Carvacrol for COVID-19

The COVID-19 pandemic has reignited interest in traditional medicinal plants as potential therapeutic agents. This study examined the chemical composition, cytotoxicity, and antimicrobial activity of essential oils from six Moroccan medicinal plants, namely, Eucalyptus globulus, Artemisia absinthium, Syzygium aromaticum, Thymus vulgaris, Artemisia alba, and Santolina chamaecyparissus, which are commonly used by the Moroccan population for COVID-19 prevention. The chemical composition of each essential oil was determined using gas chromatography–mass spectrometry (GC–MS) to identify key compounds. Cytotoxicity was evaluated in the Vero E6 cell line, which is frequently used in SARS-CoV-2 research, using the neutral red assay, with oil concentrations ranging from 25 to 100 µg/mL. Antimicrobial activity was tested against standard reference strains, including Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), Staphylococcus aureus (ATCC 25923), Candida albicans (ATCC 10231), and Bacillus subtilis (ATCC 6633), using the disc diffusion method. GC–MS analysis revealed significant components such as spathulenol (15%) and caryophyllene oxide (7.67%) in Eucalyptus globulus and eugenol (54.96%) in Syzygium aromaticum. Cytotoxicity assays indicated that higher concentrations of essential oils significantly reduced cell viability, with Thymus vulgaris showing the highest IC50 (8.324 µM) and Artemisia absinthium the lowest (18.49 µM). In terms of antimicrobial activity, Eucalyptus globulus had the strongest effect, with a 20 ± 0.00 mm inhibition zone against Bacillus subtilis, whereas both Syzygium aromaticum and Artemisia herba-alba had a 12.25 ± 0.1 mm inhibition zone against the same strain. These findings suggest that these essential oils have significant therapeutic potential, particularly in combating antimicrobial resistance and exerting cytotoxic effects on viral cell lines. Further research is necessary to explore their mechanisms of action and ensure their safety for therapeutic use.

Novel coronavirus COVID-19 (SARS-CoV-2), the unexpected pandemic that been caused severe fright worldwide. It has presented the world with one of the most difficult global public health crises and the arrival of COVID-19 has kept the whole world on their toes. The spread of COVID19 has become a health emergency and attention has been raised worldwide to design prevention and management strategy. Although several clinical trials are ongoing, no approved medications from Food and Drug Administration are available at a time, after while some preventative vaccines have been developed, manufactured and deployed depending on variant of COVID-19. As situation warrants for the exploration of a successful antiviral, there should be a search for the remedies in nature medicine. Medicinal plants and their metabolites have long been used as a treatment option for various life-threatening diseases with minimal side effects. Thus this review aims to summarize previous outcomes concerning the role of medicinal plants in treating several life-threatening diseases for the potential medicinal plants used in the case of COVID-19 treatment. Some of these includes Turmeric (Curcuma longa Linn.), Black Cumin (Nigella sativa L.), Garlic (Allium sativum L.), and Ginger (Zingiber officinale Rosc.). These are important traditional herbal medicines to cure many complicated health ailments. However, further extensive researches and trials are suggested to discover the role of medicinal plants for management of the pandemic. Moreover, the use of potential medicinal plants for specific variant of COVID-19 and others life-threatening diseases has to be investigated.

The search for effective therapeutics against COVID-19 remains imperative, and natural compounds have emerged as promising candidates. Our study explores the potential of bioactive phytochemicals from the traditional Siddha formulation MilagaiKudineer as inhibitors against key target proteins of the SARS-CoV-2 virus. Through in-silico docking analyses, the interactions of phytochemicals from Cuminum cyminum, Curcuma longa, and Capsicum annuum with the receptor-binding domain of the SARS-CoV-2 spike glycoprotein (PDB ID: 6VSB), the SARS-CoV2 RNA-dependent RNA polymerase (PDB ID: 6NUR), and the main protease, 3CL pro (PDB ID: 6LU7) were examined. Notable compounds such as Curcumin, Quercetin, Capsaicin, and Ascorbic acid demonstrated significant binding affinities towards these viral targets, suggesting mechanisms by which these phytochemicals may disrupt viral entry and replication. Our findings also highlight the potential of compounds like Carvacrol, Cuminaldehyde, Linalool, and Dihydrocapsaicin in mediating antiviral effects by interfacing with key amino acid residues of the spike glycoprotein. These interactions are indicative of their capacity to hinder the virus-host cellbinding process. Moreover, the interaction of select phytochemicals with the SARS-CoV2 RNA-dependent RNA polymerase and the 3CLpro enzyme suggests a possible inhibitory effect on viral replication. Given the promising interactions observed, these phytochemicals warrant further investigation through in vitro and in vivo studies to validate their antiviral efficacy against COVID-19. This research underscores the importance of exploring traditional medicinal formulations for potential therapeutic agents in the fight against emerging infectious diseases.

