Non-cytotoxic Thymus capitata extracts prevent Bovine herpesvirus-1 infection in cell cultures

Abstract

BackgroundBovine herpes virus type 1 (BHV-1) still causes great economic loss to the livestock industry and trade because there aren’t any available drugs that proved to be fully effective against it. In this study, the cytotoxicity and the antiviral activities of the Thymus capitata extracts were evaluated for the development of new, non toxic and specific anti-herpesvirus drug. Aqueous extracts (AE), ethanolic extracts (EE) and essential oil (EO) of the aerial parts of Thymus capitata were analyzed to determine their chemical compositions by gas chromatography, and high performance liquid chromatography combined with mass spectrometry. Their cytotoxicity and antiviral activities against Bovine Herpesvirus type 1 (BHV-1) were evaluated by quantifying the reduction of the viral cytopathic effect using Madin-Darby Bovine Kidney cell line with colorimetric assay. T. capitata extracts were added at different stages of the viral infection to investigate and better quantify their potential inhibitory effects.ResultsPolyphenols and flavonoids were the major compounds found in T. capitata EO, EE and AE. The cytotoxic concentrations at 50% were 48.70, 189 and 289 μg ml−1 for EO, EE and AE, respectively. The inhibitor concentrations at 50% for the EO, EE and AE, were 3.36, 47.80 and 164 μg ml−1, respectively. The selectivity index anti-BHV-1 values were 14.49, 3.95 and 1.81 for EO, EE and AE, respectively. Thus, the EO extracts were the most efficient antiviral compounds. T. capitata extracts affect mainly the adsorption of BHV-1 virus to host cells.ConclusionT. capitata extracts inhibit the viral replication by interfering with the early stages of viral adsorption and replication. Thus, T. capitata is a potential candidate for anti-herpesvirus treatment.

Inhibition of HSV‐2 infection by pure compounds from Thymus capitatus extract in vitro

“…Although HSV‐1 and HSV‐2 are structurally and genetically similar, their sensitivity to antiviral compounds may vary depending on the strains and cell type used in antiviral assays as reported for instance in Leary, Wittrock, Sarisky, Weinberg, and Levin (). Similar antiviral results were previously observed against bovine herpesvirus Type 1 infection with EC 50 values of 164, 47.8, and 3.3 μg/ml, respectively (Boubaker‐Elandalousi et al, ). These data indicate a broad spectrum of action of T. capitatus extracts against Herpes viruses.…”

“…The ethanolic and aqueous extracts (EE and AE) were prepared as previously described (Boubaker‐Elandalousi et al, ). The essential oil (EO) was prepared by dissolving 100 g of dried plant material in 1 L of distilled water and then submitted to microwave‐assisted hydro‐distillation at 40 °C during 4 hr, in a Clevenger type apparatus.…”

Antiviral effect of lithium chloride on infection of cells by porcine parvovirus

“…The relative cell viability rate was determined for each concentration as (OD 450 drug)/(OD 450 control) 9 100. LiCl concentrations below the 50 % cytostatic concentration (CC 50 ) were defined as non-toxic concentrations [19].…”

Potential of selected Lamiaceae plants in anti(retro)viral therapy

“…A notable number of studies reviewed in this paper have also tried to detect the exact M-o-A of IS. This was achieved through the time-of-addition (T-o-A) study, which is comprised of assays with different procedures of addition of IS, viral suspension and cell cultures [48,[54][55][56][62][63][64]66,68,69,71,73,74,77,82,87,88,91,92,94,104,106,112]. Based on the highest activity in a certain assay, a conclusion about the exact type of M-o-A can be derived (Fig.…”