Inhibition of herpes simplex virus replication by cobra alpha-neurotoxoid.

A peptide, prepared by gentle oxidative detoxification of a methionine-free cobra alpha-neurotoxin, was evaluated for antiviral activities in vivo and in vitro. When added to BHK cells before infection the peptide reduced herpes simplex virus type 1 (HSV-1)-induced TCD50 in a dose- and time-dependent manner. The antiviral effect was also expressed on initiation of cell treatment 1 h after infection if the peptide was left in contact with cells. Single, intracerebral doses of the toxoid in suckling mice significantly increased 50% survival times, and reduced virus replication in the infected brain tissues. Cutaneous lesions and resultant scar formation induced by HSV-1 in hairless mice were also significantly reduced by subcutaneous peptide injections.