The effect of Astragalus polysaccharide on the Epstein-Barr virus lytic cycle.

Effects of a polysacharide from Chinese herbal plant Astragalus membranaceus (APS) on the expression of Epstein-Barr virus (EBV) immediate early proteins Zta, Rta and EA-D in Raji cells were examined. EBV switch from latent to lytic cycle in Raji cells was induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) and sorbol butyrate (SB) and the effects of APS were examined by immunofluorescence, western blotting and flow cytometry. APS in a non-cytotoxic concentration of 30 μg/ml significantly suppressed the expression of Zta, Rta and EA-D during the EBV lytic cycle. Our observations indicate that APS is potentially useful as an anti-EBV drug.