A prospective, controlled study of SNS01 (ectoine nasal spray) compared to BNO-101 (phytotherapeutic dragées) in patients with acute rhinosinusitis

Ectoine Globally Hypomethylates DNA in Skin Cells and Suppresses Cancer Proliferation

Epigenetic modifications, mainly aberrant DNA methylation, have been shown to silence the expression of genes involved in epigenetic diseases, including cancer suppression genes. Almost all conventional cancer therapeutic agents, such as the DNA hypomethylation drug 5-aza-2-deoxycytidine, have insurmountable side effects. To investigate the role of the well-known DNA protectant (ectoine) in skin cell DNA methylation and cancer cell proliferation, comprehensive methylome sequence analysis, 5-methyl cytosine (5mC) analysis, proliferation and tumorigenicity assays, and DNA epigenetic modifications-related gene analysis were performed. The results showed that extended ectoine treatment globally hypomethylated DNA in skin cells, especially in the CpG island (CGIs) element, and 5mC percentage was significantly reduced. Moreover, ectoine mildly inhibited skin cell proliferation and did not induce tumorigenicity in HaCaT cells injected into athymic nude mice. HaCaT cells treated with ectoine for 24 weeks modulated the mRNA expression levels of Dnmt1, Dnmt3a, Dnmt3b, Dnmt3l, Hdac1, Hdac2, Kdm3a, Mettl3, Mettl14, Snrpn, and Mest. Overall, ectoine mildly demethylates DNA in skin cells, modulates the expression of epigenetic modification-related genes, and reduces cell proliferation. This evidence suggests that ectoine is a potential anti-aging agent that prevents DNA hypermethylation and subsequently activates cancer-suppressing genes.

Effectiveness and Tolerability of Ectoin® Mouth and Throat Spray Althaea Honey (ERS09) for Sore Throat due to Acute Pharyngitis and Dry Cough: A Multicentre, Actively Controlled, Open Label Study in Germany

Acute pharyngitis can cause sore throat. This multicentre, active-controlled, randomised, open-label, and parallel-group study, conducted according to the German Medical Devices Act, compared the effectiveness and tolerability of ERS09 mouth and throat spray with a well-established device for the treatment of sore throat caused by acute pharyngitis and dry cough. Patients were randomised 1:1 into ERS09/comparator groups (EMSER® Sore Throat Spray) for 7 ± 2 days. Patients and investigators reported effectiveness (change in total symptom score [TSS]) and safety endpoints (incidence of adverse events [AEs]; adverse device effects [ADEs]). A total of 186 patients were included (ERS09: n = 92; comparator: n = 94). The baseline-adjusted mean TSS over 7 days was -90.14 and -74.91 in the ERS09 and comparator groups, respectively (p < 0.05). The majority of patients reached a 50% reduction in symptoms by day 6 (ERS09 = 78.85; comparator = 75.8%). Most patients reported a soothing effect within five minutes (ERS09 = 82%; comparator = 71%). Improvements in individual symptoms were similar with no significant differences between groups; more patients in the ERS09 group reported an improvement in pharyngeal redness/swelling. Three AEs unrelated to medication, one ADE following ERS09, and no serious AE/ADE were reported. ERS09 was as well tolerated and effective as the established device, showing greater improvement in the management of some symptoms and greater patient preference.

Production and Recovery of Ectoine: A Review of Current State and Future Prospects

Ectoine (1,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid) is a revolutionizing substance with vast applications in the cosmetic and food industries. Ectoine is often sourced from halobacteria. The increasing market demand for ectoine has urged the development of cost-effective and sustainable large-scale production of ectoine from microbial sources. This review describes the existing and potential microbial sources of ectoine and its derivatives, as well as microbial production and fermentation approaches for ectoine recovery. In addition, conventional methods and emerging technologies for enhanced production and recovery of ectoine from microbial fermentation with a focus on the aqueous biphasic system (ABS) are discussed. The ABS is a practically feasible approach for the integration of fermentation, cell disruption, bioconversion, and clarification of various biomolecules in a single-step operation. Nonetheless, the implementation of the ABS on an industrial-scale basis for the enhanced production and recovery of ectoine is yet to be exploited. Therefore, the feasibility of the ABS to integrate the production and direct recovery of ectoine from microbial sources is also highlighted in this review.

