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

Abstract

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.

International consensus statement on allergy and rhinology: Allergic rhinitis – 2023

“…In this respect, numerous clinical trials have been conducted using parallel‐group or cross‐over designs in order to test the efficacy of drugs with prophylactic therapeutic potential, such as INCS, 1485–1489 or with immediate therapeutic activity, such as antihistamines 1490–1496 . Novel anti‐inflammatory compounds, 1497–1501 drug‐free nasal fluids, 1502,1503 and probiotics 1504,1505 have also been tested by this method. Additionally, the efficacy of AIT 1506–1517 and air cleaners 1518,1519 has been tested, as well as the influence of allergic nasal symptoms on the absorption of nasally applied drugs 1520 .…”

The use of environmental exposure chambers in studies related to ocular surface effects

“…The authors noted that EEC induced homogeneous and reproducible ocular reactions, as the scores were not different during three exposures separated by 1 week. Effects of ectoine-containing nasal spray and eye drops on symptoms of seasonal allergic rhinoconjunctivitis following EEC exposure to pollens have been evaluated [27]. Ectoine significantly improved the singular symptoms of 'sneezing', 'watery eyes' and 'itchy eyes' as well as 'itchy ear/palate' in comparison to placebo.…”

Effectiveness of Ectoin lozenges on oropharyngeal allergic symptoms

“…Ectoin ® is a compatible solute with membrane‐protecting and inflammation‐reducing properties, whose clinical efficacy in AR has already been reported. 7 …”

“…Ectoin ® is a compatible solute with membrane-protecting and inflammationreducing properties, whose clinical efficacy in AR has already been reported. 7 The current study investigated therapeutic and preventive effects of Ectoin ® lozenges on oropharyngeal allergic symptoms using the initiation of SLIT as a study model.…”