrome (MERS), the higher transmissibility of SARS-CoV-2 has caused the total fatality to surpass other viral diseases, reaching more than 1 million globally as of October 6, 2020. The rate at which the disease is spreading calls for a therapy that is useful for treating a large population. Multiple intersecting viral and host factor targets involved in the life cycle of the virus are being explored. Because of the frequent mutations, many coronaviruses gain zoonotic potential, which is dependent on the presence of cell receptors and proteases, and therefore the targeting of the viral proteins has some drawbacks, as strain-specific drug resistance can occur. Moreover, the limited number of proteins in a virus makes the number of available targets small. Although SARS-CoV and SARS-CoV-2 share common mechanisms of entry and replication, there are substantial differences in viral proteins such as the spike (S) protein. In contrast, targeting cellular factors may result in a broader range of therapies, reducing the chances of developing drug resistance. In this Review, we discuss the role of primary host factors such as the cell receptor angiotensin-converting enzyme 2 (ACE2), cellular proteases of S protein priming, post-translational modifiers, kinases, inflammatory cells, and their pharmacological intervention in the infection of SARS-CoV-2 and related viruses.

The past, present and future of RNA respiratory viruses: influenza and coronaviruses

Influenza virus and coronaviruses continue to cause pandemics across the globe. We now have a greater understanding of their functions. Unfortunately, the number of drugs in our armory to defend us against them is inadequate. This may require us to think about what mechanisms to address. Here, we review the biological properties of these viruses, their genetic evolution and antiviral therapies that can be used or have been attempted. We will describe several classes of drugs such as serine protease inhibitors, heparin, heparan sulfate receptor inhibitors, chelating agents, immunomodulators and many others. We also briefly describe some of the drug repurposing efforts that have taken place in an effort to rapidly identify molecules to treat patients with COVID-19. While we put a heavy emphasis on the past and present efforts, we also provide some thoughts about what we need to do to prepare for respiratory viral threats in the future.

An overview of efficacy and safety of ambroxol for the treatment of acute and chronic respiratory diseases with a special regard to children

Introduction: Ambroxol (2-amino-3,5-dibromo-N-[trans-4-hydroxycyclohexyl]benzylamine), an over-the-counter product, is a mucoactive agent and has been used widely to treat both acute and chronic respiratory diseases since 1978. This review aims to provide an overview of the clinical evidence available on the use of ambroxol in children with acute and chronic respiratory diseases. Data for this review were obtained from both published and unpublished clinical studies, and real-world evidence studies. Although conducted prior to the introduction of Good Clinical Practice (GCP), these studies, representing almost 1,300 pediatric patients, report strong clinical outcomes following the use of ambroxol in pediatric patients. Furthermore, efficacy findings were consistent irrespective of age, including for patients as young as 1 month old. Additionally, the majority of studies found ambroxol to be well tolerated in children. Taken together, the clinical evidence for ambroxol shows treatment effects that offer significant benefits to pediatric patients for its licensed use as a secretolytic therapy in acute and chronic bronchopulmonary disorders associated with abnormal mucus secretion and impaired mucus transport. The findings from this review indicate that ambroxol, for its intended over-the-counter indications, is both efficacious and well tolerated in children and that the favorable benefit/risk profile of ambroxol reported in adults extends to the pediatric population, starting from early infancy, with acute and chronic respiratory diseases.

Protective effects of ambroxol in psoriasis like skin inflammation: Exploration of possible mechanisms