High-efficiency production of 5-hydroxyectoine using metabolically engineered Corynebacterium glutamicum

BACKGROUND

Extremolytes enable microbes to withstand even the most extreme conditions in nature. Due to their unique protective properties, the small organic molecules, more and more, become high-value active ingredients for the cosmetics and the pharmaceutical industries. While ectoine, the industrial extremolyte flagship, has been successfully commercialized before, an economically viable route to its highly interesting derivative 5-hydroxyectoine (hydroxyectoine) is not existing.

RESULTS

Here, we demonstrate high-level hydroxyectoine production, using metabolically engineered strains of C. glutamicum that express a codon-optimized, heterologous ectD gene, encoding for ectoine hydroxylase, to convert supplemented ectoine in the presence of sucrose as growth substrate into the desired derivative. Fourteen out of sixteen codon-optimized ectD variants from phylogenetically diverse bacterial and archaeal donors enabled hydroxyectoine production, showing the strategy to work almost regardless of the origin of the gene. The genes from Pseudomonas stutzeri (PST) and Mycobacterium smegmatis (MSM) worked best and enabled hydroxyectoine production up to 97% yield. Metabolic analyses revealed high enrichment of the ectoines inside the cells, which, inter alia, reduced the synthesis of other compatible solutes, including proline and trehalose. After further optimization, C. glutamicum Ptuf ectD^PST achieved a titre of 74 g L^-1 hydroxyectoine at 70% selectivity within 12 h, using a simple batch process. In a two-step procedure, hydroxyectoine production from ectoine, previously synthesized fermentatively with C. glutamicum ectABC^opt, was successfully achieved without intermediate purification.

CONCLUSIONS

C. glutamicum is a well-known and industrially proven host, allowing the synthesis of commercial products with granted GRAS status, a great benefit for a safe production of hydroxyectoine as active ingredient for cosmetic and pharmaceutical applications. Because ectoine is already available at commercial scale, its use as precursor appears straightforward. In the future, two-step processes might provide hydroxyectoine de novo from sugar.

Topical Ectoine Application in Children and Adults to Treat Inflammatory Diseases Associated with an Impaired Skin Barrier: A Systematic Review

Introduction

Inflammatory skin diseases are a significant burden on affected patients. Inflammation is caused by various stress factors to the epidermis resulting in, e.g., dryness, redness, and pruritus. Emollients are used in basic therapy to restore the natural skin barrier and relieve symptoms. A systematic review was performed to evaluate the efficacy and safety of ectoine-containing topical formulations in inflammatory skin diseases characterized by an impaired skin barrier.

Methods

A systematic review was carried out in PubMed, the Cochrane Library, and Microsoft Academic up to October 2021. Inclusion criteria were ectoine-containing topical formulations (creams, emollients) used for (adjuvant) therapy of inflammatory skin diseases. Clinical studies of any design published in any language were included.

Results

A total of 230 references were screened for eligibility, of which six were selected for inclusion in the review (five studies on atopic dermatitis and one study on prevention and management of retinoid dermatitis). The application of topical formulations containing 5.5–7.0% ectoine positively influenced skin dryness and, consequently, pruritus and dermatitis-specific scores in patients with atopic dermatitis. Especially in infants and children, who belong to the most frequently affected group, the formulations were well-tolerated when applied for up to 4 weeks. In studies where ectoine was used as an adjuvant therapy, application was associated with a decreased need for pharmacological therapy and also improved the effectiveness of, e.g., topical corticosteroids. In patients undergoing isotretinoin therapy, ectoine was as effective as dexpanthenol in reducing retinoid dermatitis or improving symptoms.

Conclusion

Ectoine is an effective natural substance with an excellent tolerability and safety profile, representing a beneficial alternative as basic therapy or to increase the efficacy of the pharmacological treatment regimen for patients with inflammatory skin diseases, including infants and children.

Effects of ectoine containing nasal spray and eye drops on symptoms of seasonal allergic rhinoconjunctivitis

BACKGROUND

Patients are often dissatisfied with the symptom control obtained from available pharmacological treatments for seasonal allergic rhinoconjunctivitis (ARC). Therefore, patients seek for alternative, nonpharmacological options to treat their symptoms. Here, we assessed the efficacy of ectoine nasal spray and ectoine eye drops in comparison to placebo to prevent nasal and ocular symptoms following exposure to pollen in patients with ARC.

