Purification of a hemagglutinant fraction from crotalid venom: in vitro and in vivo evaluation of cell damage

Abstract

Some crotalid venoms have a hemagglutinant fraction with affinity to cell receptors. This can be used as an antiviral agent that blocks adsorption of the virus in the cell membrane. One of these fractions was isolated and its innocuity compared to the effect of complete venoms. A. piscivorus, A. contortix and C. scutulatus venoms were tested, with the first exhibiting the highest activity (64, 32 and 2 hemagglutinant units [HU], respectively). Maximum non-lethal dosage in mice was 1.75 mg/30 g body weight for C. scutulatus and = 4.0 mg/30 g body weight for the other venoms. Macroscopically, A. piscivorus and A. contortix caused massive edema and blood infiltration. Microscopically all three venoms caused acute myositis of varying severity. Inoculation of Madin Darby Bovine Kidney (MDBK) cultures with venomslead to monolayer detachment or agglutination at 6 µ µµµµg/ml for A. piscivorus, 12 µ g/ml for A. contortix and 195 µ g/ml for C. scutulatus. Because of its relatively high activity, the hemagglutinant fraction of the A. piscivorus venom was isolated by reverse phase high pressure liquid chromatography (HPLC-RP). Inoculation of mice with this fraction at 4.25 µ µµ µ g/0.2 ml did not cause macroscopic or microscopic damage, and it did not alter MDBK cells at = 1.062 µ µµ µµg/ml. Hemagglutination reduction, from 64 to 16 HU, caused by the fraction in neuraminidase-treated red cells indicated a probable preference for binding to sialic acid receptors. Results demonstrate that purification of the venom hemagglutinant fraction eliminates other damage-causing components, allowing its use as an antiviral.