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Quercetin for COVID-19
11 studies from 109 scientists
1,436 patients in 7 countries
Statistically significant lower risk for ICU, hospitalization, recovery, cases, and viral clearance.
43% lower risk in 10 RCTs CI 16-62%
Studies typically use advanced formulations for greatly improved bioavailability.
COVID-19 Quercetin studies. Jun 2024.
0 0.5 1 1.5+ All studies 49% With exclusions 41% Mortality 61% Hospitalization 48% Recovery 34% Cases 93% Viral clearance 56% RCTs 43% RCT mortality 61% Prophylaxis 93% Early 32% Late 34% Favorsquercetin Favorscontrol
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Quercetin was adopted in part of 1 country. Submit updates/corrections. Summary.
Jun 13
Covid Analysis Quercetin for COVID-19: real-time meta analysis of 11 studies
Statistically significant lower risk is seen for ICU admission, hospitalization, recovery, cases, and viral clearance. 10 studies from 8 independent teams in 7 countries show significant improvements. Meta analysis using the most serious ..
May 25
Beşler et al., Clinical Science of Nutrition, doi:10.62210/ClinSciNutr.2024.86 Investigation of potential effects of quercetin on COVID-19 treatment: a systematic review of randomized controlled trials
Systematic review of RCTs investigating quercetin for COVID-19. Five studies with a total of 803 participants were included. Authors found that quercetin treatment led to reductions in cases, viral persistence, hospitalization, oxygen req..
May 15
Irfan et al., BMC Infectious Diseases, doi:10.1186/s12879-024-09387-w Phytoconstituents of Artemisia Annua as potential inhibitors of SARS CoV2 main protease: an in silico study
In Silico study showing that quercetin binds strongly to the SARS-CoV-2 main protease (Mpro) and may be a potential inhibitor of viral replication. Authors screened 25 compounds from Artemisia annua and found that quercetin had one of the..
Apr 30
Ho et al., Heliyon, doi:10.1016/j.heliyon.2024.e30080 Therapeutic Implications of Quercetin and its Derived-products in COVID-19 Protection and Prophylactic
Review of quercetin and its derivatives for prevention and treatment of COVID-19. Authors discuss molecular docking evidence showing quercetin and its derivatives can bind to multiple SARS-CoV-2 proteins including the main protease, spike..
Apr 26
Nalban et al., Journal of Proteins and Proteomics, doi:10.1007/s42485-024-00136-w Targeting COVID-19 (SARS-CoV-2) main protease through phytochemicals of Albizia lebbeck: molecular docking, molecular dynamics simulation, MM–PBSA free energy calculations, and DFT analysis
In Silico study showing potential benefits of quercetin and other phytochemicals from Albizia lebbeck as SARS-CoV-2 main protease (Mpro) inhibitors. Using molecular docking, the authors identified four promising compounds: vicenin 2, myri..
Apr 24
Manca et al., Viruses, doi:10.3390/v16050665 Exploring the Antiviral Potential of Esters of Cinnamic Acids with Quercetin
In Vitro study showing that esters of cinnamic acids with quercetin, particularly ester 7, inhibit SARS-CoV-2 and hCoV-OC43 coronavirus infection in Vero-76 and Vero E6 cells. Mechanism of action studies suggest ester 7 may inhibit corona..
Apr 22
Zhou et al., PLOS ONE, doi:10.1371/journal.pone.0300441 Bioinformatics and system biology approaches to determine the connection of SARS-CoV-2 infection and intrahepatic cholangiocarcinoma
In Silico study suggesting that quercetin and tetrandrine are potential treatments for COVID-19 and intrahepatic cholangiocarcinoma (ICC). Authors identify 70 shared differentially expressed genes between COVID-19 and ICC, indicating simi..
Apr 16
Mohebbi et al., PLOS ONE, doi:10.1371/journal.pone.0298201 In silico study of alkaloids with quercetin nucleus for inhibition of SARS-CoV-2 protease and receptor cell protease
In Silico study showing that the alkaloids with a quercetin nucleus may inhibit SARS-CoV-2 infection by binding to the main protease (Mpro) and the host cell protease TMPRSS2. Molecular docking analysis found three compounds, Phyllospadin..
Apr 13
Vaiss et al., European Journal of Pharmaceutical Sciences, doi:10.1016/j.ejps.2024.106766 Curcumin and quercetin co-encapsulated in nanoemulsions for nasal administration: a promising therapeutic and prophylactic treatment for viral respiratory infections
In Vitro and Ex Vivo study showing that curcumin and quercetin co-encapsulated in nanoemulsions (NEs) for nasal administration inhibited murine β-coronavirus (MHV-3) infection. MHV-3 belongs to the same family as SARS-CoV-2. Authors found..
Apr 12
Fang et al., Journal of Nanobiotechnology, doi:10.1186/s12951-024-02435-2 Development of nanoparticles incorporated with quercetin and ACE2-membrane as a novel therapy for COVID-19
In Vitro study showing that nanoparticles coated with both ACE2-containing cell membranes and quercetin (CM-NP-Q) inhibit SARS-CoV-2 infection in human lung cells. Authors developed nanoparticles incorporated with quercetin (NP-Q), ACE2-c..
Apr 5
Waqas et al., Current Medicinal Chemistry, doi:10.2174/0109298673292839240329081008 Discovery of Novel Natural Inhibitors Against SARS-CoV-2 Main Protease: A Rational Approach to Antiviral Therapeutics
In Silico and In Vitro study showing potential inhibition of SARS-CoV-2 main protease (Mpro) by quercetin and four other natural compounds isolated from medicinal plants. Authors used molecular docking, molecular dynamics simulations, and..
