In vitro antiherpes effects of a C-glycosylflavonoid-enriched fraction of Cecropia glaziovii Sneth

Aims: To investigate the in vitro antiherpes effects of the crude aqueous extract obtained from Cecropia glaziovii leaves and their related fractions, the n-butanol fraction (n-BuOH) and the C-glycosylflavonoid-enriched fraction (MeOH_AMB), and to determine the viral multiplication step(s) upon which this C-glycosylflavonoid-enriched fraction acts. Methods and Results: The antiviral activity was evaluated against human herpes virus types 1 and 2 (HHV-1, HHV-2) by plaque reduction assay. The mode of action of the most active fraction was investigated by a set of assays, and the results demonstrated that MeOH_AMB fraction exerts anti-herpes action by the reduction of viral infectivity (only against HHV-2); by the inhibition of virus entry into cells; by the inhibition of cell-to-cell virus spread as well as by the impaired levels of envelope proteins of HHV-1. The high-performance liquid chromatography (HPLC)-photo-diode array (PDA) analysis showed that the C-glycosylflavonoids are the major constituents of this fraction. Conclusions: These data showed that the MeOH_AMB fraction has an antiviral activity against HHV types 1 and 2. The C-glycosylflavonoids are the major constituents of this fraction, which suggests that they could be one of the compounds responsible for the detected anti-herpes activity. Significance and Impact of the Study: The MeOH_AMB fraction can be regarded as a phytopharmaceutical candidate for the treatment of herpetic infections.