Enhancement of lung levels of antibiotics by ambroxol and bromhexine

Synergistic action of mucoactive drugs and phages against Pseudomonas aeruginosa and Klebsiella pneumoniae

N-acetylcysteine (NAC) and ambroxol hydrochloride (AMB) are commonly prescribed alongside antibiotics to alleviate sputum retention in lower respiratory tract infections, which are often caused by bacterial pathogens. With the rising threat of antibiotic resistance, phage therapy has emerged as a promising alternative alongside. However, no studies have explored the potential interactions between phages and these mucoactive agents despite their frequent concurrent use during phage therapy. Therefore, investigating the potential synergy and its subsequent impact on phage infection dynamics could enhance clinical strategies for treating bacterial infections with phages. Our study utilized Pseudomonas aeruginosa strain ZS-PA-35 and Klebsiella pneumoniae strain Kp36, alongside their respective phages, to investigate their interactions in the presence of NAC or AMB. Our findings indicate that, under specific conditions, these mucoactive agents can function as adjuvants to lytic phages, enhancing bacterial susceptibility to phage infection and facilitating subsequent phage proliferation. Our study revealed that these synergistic interactions are strongly influenced by the physiological characteristics of the phages, the surrounding microenvironments, and the physiology of host tissues, as varying outcomes of phage-host interactions were observed among different phages and across distinct media. Taken together, our results emphasize the complexity of interactions between phages and NAC or AMB, underscoring the need for caution when using combination treatments.IMPORTANCEN-acetylcysteine (NAC) and ambroxol hydrochloride (AMB) are used in medical treatment of patients with acute and chronic bronchitis. Often, the choice of NAC or AMB is empirically determined by physicians. However, the potential impact of combining NAC or AMB with phage therapy remains unclear. To address this gap, a comprehensive understanding of their interplay is crucial to determine any potential synergistic effects. This study aims to elucidate how NAC or AMB influence phages targeting different receptors, thereby affecting their antibacterial activity against Pseudomonas aeruginosa and Klebsiella pneumoniae. Our results suggest that, under certain conditions, NAC or AMB provides an adjuvant effect by rendering the cells more susceptible to phage infection. These results contribute to advancing our understanding of the clinical combination of mucoactive agents and phage therapy, offering insights for optimizing treatment efficacy.

Efficacy of Ambroxol Combined with Loquat Syrup on Bacterial Pneumonia in Mice

Purpose

Bacterial pneumonia is a prevalent respiratory disease and a primary cause of death among hospitalized patients. Ambroxol and loquat syrup are widely utilized pharmaceuticals for managing respiratory infections in China. This study investigates the potential application and efficacy of combining ambroxol with loquat syrup for treating bacterial pneumonia.

Methods

In this study, mice with P. aeruginosa-induced bacterial pneumonia were used to evaluate the therapeutic effects of ambroxol, loquat syrup, and their combination. A bacterial plate coating assay was performed to measure the P. aeruginosa content in saliva, lung tissue, and bronchoalveolar lavage fluid (BALF). A plate colony counting assay was conducted to assess the antibacterial activity of ambroxol and loquat syrup. Serum, BALF, and lung tissues were analyzed using qPCR, ELISA, immunohistochemistry, and hematoxylin-eosin staining to evaluate disease severity.

Results

In this study, the experimental results demonstrate that, compared to treatment with ambroxol and/or loquat syrup alone, the combined administration of ambroxol and loquat syrup significantly increases the volume of saliva expectorated by mice infected with bacteria, concurrently augmenting bacterial presence in saliva while diminishing bacterial burden in the lungs, with significant differences observed (p<0.05). Furthermore, the combined therapy of ambroxol and loquat syrup achieved better therapeutic effects on P. aeruginosa pneumonia compared to ambroxol and/or loquat syrup alone (p<0.05), as evidenced by significantly reduced P. aeruginosa-induced lung injury, improved lung permeability, decreased inflammatory cell infiltration, and lower expression of inflammatory cytokines.

Conclusion

These findings suggest that the combination therapy of ambroxol and loquat syrup presents a safe and feasible new treatment strategy for bacterial pneumonia, offering promising benefits for ameliorating lung tissue damage and inflammation.

