No abstract

The sulphated polymers, such as polyvinylalcohol sulphate (PVAS) and its co-polymer with acrylic acid (PAVAS), have proved to be potent inhibitors for herpes simplex virus, human cytomegalovirus, vesicular stomatitis virus, respiratory syncytial virus, Sindbis virus, Semliki Forest virus, Junin virus, Tacaribe virus, murine sarcoma virus and human immunodeficiency virus. They are not inhibitory to non-enveloped viruses, such as poliovirus and reovirus. The broad-spectrum antiviral effects of these compounds depend on their molecular weight and degree of sulphation. Pharmacokinetic studies in rabbits have indicated that after intravenous bolus injection the serum concentrations of these compounds decay biphasically, with an initial half-life of approximately 90–120 min.

Novel synthetic sulfated polymers, namely, sulfated polyvinyl alcohol (PVAS) and sulfated copolymers of acrylic acid with vinyl alcohol (PAVAS), proved to be potent and selective inhibitors of human immunodeficiency virus type 1 (HIV-1) and HIV-2 in vitro. The compounds completely inhibited HIV-1-induced cytopathogenicity in MT-4 cells and HIV-1 antigen expression in CEM cells at a concentration of 0.8 micrograms/ml. They were equally effective against HIV-2 replication. In addition, and in contrast to azidothymidine, PAVAS and PVAS suppressed HIV-1-induced giant cell (syncytium) formation, a process that may account for the depletion of T4 lymphocytes in patients with acquired immunodeficiency syndrome. PAVAS and PVAS completely blocked giant cell formation at a concentration of 4 micrograms/ml, whereas for dextran sulfate a concentration of 100 micrograms/ml was required to achieve complete inhibition of giant cell formation. As has been demonstrated previously for the sulfated polysaccharides, the mechanism of action of PAVAS and PVAS resides in the inhibition of virus adsorption to the cells.