METHODS

In this double-blind, randomized, placebo-controlled, cross-over study, 46 patients with ARC applied ectoine eye drops and nasal spray in immediate succession or placebo eye drops and nasal spray for 13 days before ARC symptoms were induced in an environmental exposure chamber. Primary endpoint was the baseline-adjusted area under the curve (AUC) posttreatment total nasal symptom score (TNSS) and the total ocular symptom score (TOSS) using analysis of covariance. Secondary endpoints were, amongst others, total nonnasal symptoms score (TNNSS) and nasal patency (measured using acoustic rhinometry).

RESULTS

Treatment with both ectoine and placebo reduced TNSS, TOSS, and TNNSS upon allergen exposure. The analysis of parameters at baseline and after allergen exposure demonstrated that ectoine induced a clinically relevant improvement in ARC symptoms compared to placebo: the least square mean difference for baseline-adjusted AUC was -1.87 for TNSS, -1.45 for TOSS and -2.20 for TNNSS. The mean change from baseline AUC of TNNSS for ectoine was also significantly greater than for placebo (-5.49 vs. -3.46; p = 0.011). Ectoine significantly improved the singular symptoms "sneezing," "watery eyes" and "itchy eyes" (p ≤ 0.021) as well as "itchy ear/palate" (p = 0.036) in comparison to placebo. Mean cross sectional areas of the nasal cavity were reduced to a lesser extent after treatment with ectoine (-0.020 ± 0.022) than with placebo (-0.047 ± 0.029). The current study also demonstrated a very good safety profile of ectoine treatment. Few AEs with comparable numbers in both treatment groups were reported during the study, which were mild in severity and resolved without medical treatment.

CONCLUSION

The study suggests that ectoine is effective in reducing nasal and ocular symptoms associated with ARC. Being a natural, bacteria derived stress protection molecule functioning by a physical mode of action, it therefore represents an alternative nonpharmacological treatment option.

Protective effect of the extremolytes ectoine and hydroxyectoine in a porcine organ culture

Purpose

Hypoxic damage to the retina is a relevant component of neurodegenerative pathologies such as glaucoma or retinal ischemia. In porcine retina organ cultures, hypoxic damage can be induced by applying cobalt chloride (CoCl₂). The aim of our study was to investigate possible neuroprotective effects of the extremolytes ectoine and hydroxyectoine in this hypoxia-damaged retina model.

Methods

To simulate hypoxia, porcine retina organ cultures were damaged with 300 μM CoCl₂ for 48 h starting on day 1 (n = 8–9/group). In order to investigate the possible neuroprotective effects of ectoine and hydroxyectoine, 0.5 mM of each extremolyte was added to the culture at the same time as the stressor and for the same duration. On day 8, the retina organ cultures were taken for (immuno)-histochemical examinations. Retinal ganglion cells (RGCs), macroglia, and apoptotic and hypoxic cells were detected with appropriate markers followed by cell counts and group comparisons.

Results

Treatment with ectoine resulted in RGC protection (p < 0.05) and reduced rate of apoptosis (p < 0.001) in hypoxia-treated retina organ cultures. However, the macroglia area and the amount of hypoxic, HIF-1α⁺ cells were unaffected by the ectoine treatment (p = 0.99). Treatment with hydroxyectoine also protected RGCs (p < 0.01) by inhibiting apoptosis (p < 0.001). In addition, the number of hypoxic, HIF-1α⁺ cells could be significantly reduced by treatment with hydroxyectoine (p < 0.05). The macroglia area on the other hand was unchanged after CoCl₂ and treatment with hydroxyectoine.

Conclusion

Both extremolytes had a protective effect on CoCl₂-induced hypoxia in the porcine retina organ culture. Regarding the reduction of hypoxic stress, hydroxyectoine appears to be more effective. Thus, both extremolytes represent an interesting potential new therapeutic approach for patients with ocular diseases in which hypoxic processes play a significant role.

