Saxifraga spinulosa-Derived Components Rapidly Inactivate Multiple Viruses Including SARS-CoV-2

Abstract

Novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza A virus (IAV), and norovirus (NV) are highly contagious pathogens that threaten human health. Here we focused on the antiviral potential of the medicinal herb, Saxifraga spinulosa (SS). Water-soluble extracts of SS were prepared, and their virus-inactivating activity was evaluated against the human virus pathogens SARS-CoV-2 and IAV; we also examined virucidal activity against feline calicivirus and murine norovirus, which are surrogates for human NV. Among our findings, we found that SS-derived gallocatechin gallate compounds were capable of inactivating all viruses tested. Interestingly, a pyrogallol-enriched fraction (Fr 1C) inactivated all viruses more rapidly and effectively than did any of the component compounds used alone. We found that 25 µg/mL of Fr 1C inactivated >99.6% of SARS-CoV-2 within 10 s (reduction of ≥2.33 log10 TCID50/mL). Fr 1C resulted in the disruption of viral genomes and proteins as determined by gel electrophoresis, electron microscopy, and reverse transcription–PCR. Taken together, our results reveal the potential of Fr 1C for development as a novel antiviral disinfectant.

The SARS-CoV-2-Inactivating Activity of Hydroxytyrosol-Rich Aqueous Olive Pulp Extract (HIDROX®) and Its Use as a Virucidal Cream for Topical Application

“…These mixtures were incubated at 25 °C for 0 (no reaction time) or 24 h and then mixed with sodium dodecyl sulfate (SDS)-buffer with 2-mercaptoethanol (FUJIFILM Wako Pure Chemical Co.). The samples were subjected to SDS–polyacrylamide gel electrophoresis (SDS–PAGE) and Western blotting as described in [ 11 ]. S protein S1 subunit, S protein RBD, S protein S2 subunit, and N protein were detected using primary and secondary antibodies as shown in Table S1 .…”

“…The use of natural compounds from plants with proven activity against pathogenic viruses is one such strategy. Exploratory research of natural components that show anti-SARS-CoV-2 activity is being actively conducted and some candidate components have been reported by us and other groups in vitro [ 11 , 12 , 13 ]. Plant polyphenols are naturally-derived compounds that show antiviral activity against various pathogenic viruses [ 14 ].…”

Biological activity evaluations of chemical constituents derived from Mongolian medicinal forage plants and their applications in combating infectious diseases and addressing health problems in humans and livestock

“…4) and epigallocatechin gallate (EGCG) (17, Fig. 4), from Saxifraga spinulosa showed potent activity against the influenza A virus, feline calicivirus, murine norovirus, and SARS-CoV-2 [41]. The effects of EGCG have been investigated by many groups because it is a typical tea catechin.…”

The Hydroalcoholic Extract of Uncaria tomentosa (Cat’s Claw) Inhibits the Infection of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) In Vitro

“…The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused serious public health problems since it was identified in Wuhan (China) in late 2019 [ 1 ]. The World Health Organization (WHO) declared coronavirus disease 2019 (COVID-19) a pandemic on March 11, 2020 [ 2 ]. According to the latest report of the WHO, there have been 88,383,771 confirmed cases of COVID-19, including 1,919,126 deaths, as of 10 January 2021 [ 3 ].…”