Silybin for COVID-19

AbstractTo attain promising pharmacotherapies, researchers have applied drug repurposing (DR) techniques to discover the candidate medicines to combat the coronavirus disease 2019 (COVID-19) outbreak. Although many DR approaches have been introduced for treating different diseases, only structure-based DR (SBDR) methods can be employed as the first therapeutic option against the COVID-19 pandemic because they rely on the rudimentary information about the diseases such as the sequence of the severe acute respiratory syndrome coronavirus 2 genome. Hence, to try out new treatments for the disease, the first attempts have been made based on the SBDR methods which seem to be among the proper choices for discovering the potential medications against the emerging and re-emerging infectious diseases. Given the importance of SBDR approaches, in the present review, well-known SBDR methods are summarized, and their merits are investigated. Then, the databases and software applications, utilized for repurposing the drugs against COVID-19, are introduced. Besides, the identified drugs are categorized based on their targets. Finally, a comparison is made between the SBDR approaches and other DR methods, and some possible future directions are proposed.

COVID-19 pandemic caused by the novel SARS-CoV-2 has impacted human livelihood globally. Strenuous efforts have been employed for its control and prevention; however, with recent reports on mutated strains with much higher infectivity, transmissibility, and ability to evade immunity developed from previous SARS-CoV-2 infections, prevention alternatives must be prepared beforehand in case. We have perused over 128 recent works (found on Google Scholar, PubMed, and ScienceDirect as of February 2023) on medicinal plants and their compounds for anti-SARS-CoV-2 activity and eventually reviewed 102 of them. The clinical application and the curative effect were reported high in China and in India. Accordingly, this review highlights the unprecedented opportunities offered by medicinal plants and their compounds, candidates as the therapeutic agent, against COVID-19 by acting as viral protein inhibitors and immunomodulator in (32 clinical trials and hundreds of in silico experiments) conjecture with modern science. Moreover, the associated foreseeable challenges for their viral outbreak management were discussed in comparison to synthetic drugs.

Background: Coronavirus disease 2019 (COVID‑19) is caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and is associated with a high level of mortality. Objective: This updated review aims to present the most important traditional medicinal plants and some of their secondary metabolites that have previously and more recently been shown to affect viruses and may represent a beneficial contributory step against SARS-CoV-2 as the cause of COVID-19. Moreover, the mechanism aspects of these secondary metabolites were discussed, which may help find more reliable drugs against SARS-CoV-2. Methods: Articles were searched in scientific websites including Google Scholar, Scopus, Web of Science, PubMed, and IranMedex using the search terms herbal medicine and traditional medicine with coronavirus, SARS-CoV-2, or COVID-19. Human, animal, and in vitro studies were identified in the search. Results: Medicinal plants and their secondary metabolites may possess a potential role in combating this disease, and researchers suggest that some of these plants and their constituent compounds have inhibitory activity on coronaviruses. Numerous medicinal plants, their extracts, and secondary metabolites have been investigated over a period of time for antiviral activity. Among them, kaempferol, silybin, myricitrin, licoleafol, and curcumin are promising agents with potential activity against SARS-CoV-2. Natural compounds can form strong bonds with the active sites of SARS-CoV-2 protease. Structural and non-structural SARS-CoV-2 proteins such as Spike protein, PLpro, and 3CLpro are inhibited by these phytochemicals. Conclusion: Prospective treatments targeted at the life cycle stages of the virus may eventuate from research endeavors, and it must not be discounted that therapy originally derived from plant secondary metabolite sources may potentially have a part to play.