Topical Ectoine: A Promising Molecule in the Upper Airways Inflammation-A Systematic Review

To date, topical therapies guarantee a better delivery of high concentrations of pharmacologic agents to the mucosa of the upper airways (UA). Recently, topical administration of ectoine has just been recognized as adjuvant treatment in the Allergic Rhinitis (AR) and Rhinosinusitis (ARS). The aim of this work is to review the published literature regarding all the potential therapeutic effects of ectoine in the acute and chronic inflammatory diseases of UA. Pertinent studies published without temporal limitation were selected searching on MEDLINE the following terms: “ectoine” and “nasal spray,” “oral spray,” “upper respiratory tract infections,” “rhinosinusitis,” “rhinitis,” “rhinoconjunctivitis,” “pharyngitis,” and “laryngitis.” At the end of our selection process, six relevant publications were included: two studies about the effect of ectoine on AR, one study about ARS, one study about rhinitis sicca anterior, and two studies about acute pharyngitis and/or laryngitis. Due to its moisturizing and anti-inflammatory properties, topical administration of ectoine could play a potential additional role in treatment of acute and chronic inflammatory diseases of UA, in particular in the management of sinonasal conditions improving symptoms and endoscopic findings. However, these results should be viewed cautiously as they are based on a limited number of studies; some of them were probably underpowered because of their small patient samples.

Effect of ectoine, hydroxyectoine and β-hydroxybutyrate on the temperature and pressure stability of phospholipid bilayer membranes of different complexity

Previous research has shown that ectoines fluidize lipid monolayers by increasing the liquid expanded region in DPPC monolayers and also decreasing the line tension responsible for the phase morphology. Here, we explored possible effects of the compatible osmolytes ectoine, hydroxyectoine and β-hydroxybutyrate on lipid bilayer membranes, including effects of temperature and pressure. The effect of the protective osmolytes on the phase transition of DPPC bilayers was investigated by fluorescence spectroscopy, differential scanning calorimetry and pressure perturbation calorimetry. A slight change of the phase behavior was observed, which resulted in a stabilization of the gel phase, which may be caused by an alteration of the hydration properties at the lipid interface and H-bond and electrostatic interactions in the headgroup region. We then explored the cosolvents' effects on giant unilamellar vesicles (GUVs) formed by lipid mixtures exhibiting phase separation into liquid-ordered (l_o) and liquid-disordered (l_d) domains using BODIPY-PC and the DiI₁₈ dye as labels. The presence of both, ectoine and hydroxyectoine showed significant effects on the lateral organization increasing the fluid domains. Moreover, we observed a considerable increase in the adhesion behavior of small vesicles onto GUV surfaces. Diffusion studies by fluorescence recovery after photobleaching experiments on POPC giant vesicles quantitatively showed a hydroxyectoine-induced increase of the diffusion coefficient values, clearly demonstrating an increase in the lateral mobility of lipid within the bilayer membrane. This study provides clear evidence for the fluidizing effect of the compatible solutes on bilayer lipid membranes. A marked effect, however, was only detected if phase separated domains exist.

Ectoine lozenges in the treatment of acute viral pharyngitis: a prospective, active-controlled clinical study

PURPOSE

Acute pharyngitis is an uncomfortable disorder mostly caused by viruses and for which antibiotics are unwarranted. This study compared lozenges containing ectoine, a natural extremolyte, with hyaluronic acid lozenges and hypertonic saline gargle for symptomatic treatment of acute viral pharyngitis.

METHODS

This prospective, controlled clinical study, recruited 90 patients with moderate-to-severe pharyngitis symptoms who chose to use either ectoine (n = 35), hyaluronic acid (n = 35), or saline gargle (n = 20). Patients applied their 7-day treatment from the inclusion visit (V1) until the end-of-study visit (V2). Patients' pharyngitis symptoms, general health, general treatment effectiveness and tolerability, and patient compliance were assessed by investigators and patients.

RESULTS

The sum score for three primary symptoms (pain on swallowing, urge to cough, and hoarseness) decreased by 79.5% (ectoine), 72.2% (hyaluronic acid), and 44.8% (saline gargle). Both lozenges were significantly superior to saline gargle (P < 0.05). Regarding general health improvement, ectoine was significantly superior to saline gargle (72.5% vs. 45.2%, P < 0.05), but hyaluronic acid (63.3%) was not. At V2, 65.7% of patients receiving ectoine reported "very good" general health vs. 48.6% of those receiving hyaluronic acid and 20.0% using saline gargle. Ectoine was significantly superior (P < 0.05) to both hyaluronic acid and saline gargle in terms of tolerability and patient compliance. No patients taking ectoine reported unpleasant sensations while applying their treatment, whereas almost half of patients using hyaluronic acid lozenges and saline gargle did.

