In vitro effect of beclomethasone dipropionate and flunisolide on the mobility of human nasal cilia

DMBT1 is upregulated in cystic fibrosis, affects ciliary motility, and is reduced by acetylcysteine

BACKGROUND

Cystic fibrosis (CF) is the most common genetic disorder in the Caucasian population. Despite remarkable improvements in morbidity and mortality during the last decades, the disease still limits survival and reduces quality of life of affected patients. Moreover, CF still represents substantial economic burden for healthcare systems. Inflammation and infection already start in early life and play important roles in pulmonary impairment. The aim of this study is to analyze the potential role of DMBT1, a protein with functions in inflammation, angiogenesis, and epithelial differentiation, in CF.

RESULTS

Immunohistochemically DMBT1 protein expression was upregulated in lung tissues of CF patients compared to healthy controls. Additionally, pulmonary expression of Dmbt1 was approximately 6-fold increased in an established transgenic mouse model of CF-like lung disease (ENaC tg) compared to wild-type mice as detected by qRT-PCR. Since acetylcysteine (ACC) has been shown to reduce inflammatory markers in the airways, its potential influence on DMBT1 expression was analyzed. A549 cells stably transfected with an expression plasmid encoding the largest (8kb) DMBT1 variant (DMBT1+ cells) or an empty vector control (DMBT1- cells) and incubated with ACC both showed significantly reduced DMBT1 concentrations in the culture medium (p = 0.0001). To further elucidate the function of DMBT1 in pulmonary airways, respiratory epithelial cells were examined by phase contrast microscopy. Addition of human recombinant DMBT1 resulted in altered cilia motility and irregular beat waves (p < 0.0001) suggesting a potential effect of DMBT1 on airway clearance.

CONCLUSIONS

DMBT1 is part of inflammatory processes in CF and may be used as a potential biomarker for CF lung disease and a potential tool to monitor CF progression. Furthermore, DMBT1 has a negative effect on ciliary motility thereby possibly compromising airway clearance. Application of ACC, leading to reduced DMBT1 concentrations, could be a potential therapeutic option for CF patients.

Influence of Intranasal Drugs on Human Nasal Mucociliary Clearance and Ciliary Beat Frequency

The nasal mucociliary clearance system, which comprises epithelial cilia and mucus from goblet cells, is an important intrinsic defense mechanism of the upper respiratory tract. Intranasal drugs and additives can have a detrimental effect on ciliary activity and mucociliary clearance, and thus impact the integrity of nasal defense mechanisms. This article discusses the current literature on the effects of different classes of intranasal drugs including intranasal corticosteroids, antihistamines, decongestants, antimicrobials and antivirals, as well as various drug excipients and nasal irrigation solutions on human nasal mucociliary clearance and ciliary beat frequency. Available data indicate that some intranasal formulations tend to hamper nasal ciliary function and mucociliary clearance. Therefore, it is of great importance to assess the effects of intranasal drugs and additives on mucociliary function before they are recommended as therapy for different nasal conditions.

Identification of drugs that restore primary cilium expression in cancer cells

The development of cancer is often accompanied by a loss of the primary cilium, a microtubule-based cellular protrusion that functions as a cellular antenna and that puts a break on cell proliferation. Hence, restoration of the primary cilium in cancer cells may represent a novel promising approach to attenuate tumor growth. Using a high content analysis-based approach we screened a library of clinically evaluated compounds and marketed drugs for their ability to restore primary cilium expression in pancreatic ductal cancer cells. A diverse set of 118 compounds stimulating cilium expression was identified. These included glucocorticoids, fibrates and other nuclear receptor modulators, neurotransmitter regulators, ion channel modulators, tyrosine kinase inhibitors, DNA gyrase/topoisomerase inhibitors, antibacterial compounds, protein inhibitors, microtubule modulators, and COX inhibitors. Certain compounds also dramatically affected the length of the cilium. For a selection of compounds (Clofibrate, Gefitinib, Sirolimus, Imexon and Dexamethasone) their ability to restore ciliogenesis was confirmed in a panel of human cancer cell line models representing different cancer types (pancreas, lung, kidney, breast). Most compounds attenuated cell proliferation, at least in part through induction of the primary cilium, as demonstrated by cilium removal using chloral hydrate. These findings reveal that several commonly used drugs restore ciliogenesis in cancer cells, and warrant further investigation of their antineoplastic properties.

