Pharmaceutical Prospects of Curcuminoids for the Remedy of COVID-19: Truth or Myth

Abstract

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is a positive-strand RNA virus, and has rapidly spread worldwide as a pandemic. The vaccines, repurposed drugs, and specific treatments have led to a surge of novel therapies and guidelines nowadays; however, the epidemic of COVID-19 is not yet fully combated and is still in a vital crisis. In repositioning drugs, natural products are gaining attention because of the large therapeutic window and potent antiviral, immunomodulatory, anti-inflammatory, and antioxidant properties. Of note, the predominant curcumoid extracted from turmeric (Curcuma longa L.) including phenolic curcumin influences multiple signaling pathways and has demonstrated to possess anti-inflammatory, antioxidant, antimicrobial, hypoglycemic, wound healing, chemopreventive, chemosensitizing, and radiosensitizing spectrums. In this review, all pieces of current information related to curcumin-used for the treatment and prevention of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection through in vitro, in vivo, and in silico studies, clinical trials, and new formulation designs are retrieved to re-evaluate the applications based on the pharmaceutical efficacy of clinical therapy and to provide deep insights into knowledge and strategy about the curcumin’s role as an immune booster, inflammatory modulator, and therapeutic agent against COVID-19. Moreover, this study will also afford a favorable application or approach with evidence based on the drug discovery and development, pharmacology, functional foods, and nutraceuticals for effectively fighting the COVID-19 pandemic.

The exploration of phytocompounds theoretically combats SARS-CoV-2 pandemic against virus entry, viral replication and immune evasion

“…The severe inflammation and cytokine storms are the most fatal etiology of COVID-19. There are several scientific reports of phytocompounds can bind and affect COVID-19 relative cytokines pathways, such as curcumin, quercetin, kaempferol, and luteolin can form binding interaction with TNF, IL-6, NF-κB [92] , [93] , [94] . As anti-inflammatory role of dexamethasone, phytocompounds can also interfere cytokine production, affect inflammatory response and attenuate immunity but the less intense of adverse effect when compared with dexamethasone.…”

Antioxidant, Anti-inflammatory, and Immunomodulatory Roles of Nonvitamin Antioxidants in Anti-SARS-CoV-2 Therapy

“… 264 , 275 , 276 Given the restricted bioavailability of most polyphenols, the systemic effects of these phytocompounds have been ascribed to the gene-mediated antioxidative, anti-inflammatory, and immunomodulatory attributes that were exploited to defend host cells and mitigate illness severity in COVID-19. 3 , 277 It has been found that the antioxidant and antiviral activities are exerted in the gastrointestinal system where polyphenols are present in high concentrations. 277 The intake of fruits and vegetables can support and maintain a positive health status by overcoming oxidative stress, inflammation, as well as the associated pathologies.…”

“…It has been shown that these phytocompounds can be involved in preventing and treating a series of chronic degenerative pathologies, including nutritional diseases, such as metabolic syndrome, type 2 diabetes mellitus, nonalcoholic fatty liver disease, insulin resistance, or atherosclerosis. Their pharmacological potential was also noticed in inflammatory lung diseases. , Moreover, polyphenols are endowed with inhibitory activity exhibited against viral components and actions. ,, Given the restricted bioavailability of most polyphenols, the systemic effects of these phytocompounds have been ascribed to the gene-mediated antioxidative, anti-inflammatory, and immunomodulatory attributes that were exploited to defend host cells and mitigate illness severity in COVID-19. , It has been found that the antioxidant and antiviral activities are exerted in the gastrointestinal system where polyphenols are present in high concentrations . The intake of fruits and vegetables can support and maintain a positive health status by overcoming oxidative stress, inflammation, as well as the associated pathologies.…”

“…These aspects sustain the importance of antioxidant intervention in preventing and alleviating both oxidative stress and activation of inflammatory cytokines. 1 − 3 …”

“…Increased oxidative stress, activation of pro-oxidative pathways, and inflammatory burst are often encountered in COVID-19 severity, mainly when this pathology is associated with chronic diseases encompassing lowered antioxidant defense. These aspects sustain the importance of antioxidant intervention in preventing and alleviating both oxidative stress and activation of inflammatory cytokines. − …”