Seven Compounds from Turmeric Essential Oil Inhibit Three Key Proteins Involved in SARS-CoV-2 Cell Entry and Replication in silico

Introduction: Turmeric rhizome (<italic>Cucurma longa</italic> L.) has showed great potential as a traditional drug in folk medicine of several countries. In light of the prominent use of turmeric rhizome in treating both respiratory and viral diseases, we aimed to dock major compounds from the essential oil of turmeric against three key proteins involved in COVID-19 cell entry and replication. Methods: The essential oil of turmeric rhizome was obtained using a hydrodistillation technique, and the chemical characterization of the oil was investigated using GC-MS/GC-FID. Then, main compounds were docked with the key proteins of COVID-19. Results: A total of 26 components were identified in the essential oil extracted from the rhizomes <italic>via</italic> GC-MS/GC-FID. Seven dominant compounds (turmerone (31.4%), ar-turmerone (16.1%), turmerol (14.6%), terpinolene (11.0%), α-zingiberene (5.2%), β-sesquiphellandrene (4.8%), and β-caryophyllene (3.5%)) were docked against COVID-19 main protease, papain-like protease (PLpro), spike protein and 3C-like protease (3CLpro), and the best inhibitor was picked according to the calculated binding affinity and non-bonding interactions with the protein active site. β-sesquiphellandrene and α-zingiberene showed highest besides the same binding affinity towards COVID-19 virus (−6.38 and −6.39kcal/mol, respectively). α-zingiberene was found to bind at the active site of the COVID-19 protein and interacted with different non-bonding interactions, while turmerol showed the highest affinity (−5.78kcal/mol) against CLpro enzyme by binding with Met165, Leu141, Met49, Ser144, Cys145, and Glu166 residues. Conclusion: The essential oil of turmeric harbors a blend of potentially bioactive compounds that may be considered as a good target against COVID-19 virus and warrants further experimental studies. [ABSTRACT FROM AUTHOR] Copyright of Journal of Computational Biophysics & Chemistry is the property of World Scientific Publishing Company and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Phytochemicals from Plant Foods as Potential Source of Antiviral Agents: An Overview.

To date, the leading causes of mortality and morbidity worldwide include viral infections, such as Ebola, influenza virus, acquired immunodeficiency syndrome (AIDS), severe acute respiratory syndrome (SARS) and recently COVID-19 disease, caused by the SARS-CoV-2 virus. Currently, we can count on a narrow range of antiviral drugs, especially older generation ones like ribavirin and interferon which are effective against viruses in vitro but can often be ineffective in patients. In addition to these, we have antiviral agents for the treatment of herpes virus, influenza virus, HIV and hepatitis virus. Recently, drugs used in the past especially against ebolavirus, such as remdesivir and favipiravir, have been considered for the treatment of COVID-19 disease. However, even if these drugs represent important tools against viral diseases, they are certainly not sufficient to defend us from the multitude of viruses present in the environment. This represents a huge problem, especially considering the unprecedented global threat due to the advancement of COVID-19, which represents a potential risk to the health and life of millions of people. The demand, therefore, for new and effective antiviral drugs is very high. This review focuses on three fundamental points: (1) presents the main threats to human health, reviewing the most widespread viral diseases in the world, thus describing the scenario caused by the disease in question each time and evaluating the specific therapeutic remedies currently available. (2) It comprehensively describes main phytochemical classes, in particular from plant foods, with proven antiviral activities, the viruses potentially treated with the described phytochemicals. (3) Consideration of the various applications of drug delivery systems in order to improve the bioavailability of these compounds or extracts. A PRISMA flow diagram was used for the inclusion of the works. Taking into consideration the recent dramatic events caused by COVID-19 pandemic, the cry of alarm that denounces critical need for new antiviral drugs is extremely strong. For these reasons, a continuous systematic exploration of plant foods and their phytochemicals is necessary for the development of new antiviral agents capable of saving lives and improving their well-being.