The World Health Organization’s declaration of the end of the health emergency may have been premature, as the world grapples with the ongoing COVID-19 pandemic and its long-term effects. Scientists from Tecnológico Nacional de México/Instituto Tecnológico de Oaxaca propose a potential solution: the use of quercetin to manage the oxidative stress associated with Long COVID or post-acute sequelae of COVID-19.
Persistent COVID, also known as Long COVID, is a condition characterized by persistent symptoms even after recovering from the acute infection. It poses significant challenges for the medical community, with various contributing factors such as immune dysregulation, microbiota conditions, and blood coagulation. Among these factors, oxidative stress plays a crucial role in the pathogenesis of persistent COVID, leading to chronic inflammation and worsening symptoms.
Quercetin, a flavonoid found in fruits, vegetables, seeds, and plant-derived beverages, has been identified as a potential therapeutic agent due to its antioxidant properties. It can neutralize free radicals, inhibit enzymes involved in cell death, and increase the production of endogenous antioxidants. Quercetin has also shown efficacy in treating other conditions such as Type 2 diabetes mellitus, highlighting its versatility as a therapeutic agent.
In the context of persistent COVID, oxidative stress is linked to the cytokine storm, coagulation mechanisms, and hypoxia. Quercetin addresses these challenges through its antioxidant, anti-inflammatory, anticarcinogenic, and immunoprotective functions. It promotes mitochondrial biogenesis, inhibits lipid peroxidation, and controls platelet aggregation, mitigating the effects of oxidative stress.
Furthermore, quercetin has shown promising antiviral properties against various viruses, including SARS-CoV-2. It inhibits enzymes involved in virus replication and alters the expression of target proteins. When combined with Vitamin C, it demonstrates a synergistic effect, disrupting virus entry and replication while enhancing immune responses.
However, the bioavailability and solubility of quercetin present challenges to its efficacy. The varying content of quercetin in foods makes it difficult to achieve therapeutic levels through diet alone. To overcome this limitation, nanotherapy using nanocarriers has emerged as a potential solution. Organic and inorganic nanoparticles can enhance the delivery and retention of quercetin, addressing the challenges related to its limited transport across biological barriers.
In conclusion, the prevalence of persistent COVID symptoms calls for effective treatments, and quercetin emerges as a promising candidate. Its antioxidant, anti-inflammatory, and antiviral properties position it as a potential therapeutic agent for managing oxidative stress in persistent COVID. Ongoing research, including the exploration of nanotherapeutic approaches, holds promise for optimizing quercetin’s bioavailability and enhancing its therapeutic impact. As the medical community continues to unravel the complexities of Long COVID, quercetin may offer relief and improve the quality of life for those affected.