A polyphenol rich plant extract, CYSTUS052, exerts anti influenza virus activity in cell culture without toxic side effects or the tendency to induce viral resistance

Qualitative evaluation of composition of the volatile fraction in commercial samples of Cistus incanus L.

“…Water extracts from C. incanus L. exhibit high antioxidant activity and influence the DNA splitting [17]. The research confirms also an antiviral in vitro activity of the preparations made of hairy rockrose against the HIV-1, HIV-2, and flu viruses [18,19].…”

Antiviral activity and possible mechanisms of action of pentagalloylglucose (PGG) against influenza A virus

“…Thereby, it is conceivable that the inhibitory effect of PGG was mainly caused by the direct interaction of PGG with virus. Numerous studies have demonstrated that plant polyphenols including the tea catechins (-) epigallocatechin gallate (EGCG) and theaflavin digallate [34], resveratrol (RV) [26], a polyphenol rich extract (CYSTUS052) [11], pomegranate polyphenol extract (PPE) [13] , oligonol [12], and Hydroxytyrosol (HT) [38], have potent antiviral activity against influenza virus, that are related to the nature of their interactions with viral particles. Additionally, indirect effects of some polyphenols, such as EGCG and strictinin, on host cells that might interfere with virus-cell membrane fusion have also been suggested [23,32].…”

“…HI assay was carried out as described by Christina Ehrhardt et al [10]. Briefly, serial two-fold dilutions of PGG (25µl) were prepared, mixed with equal volume of influenza virus solution (2 2 of HA units/25µl).…”

Characterization of the Influenza Virus Inhibiting Fractions of Bergenia ligulata

“…Similarly, anti-influenza activity of pomegranate polyphenols is modulated by small changes in envelope glycoproteins (Sundararajan et al 2010). On the other hand, virus inhibitory effect of polyphenol rich extract of Cistus incanus to be mainly due to binding of the polymeric polyphenol components of the extract to the virus surface, thereby inhibiting binding of the hemagglutinin to cellular receptors (Ehrhardt et al 2007). In our previous study of pre-treatment of MDCK cells with B. ligulata extract before virus infection confirmed that the extract has effect on the early stage of viral infection by preventing the binding of virus particle to the cells (Rajbhandari et al 2003).…”