Comparative Pharmacokinetics and Egg Residues of Amoxicillin, Single and in Combination with Bromhexine, in Laying Hens

The need for antibiotics in commercial laying hens is increasing owing to intensive farming systems. Amoxicillin trihydrate (AMX), an aminopenicillin β-lactam antibiotic, exerts broad bactericidal activity. However, its short half-life necessitates frequent administration to ensure efficacy, thus limiting its use. Herein, we investigated the effect of concurrent administration of bromhexine hydrochloride (BRM), a mucolytic agent, on AMX pharmacokinetics, performing a comparative pharmacokinetic analysis of AMX administration alone and in combination with BRM. AMX (50 mg/kg) was administered by oral gavage once daily for three days alone or in combination with 10 mg/kg BRM. Plasma and egg samples were collected to evaluate pharmacokinetic profiles and egg residues. The area under the curve and maximum plasma concentration values were significantly higher in the AMX + BRM group than the AMX only group. However, there were no significant differences in AMX half-life in the elimination phase (T1/2), elimination rate constant (kel), or apparent clearance (CL/F) values. In the egg residue study, the withdrawal period for AMX was 5 days in both groups, with no significant difference when using the maximum residue limit (MRL) of 10 μg/kg. The concentration of BRM in the eggs remained at 100 μg/kg up to the fourth day following drug administration. Conclusion: These results confirmed that BRM co-administration increased systemic exposure to AMX, with a negligible residual impact of amoxicillin in eggs.

Development of a rapid method for the simultaneous determination of aminophylline, doxofylline, bromhexine, and ambroxol by HPLC

Introduction: Antitussive and expectorant drugs such as aminophylline (APL), doxofylline (DXL), bromhexine hydrochloride (BXH), and ambroxol hydrochloride (AXH), either individually or in combination, are widely used in the prevention and treatment of respiratory diseases. The study aimed to establish a high-performance liquid chromatography (HPLC) method for the simultaneous determination of these four drugs and to investigate their stability in 0.9% sodium chloride injection or 5% glucose injection over 48 hours. Methods: An InertSustain C18 column (150 mm × 4.6 mm, 5 μm) was used. The mobile phase consisted of acetonitrile and 50 mmol·L-1 potassium dihydrogen phosphate solution (pH 4.0) with gradient elution. The flow rate was 0.8 mL·min-1, and the column temperature was maintained at 30°C. The stability of APL, DXL, BXH, and AXH in 0.9% sodium chloride and 5% glucose injections over 48 h was determined using HPLC. Results: APL, DXL, BXH, and AXH showed good linearity within the ranges of 0.01 to 0.20, 0.003-0.06, 0.015-0.30, and 0.016-0.16 mg·mL-1, respectively (r > 0.999). The intraday and interday relative standard deviations were <2%, with recovery rates between 98.4% and 102.2%. The four drugs remained colorless and clear in infusion mixtures. The pH value fluctuated within ±0.3 over 48 hours, and the relative percentage content of the drugs ranged from 95.0% to 105.0%. Conclusion: The established HPLC method is simple, reliable, and stable, allowing for the simultaneous determination of the four antitussive and expectorant drugs. APL, DXL, BXH, and AXH were stable within 48 hours when mixed with 0.9% sodium chloride and 5% glucose injections.

Enhancing pulmonary delivery and immunomodulation of respiratory diseases through virus-mimicking nanoparticles

This study introduces the nanobromhexine lipid particle (NBL) platform designed for effective pulmonary drug delivery. Inspired by respiratory virus transport mechanisms, NBL address challenges associated with mucus permeation and inflammation in pulmonary diseases. Composed of low molecular weight polyethylene glycol-coated lipid nanoparticles with bromhexine hydrochloride, NBL exhibit a size of 118 ± 24 nm, a neutral zeta potential, osmolarity of 358 ± 28 mOsmol/kg, and a pH of 6.5. Nebulizing without leakage and showing no toxicity to epithelial cells, NBL display mucoadhesive properties with a 60% mucin-binding efficiency. They effectively traverse the dense mucus layer of Calu-3 cultures in an air-liquid interface, as supported by a 55% decrease in MUC5AC density and a 29% increase in nanoparticles internalization compared to non-exposed cells. In assessing immunomodulatory effects, NBL treatment in SARS-CoV-2-infected lung cells leads to a 40-fold increase in anti-inflammatory MUC1 gene expression, a proportional reduction in pro-inflammatory IL-6 expression, and elevated anti-inflammatory IL-10 expression. These findings suggest a potential mechanism to regulate the excessive IL-6 expression triggered by virus infection. Therefore, the NBL platform demonstrates promising potential for efficient pulmonary drug delivery and immunomodulation, offering a novel approach to addressing mucus permeation and inflammation in pulmonary diseases.

