Efficacy and safety of add-on Viola odorata L. in the treatment of COVID-19: A randomized double-blind controlled trial.

"Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper."

"Mohammad Sadegh Adel Mehraban: Formal analysis, Investigation, Project administration, Funding acquisition. Meysam Shirzad: Conceptualization, Methodology, Software, Writing – review & editing, Supervision, Project administration, Funding acquisition. Leila Mohammad Taghizadeh Kashani: Resources, Writing – original draft, Funding acquisition. Mohammad Mahdi Ahmadian-Attari: Conceptualization, Data curation, Writing – review & editing. Ali Akbar Safari: Validation, Data curation. Narges Ansari: Investigation, Supervision, Project administration, Funding acquisition. Hossein Hatami: Conceptualization, Methodology, Supervision. Mohammad Kamalinejad: Conceptualization, Methodology."

"This study was a randomized parallel-group double-blind controlled trial conducted from April 21st, 2021 to May 21st, 2021 at Al-Zahra general hospital, Isfahan, Iran. The trial was performed in accordance with the principles of the Declaration of Helsinki approved by the ethics committee of Tehran University of Medical Sciences (TUMS) under the registration number IR.TUMS.MEDICINE.REC.1399.784. Moreover, it was registered at the Iranian Registry of Clinical Trials (IRCT20190409043215N2). We studied outpatients suffering from respiratory manifestations referring to the COVID-19 center. Prevalent COVID-19 manifestations were defined according to WHO guidelines, and recent pieces of evidence(; ; )."