In 2020, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) challenged the world with a global outbreak that led to millions of deaths worldwide. Coronavirus disease 2019 (COVID-19) is the symptomatic manifestation of this virus, which can range from flu-like symptoms to utter clinical complications and even death. Since there was no clear medicine that could tackle this infection or lower its complications with minimal adverse effects on the patients’ health, the world health organization (WHO) developed awareness programs to lower the infection rate and limit the fast spread of this virus. Although vaccines have been developed as preventative tools, people still prefer going back to traditional herbal medicine, which provides remarkable health benefits that can either prevent the viral infection or limit the progression of severe symptoms through different mechanistic pathways with relatively insignificant side effects. This comprehensive review provides scientific evidence elucidating the effect of 10 different plants against SARS-CoV-2, paving the way for further studies to reconsider plant-based extracts, rich in bioactive compounds, into more advanced clinical assessments in order to identify their impact on patients suffering from 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.

Abstract Background The recent outbreak of the Coronavirus pandemic resulted in a successful vaccination program launched by the World Health Organization. However, a large population is still unvaccinated, leading to the emergence of mutated strains like alpha, beta, delta, and B.1.1.529 (Omicron). Recent reports from the World Health Organization raised concerns about the Omicron variant, which emerged in South Africa during a surge in COVID-19 cases in November 2021. Vaccines are not proven completely effective or safe against Omicron, leading to clinical trials for combating infection by the mutated virus. The absence of suitable pharmaceuticals has led scientists and clinicians to search for alternative and supplementary therapies, including dietary patterns, to reduce the effect of mutated strains. Main body This review analyzed Coronavirus aetiology, epidemiology, and natural products for combating Omicron. Although the literature search did not include keywords related to in silico or computational research, in silico investigations were emphasized in this study. Molecular docking was implemented to compare the interaction between natural products and Chloroquine with the ACE2 receptor protein amino acid residues of Omicron. The global Omicron infection proceeding SARS-CoV-2 vaccination was also elucidated. The docking results suggest that DGCG may bind to the ACE2 receptor three times more effectively than standard chloroquine. Conclusion The emergence of the Omicron variant has highlighted the need for alternative therapies to reduce the impact of mutated strains. The current review suggests that natural products such as DGCG may be effective in binding to the ACE2 receptor and combating the Omicron variant, however, further research is required to validate the results of this study and explore the potential of natural products to mitigate COVID-19. Graphical abstract

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.

The COVID-19 pandemic that broken out in 2020 is becoming more worrying for the world. Although there is no 100 % success against COVID-19, certain synthetic drugs are currently used despite various side effects. Therefore, studies on the discovery of new treatment alternatives come to the fore. Studies so far show that natural products are still important resources for the discovery of new therapeutic agents. Plant-derived essential oils are complex volatiles composed of various phytochemicals, mostly containing compounds such as sesquiterpenes, monoterpenes, and phenylpropanoids. In this study, especially thymol and carvacrol compounds specific to the Lamiaceae (Labiate) family and aromatic monoterpenes derived from these compounds were modeled against COVID-19. Results were compared with remdesivir, hydroxychloroquine, and favipiravir used as synthetic drugs. Dock and molecular dynamics simulations analyzed these molecules’ potential inhibitor efficiency of the SARS-CoV2 Mpro. Lipinski parameters and Docking results were demonstrated that ligands carvacrol (2), carvacryl acetate (11) and cuminaldehyde (12) are potential inhibitors towards COVID-19. According to the results, it is seen that medicinal aromatic herbs, which contain these volatile components with the fewer side effects than synthetic drugs, have the potential to be used as supplements in the pharmaceutical industry.