Mucus Hypersecretion in Chronic Obstructive Pulmonary Disease and Its Treatment

Most patients diagnosed with chronic obstructive pulmonary disease (COPD) present with hallmark features of airway mucus hypersecretion, including cough and expectoration. Airway mucus function as a native immune system of the lung that severs to trap particulate matter and pathogens and allows them to clear from the lung via cough and ciliary transport. Chronic mucus hypersecretion (CMH) is the main factor contributing to the increased risk of morbidity and mortality in specific subsets of COPD patients. It is, therefore, primarily important to develop medications that suppress mucus hypersecretions in these patients. Although there have been some advances in COPD treatment, more work remains to be done to better understand the mechanism underlying airway mucus hypersecretion and seek more effective treatments. This review article discusses the structure and significance of mucus in the lungs focusing on gel-forming mucins and the impacts of CMH in the lungs. Furthermore, we summarize the article with pharmacological and nonpharmacological treatments as well as novel and interventional procedures to control CMH in COPD patients.

Degradation kinetics and formation of regulated and emerging disinfection by-products during chlorination of two expectorants ambroxol and bromhexine

Ambroxol hydrochloride (AMB) and bromhexine hydrochloride (BRO) are classic expectorants and bronchosecretolytic pharmaceuticals. In 2022, both AMB and BRO were recommended by medical emergency department of China to alleviate cough and expectoration for symptoms caused by COVID-19. The reaction characteristics and mechanism of AMB/BRO with chlorine disinfectant in the disinfection process were investigated in this study. The reaction of chlorine with AMB/BRO were well described by a second-order kinetics model, first-order in both AMB/BRO and chlorine. The second order rate reaction constant of AMB and BRO with chlorine at pH 7.0 were 1.15 × 10² M^-1s^-1 and 2.03 × 10² M^-1s^-1, respectively. During chlorination, a new class of aromatic nitrogenous disinfection by-products (DBPs) including 2-chloro-4, 6-dibromoaniline and 2, 4, 6-tribromoaniline were identified as the intermediate aromatic DBPs by gas chromatography-mass spectrometry. The effect of chlorine dosage, pH, and contact time on the formation of 2-chloro-4, 6-dibromoaniline and 2, 4, 6-tribromoaniline were evaluated. In addition, it was found that bromine in AMB/BRO were vital bromine source to greatly promote the formation of classic brominated DBPs, with the highest Br-THMs yields of 23.8% and 37.8%, respectively. This study inspired that bromine in brominated organic compounds may be an important bromine source of brominated DBPs.

Low-cost anti-mycobacterial drug discovery using engineered E. coli

Whole-cell screening for Mycobacterium tuberculosis (Mtb) inhibitors is complicated by the pathogen's slow growth and biocontainment requirements. Here we present a synthetic biology framework for assaying Mtb drug targets in engineered E. coli. We construct Target Essential Surrogate E. coli (TESEC) in which an essential metabolic enzyme is deleted and replaced with an Mtb-derived functional analog, linking bacterial growth to the activity of the target enzyme. High throughput screening of a TESEC model for Mtb alanine racemase (Alr) revealed benazepril as a targeted inhibitor, a result validated in whole-cell Mtb. In vitro biochemical assays indicated a noncompetitive mechanism unlike that of clinical Alr inhibitors. We establish the scalability of TESEC for drug discovery by characterizing TESEC strains for four additional targets.

A selective PPM1A inhibitor activates autophagy to restrict the survival of Mycobacterium tuberculosis

Metal-dependent protein phosphatases (PPMs) have essential roles in a variety of cellular processes, including inflammation, proliferation, differentiation, and stress responses, which are intensively investigated in cancer and metabolic diseases. Targeting PPMs to modulate host immunity in response to pathogens is an ambitious proposition. The feasibility of such a strategy is unproven because development of inhibitors against PPMs is challenging and suffers from poor selectivity. Combining a biomimetic modularization strategy with function-oriented synthesis, we design, synthesize and screen more than 500 pseudo-natural products, resulting in the discovery of a potent, selective, and non-cytotoxic small molecule inhibitor for PPM1A, SMIP-30. Inhibition of PPM1A with SMIP-30 or its genetic ablation (ΔPPM1A) activated autophagy through a mechanism dependent on phosphorylation of p62-SQSTM1, which restricted the intracellular survival of Mycobacterium tuberculosis in macrophages and in the lungs of infected mice. SMIP-30 provides proof of concept that PPMs are druggable and promising targets for the development of host-directed therapies against tuberculosis.

Drug-based therapeutic strategies for COVID-19-infected patients and their challenges

Emerging epidemic-prone diseases have introduced numerous health and economic challenges in recent years. Given current knowledge of COVID-19, herd immunity through vaccines alone is unlikely. In addition, vaccination of the global population is an ongoing challenge. Besides, the questions regarding the prevalence and the timing of immunization are still under investigation. Therefore, medical treatment remains essential in the management of COVID-19. Herein, recent advances from beginning observations of COVID-19 outbreak to an understanding of the essential factors contributing to the spread and transmission of COVID-19 and its treatment are reviewed. Furthermore, an in-depth discussion on the epidemiological aspects, clinical symptoms and most efficient medical treatment strategies to mitigate the mortality and spread rates of COVID-19 is presented.