CONCLUSION

Treatment with ectoine lozenges significantly relieves moderate-to-severe symptoms of acute viral pharyngitis and is more effective and tolerable than treatments with hyaluronic acid lozenges and hypertonic saline gargle.

Ectoine-Containing Inhalation Solution versus Saline Inhalation Solution in the Treatment of Acute Bronchitis and Acute Respiratory Infections: A Prospective, Controlled, Observational Study

Purpose

This study investigated an inhalation solution containing ectoine, a bacterial-derived extremolyte, for the treatment of acute bronchitis and acute respiratory infections in comparison with saline inhalation solution.

Methods

This prospective, controlled, observational study comprised an inclusion visit (day 1), a final visit (day 7), and a follow-up questionnaire (day 17). The treatment itself was administered from day 1 to day 7. The Bronchitis Severity Score, patients' general health, general effectiveness of the treatment, tolerability, and adverse events were compared between two groups.

Results

In total, 135 patients were recruited; 79 patients received ectoine inhalation solution and 56 saline inhalation solution. After treatment, symptom scores decreased significantly in both groups (P < 0.05); the reduction in symptom scores was slightly greater in the ectoine group than in the saline group. The first significant reduction in symptom scores (P < 0.05) occurred earlier in the ectoine group than in the saline group. The differences in the area under the curve for the symptoms of dyspnea and auscultation findings were significant in favor of ectoine (P < 0.05). After treatment, more patients and physicians in the ectoine group assessed their or their patients' condition as “completely recovered” or “greatly improved” than those in the saline group. Almost all patients and physicians assessed the tolerability of both treatments as “good” or “very good”.

Conclusions

Ectoine inhalation solution seems to be slightly more effective than saline inhalation solution for the treatment of acute bronchitis and acute respiratory infections.

Efficacy and tolerability of an ectoine mouth and throat spray compared with those of saline lozenges in the treatment of acute pharyngitis and/or laryngitis: a prospective, controlled, observational clinical trial

The aim of this observational trial was to evaluate the efficacy and tolerability of a mouth and throat spray containing ectoine in the treatment of acute pharyngitis and/or laryngitis. The outcome was compared with control treatment using saline lozenges. This study was designed as a prospective, controlled, non-randomized, observational multicenter clinical trial and was conducted in Germany. The study population consisted of 95 patients. The decision for treatment with either spray or lozenges was based on the patients’ preference for pharyngeal or oral application. Investigators assessed symptoms specific to acute pharyngitis/laryngitis and determined the pharyngitis symptom score. Both patients and investigators evaluated the tolerability and efficacy of the treatment applied. Treatment with the spray showed higher efficacy, 1.95 ± 0.81 versus 1.68 ± 0.67 (investigators) and 1.97 ± 0.88 versus 1.57 ± 0.69 (patients, p < 0.05). Treatment with the spray resulted in significantly greater reduction of cervical lymph node swelling (p < 0.05), ∆ spray = 0.44 ± 0.62, ∆ lozenges = 0.21 ± 0.62. The lozenges showed some advantage in relieving cough, ∆ lozenges = 0.62 ± 0.94 versus ∆ spray = 0.44 ± 0.85. Both patients and investigators rated the tolerability of both medical devices as “good” to “very good”. Adverse events of mild to moderate severity were either possibly related or not related to the medical devices used. No serious adverse events occurred. Taken together, while the tolerability was consistent in both treatment groups, the ectoine-based spray showed superior efficacy in treating acute pharyngitis and/or laryngitis.

Potential applications of stress solutes from extremophiles in protein folding diseases and healthcare

Protein misfolding, aggregation and deposition in the brain, in the form of amyloid, are implicated in the etiology of several neurodegenerative disorders, such as Alzheimer's, Parkinson's and prion diseases. Drugs available on the market reduce the symptoms, but they are not a cure. Therefore, it is urgent to identify promising targets and develop effective drugs. Preservation of protein native conformation and/or inhibition of protein aggregation seem pertinent targets for drug development. Several studies have shown that organic solutes, produced by extremophilic microorganisms in response to osmotic and/or heat stress, prevent denaturation and aggregation of model proteins. Among these stress solutes, mannosylglycerate, mannosylglyceramide, di-myo-inositol phosphate, diglycerol phosphate and ectoine are effective in preventing amyloid formation by Alzheimer's Aβ peptide and/or α-synuclein in vitro. Moreover, mannosylglycerate is a potent inhibitor of Aβ and α-synuclein aggregation in living cells, and mannosylglyceramide and ectoine inhibit aggregation and reduce prion peptide-induced toxicity in human cells. This review focuses on the efficacy of stress solutes from hyper/thermophiles and ectoines to prevent amyloid formation in vitro and in vivo and their potential application in drug development against protein misfolding diseases. Current and envisaged applications of these extremolytes in neurodegenerative diseases and healthcare will also be addressed.