The effect of drugs and other compounds on the ciliary beat frequency of human respiratory epithelium

BACKGROUND

Cilia in the human respiratory tract play a critical role in clearing mucus and debris from the airways. Their function can be affected by a number of drugs or other substances, many of which alter ciliary beat frequency (CBF). This has implications for diseases of the respiratory tract and nasal drug delivery. This article is a systematic review of the literature that examines 229 substances and their effect on CBF.

METHODS

MEDLINE was the primary database used for data collection. Eligibility criteria based on experimental design were established, and 152 studies were ultimately selected. Each individual trial for the substances tested was noted whenever possible, including concentration, time course, specific effect on CBF, and source of tissue.

RESULTS

There was a high degree of heterogeneity between the various experiments examined in this article. Substances and their general effects (increase, no effect, decrease) were grouped into six categories: antimicrobials and antivirals, pharmacologics, human biological products, organisms and toxins, drug excipients, and natural compounds/other manipulations.

CONCLUSION

Organisms, toxins, and drug excipients tend to show a cilioinhibitory effect, whereas substances in all other categories had mixed effects. All studies examined were in vitro experiments, and application of the results in vivo is confounded by several factors. The data presented in this article should be useful in future respiratory research and examination of compounds for therapeutic and drug delivery purposes.

Endoscopic dacryocystorhinostomy appears to impair nasal mucociliary clearance

We conducted a prospective study of 50 adults to investigate changes in nasal mucociliary clearance following endoscopic intranasal dacryocystorhinostomy (DCR). Each operation was performed with the use of a drill to perforate the lateral nasal wall in order to reach the lacrimal sac. Each patient's mucociliary clearance time (MCT) was determined by the saccharin test on both the operated and nonoperated sides; the preoperative times were compared with postoperative measurements made 1 and 3 months following DCR. Preoperatively, the mean MCTs were 14.48 minutes on the operated side and 14.50 minutes on the nonoperated side-not a statistically significant difference (p > 0.05). Postoperatively, the corresponding MCTs were 25.22 and 14.98 minutes at 1 month and 18.44 and 15.62 minutes at 3 months. On the operated side, both postoperative MCTs were significantly longer than the preoperative value (p < 0.001), while on the nonoperated side, neither postoperative MCT was significantly different from the preoperative value (p > 0.05). Also, the postoperative MCTs were significantly longer on the operated side than on the nonoperated side at both 1 month (p < 0.001) and 3 months (p < 0.05). Only 1 of the 50 operations was considered to be unsuccessful; the reason for this surgical failure was the patient's ongoing complaints of chronic postoperative dacryocystitis. We conclude that endoscopic DCR disturbs mucociliary clearance. Changes in MCTs may be attributable to injury to the nasal mucosa or to the continuous flow of tears through the nasal mucosa.

Formulation considerations of intranasal corticosteroids for the treatment of allergic rhinitis

OBJECTIVE

To examine how various aspects of an intranasal corticosteroid (INS) formulation may influence the efficacy, tolerability, and patient preference and adherence to INS therapy.

DATA SOURCES

A PubMed search of the literature was conducted for studies on allergic rhinitis published between January 1977 and January 2006 using the keywords intranasal corticosteroid, preservatives, benzalkonium chloride, and tonicity.

STUDY SELECTION

Prospective studies, retrospective studies, and case reports were selected for inclusion in this review.

RESULTS

Currently available INSs are effective first-line treatments for allergic rhinitis. Differences in patient preference for a particular INS are largely attributable to sensory attributes of the nasal spray, which arise from characteristics of the formulation. Additives and preservatives can cause tolerability issues by irritating the mucosal membranes and causing nasal drying, or they can confer an unpleasant odor or taste to an INS formulation. The relative osmotic pressure, or tonicity, of an INS can modulate nasal absorption and retention, thereby potentially influencing the clinical efficacy. Characteristics such as delivery device and spray volume can affect a patient's perception and experience with a particular INS. Newer INSs, such as ciclesonide, are in development for the treatment of allergic rhinitis, and consideration of the formulation characteristics of these agents is an important part of the development process.

CONCLUSIONS

INSs are an effective treatment option for patients with allergic rhinitis; however, there is room for formulation improvement. Optimization of formulation may increase the efficacy, tolerability, and patient preference and adherence to INSs.