The purpose of this study was to investigate the protective effects of ambroxol in psoriasis-like skin inflammation both in vitro and in vivo and delineate the molecular mechanism of ambroxol. Our data demonstrated that ambroxol has an imperative role in inhibiting the lipopolysaccharide (LPS) stimulated nitrite levels, total cellular and mitochondrial reactive oxygen species level which was determined by Griess assay, DCFDA, and MitoSOX Red staining, respectively. We found that ambroxol remarkably reduced imiquimod (IMQ) induced epidermal hyperplasia, psoriasis area and severity index (PASI) scoring, splenomegaly, skin, and ear fold thickness. In addition, the histopathological evaluation revealed that ambroxol topical and subcutaneous treatment eloquently reduced psoriasiform lesions including acanthosis. Moreover, with ambroxol intervention, the levels of antioxidants glutathione (GSH), superoxide dismutase (SOD), and IL-10 were found to be increased along with a reduction in nitrite levels in skin tissues. On the other hand, ambroxol treatment significantly reduced imiquimod-induced levels of inflammatory cytokines such as IL-1β, IL-6, IL-17, IL-22, IL-23, TGF-β, and TNF-α. Furthermore, from immunoblotting, we found a decrease in the protein expression of nitrotyrosine, iNOS, NF-κB and MAPKs signaling cascade with a concomitant increase in the expression of Nrf-2 and SOD-1 in RAW 264.7 cells and skin tissues by ambroxol. Similar findings were observed by immunofluorescence in macrophages. Moreover, ambroxol downregulated the ICAM-1 and Ki67 expression observed in skin tissues. Collectively, our results demonstrate that ambroxol may have intriguing therapeutic possibilities in attenuating psoriasis.

Safety of ambroxol in the treatment of airway diseases in adult patients

INTRODUCTION

Ambroxol is a widely used secretolytic and mucoactive over-the-counter agent primarily used to treat respiratory diseases associated with viscid mucus. Following post-marketing reports of hypersensitivity reactions and severe cutaneous adverse reactions (SCARs) possibly linked to ambroxol, the European Union's Pharmacovigilance Risk Assessment Committee (PRAC) initiated in April 2014 a review of the safety of ambroxol in all its registered indications, which was finalized in 2016. Areas covered: Here, we evaluate the clinical safety of ambroxol and provide an expert opinion on the benefit-risk balance of ambroxol in the treatment of adult patients with bronchopulmonary diseases. The evidence for this review is derived from clinical trials of ambroxol that were provided to the PRAC by the marketing authorization holders of ambroxol-containing medicines. Expert opinion: Clinical experience accumulated from randomized clinical trials and observational studies suggests that ambroxol is a safe and well-tolerated treatment of bronchopulmonary diseases, with a well-balanced and favorable benefit-risk profile. All reported adverse events were mild and self-limiting, and the risk of SCARs with ambroxol is low. Further investigations could address the safety and efficacy of ambroxol in pediatric lung diseases and in additional therapeutic indications, such as biofilm-dependent airway disease and lysosomal storage disorders.

Different ventilation modes combined with ambroxol in the treatment of respiratory distress syndrome in premature infants

The aim of the present study was to compare the effectiveness of different modes of mechanical ventilation in combination with secretolytic therapy with ambroxol in premature infants with respiratory distress syndrome. Seventy-three premature infants with hyaline membrane disease (HMD) (stage III–IV), also known as respiratory distress syndrome, who were supported by mechanical ventilation in the neonatal intensive care unit (NICU) of Xuzhou Central Hospital, were involved in the present study, between January 2013 and February 2015. Forty cases were randomly selected and treated with high frequency oscillatory ventilation (HFOV), forming the HFOV group, whereas 33 cases were selected and treated with conventional mechanical ventilation (CMV), forming the CMV group. Patients in the two groups were administered ambroxol intravenously at a dosage rate of 30 mg/kg body weight at the beginning of the study. The present study involved monitoring the blood gas index as well as changes in the respiratory function index in the two groups. Additionally, the incidence of complications in the premature infants in the two groups was observed prior to and following the ventilation. Pulmonary arterial oxygen tension (PaO₂), the PaO₂/fraction of inspired oxygen (FiO₂) ratio, the oxygenation index [OI = 100 × mean airway pressure (MAP) × FiO₂/PaO₂], as well as the arterial/alveolar oxygen partial pressure ratio (a/APO₂) = PaO₂/(713 × FiO₂ partial pressure of carbon dioxide (PaCO₂)/0.8) of the patients in the HFOV group after 1, 12 and 24 h of treatment were significantly improved as compared to the patients of the CMV group. However, there was no significant difference between patients in the two groups with regard to the number of mortalities, complications such as pneumothorax, bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP), intraventricular hemorrhage (IVH), periventricular leukomalacia (PVL), and the time of ventilation. In conclusion, combining HFOV with ambroxol secretolytic therapy is a more viable option, as the combined treatment resulted in significant improvements in arterial blood gas levels, oxygenation and the respiratory function of lungs in preterm infants.

