In vitro inhibition of bovine herpes virus 1 reproduction with native and microencapsulated proteinase inhibitor aprotinin.

This study evaluated the antiviral effect of various dosage forms of proteinase inhibitor-aprotinin as a potential remedy for prophylactics and therapy of infectious bovine rhinotracheitis. Formulations of the inhibitor were tested for their influence on bovine herpes virus reproduction in cell cultures. Starch/bovine serum albumin microcapsules with aprotinin were prepared using interfacial cross-linking with terephthaloyl chloride and characterized for their morphology, size and release of the inhibitor. Two types of these microcapsules-impregnated and loaded with the inhibitor-were used in virus infectious studies. Native aprotinin possessed palpable dose-dependent antiviral effect inhibiting the virus reproduction up to 4.0 lg (10000-fold) and delaying the cytopathic effect up to 96 h in the concentration 800-3300 TIU/ml. The bioadhesive, biodegradable aprotinin-loaded microcapsules were the most effective antiviral drug as this formulation allowed to decrease virus infectious titer up to 4.0 lg and a delay in the cytopathic effect of up to 144 h in lesser doses of inhibitor compared with the native form. In comparison the antiviral effect of microcapsules impregnated with aprotinin was not so appreciable. It was interesting to note that the results of the experiments on diverse cultures were very similar. This was because the drugs influenced the fundamental processes of virus replication cycle.