Mar 18
Vajdi et al., Pharmacological Reports, doi:10.1007/s43440-024-00585-6 Effect of polyphenols against complications of COVID-19: current evidence and potential efficacy
Review of polyphenols for COVID-19. Authors note that polyphenols can inhibit key SARS-CoV-2 enzymes involved in viral replication and infection, and that many polyphenols have well-established safety profiles. Authors recommend additiona..
Mar 13
Chen et al., Phytotherapy Research, doi:10.1002/ptr.8175 Effect and mechanism of quercetin or quercetin‐containing formulas against COVID‐19: From bench to bedside
Review of quercetin and quercetin-containing formulas for COVID-19. Quercetin exhibits antiviral, anti-inflammatory, immunomodulatory, antioxidative, and antithrombotic effects relevant to COVID-19, with strong preclinical evidence. Autho..
Mar 7
Hasanah et al., International Journal of Applied Pharmaceutics, doi:10.22159/ijap.2024v16i2.50128 Decoding the therapeutic potential of empon-empon: a bioinformatics expedition unraveling mechanisms against COVID-19 and atherosclerosis
In Silico study of compounds in empon-empon showing that quercetin may be beneficial for treating COVID-19 and atherosclerosis by inhibiting key signaling targets. Authors found that quercetin exhibits strong binding affinity to EP300 and..
Feb 29
Yong et al., International Journal of Nanomedicine, doi:10.2147/ijn.s451206 Natural Products-Based Inhaled Formulations for Treating Pulmonary Diseases
Review of nanoformulations for inhaled therapeutics for respiratory diseases including potential for COVID-19. Inhaled formulations deliver treatment directly to both the upper and lower respiratory tract, enabling higher local concentrat..
Feb 28
Shaik et al., Indian Drugs, doi:10.53879/id.61.02.13859 Computational identification of selected bioactive compounds from Cedrus deodara as inhibitors against SARS-CoV-2 main protease: a pharmacoinformatics study
In Silico study showing that quercetin binds strongly to the SARS-CoV-2 main protease (Mpro). Authors found that out of 49 phytoconstituents from Cedrus deodara, quercetin exhibited the lowest binding energy of approximately -7.2 kcal/mol..
Jan 29
Singh et al., Research Square, doi:10.21203/ Unlocking the potential of phytochemicals in inhibiting SARS-CoV-2 M Pro protein - An in-silico and cell-based approach
In Silico and In Vitro study including quercetin and curcumin derivatives as potential SARS-CoV-2 main protease (Mpro) inhibitors. Molecular dynamics simulations and virtual screening identified quercetin and curcumin derivatives demethox..
Jan 26
Silva et al., Observatório de la Economía Latinoamericana, doi:10.55905/oelv22n1-192 Therapeutic and prophylactic effects of quercetin in the treatment of Covid-19: a systematic review
Systematic review of 8 RCTs showing faster recovery, faster viral clearance, and fewer COVID-19 cases with quercetin. Quercetin was well tolerated with no significant adverse events.
Jan 25
Roy et al., Virology Journal, doi:10.1186/s12985-024-02299-w Quercetin inhibits SARS-CoV-2 infection and prevents syncytium formation by cells co-expressing the viral spike protein and human ACE2
In Vitro study showing inhibition of SARS-CoV-2 infection and syncytium formation by quercetin in Vero E6 and Caco-2 cells at 100-400μM concentrations. Authors found that quercetin prevented the proteolytic processing of the SARS-CoV-2 sp..
Jan 9
Agrawal et al., Natural Product Communications, doi:10.1177/1934578X231219560 Antiviral Significance of Isoquercetin (Quercetin-3-O-Glucoside) With Special Reference to its Anti-Coronaviral Potential
Review of the broad-spectrum antiviral significance of isoquercetin (quercetin-3-O-glucoside), focusing on SARS-CoV-2. Authors describe evidence from many studies showing inhibitory effects of isoquercetin on several stages of the viral l..
Jan 2
El-Megharbel et al., PeerJ, doi:10.7717/peerj.15638 Chemical and spectroscopic characterization of (Artemisinin/Quercetin/ Zinc) novel mixed ligand complex with assessment of its potent high antiviral activity against SARS-CoV-2 and antioxidant capacity against toxicity induced by acrylamide in male rats
In Vitro and animal study showing that a novel artemisinin/quercetin/zinc (Art/Q/Zn) complex exhibits potent anti-SARS-CoV-2 activity (IC50 = 10.14 μg/ml) without cytotoxicity (CC50 = 208.5 μg/ml). The complex alleviates acrylamide-induce..
Dec 26
Matías-Pérez et al., Frontiers in Nutrition, doi:10.3389/fnut.2023.1278039 Relationship of quercetin intake and oxidative stress in persistent Covid
Discussion of the potential of quercetin for persistent COVID-19 symptoms resulting from oxidative stress. Authors explain how COVID-19 leads to oxidative stress through inflammation, cytokine storms, and coagulation abnormalities. Querce..
Dec 17
Georgiou et al., Molecules, doi:10.3390/molecules28248141 Quercetin: A Potential Polydynamic Drug
Review of the biological and medicinal properties of quercetin, particularly its anti-inflammatory, antioxidant, anti-tumor, and antiviral effects. Quercetin demonstrates promise against SARS-CoV-2 as evidenced by its binding interactions..