In vitro effects of flunisolide on MMP-9, TIMP-1, fibronectin, TGF-beta1 release and apoptosis in sputum cells freshly isolated from mild to moderate asthmatics

BACKGROUND

Corticosteroids play an important role in inflammation and remodelling of airways and are considered an important therapeutic target in asthma. Inflammation in asthma is characterized by a dysregulation of eosinophil apoptosis and of markers of airways remodelling. We evaluated the ability of flunisolide to inhibit in vitro the release of metalloproteinases-9 (MMP-9), tissue inhibitor metalloproteinases-1 (TIMP-1), transforming growth factor (TGF-beta) and fibronectin by sputum cells (SC) as well as to induce sputum eosinophil apoptosis.

METHODS

The SC, isolated from induced sputum samples of 12 mild-to-moderate asthmatics, were cultured for 24 h in the presence or absence of flunisolide (1, 10 and 100 microM). The release of mediators was assessed by enzyme-linked immunosorbent assay (ELISA) whereas apoptosis was studied by TUNEL technique.

RESULTS

Flunisolide (10 microM) significantly reduced MMP-9 and TIMP-1 (P = 0.0011 and P < 0.0001 respectively) and increased MMP-9/TIMP-1 molar ratio (P = 0.004). In addition, flunisolide decreased TGF-beta and fibronectin release by SC (P = 0.006; and P < 0.0001 respectively) and increased eosinophil apoptosis (P < 0.001).

CONCLUSIONS

These results demonstrate that flunisolide may play an important role in the inhibition of airway inflammation and remodelling, by promoting the resolution of eosinophilic inflammation and by inhibiting the release of MMP-9, TIMP-1, TGF-beta and fibronectin.

Benzalkonium chloride as a preservative in nasal solutions: re-examining the data

Recent studies have suggested that benzalkonium chloride (BKC), an antimicrobial agent used as a preservative in nasal sprays, lacks deleterious effects on the nasal ciliated epithelium. Other data, including recent in vivo findings, suggest that BKC may, in fact, produce adverse clinical effects on human nasal tissue, including the aggravation of rhinitis medicamentosa. Toxic effects have also been reported. In light of the discrepancy between negative results and studies suggesting no safety concerns, we consider the possibility of problems in the design and methodology of some of the studies and in the interpretation of results. Clearly, further research is warranted to clarify the significance of conflicting findings. In the meantime, without conclusive data regarding BKC and the possibility of harmful effects, the use of nasal formulations without BKC might be a reasonable alternative.

Is the use of benzalkonium chloride as a preservative for nasal formulations a safety concern? A cautionary note based on compromised mucociliary transport

BACKGROUND

Topical nasal solution and suspension delivery systems are available for short- and long-acting vasoconstrictors, ipratropium, cromolyn, azelastine, and glucocorticosteroids. The use of intranasal glucocorticosteroids has increased substantially because the efficacy of these agents has been well established for the treatment of perennial and seasonal allergic rhinitis. Adverse local effects of burning, irritation, and dryness are occasionally associated with glucocorticosteroid nasal preparations. Benzalkonium chloride (BKC) is a quaternary ammonium antimicrobial agent included in some nasal solutions (including glucocorticosteroids) to prevent the growth of bacteria. Some reports suggest that BKC in nasal sprays may cause adverse effects, including reduced mucociliary transport, rhinitis medicamentosa, and neutrophil dysfunction.

OBJECTIVE

This article summarizes recent literature about possible adverse biologic effects associated with BKC as a nasal spray preservative by examining its effects on the following properties of mucociliary transport: ciliary motion, ciliary form, ciliary beat frequency, electron microscopy, and particle movement/saccharin clearance tests.

CONCLUSION

Both animal and human in vitro data suggest that BKC promotes ciliostasis and reduction in mucociliary transport that may be partially masked by absorption and dilution effects occurring in respiratory mucus. These possible confounding factors may account for several disparate human in vivo results. The use of BKC-free glucocorticosteroid formulations should be considered, particularly in patients who complain of nasal burning, dryness, or irritation.

The effects of topical nasal steroids on rat respiratory mucosa in vivo, with special reference to benzalkonium chloride

Fifty rats were treated with topical nasal steroids with and without the preservative benzalkonium chloride in their right nostril twice daily for 21 days, while the left nostrils were exposed to 0.9% NaCl. By cutting the noses serially in frontal sections, the structure of the mucosal lining of all parts of the nose could be investigated. Areas with squamous cell metaplasia were observed in all nostrils exposed to topical steroids containing benzalkonium chloride. Such alterations were not observed in any nasal cavities exposed to the topical nasal steroid without the preservative or to 0.9% NaCl. In conclusion, benzalkonium chloride appears to be potentially toxic to the mucosa in vivo.

