A natural sulphated mucopolysaccharide (OKU40), extracted from a marine plant Dinoflagellata, and an artificial sulphated polysaccharide (OKU41), prepared from a marine Pseudomonas, displayed antiviral activities against several enveloped viruses. OKU40 and OKU41 were found to be homogenous in electrophoresis and sedimation velocity and had a molecular weight of 8.0 x 106 and 5.0 x 106, respectively The sulphation rate of OKU40 and OKU41 was 8.9% and 5.4%, respectively. Each OKU40 and OKU41 inhibited the cytopathic effect of human immunodeficiency virus type 1 (HIV-1), type 2 (HIV-2) and zidovudine-resistant HIV-1 in MT-4 cells at similar concentrations to those of dextran sulphate (molecular weight: 5000) (50% inhibitory concentrations: 0.86-1.95 μg mL-1), whereas these compounds did not affect the growth and viability of mock-infected MT-4 cells at concentrations up to 500 μg mL-1. These compounds proved inhibitory not only to HIV-1 and HIV-2 but also to other enveloped viruses, i.e, herpes simplex virus type 1, influenza virus A and B, respiratory syncytial virus and measles virus, OKU40 and OKU41 suppressed syncytium formation induced by cocultivation of MOLT-4/III(B) and MOLT-4 cells at concentrations higher than 20 μg mL-1. Although OKU41 inhibited the binding of HIV-1 to the host cells and the binding of anti-gp120 monoclonal antibody to HIV-1 gp120, OKU40 did not inhibit these bindings, suggesting that the mechanism of anti-HIV activity of OKU40 and OKU41 may be primarily due to the inhibition of virus cell fusion and viral adsorption to the host cells, respectively. Furthermore, these compounds did not inhibit to the blood coagulation process at a concentration that was significantly inhibitory to HIV replication. The compounds appear to have an interesting potential as virucidal agents.
ASJC Scopus subject areas
- Drug Discovery