Potential Clinical Benefits of Quercetin in the Early Stage of COVID-19: Results of a Second, Pilot, Randomized, Controlled and Open-Label Clinical Trial

Figures & data

Figure 1 Chemical structure of quercetin.

Figure 2 Flow Diagram of the study.

Table 1 Outpatients’ Sex, Age, Comorbidities, and Symptoms at Time of Enrollment

Group SC		Group QP	p
N	21	21	n. s.
Sex: Male/Female	10/11	10/11	n. s.
Age	56.2 ± 3.3	42.5 ± 3.3	0.0056
Comorbidities*
> 2	2	2	n. s.
> 1	5	4	n. s.
1	5	4	n. s.
0	9	11	n. s.
Symptoms
Fever	19	17	n. s.
Cough	12	11	n. s.
Myalgia	10	12	n. s.
Dyspnoea	3	3	n. s.
Sore throat	8	11	n. s.
Headache	0	1	n. s.
Flu-like	2	2	n. s.
Weakness	1	1	n. s.

Notes: Age is expressed as mean ± standard deviation; *Observed comorbidities were: hypertension, type 2 diabetes, heart disease, kidney disease, hypercholesterolemia, asthma/allergy.

Abbreviations: SC, standard care; QP, formulated quercetin (+Standard Care); n. s., not significant.

Table 2 Clinical Outcomes in the Two Groups

	Group SC	Group QP	p
RT-PCR (positive subjects)			0.0002
At enrollment	21/21 (100%)	21/21 (100%)
At day 7	19/21 (90.5%)	5/21 (24%)
At day 14	4/21 (19%)	0/21 (0%)
At day 21	0/20 (0%)	0/21 (0%)
Symptoms variation°			0.0118
Healed	4/21 (19%)	12/21 (57%)
Improved	17/21 (81%)	8/21 (38%)
Unchanged	0/21 (0%)	1/21 (5%)
CRP* (mg/L)			n. s.
At enrollment	30.5± 27.9	27.2 ± 27.0
Day 7	18.1± 22.9	12.3 ± 16.5
LDH* (U/L)			0.0001
At enrollment	364.9± 139.9	418.6 ± 192.9
Day 7	327.6± 128.9	270.0 ± 119.6
Ferritin* (ng/mL)			0.0029
At enrollment	687.8± 879.1	532.7 ± 264.9
Day 7	557.5± 642.6	319.7 ± 151.6
D-dimer* (ng/mL)			n. s.
At enrollment	282.0 ± 240.0	211.5 ± 65.7
Day 7	183.6 ± 111.8	186.3 ± 50.8
Hospitalized patients	1/21 (4.8%)	0/21 (0%)	n. s.
Patients in ICU	1/21 (4.8%)	0/21 (0%)	n. s.
Deaths	1/21 (4.8%)	0/21 (0%)	n. s.

Notes: °Regarding to symptoms, “healed” are those patients who manifest on Day 1 one or more symptoms, but no symptoms on Day 7; “improved” are those patients who show fewer symptoms on Day 7 than on Day 1; “unchanged” are those patients not affected, between the two periods, by variations in their symptoms’ frequency. *Values are expressed as mean ± standard deviation.

Abbreviations: SC, standard care; QP, formulated quercetin (+Standard Care); RT-PCR, real-time reverse-transcriptase polymerase chain reaction; LDH, lactate dehydrogenase; ICU, intensive care unit; n. s., not significant.