Dec 12
Dinda et al., European Journal of Medicinal Chemistry Reports, doi:10.1016/j.ejmcr.2023.100125 Anti-SARS-CoV-2, antioxidant and immunomodulatory potential of dietary flavonol quercetin: Focus on molecular targets and clinical efficacy
Review of the antiviral, antioxidant, and anti-inflammatory properties of the flavonoid quercetin and its glycosides. Authors review their ability to inhibit infections of SARS-CoV-2 and other coronaviruses by interfering with viral entry..
Dec 11
Akinwumi et al., Egyptian Journal of Medical Human Genetics, doi:10.1186/s43042-023-00456-4 Evaluation of therapeutic potentials of some bioactive compounds in selected African plants targeting main protease (Mpro) in SARS-CoV-2: a molecular docking study
In Silico study showing potential antiviral benefits of quercetin, catechin, epicatechin, vitexin, kaempferol, gamma-sitosterol, and kaur-16-ene against the SARS-CoV-2 main protease (Mpro). Molecular docking analysis showed that these com..
Dec 1
Yang et al., Medicine, doi:10.1097/MD.0000000000036238 Active ingredient and mechanistic analysis of traditional Chinese medicine formulas for the prevention and treatment of COVID-19: Insights from bioinformatics and in vitro experiments
Analysis of TCM treatments for COVID-19 including In Silico and In Vitro analysis of quercetin, a common ingredient in TCM treatments. Results suggest that quercetin may help alleviate COVID-19-associated inflammation by reducing levels o..
Nov 30
Chandran et al., Bioinformation, doi:10.6026/973206300191081 Molecular docking analysis of quercetin with known CoVid-19 targets
In Silico analysis of quercetin for COVID-19. Molecular docking simulations suggest quercetin may bind more strongly than remdesivir to SARS-CoV-2 targets including ACE2, the spike protein, and some host proteins involved in viral entry. ..
Nov 28
Zheng et al., Virology Journal, doi:10.1186/s12985-023-02144-6 Effects of Lianhuaqingwen Capsules in adults with mild-to-moderate coronavirus disease 2019: an international, multicenter, double-blind, randomized controlled trial
39% improved recovery (p<0.0001) and 11% improved viral clearance (p=0.21). RCT 815 mild-to-moderate COVID-19 patients in China, 410 treated with Lianhuaqingwen (LHQW) for 14 days, showing improved recovery with treatment. 86.8% of the LHQW group achieved symptom resolution by day 14 compared to 71.9% for placebo..
Nov 23
DiGuilio et al., Frontiers in Cell and Developmental Biology, doi:10.3389/fcell.2023.1271201 Quercetin improves and protects Calu-3 airway epithelial barrier function
In Vitro analysis of quercetin on airway epithelial barrier function using the Calu-3 cell culture model. Results show that quercetin increases transepithelial electrical resistance and decreases transepithelial leaks, indicating improved..
Nov 20
Mirza et al., Pharmaceuticals, doi:10.3390/ph16111631 Quercetin as a Therapeutic Product: Evaluation of Its Pharmacological Action and Clinical Applications—A Review
Review of the pharmacological actions, clinical trials, patents, marketed products, and approaches to improving the bioavailability of the flavonoid quercetin. Quercetin has shown therapeutic potential as an antioxidant, anti-inflammatory..
Nov 11
Qin et al., Medical Data Mining, doi:10.53388/MDM202407003 Exploring the bioactive compounds of Feiduqing formula for the prevention and management of COVID-19 through network pharmacology and molecular docking
In Silico study of components of Feiduqing finding that quercetin, among other compounds, has significant binding affinity to PTGS2, HSP90AA1, SARS-CoV-2 Mpro, and ACE2, suggesting that quercetin may have therapeutic potential for COVID-1..
Nov 10
Zhang et al., Journal of Medical Virology, doi:10.1002/jmv.29208 Discovery of the covalent SARS‐CoV‐2 Mpro inhibitors from antiviral herbs via integrating target‐based high‐throughput screening and chemoproteomic approaches
In Vitro study showing that quercetin can potently inhibit SARS-CoV-2 Mpro activity. Screening of 60 antiviral herbs showed Lonicera japonica extract inhibited Mpro in a time-dependent manner, indicating the presence of covalent cysteine-..
Nov 3
Wu et al., Frontiers in Immunology, doi:10.3389/fimmu.2023.1264447 SARS-CoV-2 N protein induced acute kidney injury in diabetic db/db mice is associated with a Mincle-dependent M1 macrophage activation
In Vitro and mouse study showing that quercetin may ameliorate COVID-19 associated acute kidney injury through modulation of macrophage polarization by blocking the Mincle/Syk/NF-kB pathway. Authors suggest that the SARS-CoV-2 N protein c..
Nov 2
Moschovou et al., International Journal of Molecular Sciences, doi:10.3390/ijms242115894 Exploring the Binding Effects of Natural Products and Antihypertensive Drugs on SARS-CoV-2: An In Silico Investigation of Main Protease and Spike Protein
In Silico molecular docking and molecular dynamics analysis identifying curcumin, quercetin, rosmarinic acid, and salvianolic acid B as having favorable binding to Mpro and three distinct sites on the S protein. Molecular dynamics simulat..
