Page 44 - JCTR-11-3

Journal of Clinical and

Translational Research

REVIEW ARTICLE
Greek poplar-type propolis as an adjunct

therapy in hospitalized COVID-19 adults:
A randomized controlled trial protocol

Giorgos Tzigkounakis * and Jonathan Brown 2
1
1 Department of Research, Health and Resilience Institute, Athens, Greece
2 Department of Nutrition, Food and Exercise Sciences, Faculty of Health and Medical Sciences,
University of Surrey, Guildford, Surrey, United Kingdom

Abstract

Background: Despite the rapid development and distribution of COVID-19 vaccines,
the pandemic continues to challenge global health systems. With vaccine inequity
and hesitancy, especially in low-income populations and specific demographic
cohorts, alternative therapeutic strategies to mitigate COVID-19 symptoms and
reduce viral clearance time remain vital. Propolis, a natural bee product with
immunomodulatory and antiviral properties, has demonstrated efficacy against
other viral pathogens, suggesting potential as an adjunctive therapy for COVID-19.
*Corresponding author: Objectives: This study protocol outlines a randomized, triple-blind, placebo-
Giorgos Tzigkounakis controlled clinical trial to assess the efficacy of a Greek propolis hydroalcoholic
(info@healthandresilience.org) extract as an adjunct to standard care in hospitalized COVID-19 patients. The
Citation: Tzigkounakis G, Brown J. primary objectives are to evaluate the extract’s impact on viral clearance time and
Greek poplar-type propolis as an hospitalization duration, with secondary objectives examining body temperature,
adjunct therapy in hospitalized
COVID-19 adults: A randomized cough severity, quality of life, and safety. Methods: A total of 441 severe acute
controlled trial protocol. J Clin respiratory syndrome coronavirus 2-positive adult patients will be enrolled and
Transl Res. 2025;11(3):38-49. stratified by age and vaccination status. Participants will be randomly assigned to
doi: 10.36922/jctr.24.00073
one of three arms: (i) propolis extract, (ii) placebo, or (iii) control (standard care
Received: October 30, 2024 only). Primary outcomes include time to negative reverse transcription polymerase
1st revised: January 12, 2025 chain reaction tests and hospital discharge. Secondary measures involve cough
severity and quality-of-life assessments through Visual Analog Scale and Leicester
2nd revised: March 11, 2025
Cough Questionnaire scores, fever duration and resolution patterns, and safety
Accepted: March 26, 2025 through adverse events and mortality tracking. Statistical analysis will include
Published online: May 16, 2025 Kaplan–Meier survival curves, Cox regression for confounders, and analysis of
variance for quality-of-life scores. Conclusion: This study aims to validate the
Copyright: © 2025 Author(s).
This is an Open-Access article therapeutic potential of propolis as a natural, accessible adjunctive treatment for
distributed under the terms of the COVID-19. Findings may provide critical evidence supporting propolis in symptom
Creative Commons AttributionNon- relief, viral clearance, and healthcare burden reduction in resource-limited settings.
Commercial 4.0 International (CC
BY-NC 4.0), which permits all Relevance for patients: Participants in the intervention arm may experience
non-commercial use, distribution, improved clinical outcomes, such as faster recovery and symptom alleviation,
and reproduction in any medium, while all patients will continue to receive standard care in alignment with current
provided the original work is
properly cited. clinical protocols.
Publisher’s Note: AccScience
Publishing remains neutral with Keywords: SARS-CoV-2; COVID-19; Propolis; Adjunct therapy; Nutraceuticals;
regard to jurisdictional claims in
published maps and institutional Randomized controlled trial; Immune modulation
affiliations.

Volume 11 Issue 3 (2025) 38 doi: 10.36922/jctr.24.00073