Anti-equine arteritis virus activity of ethanolic extract and compounds from Origanum vulgare

Abstract

The equine arteritis virus (EAV) is responsible by an important respiratory and reproductive disease in equine populations and there is no specific antiviral treatment available. The objective of this study was to investigate the activity of an ethanolic crude extract of Origanum vulgare (EEO) and of isolated compound caffeic acid, p-coumaric acid, rosmarinic acid, quercetin, luteolin, carnosol, carnosic acid, kaempferol and apigenin against EAV. The assays were performed using non-cytotoxic concentrations. The antiviral activity was monitored initially by cytopathic effect inhibition (CPE) assay in RK13 cells in the presence or absence of EEO. Pre-incubated cells with EEO were also examined to show prophylactic effect. Direct viral inactivation by EEO and isolated compounds was evaluated by incubation at 37°C or 20°C. After the incubation period, the infectivity was immediately determined by virus titrations on cell cultures and expressed as 50% tissue culture infective dose (TCID 50 )/100 µL. There was significant virucidal activity of EEO and of the compounds caffeic acid, p-coumaric acid, quercetin, carnosic acid and kaempferol. When EEO was added after infection, EEO inhibited the virus growth in infected cells, as evidenced by significant reduction of the viral titre. The results provide evidence that the EEO exhibit an inhibitory effect anti-EAV. Among the main compounds evaluated, caffeic acid, p-coumaric acid, carnosic acid, kaempferol and mainly quercetin, contributed to the activity of EEO. EEO may represent a good prototype for the development of a new antiviral agent, presenting promising for combating arteriviruses infections. Key words: Antimicrobial. Antiviral. Cytotoxicity. Origanum sp. Virucidal. ResumoO virus da arterite equine (EAV) é responsável por uma importante doença respiratória e reprodutiva na população de equinos e não há tratamento antiviral específico disponível. O objetivo desse estudo foi investigar a atividade de um extrato etanólico de Origanum vulgare (EEO) e dos compostos isolados ácido caféico, ácido p-cumarico, ácido rosmarínico, quercetina, luteolina, carnosol, ácido carnósico, campferol e apigenina contra o EAV. Os ensaios foram realizados com concentrações não citotóxicas. A atividade antiviral foi monitorada inicialmente por um ensaio de inibição de efeito citopático (CPE) em células RK13 na presença ou ausência do EEO. Células pré-incubadas com o EEO foram também examinadas para a presença de efeito profilático. Inativação direta do EAV pelo EEO e pelos compostos isolados foi avaliada mediante incubação a 37°C ou 20°C. Após o período de incubação, a infectividade foi imediatamente determinada por titulação viral em cultivo celular sendo expresso como dose infectiva a 50% (TCID 50 )/100 µL. Houve significativa atividade virucida do EEO e dos compostos ácido caféico, ácido p-cumarico, quercetina, ácido carnósico e campferol. Quando o EEO foi adicionado após a infecção, o EEO inibiu a replicação do vírus nas células infectadas, o que foi evidenciado pela redução s...

In vitro antibacterial activity of crude ethanolic extract from the leaves of Origanum vulgare, against Staphylococcus aureus ATCC 29213, Pseudomonas aeruginosa ATCC 27853 and Escherichia coli ATCC 25922

“…aureus, but varies against Gram-negative bacteria such as E. coli, K. pneumoniae, P. aeruginosa [19][20][21] and even depending on the solvent such as ethanol and methanol allow the isolation of bioactive compounds of great interest in their antioxidant, antibacterial and antifungal action [22][23][24] , as well as their finding with antiviral activity 25 .…”

Potential of Natural Therapeutics Against SARS-CoV-2: Phenolic Compounds and Terpenes

“…Quercetin, rosmarinic acid, and hesperitin have also shown good binding affinity with SARS-CoV-2 viral protein targets in silico virtual screening 70 . Due to caffeic acid, p-coumaric acid, kaempferol and mainly quercetin, which are the phenolic compounds detected with ethanol of Origanum vulgare, the plant shows an inhibitory effect against Alphaarterivirus equid which causes the equine viral arteritis (EVA) diseases 71 . A study has shown that baicalein, a flavonoid extracted from the roots of S. baicalensis, inhibits the activity of SARS-CoV-2 3CL pro in vitro.…”

Nanotechnology Applications of Flavonoids for Viral Diseases

“…Pseudorabies virus (PRV) [211], SARS (kaempferol, kaempferol glycosides, and acylated kaempferol glucoside derivatives (such as afzelin, juglanin, tiliroside, and tiliroside derivatives)) [212], Japanese encephalitis virus (JEV) [130,213] 6 , Equine Arteritis virus (EAV) [214], SARS-CoV-2 [215][216][217][218][219], HIV-1 [220][221][222], H1N1 Influenza virus [223], HSV-1 and HSV-2 [224], H9N2 swine Influenza virus [225] Table 1. Cont.…”