Oct 17
Pan et al., Computational and Structural Biotechnology Journal, doi:10.1016/j.csbj.2023.10.029 Quercetin: A promising drug candidate against the potential SARS-CoV-2-Spike mutants with high viral infectivity
In Silico and In Vitro study of quercetin showing inhibition of SARS-CoV-2 for wildtype and 6 different variants. Molecular docking and dynamics simulation analyses showed that quercetin binds in a cavity at the spike-ACE2 interface, sugg..
Oct 6
Ahmed et al., International Journal of Diabetes Management, doi:10.61797/ijdm.v2i2.259 Evaluation of the Effect of Zinc, Quercetin, Bromelain and Vitamin C on COVID-19 Patients
Case series of 22 hospitalized COVID-19 patients showing that a combination of quercetin 800mg, bromelain 165mg, zinc acetate 50mg and vitamin C 1g daily for 3-5 days was safe when given with other treatments. Authors include In Silico mo..
Sep 26
Ziaei et al., Food Science & Nutrition, doi:10.1002/fsn3.3715 The effect of quercetin supplementation on clinical outcomes in COVID‐19 patients: A systematic review and meta‐analysis
Systematic review and meta analysis of 5 studies, showing significantly lower mortality, ICU admission, and hospitalization with quercetin treatment.
Sep 19
Thapa et al., Makara Journal of Science, doi:10.7454/mss.v27i3.1609 In-silico Approach for Predicting the Inhibitory Effect of Home Remedies on Severe Acute Respiratory Syndrome Coronavirus-2
In Silico analysis showing that curcumin and quercetin may be beneficial for COVID-19 by binding to the main protease (Mpro), spike protein, and ACE2 receptor. Both compounds had suitable ADME properties and minimal predicted toxicity.
Sep 5
Xu et al., Proceedings of the National Academy of Sciences, doi:10.1073/pnas.2309870120 Reply to Yan et al.: Quercetin possesses a fluorescence quenching effect but is a weak inhibitor against SARS-CoV-2 main protease
In Vitro study [Yan] and associated response from the original authors [Xu], collectively showing that quercetin and echinatin had weak SARS-CoV-2 protease inhibition in SDS-PAGE assays [Xu], despite false positive FRET results from MCA-A..
Sep 5
Yan et al., Proceedings of the National Academy of Sciences, doi:10.1073/pnas.2309289120 Reframing quercetin as a promiscuous inhibitor against SARS-CoV-2 main protease
In Vitro study [Yan] and associated response from the original authors [Xu], collectively showing that quercetin and echinatin had weak SARS-CoV-2 protease inhibition in SDS-PAGE assays [Xu], despite false positive FRET results from MCA-A..
Sep 1
Shaker et al., Iranian Journal of Medical Sciences, doi:10.30476/ijms.2023.98947.3102 Anti-cytokine Storm Activity of Fraxin, Quercetin, and their Combination on Lipopolysaccharide-Induced Cytokine Storm in Mice: Implications in COVID-19
Mouse study showing benefit with quercetin for COVID-19 treatment by reducing proinflammatory cytokines and protecting lung and kidney tissues against lipopolysaccharide-induced damage. Lipopolysaccharide is used to induce cytokine storm ..
Aug 25
Alkafaas et al., Virology Journal, doi:10.1186/s12985-023-02160-6 A study on the effect of natural products against the transmission of B.1.1.529 Omicron
Review of natural products for SARS-CoV-2 omicron including an In Silico study showing quercetin, curcumin, ascorbic acid, nigellidine, and chloroquine among many compounds docked to the ACE2 metallopeptidase domain. Quercetin, curcumin, ..
Aug 25
Singh et al., Middle East Research Journal of Pharmaceutical Sciences, doi:10.36348/merjps.2023.v03i04.001 Flavonoids as Potent Inhibitor of SARS-CoV-2 Nsp13 Helicase: Grid Based Docking Approach
In Silico analysis molecular docking analysis predicting that quercetin, rutin, isorhamnetin, and tamarixetin bind well with SARS-CoV-2 Nsp13 helicase enzyme. The proposed mechanism of action is that these flavonoids can inhibit the ATPas..
Aug 3
Micek et al., Frontiers in Nutrition, doi:10.3389/fnut.2023.1241016 Association of dietary intake of polyphenols, lignans, and phytosterols with immune-stimulating microbiota and COVID-19 risk in a group of Polish men and women
Dietary analysis of 95 adults in Poland, showing lower risk of COVID-19 with higher intake of polyphenols, lignans, and phytosterols. Results were statistically significant for total phytosterols, secoisolariciresinol, β-sitosterol, matai..
Jul 13
Mandal et al., Journal of Traditional and Complementary Medicine, doi:10.1016/j.jtcme.2023.07.004 In silico anti-viral assessment of phytoconstituents in a traditional (Siddha Medicine) polyherbal formulation – Targeting Mpro and pan-coronavirus post-fusion Spike protein
In Silico analysis of phytoconstituents of Kabasura Kudineer against SARS-CoV-2 spike protein and Mpro, showing that quercetin (Mpro) and gallic acid (spike) had the highest binding affinity and stability.
Jun 30
Sai Ramesh et al., International Journal of Biological Macromolecules, doi:10.1016/j.ijbiomac.2023.125553 Computational analysis of the phytocompounds of Mimusops elengi against spike protein of SARS CoV2 – An Insilico model
In Silico study finding that quercetin and hederagenin showed very high binding affinities for COVID-19 associated receptors MMP9 and IL6.