Biotransformation of bromhexine by Cunninghamella elegans, C. echinulata and C. blakesleeana

Fungi is a well-known model used to study drug metabolism and its production in in vitro condition. We aim to screen the most efficient strain of Cunninghamella sp. among C. elegans, C. echinulata and C. blakesleeana for bromhexine metabolites production. We characterized the metabolites produced using various analytical tools and compared them with mammalian metabolites in Rat liver microsomes (RLM). The metabolites were collected by two-stage fermentation of bromhexine with different strains of Cunninghamella sp. followed by extraction. Analysis was done by thin layer chromatography, high performance thin layer chromatography, Fourier transform infrared spectroscopy, high performance liquid chromatography and Liquid chromatography–mass spectrometry. The role of Cytochrome P3A4 (CYP3A4) enzymes in bromhexine metabolism was studied. Fungal incubates were spiked with reference standard – clarithromycin to confirm the role of CYP3A4 enzyme in bromhexine metabolism. Three metabolites appeared at 4.7, 5.5 and 6.4 min retention time in HPLC. Metabolites produced by C. elegans and RLM were concluded to be similar based on their retention time, peak area and peak response of 30.05%, 21.06%, 1.34%, and 47.66% of three metabolites and bromhexine in HPLC. The role of CYP3A4 enzyme in metabolism of bromhexine and the presence of these enzymes in Cunninghamella species was confirmed due to absence of peaks at 4.7, 5.4 and 6.7 min when RLM were incubated with a CYP3A4 enzyme inhibitor – clarithromycin.

Cough: neurophysiology, methods of research, pharmacological therapy and phonoaudiology

Introduction: The cough is the more common respiratory symptom in children and adults.

Objective: To present a revision on the neurophysiology and the methods for study of the consequence of the cough, as well as the pharmacotherapy and phonoaudiology therapy of the cough, based on the works published between 2005 and 2010 and indexed in the bases Medline, Lilacs and Library Cochrane under them to keywords “cough” or “anti-cough”.

Synthesis of the data: The consequence of the cough involves activation of receiving multiples becomes vacant in the aerial ways and of neural projections of the nucleus of the solitary treatment for other structures of the central nervous system. Experimental techniques allow studying the consequence of the cough to the cellular and molecular level to develop new anti-cough agents. It does not have evidences of that anti-cough exempt of medical lapsing they have superior effectiveness to the one of placebo for the relief of the cough. The phonoaudiology therapy can benefit patients with refractory chronic cough to the pharmacological treatment, over all when paradoxical movement of the vocal folds coexists.

Final Comments: The boarding to multidiscipline has basic paper in the etiological diagnosis and treatment of the cough. The otolaryngologist must inform the patients on the risks of the anti-cough of free sales in order to prevent adverse poisonings and effect, especially in children.

Ambroxol hydrochloride in the management of idiopathic pulmonary fibrosis: Clinical trials are the need of the hour

Idiopathic pulmonary fibrosis (IPF) is a debilitating lung disease of unknown etiology. Its pathogenesis remains poorly elucidated but aberrant wound healing is central to its pathology. It has a median survival time of 3 to 5 years. None of the treatment modality or drugs tried in its management has so far changed the overall outcome. Recent in vitro and experimental studies have shown that ambroxol hydrochloride exerts several newer actions, namely the surfactant stimulatory, anti-imflammatory and anti-oxidant actions, in addition to its being a secrrtolytic and mucokinetic agent. The anti inflammatory and anti-fibrotic properties of the drug are due to its ability to block the release of oxidant stress markers, cytokines, leukotrienes, MPO activity, hydroxyproline content, nitic oxide and/or collagen I & III mRNA in the local milieu while preserving the SOD and GSH-PX activities. In human studies also, the agent was able to block the expression of TGF-beta and TNF-alpha in plasma and preserving the carbon monoxide diffusion capacity of the lungs in lung cancer patients on radiation therapy. Thus, ambroxol may have the potential to check the dysregulated healing process that is typical of IPF. This, coupled with its safety profile for human use, warrants clinical trials of the drug in the management of IPF.