Action of a new antibiotic, neo-enactin, on the cell membrane and its application to combination treatment in a cultured tumor cell system.

Neo-enactin, a new antibiotic obtained from a Streptoverticillium, was found to act on the eukaryotic cell membrane and induce changes in the transport of molecules across the cell membrane. Neo-enactin markedly potentiated the action of the antitumor agents bleomycin and vincristine in vitro. The uptake of [14C]vincristine by HeLa cells was enhanced 3.4-fold in the presence of neo-enactin. It is suggested that the potentiation of a second drug by neo-enactin may result from enhanced permeation of that drug.