Chemical Composition and Antiviral Effect of Extracts of Origanum vulgare

This study aimed determine the activity of aqueous and ethanolic extracts of Origanum vulgare against some viruses of veterinary importance (bovine viral diarrhea virus (BVDV), equine arteritis virus (EAV), equine influenza virus (EIV), feline calicivirus (FCV), canine distemper virus (CDV), canine adenovirus (CAV), and canine cororavirus (CCoV) by evaluating the possibility of inhibition of viral particles production. The aqueous extract from 1600 μg/mL did not show cytotoxicity for all cellular lineages evaluated, Madin Darby bovine kidney cells (MDBK), Rabbit kidney cells (RK 13), Madin Darby canine kidney cells (MDCK) and Crandell feline kidney cells (CRFK), and the ethanolic extract of Origanum vulgare was not toxic at 600 μg/mL. The addition of aqueous extract of Origanum vulgare in media resulted in a significant reduction of the EAV titer from 105.42 infecting dose for cellular culture at 50% (TCID50) to 102.09 TCID50/100 μL while in the presence of the ethanolic extract of Origanum vulgare in media resulted in a significant reduction of the EAV titer from 105.42 TCID50 to 100.79 TCID50/100 μL. To CDV the addition of aqueous extract resulted in a reduction from 102.00 TCID50 to 100.00 TCID50/100 μL while in the presence of the ethanolic extract titers were reduced from 102.00 TCID50 to 101.50 TCID50/100 μL. No significant differences in titers regarding the others analyzed viruses were detected. With respect to chemical analysis of the extracts of Origanum vulgare, were identified in the ethanol extract phenolics rosmarinic acid, caffeic acid, carnosol, p-coumaric acid, carnosic acid, luteolin, apigenin, kaempferol and quercetin. In aqueous extracts of Origanum vulgare were detected rosmarinic acid, p-coumaric acid carnosic acid, luteolin, apigenin, kaempferol and quercetin. The data obtained stimulate other biological assays in order to determine which compounds are responsible for the antiviral activity as well as which are the mechanisms involved. The results presented and the considerations we were able to draw from them allowed us to conclude that the ethanolic extract of Origanum vulgare demonstrated lower cell viability than the aqueous extract and has significant antiviral activity against EAV and the both aqueous and ethanolic extracts have antiviral action against CDV.