In Vitro Antiviral Evaluations of Coldmix ® : An Essential Oil Blend against SARS-CoV-2.

Coldmix ® is a commercially available Eucalyptus aetheroleum and, Abies aetheroleum blend for medicinal applications. In this present study, the in vitro antiviral potential of Coldmix ® , and its major constituents 1,8-cineole and α-pinene were evaluated by using the in vitro ACE2 enzyme inhibition assay as well as the direct contact test against SARS-CoV-2. The observed ACE2 enzyme inhibitory activity of Coldmix ® , 1,8-cineole, and α-pinene were 72%, 88%, and 80%, respectively; whereas in the direct contact test in the vapor phase, the destruction of the virus was 79.9% within 5 min and 93.2% in the 30th min, respectively. In a similar Coldmix ® vapor phase setup using the in vitro cytotoxicity cell assay, E6 VERO healthy cells were experimentally not affected by toxicity. According to the promising initial antiviral results of Coldmix ® and the individually tested constituents, detailed further in vivo evaluation using different virus classes is suggested.