Extract from Cistus × Incanus L. Pandalis also Effective Against “British” Alpha (B.1.1.7) and “South African” Beta (B.1.351) SARS-CoV-2 Variants

Jens-Martin Traeder

doi:10.11648/j.jdmp.20210702.13

Abstract

Background: In previous studies, a special extract from Cistus × incanus L. Pandalis (Cystus Pandalis® extract) has already proven to be effective against SARS-CoV-2 in vitro. We assume that an effect was also likely against the new SARS-CoV-2 variants, like the “British” alpha variant (B.1.1.7) as well as against the “South African” beta variant (B.1.351). Methods: To verify this, we investigated the inhibition of the cytopathic effect (CPE) of the coronaviruses by the Cystus Pandalis® extract in a cell model with human intestinal cells (Caco-2). We inoculated viral pre-treated cells with the herbal extract (A), and we mixed pre-treated viruses with the herbal extract in the cell cultures (B). Result: We observed an almost complete inhibition of virus growth by Cystus Pandalis® extract at concentrations of more than 100 μg/ml. The calculated IC50 (mean inhibitory concentration) for the “British” alpha variant (B.1.1.7) as well as for the “South African” beta variant (B.1.351) is below 50 μg/ml. There was no significant difference in the results in the two different ways of treatment. Conclusion: Extract from Cistus × incanus L. Pandalis (Cystus Pandalis® extract) can prevent in in-vitro cell cultures infections with SARS-CoV-2. Due to the high in vitro activity against the new variants, it also appears reasonable in the future to use Cystus Pandalis® as prophylaxis against infections with SARS-CoV-2. A development of resistance is unlikely. People tolerate the extract very well. It has no significant side effects.

Highlights

There are still hardly any therapeutic approaches against COVID-19
We used a multiplicity of infection (MOI) of 0.01 for both virus variants. 48 h after infection, we evaluated visually the cytopathogenic effect (CPE) by two independent technicians
In order to investigate at which concentration of Cystus Pandalis® extract an antiviral activity against the “British” alpha (B.1.1.7) and “South African” beta (B.1.351) SARS-CoV-2 variants can be observed, it was determined to what extent the virus-related cytopathic effect (CPE) was absent at the different test concentrations

Summary

Introduction

There are still hardly any therapeutic approaches against COVID-19. Even though vaccination campaigns are slowly starting, at least in some industrialized countries, many people are currently still without a vaccination offer or do not want to accept it for various reasons. [1] In Europe and Germany, the alpha (B.1.1.7 called “British”) and beta (B.1.351 called “South African”) SARS-CoV-2 variants are noteworthy, which have almost completely displaced the original wild type since the beginning of the year. Cystus Pandalis® extract is an herbal preparation based on the variety of the Hoary rockrose Cistus × incanus L. People used Cistus × incanus L. in traditional folk medicine since the 4th century BC for its anti-inflammatory, anti-ulcerogenic, antimicrobial and wound-healing properties. A special extract from Cistus × incanus L. Pandalis (Cystus Pandalis® extract) has already proven to be effective against SARS-CoV-2 in vitro. We assume that an effect was likely against the new SARS-CoV-2 variants, like the “British” alpha variant (B.1.1.7) as well as against the “South African” beta variant (B.1.351)

Methods

Results

Discussion

Conclusion