Pulmonary surfactants affinity Pluronic-hybridized liposomes enhance the treatment of drug-resistant lung cancer

For a long time, the incidence and mortality of lung cancer have ranked first among all kinds of cancers, of which the major type is non-small cell lung cancer (NSCLC). Until now, chemotherapy and radiotherapy are still the first choice for patients with advanced or metastatic NSCLC. However, the emergence of multi-drug resistance (MDR) always leads to the failure of chemotherapy and increases cancer-related mortality. In this study, we prepared a Pluronic-hybridized paclitaxel-loaded liposome (PPL), which was used in combination with ambroxol (Ax) to not only resensitize drug-resistant tumor cells, but also increase the preparation retention in the lung. On the one hand, Ax induced the production of pulmonary surfactants (PS) and responsively improved the accumulation of pulmonary surfactants affinity liposomes whose skeleton was exogenous pulmonary surfactant phospholipids DPPC, because of the specific affinity of phospholipids related to pulmonary surfactant proteins. On the other hand, drug-resistant tumor cells were resensitized due to the inhibition of autophagy by Ax and the reduced expression of the drug-resistant protein P-glycoprotein (P-gp) by Pluronic P105. Therefore, we concluded that the combination of PPL and Ax achieved excellent killing tumor effects through multi-path and multi-strategy, having great application prospects in the future.

Ambroxol Treatment Suppresses the Proliferation of Chlamydia pneumoniae in Murine Lungs

Ambroxol (Ax) is used as a mucolytics in the treatment of respiratory tract infections. Ax, at a general dose for humans, does not alter Chlamydia pneumoniae growth in mice. Therefore, we aimed to investigate the potential anti-chlamydial effect of Ax at a concentration four timed higher than that used in human medicine. Mice were infected with C. pneumoniae and 5-mg/kg Ax was administered orally. The number of recoverable C. pneumoniae inclusion-forming units (IFUs) in Ax-treated mice was significantly lower than that in untreated mice. mRNA expression levels of several cytokines, including interleukin 12 (IL-12), IL-23, IL-17F, interferon gamma (IFN-γ), and surfactant protein (SP)-A, increased in infected mice treated with Ax. The IFN-γ protein expression levels were also significantly higher in infected and Ax-treated mice. Furthermore, the in vitro results suggested that the ERK 1/2 activity was decreased, which is essential for the C. pneumoniae replication. SP-A and SP-D treatments significantly decreased the number of viable C. pneumoniae IFUs and significantly increased the attachment of C. pneumoniae to macrophage cells. Based on our results, a dose of 5 mg/kg of Ax exhibited an anti-chlamydial effect in mice, probably an immunomodulating effect, and may be used as supporting drug in respiratory infections caused by C. pneumoniae.

Ambroxol Hydrochloride Inhibits the Interaction between Severe Acute Respiratory Syndrome Coronavirus 2 Spike Protein's Receptor Binding Domain and Recombinant Human ACE2

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), enters the host cells through two main pathways, both involving key interactions between viral envelope-anchored spike glycoprotein of the novel coronavirus and the host receptor, angiotensin-converting enzyme 2 (ACE2). To date, SARS-CoV-2 has infected up to 26 million people worldwide; yet, there is no clinically approved drug or vaccine available. Therefore, a rapid and coordinated effort to re-purpose clinically approved drugs that prevent or disrupt these critical entry pathways of SARS-CoV-2 spike glycoprotein interaction with human ACE2, could potentially accelerate the identification and clinical advancement of prophylactic and/or treatment options against COVID-19, thus providing possible countermeasures against viral entry, pathogenesis and survival. Herein, we discovered that Ambroxol hydrochloride (AMB), and its progenitor, Bromhexine hydrochloride (BHH), both clinically approved drugs are potent effective modulators of the key interaction between the receptor binding domain (RBD) of SARS-CoV-2 spike protein and human ACE2. We also found that both compounds inhibited SARS-CoV-2 infection-induced cytopathic effect at micromolar concentrations. Therefore, in addition to the known TMPRSS2 activity of BHH; we report for the first time that the BHH and AMB pharmacophore has the capacity to target and modulate yet another key protein-protein interaction essential for the two known SARS-CoV-2 entry pathways into host cells. Altogether, the potent efficacy, excellent safety and pharmacologic profile of both drugs along with their affordability and availability, makes them promising candidates for drug repurposing as possible prophylactic and/or treatment options against SARS-CoV-2 infection.

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.