Jun 22
Gérain et al., Frontiers in Nutrition, doi:10.3389/fnut.2023.1137407 NASAFYTOL® supplementation in adults hospitalized with COVID-19 infection: results from an exploratory open-label randomized controlled trial
91% lower combined mortality/ICU admission (p=0.02), 89% lower ventilation (p=0.05), 89% lower ICU admission (p=0.05), and 73% higher hospital discharge (p=0.07). RCT 49 hospitalized COVID-19 patients, 25 treated with curcumin and quercetin, shower lower mortality/ICU admission and improved recovery with treatment. All patients received vitamin D. 336mg curcumin, 520mg quercetin, and 18μg vitamin D..
Jun 3
Corbo et al., Biotechnology & Biotechnological Equipment, doi:10.1080/13102818.2023.2222196 Inhibitory potential of phytochemicals on five SARS-CoV-2 proteins: in silico evaluation of endemic plants of Bosnia and Herzegovina
In Silico study of phytochemicals from 28 plants identifying hesperidin and quercetin as having the highest binding affinity for SARS-CoV-2 RdRp. The highest affinity for Mpro was observed for genistein and hesperidin, with both compounds..
Jun 2
Azmi et al., 11th International Seminar on New Paradigm and Innovation on Natural Sciences and its Application, doi:10.1063/5.0140285 Utilization of quercetin flavonoid compounds in onion (Allium cepa L.) as an inhibitor of SARS-CoV-2 spike protein against ACE2 receptors
In Silico study showing high affinity binding between the SARS-CoV-2 spike protein and quercetin, and analysis of the quercetin content of onion.
Jun 1
Alanzi et al., Future Virology, doi:10.2217/fvl-2022-0184 Structure-based virtual identification of natural inhibitors of SARS-CoV-2 and its Delta and Omicron variant proteins
In Silico study showing the flavonoid quercetin and its derivative quercetin-3-acetyl-glucoside exhibit potential inhibitory activity against SARS-CoV-2 main protease, helicase, and spike proteins. Related flavonoids like rutin and kaempf..
May 18
Yang et al., Frontiers in Pharmacology, doi:10.3389/fphar.2023.1188086 In silico evidence implicating novel mechanisms of Prunella vulgaris L. as a potential botanical drug against COVID-19-associated acute kidney injury
In Silico study identifying quercetin, luteolin and kaempferol as potentially protective for COVID-19 acute kidney injury.
May 15
Massimo Magro et al., Journal of Modern Biology and Drug Discovery, doi:10.53964/jmbdd.2023004 Use of Quercetin for Therapeutic Purposes in COVID-19 Infections: The Opinion of the Geriatrician Doctor
Review of the antiviral properties and potential benefits of quercetin for COVID-19.
Apr 24
Xu et al., Proceedings of the National Academy of Sciences, doi:10.1073/pnas.2301775120 Bioactive compounds from Huashi Baidu decoction possess both antiviral and anti-inflammatory effects against COVID-19
In Vitro study of compounds from Huashi Baidu (Q-14), showing dose-dependent inhibition of SARS-CoV-2 with quercetin. Authors also perform a mouse study showing that Q-14 decreases SARS-CoV-2 viral load and reduces pulmonary inflammation...
Mar 31
Wang et al., Society of Toxicology Conference, 2023 Computational Analysis of Lianhua Qingwen as an Adjuvant Treatment in Patients with COVID-19
In Silico analysis of components of Lianhua Qingwen, identifying quercetin, luteolin, wogonin, and phillyrin as potentially beneficial for COVID-19. Authors note that quercetin bound to Mpro at the same inhibitory pocket as nirmatrelvir (..
Mar 22
Ibeh et al., Informatics in Medicine Unlocked, doi:10.1016/j.imu.2023.101230 Computational studies of potential antiviral compounds from some selected Nigerian medicinal plants against SARS-CoV-2 proteins
In Silico study identifying quercetin and naringenin as potent multitarget-directed ligands for 3CLpro, PLpro, and ACE2 with favorable ADME properties.
Feb 13
Cheema et al., Reviews in Medical Virology, doi:10.1002/rmv.2427 Quercetin for the treatment of COVID-19 patients: A systematic review and meta-analysis
Systematic review and meta analysis of 6 quercetin RCTs, showing significantly lower hospitalization and ICU admission. Differences for mortality and recovery were not statistically significant.
Jan 26
Pastor-Fernández et al., Aging Cell, doi:10.1111/acel.13771 Treatment with the senolytics dasatinib/quercetin reduces SARS-CoV-2 related mortality in mice
K18-hACE2 mouse study showing reduced COVID-19 severity with quercetin and dasatinib, for both prophylaxis and early treatment.
Jan 25
Turobkulovich et al., Emergent: Journal of Educational Discoveries and Lifelong Learning Applications of quercetin for the prevention of COVID-19 in healthcare workers
96% lower mortality (p<0.0001) and 98% fewer symptomatic cases (p<0.0001). Prospective study of healthcare workers in Uzbekistan showing lower mortality and cases with quercetin prophylaxis. Very minimal details are provided, there is no baseline information, and control mortality is very high.
Jan 18
Aguado et al., bioRxiv, doi:10.1101/2023.01.17.524329 Senolytic therapy alleviates physiological human brain aging and COVID-19 neuropathology
In Vitro and animal study showing that senolytics including dasatinib + quercetin improve survival and mitigate neuropathological sequelae of SARS-CoV-2. Authors show that SARS-CoV-2 can initiate cellular senescence in the brains of COVID..