Noninterventional open-label trial investigating the efficacy and safety of ectoine containing nasal spray in comparison with beclomethasone nasal spray in patients with allergic rhinitis

Objectives. The current study aimed to compare the efficacy and safety of a classical anti-inflammatory beclomethasone nasal spray in comparison to a physic-chemical stabilizing ectoine containing nasal spray in the treatment of allergic rhinitis. Design and Methods. This was a noninterventional, open-label, observational trial investigating the effects of beclomethasone or ectoine nasal spray on nasal symptoms and quality of life. Over a period of 14 days, patients were asked to daily document their symptoms. Efficacy and tolerability were assessed by both physicians and patients. Results. Both treatments resulted in a significant decrease of TNSS values. An equivalence test could not confirm the noninferiority of ectoine treatment in comparison with beclomethasone treatment. Although clear symptom reduction was achieved with the ectoine products, the efficacy judgment showed possible advantages for the beclomethasone group. Importantly, tolerability results were comparably good in both groups, and a very low number of adverse events supported this observation. Both treatments resulted in a clear improvement in the quality of life as assessed by a questionnaire answered at the beginning and at the end of the trial. Conclusion. Taken together, it was shown that allergic rhinitis can be safely and successfully treated with beclomethasone and also efficacy and safety were shown for ectoine nasal spray.

Meta-analysis of the efficacy of ectoine nasal spray in patients with allergic rhinoconjunctivitis

Objectives. The meta-analysis aims to investigate the efficacy of ectoine nasal spray and eye drops in the treatment of allergic rhinitis and rhinoconjunctivitis symptoms. Design and Methods. This meta-analysis is based on yet unpublished data of four studies. Both nasal and eye symptoms were documented in patient diary cards. All scales were transformed into a 4-point scale: 0 = no, 1 = mild, 2 = moderate, and 3 = severe symptoms. Each symptom was analysed individually in a meta-analysis of the area under the curve values as well as in a meta-analysis of pre- and posttreatment comparison. Results. After seven days of treatment with ectoine nasal spray both nasal and ocular symptoms decreased significantly. A strong reduction of symptom severity was shown for the parameters rhinorrhoea (31.76% reduction) and nasal obstruction (29.94% reduction). Furthermore, the meta-analyses of individual symptoms to investigate the strength of effect after seven days of medication intake showed significant improvement for nasal obstruction, rhinorrhoea, nasal itching, sneezing, itching of eyes, and redness of eyes. The improvement of the symptom nasal obstruction was associated with a strong effect 0.53 (±0.26). Conclusions. The ectoine nasal spray and eye drops seem to be equally effective as guideline-recommended medication in the treatment of rhinoconjunctivitis symptoms.

Treatment of rhinitis sicca anterior with ectoine containing nasal spray

Objectives. The safety and efficacy of ectoine nasal spray and ectoine nasal spray with dexpanthenol in the treatment of rhinitis sicca were evaluated in two studies. Design and Methods. Two noninterventional observational studies were performed to evaluate the efficacy and safety of a nasal spray containing ectoine (study 1) and ectoine/dexpanthenol (study 2) over a period of two weeks including comparable numbers of patients suffering from rhinitis sicca anterior. Patients and physicians were asked to rate the efficacy in reducing symptoms and the tolerability over the treatment phase. Results. The treatment in both studies resulted in a clinical and statistical significant reduction of the main diagnosis parameters, nasal airway obstruction, and crust formation. There was also a significant reduction in the secondary diagnosis parameters in both studies. Importantly, the tolerability was very good. During the whole observational study, neither patients nor doctors stopped the medication due to unwanted effects. Conclusion. Rhinitis sicca could be successfully treated with a nasal spray containing ectoine and a nasal spray combining ectoine with dexpanthenol. The combination of both substances led to slight advantages.