RESUMEN
BRIEF OVERVIEW: Collectively the evidence obtained from across five clinical studies involving 936 adults indicate that mono-herbal preparations of Sambucus nigra L. berry (S.nigra), when taken within 48 hours of the onset of acute respiratory viral infection, may reduce the duration and severity of common cold and influenza symptoms in adults. There is currently no evidence to support the use of S.nigra berry for the treatment or prevention of COVID-19. Given the body of evidence from preclinical studies demonstrating the antiviral effects of S.nigra berry, alongside the results from clinical studies involving influenza viral infections included in this review, pre-clinical research exploring the potential effects of S.nigra berry on COVID-19 are encouraged. VERDICT: The evidence included in this review is mostly derived from clinical studies involving adult participants and examining short-term use of commercial formulations of S.nigra berry for up to 16 days. Findings from included studies suggest that mono-herbal preparations of S.nigra berry (in extract or lozenge formulation) may reduce influenza-type symptoms, including fever, headache, nasal congestion and nasal mucous discharge in adults, when taken within the first 48 hours of symptom onset. Within 2-4 days of S.nigra treatment, most adult participants experienced significant symptom reduction, by an average of 50%. Evidence regarding the effectiveness of S.nigra berry on the symptom of cough, and need for/use of medicines (including antibiotics) to treat acute respiratory infections, is currently unclear and inconsistent. Adverse events were rare with no serious events reported. Adverse events, reported in two studies, were more common in comparators than in treatments. There is currently no reliable or sufficient scientific evidence to support the use of S.nigra in pregnant or lactating women.
RESUMEN
BRIEF OVERVIEW: Based on the evidence identified in this rapid review, Hedera helix preparations and herbal complex preparations including H. helix may be a therapeutic option for treating early symptoms of respiratory tract infections. The best effectiveness for H. helix preparations has been proven for coughing, as an expectorant and to reduce the frequency and intensity of cough. Only weak evidence was found for all other researched symptoms. Both adults and children tolerate H. helix well. Currently, there is insufficient evidence to recommend the use of this supplement in the treatment or prevention of COVID-19. However, the current evidence justifies further research to better understand its applicability in coronavirus infections. VERDIC: tCurrent evidence suggests H. helix may improve the frequency and intensity of cough associated with viral respiratory infection. The overall applicability of additional findings is limited by the poorly defined outcome measures employed. However, studies focused explicitly on expectoration did report an increased conversion from dry to productive cough, and an improvement in expectoration amount, consistency and colour. These effects may be explained by a related finding of reduced oropharyngeal congestion and improved inflammatory markers (erythrocyte sedimentation rate and c-reactive protein). A decrease in frequency of night cough and respiratory pain was also reported, as was improved sleep quality and reduced cough-related sleep disturbance.Some studies also measured general respiratory tract infection symptoms and identified clinical improvement or resolution of fever, fatigue, sore throat, sneezing, wheezing, nasal congestion, post-nasal drip and body-ache. A reduced need for antibiotic prescriptions was also identified. While not consistently reported, the majority of studies also found H. helix reduced the overall severity of viral bronchitis and related conditions. Tolerability was rated as between 'good' and 'high'. Adverse events were rare or non-existent in almost all studies, and those that were reported were defined as non-serious and not drug-related.