Potential in vitro activity of Kutapressin against Epstein-Barr Virus

Background: Kutapressin (KU), a porcine liver extract with bradykinin-potentiating effects but no vitamin B 12 activity has been used in the treatment of Herpes zoster. We examined a phenol-free preparation of this drug for in vitro activity against Epstein-Ban Virus (EBV). Materials and Methods: Immortalization - inhibition assays were used to assess EBV infectivity. Mitogen stimulation and cell viability assays were used to assess kutapression toxicity. Lytic replication assays and flow cytometry were used to assess the mechanism of drug activity. Results: Seventy-five hundred mcg/ml of KU blocked the infection of 2 x 10(5) human umbilical cord mononuclear cells when added together with two strains of EBV (B95-8 and FF41). Doses as low as 250 mcg/ml were occasionally effective as well. Unlike acyclovir; KU does not inhibit vital DNA polymerase nor does it appear to compete with EBV as it binds to its receptor on the B-cell surface Conclusions: The mechanism whereby KU may inhibit EBV immortalization remains to be determined KU, a drug which is safe in humans, deserves further Study as an agent with potential to block EBV-induced immortalization of B-lymphocytes.