Abstract
Polyethylenimines (PEIs) are highly cationic compounds. SP-012, a PEI, has been reported to exert in vitro and in vivo antiviral effects against the herpes simplex virus (HSV). In this study, we evaluated the in vitro antiviral effects of branched PEIs using several viruses. Viruses were cultured in medium and treated with SP-006 (molecular weight [MW]: 2310), SP-012 (MW: 3610), SP-018 (MW: 4600), or SP-200 (MW: 16560). Antiviral activities were estimated based on the selectivity indices (SIs) calculated from the ratio between the 50% cytotoxic concentration and 50% inhibitory concentration values. Our results demonstrated that all PEIs, barring SP-200, potently inhibited acyclovir-sensitive and-resistant HSV-1 strains, HSV-2, and human corona virus, and mildly inhibited the infl uenza A and measles virus. SP-006 inhibited HSV-2 by preventing host cell attachment and penetration, and by exerting a concentration-dependent virucidal effect. These data indicate that PEIs, including SP-012 and SP-006, may be novel antiviral agents with a wide spectrum of activity.