Jan 18
Din Ujjan et al., Frontiers in Nutrition, doi:10.3389/fnut.2022.1023997 The possible therapeutic role of curcumin and quercetin in the early-stage of COVID-19—Results from a pragmatic randomized clinical trial
29% improved recovery (p=0.11) and 91% improved viral clearance (p=0.05). Small RCT with 50 outpatients, 25 treated with curcumin, quercetin, and vitamin D, showing improved recovery and viral clearance with treatment. 168mg curcumin, 260mg, 360IU vitamin D3 daily for 14 days.
Jan 17
Shorobi et al., Molecules, doi:10.3390/molecules28030938 Quercetin: A Functional Food-Flavonoid Incredibly Attenuates Emerging and Re-Emerging Viral Infections through Immunomodulatory Actions
Review of the antiviral properties of quercetin and derivatives, and potential mechanisms of action.
Jan 16
Viglione et al., The Gazette of Medical Sciences, doi:10.46766/thegms.pubheal.22120905 Intravenous high dose vitamin C and ozonated saline effective treatment for Covid -19: The Evolution of Local Standard of Care
Retrospective 479 high risk outpatients in the USA treated with a protocol including intravenous vitamin C, vitamin D, zinc, quercetin, bromelain, lactoferrin, HCQ, ivermectin, ozonated saline, azithromycin, ceftriaxone, methylprednisolon..
Jan 13
Di Pierro et al., Frontiers in Pharmacology, doi:10.3389/fphar.2022.1096853 Quercetin as a possible complementary agent for early-stage COVID-19: Concluding results of a randomized clinical trial
37% improved recovery (p=0.007) and 58% improved viral clearance (p<0.0001). RCT 100 outpatients in Pakistan, 50 treated with quercetin phytosome, showing faster viral clearance and improved recovery with treatment. Patients in the treatment group were significantly younger (41 vs. 54).
Jan 12
Nguyen et al., Bioinformatics and Biology Insights, doi:10.1177/11779322221149622 The Potential of Ameliorating COVID-19 and Sequelae From Andrographis paniculata via Bioinformatics
In Silico study identifying multiple compounds including andrographolide, quercetin, and hydroxychloroquine (used as a reference) as promising inhibitors of SARS-CoV-2. Authors note the potential synergistic effect of multiple compounds.
Dec 12
Wu et al., Molecular Therapy, doi:10.1016/j.ymthe.2022.12.002 Treatment with Quercetin inhibits SARS-CoV-2 N protein-induced acute kidney injury by blocking Smad3-dependent G1 cell cycle arrest
Mouse study showing quercetin can significantly inhibit SARS-CoV-2 induced acute kidney injury via blocking of SARS-CoV-2 N-Smad3-mediated cell death.
Nov 29
Alavi et al., Biomedicines, doi:10.3390/biomedicines10123074 Interaction of Epigallocatechin Gallate and Quercetin with Spike Glycoprotein (S-Glycoprotein) of SARS-CoV-2: In Silico Study
In Silico study suggesting efficacy of epigallocatechin gallate and quercetin for SARS-CoV-2.
Oct 18
Cosentino et al., Journal of Clinical Medicine, doi:10.3390/jcm11206138 Early Outpatient Treatment of COVID-19: A Retrospective Analysis of 392 Cases in Italy
Retrospective 392 outpatients in Italy showing 0.2% mortality with early treatment, compared with >3% in Italy at the time. Treatment varied for individual patients and included HCQ, vitamin D, vitamin C, vitamin A, zinc, quercetin, bromh..
Aug 25
Gasmi et al., Pharmaceuticals, doi:10.3390/ph15091049 Quercetin in the Prevention and Treatment of Coronavirus Infections: A Focus on SARS-CoV-2
Review of the potential benefits of quercetin for COVID-19, including inhibitory effects on several stages of the viral life cycle, antioxidant, anti-inflammatory, and immunomodulatory effects, and synergistic effects with other treatments.
Aug 10
Chellasamy et al., Journal of King Saud University - Science, doi:10.1016/j.jksus.2022.102277 Docking and molecular dynamics studies of human ezrin protein with a modelled SARS-CoV-2 endodomain and their interaction with potential invasion inhibitors
In Silico study of SARS-CoV-1&2 endodomains and ezrin docking, identifying ivermectin, quercetin, calcifediol, calcitriol, selamectin, and minocycline as potential therapeutic drugs with strong ezrin binding which may restrict viral endod..
Jun 16
Ortore et al., International Journal of Translational Medicine, doi:10.3390/ijtm2020022 Evaluation of the Clinical Effects of an Antiviral, Immunostimulant and Antioxidant Phytotherapy in Patients Suffering from COVID-19 Infection: An Observational Pilot Study
Retrospective case series of 240 patients in Italy in 2020, up to 96 years old, showing no mortality and 1.6% hospitalization with early treatment including vitamin C, quercetin, and green tea and red wine polyphenols. The formulation was..
May 20
Shah et al., medRxiv, doi:10.1101/2022.05.16.22275074 Jinhua Qinggan Granules for Nonhospitalized COVID-19 Patients: a Double-Blind, Placebo-Controlled, Randomized Controlled Trial
81% greater improvement (p<0.0001) and 8% worse viral clearance (p=0.48). RCT 300 outpatients in China, showing improved recovery with Jinhua Qinggan treatment, but no significant difference in viral clearance or radiographic findings. Jinhua Qinggan includes quercetin, rutin, luteolin, wogonin, myricetin, urso..
