Aromatic Herbs, Medicinal Plant-Derived Essential Oils, and Phytochemical Extracts as Potential Therapies for Coronaviruses: Future Perspectives

Abstract

After its recent discovery in patients with serious pneumonia in Wuhan (China), the 2019 novel coronavirus (2019-nCoV), named also Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), has spread quickly. Unfortunately, no drug or vaccine for treating human this coronavirus infection is available yet. Numerous options for controlling or preventing emerging 2019-nCoV infections may be predicted, including vaccines, interferon therapies, and small-molecule drugs. However, new interventions are likely to require months to years to develop. In addition, most of the existing antiviral treatments frequently lead to the development of viral resistance combined with the problem of side effects, viral re-emergence, and viral dormancy. The pharmaceutical industry is progressively targeting phytochemical extracts, medicinal plants, and aromatic herbs with the aim of identifying lead compounds, focusing principally on appropriate alternative antiviral drugs. Spices, herbal medicines, essential oils (EOs), and distilled natural products provide a rich source of compounds for the discovery and production of novel antiviral drugs. The determination of the antiviral mechanisms of these natural products has revealed how they interfere with the viral life cycle, i.e., during viral entry, replication, assembly, or discharge, as well as virus-specific host targets. Presently, there are no appropriate or approved drugs against CoVs, but some potential natural treatments and cures have been proposed. Given the perseverance of the 2019-nCoV outbreak, this review paper will illustrate several of the potent antiviral chemical constituents extracted from medicinal and aromatic plants, natural products, and herbal medicines with recognized in vitro and in vivo effects, along with their structure–effect relationships. As this review shows, numerous potentially valuable aromatic herbs and phytochemicals are awaiting assessment and exploitation for therapeutic use against genetically and functionally different virus families, including coronaviruses.

‘BhAVI-23’-A spice-herb based dietary infusion possessing in-vitro anti-viral potential

“…Large scale drug and phytomedicine repurposing is being currently investigated as it is plausible that anti-retroviral therapy may also be effective against SARS coronavirus [ [57] , [58] , [59] , [60] ]. ‘BhAVI-23’ displayed prominent inhibition of HIV-1 RT activity as well as infectivity of P1 (vir) phage thus ascertaining its anti-viral potential.…”

First-described recently discovered non-toxic vegetal-derived furocoumarin preclinical efficacy against SARS-CoV-2: a promising antiviral herbal drug

“…In this view, various coumarin-based hybrids possessing diverse medicinal attributes have been synthesised in the past five years by conjugating a coumarin moiety with other therapeutic pharmacophores (37). Antiviral mechanistic studies of TCM, AM, and/or EHD have revealed how they interfere with the viral life cycle, as well as virus-specific host targets (4). Herbal drugs have demonstrated a wide range of antiviral mechanisms that include inhibition of 3CLpro protein (Chinese Rhubarb extracts, Houttuynia chordata extract, hesperetin, etc.…”

“…There is continuous interest in searching for alternative antiviral drugs between phytochemical extracts, medicinal plants, and aromatic herbs. Discovery and production of novel antiviral drugs comes frequently from spices, herbal medicines, essential oils (EOs), and distilled natural products (4). Coumarins comprise a large class of compounds found within medicine herbal preparations (5)(6)(7).…”

“…It is made available under a preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in The copyright holder for this this version posted December 4, 2020. ; https://doi.org/10.1101/2020.12.04.410340 doi: bioRxiv preprint pág. 4 Reducing viral replication at the beginning of SARS-CoV-2 infection and, subsequently, the associated degree of immunopathological damage, is a critical step to mitigate and cure COVID19…”

Current targets and drug candidates for prevention and treatment of SARS-CoV-2 (COVID-19) infection

“…The significant advantage of using herbs in viral respiratory infections is due to their potent anti-inflammatory and immunostimulatory action (Patwardhan et al, 2020). Some of the active phytoconstituents in medicinal plants have inhibitory action on coronaviruses (Boukhatem and Setzer, 2020;Mani et al, 2020), however determination of functional actions on ACE2 is critical to elucidate agonist/activation or inhibitor/antagonist. Considering the pathogenesis of COVID-19, we identified some Indian medicinal plants with potent antiinflammatory, immunomodulatory, and antiviral activities for de- veloping potential treatment of COVID-19.…”