A randomized, double-blind, placebo-controlled study to evaluate the benefits of a standardized Nigella sativa oil containing 5% thymoquinone in reducing the symptoms of seasonal allergy

Abstract

Background: Allergic rhinitis (AR) or seasonal allergy characterized by sneezing, nasal congestion, nasal itching, and nasal discharge, triggered by immune reactions to environmental allergens. Present day customers also monitor the personal improvements in the area of Evidence-Based natural medicines/supplements Methods: A randomized, double-blind, placebo-controlled study was conducted on 65 participants aged 18 to 60 years having 2 or more allergic symptoms like sneezing, rhinorrhoea, nasal obstruction, and nasal itching for a cumulative period greater than 1 hour per day. The study participants received a capsule of NSO (250 mg) with 2.5 mg piperine (BioPerine) as a bioavailability enhancer or a placebo, twice a day, after food for 15 days. The primary objectives were evaluated by mean change in Total Nasal Symptom Score and the duration of AR symptoms per day from baseline to Day 15. Secondary endpoints were changes in Total Ocular Symptoms Score, AR symptom frequency and severity, serum Immunoglobulin E levels, and Patient Global Impression of Change scale. Adverse events were monitored throughout the study. Results: Sixty-five patients were enrolled and all of them completed the study, N = 33 in NSO and N = 32 in placebo. A significant reduction in Total Nasal Symptom Score and Total Ocular Symptoms Score was observed in the NSO group compared to the placebo, highlighting the potential of NSO in alleviating AR symptoms. The episodes of AR symptoms per day and the frequency of symptoms in 24 hours reduced significantly in 15 days in both groups, but the extent of improvement was significantly higher in NSO compared to placebo. Improvement in Patient Global Impression of Change was also significantly better in NSO compared to the placebo. Serum Immunoglobulin E levels decreased in NSO but were not significantly different from placebo. No clinically significant changes were observed in vital signs, liver and renal function, lipid profile, hematology, fasting blood sugar, or urine analysis at the end of the study. Conclusion: The result of the study demonstrates that NSO 250 mg with 2.5 mg piperine is an effective and well-tolerated supplement for the management of AR symptoms.