Related Experiment Video
Updated: Oct 12, 2025
Author Spotlight: Evaluating the Adjuvant Efficacy and Safety of Angong Niuhuang Pill in Viral Encephalitis Treatment
Published on: April 19, 2024
Treatment of COVID-19 patients with quercetin: a prospective, single center, randomized, controlled trial
Hasan Önal1, Bengü Arslan1, Nurcan Üçüncü Ergun1
1Department of Pediatric Nutrition and Metabolism Clinics, İstanbul Kanuni Sultan Süleyman Training and Research Hospital, İstanbul Turkey.
Abstract:
Scientific research continues on new preventive and therapeutic strategies against severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2). So far, there is no proven curative treatment, and a valid alternative therapeutic approach needs to be developed. This study is designed to evaluate the effect of quercetin in COVID-19 treatment. This was a single-centre, prospective randomized controlled cohort study. Routine care versus QCB (quercetin, vitamin C, bromelain) supplementation was compared between 429 patients with at least one chronic disease and moderate-to-severe respiratory symptoms. Demographic features, signs, laboratory results and drug administration data of patients were recorded. The endpoint was that QCB supplementation was continued throughout the follow-up period from study baseline to discharge, intubation, or death. The most common complaints at the time of hospital admission were fatigue (62.4%), cough (61.1%), anorexia (57%), thirst (53.7%), respiratory distress (51%) and chills (48.3%). The decrease in CRP and ferritin levels was higher in the QCB group (all Ps were < 0.05). In the QCB group, the increase in platelet and lymphocyte counts was higher (all Ps were < 0.05). QCB did not reduce the risk of events during follow-up. Adjustments for statistically significant parameters, including the lung stage, use of favipiravir and presence of comorbidity did not change the results. While there was no difference between the groups in terms of event frequency, the QCB group had more advanced pulmonary findings. QCB supplement is shown to have a positive effect on laboratory recovery. While there was no difference between the groups in terms of event frequency, QCB supplement group had more advanced pulmonar findings, and QCB supplement is shown to have a positive effect on laboratory recovery/results. Therefore, we conclude that further studies involving different doses and plasma level measurements are required to reveal the dose/response relationship and bioavailability of QCB for a better understanding of the role of QCB in the treatment of SARS CoV-2.
Insights
Quercetin, vitamin C, and bromelain (QCB) supplementation improved laboratory markers in COVID-19 patients but did not reduce clinical events or improve pulmonary findings. Further research is needed to clarify QCB
Area of Science:
- * Infectious Diseases
- * Pharmacology
- * Nutritional Science
Background:
- * Severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) infection lacks a definitive cure, necessitating exploration of alternative therapeutic strategies.
- * Existing treatments for COVID-19 are limited, highlighting the need for novel approaches to manage moderate-to-severe cases.
- * Quercetin, vitamin C, and bromelain (QCB) are compounds with potential anti-inflammatory and antiviral properties that warrant investigation in COVID-19 treatment.
Purpose of the Study:
- * To evaluate the therapeutic effect of QCB supplementation in patients with moderate-to-severe COVID-19.
- * To compare the outcomes of routine care versus QCB supplementation in a cohort of patients with chronic diseases.
- * To assess the impact of QCB on clinical symptoms, laboratory markers, and adverse events in COVID-19 patients.
Main Methods:
- * A single-centre, prospective randomized controlled cohort study involving 429 patients with SARS-CoV-2 infection.
- * Patients received either routine care or QCB (quercetin, vitamin C, bromelain) supplementation.
- * Data collected included demographic features, clinical signs, laboratory results, and drug administration, with follow-up until discharge, intubation, or death.
Main Results:
- * QCB supplementation led to a significantly greater decrease in C-reactive protein (CRP) and ferritin levels (P < 0.05).
- * Patients in the QCB group showed a significant increase in platelet and lymphocyte counts (P < 0.05).
- * Despite laboratory improvements, QCB did not reduce the frequency of clinical events or improve pulmonary findings; in fact, the QCB group had more advanced pulmonary issues.
Conclusions:
- * QCB supplementation demonstrates a positive effect on laboratory recovery in COVID-19 patients, indicated by improved inflammatory markers and blood cell counts.
- * QCB did not significantly alter the frequency of clinical events or improve pulmonary status in this cohort.
- * Further research is required to determine the optimal dosage, bioavailability, and dose-response relationship of QCB for SARS-CoV-2 treatment.