May 15
Rizky et al., Life Research, doi:10.53388/life2022-0205-302 The pharmacological mechanism of quercetin as adjuvant therapy of COVID-19
Review of in silico and clinical evidence supporting the use of quercetin for COVID-19.
May 1
Khan et al., Frontiers in Pharmacology, doi:10.3389/fphar.2022.898062 Oral Co-Supplementation of Curcumin, Quercetin, and Vitamin D3 as an Adjuvant Therapy for Mild to Moderate Symptoms of COVID-19—Results From a Pilot Open-Label, Randomized Controlled Trial
33% improved recovery (p=0.15) and 50% improved viral clearance (p=0.009). RCT 50 COVID+ outpatients in Pakistan, 25 treated with curcumin, quercetin, and vitamin D, showing significantly faster viral clearance, significantly improved CRP, and faster resolution of acute symptoms (p=0.154). 168mg curcumin, 260mg ..
Apr 29
Imran et al., Antioxidants, doi:10.3390/antiox11050876 The Therapeutic and Prophylactic Potential of Quercetin against COVID-19: An Outlook on the Clinical Studies, Inventive Compositions, and Patent Literature
Review of the evidence supporting the use of quercetin for COVID-19 from clinical studies and patents.
Jan 21
Goc et al., European Journal of Microbiology and Immunology, doi:10.1556/1886.2021.00022 Inhibitory effects of specific combination of natural compounds against SARS-CoV-2 and its Alpha, Beta, Gamma, Delta, Kappa, and Mu variants
In Vitro study testing combinations of plant extracts and micronutrients with several variants of SARS-CoV-2. A combination of vitamin C, N-acetylcysteine, curcumin, quercetin, resveratrol, theaflavin, naringenin, baicalin, and broccoli e..
Jan 4
Rondanelli et al., Life, doi:10.3390/life12010066 Promising Effects of 3-Month Period of Quercetin Phytosome® Supplementation in the Prevention of Symptomatic COVID-19 Disease in Healthcare Workers: A Pilot Study
93% fewer symptomatic cases (p=0.04). RCT 120 healthcare workers, 60 treated with quercetin phytosome, showing lower risk of cases with treatment. Quercetin phytosome 250mg twice a day.
Dec 28
Munafò et al., Research Square, doi:10.21203/ Quercetin and Luteolin Are Single-digit Micromolar Inhibitors of the SARS-CoV-2 RNA-dependent RNA Polymerase
In Vitro and In Silico study showing quercetin and luteolin inhibiting SARS-CoV-2 RNA-dependent RNA polymerase (RdRp).
Dec 14
Singh et al., Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease, doi:10.1016/j.bbadis.2021.166322 The spike protein of SARS-CoV-2 virus induces heme oxygenase-1: Pathophysiologic implications
In Vitro study transfecting SARS-CoV-2 viral spike protein in kidney cell lines, showing syncytia formation and upregulation of the cytoprotective gene HO-1, and that quercetin, which induces HO-1, can reduce syncytia formation. Authors c..
Dec 8
Fazio et al., Medical Science Monitor, doi:10.12659/MSM.935379 Retrospective Study of Outcomes and Hospitalization Rates of Patients in Italy with a Confirmed Diagnosis of Early COVID-19 and Treated at Home Within 3 Days or After 3 Days of Symptom Onset with Prescribed and Non-Prescribed Treatments Between November 2020 and August 2021
Retrospective 158 COVID-19 patients in Italy treated with hesperidin, quercetin, indomethacin, aspirin, omeprazole, azithromycin, LMWH, and betamethasone (treatment specific for each patient), showing significantly lower hospitalization a..
Dec 2
Shohan et al., European Journal of Pharmacology, doi:10.1016/j.ejphar.2021.1746158 The therapeutic efficacy of quercetin in combination with antiviral drugs in hospitalized COVID-19 patients: A randomized controlled trial
86% lower mortality (p=0.24) and 32% faster recovery (p=0.04). Small RCT with 60 severe hospitalized patients in Iran, 30 treated with quercetin, showing shorter time until discharge. All patients received remdesivir or favipiravir, and vitamin C, vitamin D, famotidine, zinc, dexamethasone, and magne..
Nov 14
Bahun et al., Food Chemistry, doi:10.1016/j.foodchem.2021.131594 Inhibition of the SARS-CoV-2 3CLpro main protease by plant polyphenols
In Silico and In Vitro study of plant polyphenols identifying quercetin, curcumin, ellagic acid, epigallocatechin gallate, and resveratrol as SARS-CoV-2 3CLpro inhibitors with IC50 between 11.8µM and 23.4µM. Real-time binding was analyzed..
Sep 29
Şimşek et al., Journal of Molecular Graphics and Modelling, doi:10.1016/j.jmgm.2021.108038 In silico identification of SARS-CoV-2 cell entry inhibitors from selected natural antivirals
In Silico study identifying quercetin derivatives as SARS-CoV-2 spike protein, ACE2, and neuropilin inhibitors.
Sep 1
Zupanets et al., Zaporozhye Med. J., doi:10.14739/2310-1210.2021.5.231714 Quercetin effectiveness in patients with COVID-19 associated pneumonia
29% improved recovery (p=0.5). RCT 200 patients in Ukraine, 99 treated with IV quercetin/polyvinylirolidone followed by oral quercetin/pectin, showing improved recovery with treatment.
