Sulphoevernan, a polyanionic polysaccharide, and the narcissus lectin potently inhibit human immunodeficiency virus infection by binding to viral envelope protein.

Sulphoevernan is a sulphated alpha-1----3, 1----4 polyglucan (Mr 20,000) with a helical structure. This compound effectively inhibits both human immunodeficiency virus type 1 (HIV-1) and type 2 infection of cells in vitro at concentrations around 0.5 micrograms/ml. Moreover, the compound completely inhibits HIV-1-induced syncytium formation at a concentration of 1 microgram/ml. Competition experiments with 35S-labelled sulphoevernan revealed that the mannose-specific lectin from Narcissus pseudonarcissus prevented binding of sulphoevernan to HIV-1, whereas the antibody OKT4A did not reduce the amount of sulphoevernan bound to MT-2 cells. These data indicate that the non-cytotoxic polymer sulphoevernan binds to the virus rather than to the host cell. In vivo studies, using Rauscher leukaemia virus in NMRI mice, revealed that, at a daily dose of 20 mg/kg, the animals were protected against virus-induced increases in spleen weight. From these in vitro and in vivo data we conclude that sulphoevernan has potential in the treatment of acquired immunodeficiency syndrome.

Evaluation of an antimicrobial soap formula for virucidal efficacy in vitro against human immunodeficiency virus in a blood-virus mixture.

The virucidal efficacy of a health care personnel hand wash product containing 0.5% parachlorometaxylenol in a sodium C14-16 olefin sulfonate formula was evaluated in in vitro tests with human immunodeficiency virus type 1 (HIV-1) in the presence of 50% whole human blood. The HTLV-IIIRF strain of HIV-1 was suspended in 50% medium-50% whole human blood and exposed to various dilutions of the hand wash product for 30 or 60 s. Following detoxification, residual infectivity was determined by a lytic cytopathogenic assay in MT2 cell cultures. No infectious HIV could be detected after a 30-s exposure to the hand wash product at dilutions of 1:5 and 1:10 and after a 60-s exposure at dilutions of 1:5, 1:10, 1:20, and 1:30. More than 99.9% of the virus was inactivated at these dilutions and exposure times.