Budesonide powder administration for the treatment of grass-pollen-induced allergic rhinitis

The new dry-powder inhaler system, Turbuhaler, has proved to be equivalent to metered-dose inhalers when used in the nose, and the objective of this study was to investigate the efficacy, dose-response effects, and safety of budesonide powder given in the morning during the grass pollen season to patients with grass-pollen-induced allergic rhinitis. Of 190 randomized patients, 186 were treated and 180 completed this double-blind study, which comprised a 4-week treatment period, preceded by a 1-week run-in period. The patients were randomized to three parallel treatment groups: budesonide 400 micrograms, budesonide 200 micrograms, or placebo once in the morning. Assessment of efficacy, by comparing changes in mean scores of nasal symptoms from run-in to treatment, showed a statistically significant effect for all symptoms with active treatments, as compared with placebo. The mean reduction of symptom severity was more pronounced in the 400-micrograms group than in the 200-micrograms group, and this difference was statistically significant for runny nose (P < 0.02) and combined nasal symptoms (P < 0.02). Nasal peak-inspiratory flow improved significantly in both budesonide-treated groups, as compared with placebo (P < 0.01 and P < 0.01). During the treatment period, patients on active treatment showed, on average, a reduction of all nasal symptoms, whereas the placebo-treated patients, on average, showed an increase of nasal symptoms. Approximately 40% in the high-dose group felt total control of rhinitis symptoms, as compared with 26% in the low-dose group. There was no difference between budesonide- and placebo-treated groups in side-effects.(ABSTRACT TRUNCATED AT 250 WORDS)

Powder administration of pure budesonide for the treatment of seasonal allergic rhinitis

The objective of this study was to compare the efficacy and safety of a pure powder formulation of budesonide, delivered from a new multi-dose dispenser for nasal drug application, with the commercially available budesonide pressurized aerosol, and with placebo. Of 116 patients with grass pollen-induced allergic rhinitis, 112 finished the study, which comprised a 4-week treatment period, preceded by a 1-week run-in period. The patients were randomized to four parallel treatment groups: budesonide powder 400 micrograms daily; budesonide powder 800 micrograms daily; budesonide aerosol 400 micrograms daily; and placebo powder. Treatment was given once daily in the morning. The study was double-blind regarding comparison between budesonide powder and placebo. Assessment of efficacy, made by comparing mean scores of nasal symptoms and use of rescue medication, showed equal efficacy of all three budesonide groups compared with placebo. There were no differences between budesonide-and placebo-treated groups with regard to side effects. Budesonide treatment had no demonstrable effect on the HPA-axis assessed by measurement of 24-h urine cortisol. We conclude that budesonide, delivered as pure powder from a multi-dose dispenser, is effective and safe for the treatment of seasonal allergic rhinitis. This new formulation is a good alternative to the commercially available preparations, as it does not contain carrier gas, preservatives or lubricants.

Management of allergic rhinitis: focus on intranasal agents

The clinical manifestations of allergic rhinitis are the result of an immune-mediated process after exposure of a sensitized individual to airborne allergens. The primary symptomatology includes nasal congestion, rhinorrhea, nasal and conjunctival pruritus, and sneezing. Principles of management include allergen avoidance, palliative therapy, immunotherapy, and pharmacotherapy. Oral decongestants stimulate alpha-adrenergic receptors in the nasal cavity, resulting in vasoconstriction and decreased edema. Oral antihistamines block histamine1 (H1) receptors, and may relieve rhinorrhea, sneezing, and nasal and conjunctival pruritus. Topical decongestants have a local effect on adrenergic receptors in the nasal mucosa, resulting in rapid, marked vasoconstriction. Intranasal corticosteroids inhibit mediator release from mast cells and basophils, and reduce edema of the nasal mucosa. Dexamethasone sodium phosphate, beclomethasone dipropionate, and flunisolide are currently available for intranasal administration. Cromolyn sodium inhibits allergen-induced degranulation and mediator release from sensitized cells, and is useful primarily as a prophylactic agent. Several agents, including the corticosteroids budesonide and flucortin butylester, the mast cell-stabilizing agent nedocromil sodium, the anticholinergic agent ipratropium bromide, and the H1 receptor antagonist levocabastine are being investigated for intranasal use in the management of allergic rhinitis.