Jul 6
Margolin et al., Journal of Evidence-Based Integrative Medicine, doi:10.1177/2515690X211026193 20-Week Study of Clinical Outcomes of Over-the-Counter COVID-19 Prophylaxis and Treatment
94% fewer cases (p=0.003). Retrospective 113 outpatients, 53 (patient choice) treated with zinc, quercetin, vitamin C/D/E, l-lysine, and quina, showing lower cases with treatment. Results are subject to selection bias and limited information on the groups is provid..
Jun 24
Di Pierro et al., International Journal of General Medicine, doi:10.2147/IJGM.S318949 Potential Clinical Benefits of Quercetin in the Early Stage of COVID-19: Results of a Second, Pilot, Randomized, Controlled and Open-Label Clinical Trial
74% improved viral clearance (p<0.0001). RCT 42 outpatients in Pakistan, 21 treated with quercetin phytosome, showing faster viral clearance and lower symptom severity with treatment. Patients in the treatment group were younger (43 vs. 56).
Jun 15
Kandeil et al., Pathogens, doi:10.3390/pathogens10060758 Bioactive Polyphenolic Compounds Showing Strong Antiviral Activities against Severe Acute Respiratory Syndrome Coronavirus 2
Vero E6 In Vitro study showing curcumin, hesperidin, and quercetin significantly inhibited SARS-CoV-2 replication, and In Silico analysis with promising Mpro and spike docking results.
Jun 8
Di Pierro et al., International Journal of General Medicine, doi:10.2147/IJGM.S318720 Possible Therapeutic Effects of Adjuvant Quercetin Supplementation Against Early-Stage COVID-19 Infection: A Prospective, Randomized, Controlled, and Open-Label Study
86% lower mortality (p=0.25), 94% lower ICU admission (p=0.006), and 68% lower hospitalization (p=0.003). RCT 152 outpatients in Pakistan, 76 treated with quercetin phytosome, showing lower mortality, ICU admission, and hospitalization with treatment.
Apr 8
Aguilar et al., Journal of Advances in Medical and Pharmaceutical Sciences, doi:10.9734/jamps/2021/v23i330222 Oral Quercetin in Adult Patients as a Potential Nutraceutical against Coronavirus Disease 2019 (COVID-19)
Prospective study of 52 patients treated with quercetin. There was no control group.
Jan 19
Onal et al., Turk. J. Biol., 45:518-529 (date from preprint) Treatment of COVID-19 patients with quercetin: a prospective, single center, randomized, controlled trial
94% lower ICU admission (p=0.39) and 78% higher hospital discharge (p=0.1). RCT 447 moderate-to-severe hospitalized patients in Turkey, 52 treated with quercetin, bromelain, and vitamin C, showing no statistically significant difference in clinical outcomes.
Nov 16
Rehman et al., Current Pharmaceutical Design, doi:10.2174/1381612826999201116195851 Natural Compounds as Inhibitors of SARS-CoV-2 Main Protease (3CLpro): A Molecular Docking and Simulation Approach to Combat COVID-19
In Silico study showing that the natural compounds kaempferol, quercetin, and rutin bind to the main protease (Mpro) of SARS-CoV-2, also known as 3CLpro, with high affinity. Authors find these flavonoids interact with active site residues..
Nov 16
Arslan et al., SSRN, doi:10.2139/ssrn.3682517 Synergistic Effect of Quercetin and Vitamin C Against COVID-19: Is a Possible Guard for Front Liners
92% fewer cases (p=0.03). Small prophylaxis RCT with 113 patients showing fewer cases with quercetin + vitamin C + bromelain prophylaxis. NCT04377789. Note that this paper disappeared from SSRN without explanation.
Oct 9
Derosa et al., Phytotherapy Research, doi:10.1002/ptr.6887 A role for quercetin in coronavirus disease 2019 (COVID-19)
Review noting that quercetin has a theoretical, but significant, capability to interfere with SARS-CoV-2 replication, with results showing this to be the fifth best compound out of 18 candidates.
Jun 19
Biancatelli et al., Frontiers in Immunology, doi:10.3389/fimmu.2020.01451 Quercetin and Vitamin C: An Experimental, Synergistic Therapy for the Prevention and Treatment of SARS-CoV-2 Related Disease (COVID-19)
Review of the evidence for the use of vitamin C and quercetin both for prophylaxis in high-risk populations and for the treatment of COVID-19 patients.
Apr 24
Sekiou et al., ChemRxiv, doi:10.26434/chemrxiv.12181404.v1 In-Silico Identification of Potent Inhibitors of COVID-19 Main Protease (Mpro) and Angiotensin Converting Enzyme 2 (ACE2) from Natural Products: Quercetin, Hispidulin, and Cirsimaritin Exhibited Better Potential Inhibition than Hydroxy-Chloroquine Against COVID-19 Main Protease Active Site and ACE2
In Silico study of natural compounds identifying quercetin, curcumin, hispidulin, cirsimaritin, sulfasalazine, and artemisin as potential compounds that inhibit SARS-CoV-2.
Mar 31
Zhang et al., Journal of Integrative Medicine, doi:10.1016/j.joim.2020.02.005 In silico screening of Chinese herbal medicines with the potential to directly inhibit 2019 novel coronavirus
In Silico study showing that 13 natural compounds from Chinese herbal medicines have potential anti-2019-nCoV activity by binding to viral proteins such as papain-like protease (PLpro), 3C-like protease (3CLpro), and the spike protein. Au..
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