Identification of herbal teas and their compounds eliciting antiviral activity against SARS-CoV-2 in vitro

Abstract

Background The SARS-CoV-2/COVID-19 pandemic has inflicted medical and socioeconomic havoc, and despite the current availability of vaccines and broad implementation of vaccination programs, more easily accessible and cost-effective acute treatment options preventing morbidity and mortality are urgently needed. Herbal teas have historically and recurrently been applied as self-medication for prophylaxis, therapy, and symptom alleviation in diverse diseases, including those caused by respiratory viruses, and have provided sources of natural products as basis for the development of therapeutic agents. To identify affordable, ubiquitously available, and effective treatments, we tested herbs consumed worldwide as herbal teas regarding their antiviral activity against SARS-CoV-2. Results Aqueous infusions prepared by boiling leaves of the Lamiaceae perilla and sage elicit potent and sustained antiviral activity against SARS-CoV-2 when applied after infection as well as prior to infection of cells. The herbal infusions exerted in vitro antiviral effects comparable to interferon-β and remdesivir but outperformed convalescent sera and interferon-α2 upon short-term treatment early after infection. Based on protein fractionation analyses, we identified caffeic acid, perilla aldehyde, and perillyl alcohol as antiviral compounds. Global mass spectrometry (MS) analyses performed comparatively in two different cell culture infection models revealed changes of the proteome upon treatment with herbal infusions and provided insights into the mode of action. As inferred by the MS data, induction of heme oxygenase 1 (HMOX-1) was confirmed as effector mechanism by the antiviral activity of the HMOX-1-inducing compounds sulforaphane and fraxetin. Conclusions In conclusion, herbal teas based on perilla and sage exhibit antiviral activity against SARS-CoV-2 including variants of concern such as Alpha, Beta, Delta, and Omicron, and we identified HMOX-1 as potential therapeutic target. Given that perilla and sage have been suggested as treatment options for various diseases, our dataset may constitute a valuable resource also for future research beyond virology.

Historical texts as a potential resource for plant-derived natural products against SARS-CoV-2 – the example of theReceptariumof Burkhard III von Hallwyl from 16th century Switzerland

“…Only three of the plant species in our sample appear to have so far been investigated specifically for their in vitro anti-SARS-CoV-2 activity, namely Salvia officinalis L. (Le-Trilling et al, 2022;Farzam et al, 2024), Artemisia vulgaris L. (Kazachinskaia, 2022), Sambucus nigra L. (Eggers et al, 2022;Leka et al, 2022).…”

Treating COVID-19 with Medicinal Plants: Is It Even Conceivable? A Comprehensive Review

“…In addition, essential oil phytocompounds containing low molecular weight and volatile molecules (i.e., monoterpenes, sesquiterpenes, alcohols, and ketones) proved their efficacy in disturbing the viral envelope due to their lipophilic properties, thus inhibiting their attachment to the host cell membrane [ 25 , 26 ]. Moreover, herbal infusions using sage and perilla showed a potent anti-viral effect via the activation of the heme oxygenase 1 enzyme (HMOX-1), leading to a reduction in oxidative stress, thus an inhibition of SARS-CoV-2 replication [ 27 ]. In addition, medicinal herbs are widely used to boost immunity against COVID-19, especially at an early stage of the disease, due to the presence of bioactive molecules, including vitamins and essential minerals.…”

Quantitative Analytical and Computational Workflow for Large-Scale Targeted Plasma Metabolomics

“…The metabolome coverage from these studies is limited to a few metabolites from a chemical class, such as four amino acids [ 21 ] and six steroids [ 20 ]. Another approach, using the standard addition method, was used for endogenous phytochemical quantification [ 23 ] and urinary metabolites [ 24 ] and has gained interest in targeted metabolomics. However, we observed it has severe limitations in terms of metabolome coverage and known issues with subtraction of endogenous metabolite levels [ 23 ].…”