Thymol for COVID-19

AbstractCoronaviruses (CoVs) are a family of viruses that cause infection in respiratory and intestinal systems. Different types of CoVs, those responsible for the SARS‐CoV and the new global pandemic of coronavirus disease 2019 in people, have been found. Some plants were used as food additives: spices and dietary and/or medicinal purposes in folk medicine. We aimed to provide evidence about possible effects of two Lamiaceae family plants on control or treatment of CoVs‐induced inflammation. The keywords including coronaviruses, Thymus vulgaris, Zataria multiflora, thymol, carvacrol, antivirus, and anti‐inflammatory and antioxidant effects were searched in various databases such as PubMed, Web of Sciences (ISI), and Google Scholar until September 2022. The medicinal herbs and their main ingredients, thymol and carvacrol, showed antiviral properties and reduced inflammatory mediators, including IL‐1β; IL‐6, and TNF‐α, at both gene and protein levels but increased the levels of IFN‐γ in the serum as anti‐inflammatory cytokine. These medicinal herbs and their constituents also reduce oxidative stress and enhance antioxidant capacity. The results of molecular docking analyses also indicated that polyphenol components such as thymol, carvone, and carvacrol could inhibit the entry of the viruses into the host cells in molecular docking analyses. The antiviral, anti‐inflammatory, and antioxidant effects of these plants may be due to actions of their phenolic compounds that modulate immune response and may be useful in the control and treatment of CoV‐induced lung disorder.

Aromatic plant species of the genus thymus have an important role as they have therapeutic properties such as antirheumatic, antiseptic, antispasmodic, antimicrobial, cardiac, carminative, diuretic and expectorant. It is also known that such plants strengthen the immune system and help cope with infectious diseases such as colds and flu. In this study, the effects of thymol, p-cymene, -terpinene, bornyl acetate, borneol, carvacrol, thymol methyl ether, thymol acetate, which are the main components of wild thyme (thymus serpyllum L.), on Covid-19 were investigated at the molecular level. Optimizations and molecular docking were done in Docking Server with the MMFF94 method. Major components of wild thyme were docked separately against 6LU7 protein representing the first gene form of Covid-19 and 7KDL protein representing the mutated form. Docking poses and binding energies between target proteins and wild thyme components were calculated. The results were compared with favipiravir, an antiviral drug developed against influenza virus and also used in the treatment of Covid-19. It was found that the thymol molecule, one of the main components of wild thyme, has the highest biological activity against both 6LU7 and 7KDL protein chains of Covid-19.

Covid-19 spreading have caused millions of deaths worldwide and caused sever economic shrinking resulted in high levels of inflations. The on going pandemic has pushed the pharmaceutical companies to invent different vaccines to overcome the spreading of the virus and to reduce its effect on health and economy. Unfortunately, the middle and low income countries have been struggling in providing vaccines to their people due to the high expenses associated with vaccines ordering. Thus, the interest in finding a treatment and a prevention of Covid-19 from natural products has increased not in those countries only, even in high income countries. In this review we investigated the promising natural phytochemical compounds and their published mechanism of action in a prestigious peer-reviewed research journal throw different molecular docking and in vivo and vitro techniques. Its was found that the consumption of the medicinal plants containing small phenolic and terpenoids phytoconstituent like as thymoquinone, quercetin, caffeic acid, ursolic acid, ellagic acid, vanillin, and thymol have a great therapeutic effect for curing and preventing viral infections. This review has focused on the small polyphenolic and terpenoids compounds and their potential and mechanism activity against SARS-CoV-2. Our comprehensive analysis provides mechanistic insight into plant components for virus containment prevent infections and provide better solutions through natural therapeutically active ingredients.