Quercetin Studied in COVID-19 Patients

Milan, Italy—Quercetin supplementation, in combination with standard care, could aid in improving the early conditions of COVID-19, and help prevent the severity of the SARS-CoV-2 infection, according to two new human studies. Quercetin also statistically shortens the timing of molecular test conversion from positive to negative. The studies were performed on Quercefit, a quercetin Phytosome ingredient, a branded product from Indena; the phospholipid delivery system used has been shown to increase oral absorption up to 20-fold.

Quercetin has broad-spectrum antiviral, antioxidant, anti-inflammatory, and immune-protective effects, according to a press release, making it a potential candidate to support conditions involving oxidative stress, inflammation, and immunity.

“We carried out a first prospective, randomized, controlled, and open-label study, in which in addition to standard care a daily dose of 1000mg of quercetin Phytosome was investigated for 30 days in 152 COVID-19 outpatients to disclose its adjuvant effect in treating the early symptoms and in preventing the severe outcomes of the disease,” said Ikram Ujjan, MBBX, Ph.D., Pro Vice Chancellor, Liaquat University of Medical and Health Sciences, Jamshoro, Pakistan. “According to the results of this clinical research, the add-on therapy with quercetin Phytosome has significantly reduced the need (-68.2%) and the length (-76.8%) of hospitalization, the need of non-invasive oxygen therapy (-93.3%), the progression to intensive care units (none versus eight subjects) and the number of deaths (none versus three subjects). Globally considered, using quercetin Phytosome as add-on therapy to standard care has reduced by 91.6% the days of hospitalization.”

The results of the first study led researchers to set up a second.

“In our two-week, randomized, open-label, controlled human study, we enrolled 42 COVID-19 outpatients,” explained Francesco Di Pierro, Scientific & Research Department, Velleja Research, Milan, Italy. “21 had been treated with the standard of care, and 21 with quercetin Phytosome as add-on supplementation. Our main aims were to check virus clearance and symptoms, and one of our primary endpoints was time needed to become negative at the RT-PCR for SARS-CoV-2. Our initial results demonstrated the beneficial role played by quercetin Phytosome after only one week of add-on supplementation. In particular, the use of quercetin Phytosome at the dose of 1500mg/day for one week followed using 1000mg/day for another week has demonstrated to significantly increase the clearance of the virus, reduce the symptoms occurrence, and improve disease biomarkers. An enlargement of this study is currently ongoing.”

Stefano Togni, Corporate Director for Business Development and Licensing at Indena S.p.A., commented: “As an Italian company, we are very proud to be part of such important international studies focused on a signature ingredient of Indena, such as quercetin Phytosome. This is another step of the work Indena has been committing to for 100 years, in order to support scientific research in the field of botanical active ingredients. The company’s continuous investment in innovation and design of proprietary technologies for the quality, safety, and efficacy of ingredients, are the pillars on which Indena has built its leadership in the botanical sector as well as its inspiration for the future business.”