Cistus × Incanus L. Pandalis Is Highly Effective Against Delta Variant of SARS-CoV-2 in Vitro

Abstract

Background: Recent studies have shown that a special extract from Cistus x incanus L. Pandalis (Cystus Pandalis® extract) has proven to be effective against SARS-CoV-2 in vitro and it is likely that the extract shows to be effective against other new variants of SARS-CoV-2 like the “Indian” Delta-Variety as well. Methods: In order to verify our claim, we examined how the extract Cystus Pandalis® inhibits the cytopathic action (CPE) of the Coronavirus in a cell model with human intestinal cells (Caco-2). We incubated viruses with the extract and mixed them with the cell cultures. Result: Cystus Pandalis® extract has almost completely inhibited virus growth at concentrations greater than 100 μg/ml. The calculated IC50 (mean inhibitory concentration) for the "Indian" Delta variant was 101 µg/ml. Conclusion: Cistus x incanus L. Pandalis extract (Cystus Pandalis® extract) is capable of preventing cell cultures from being infected by SARS-CoV-2 in-vitro. Because of its high in-vitro potency against the new variants of SARS-CoV-2, it is more than ever reasonable to use Cystus Pandalis® prophylactically in order to decrease the virus load. The development of resistance to the extract is not likely. People tolerate the extract very well. No significant side effects have been detected. Phytopharmaceuticals extraxted from Cistus x incanus L. Pandalis are able to combat viral infections and can help contain future pandamics by being handed in advance profilactically.