Universally available herbal teas based on sage and perilla elicit potent antiviral activity against SARS-CoV-2 variants of concern by HMOX-1 upregulation in human cells

Abstract

The current SARS-CoV-2/COVID-19 pandemic represents an unprecedented medical and socioeconomic crisis. Highly efficient treatment options preventing morbidity and mortality are not broadly available and approved drugs are hardly affordable in developing countries. Even after vaccine approvals, it will take several months until the vaccinated and convalescent individuals establish herd immunity. Meanwhile, non-pharmaceutical interventions and antiviral treatments are indispensable to curb the death toll of the pandemic. To identify cost-effective and ubiquitously available options, we tested common herbs consumed worldwide as herbal teas. We found that aqueous infusions prepared by boiling leaves of the Lamiaceae plants perilla and sage elicit potent antiviral activity against SARS-CoV-2 in human cells. Sustained antiviral activity was evident even when cells were treated for only half an hour, and in therapeutic as well as prophylactic regimens. Given the urgency, such inexpensive and broadly available substances might provide help during the pandemic - especially in low-income regions.

Turmeric Root and Its Bioactive Ingredient Curcumin Effectively Neutralize SARS-CoV-2 In Vitro

“…Traditional herbal medicines represent promising options for complementary treatment of COVID-19 diseases. To date, numerous plants and their ingredients exhibit potent antimicrobial and antiviral effects [6][7][8]. Notably, curcumin showed antimicrobial activity toward bacteria, malaria, fungi, and viruses [9].…”

The mint versus Covid hypothesis

“…The SARS-CoV-2 inhibitory effects of perilla in a cell culture model were independently reported in a peer-reviewed study by Tang and colleagues and in a preprint by Le-Trilling and colleagues [54,55]. An important aspect of the Le-Trilling study is that it used boiling water for the extraction, suggesting that the hypothetical antiviral compound or compounds are at least somewhat stable in hot water.…”

“…A more recent version of Le-Trilling and colleagues' preprint [55] suggests that principal antiviral compounds in perilla may include caffeic acid, perilla aldehyde, and perillyl alcohol. The manuscript suggests that these compounds may exert anti-SARS-CoV-2 effects through induction of cellular innate immune responses marked by heme oxygenase 1 expression.…”

Why You’ve Never Heard of the Mint Versus COVID Hypothesis: A Philosophical Perspective

“…All tea mixtures included at least one mint-family herb species with evidence of relatively potent anti-Covid effects. These included (roughly in descending order of aggregate quality of evidence for antiviral effects) field mint, perilla, sage (Salvia officinalis), oregano (Origanum vulgare), self-heal (Prunella vulgaris), catnip (Nepeta tenuifolia), and American skullcap (Scutellaria lateriflora) (Jan et al, 2021;Le-Trilling et al, 2020). Teas also included at least one pleasant-flavored mint-family herb, including (roughly in descending order of palatability) peppermint (Mentha x piperita), spearmint (Mentha spicata), lavender blossom (Lavandula angustifolia), sacred basil (Ocimum tenuiflorum), rosemary (Salvia rosmarinus), dittany, lemon balm (Melissa officinalis), mountain tea (Sideritis scardica), thyme (Thymus vulgaris), hyssop (Hyssopus offininalis), Greek sage, and patchouli (Pogostemon cablin).…”

“…Cinnamon twigs (Plum Dragon) are an excellent adjunct for mint-family teas as well as for brewed coffee. In cases where a caffeinated beverage was desirable, yerba mate (which contains high levels of the proposed active antiviral compound caffeic acid (Bojic et al, 2013;Le-Trilling et al, 2020)) was a pleasant adjunct to mint-family teas.…”