Olea europaea leaves extract downregulate Newcastle disease virus gene expression in cancer cells

Abstract

Many researches have been made to find antiviral agents from natural sources. Leaf of Olea europaea (OLE) is one of the
most important medicinal plants, as it is a well-known source of different phytochemicals. This study was carried out to
investigate the effect of using Olea europaea leaves extract on the level of viral gene expression (M and F) in Hela cell line by
using the qRT-PCR. Also, we examined the adding of interferon-beta ( IFN-b ) as an antivirus factor and analyzed the expression
of viral and IFN-b genes to identify viral targets for OLE extract. First, we propagated the virus in embryonated chicken
eggs and showed to kill embryos in different times intervals (less than 72 hours) with marked sever hemorrhage in infected
embryos, and agglutination activity reflects titer (1024) and 1×10 6.4 (TCID50). Hela cells were cultured and different concentration
of OLE extract was added; cell viability was measured by MTT assay. Gene expression showed that the expression of
the viral gene was downregulated in the present of OLE extract. Pretreatment with IFN-b downregulated viral gene expression
higher than the extract, also evaluated the IFN-b concentration by ELISA assay. OLE can be considered as antivirus agent and
used this property to help in control Newcastle disease.