STUDIES ON THE ANTI-TUMOR EFFECT OF THE BACTERIAL LIPID COMPONENT, LIPID A

I. ON SOME PHYSICOCHEMICAL PROPERTIES AND ANTITUMOR ACTIVITY OF LIPID A FRACTION

Abstract

The lipid A fractions were prepared from several bacterial species according to the method of Westphal with slight modifications. A remarkable similarity in their physicochemical properties was demonstrated.
The original lipid A fraction of E. coli consisted of ethersoluble materials (about 60 per cent), containing fatty acids, water soluble materials, containing glucosamine, unknown amino sugar, eight or more ninhydrin positive substances, presumably amino acids, and phosphoric acid.
The repeated intraperitoneal injections of the aqueous or oily suspension of the lipid A fraction showed a definite inhibitory effect against mouse Ehrlich ascites tumors, and about 40 to 60 per cent of the treated animals survived.
The repeated subcutaneous injections of the lipid A had no inhibitory effect on the development of tumor ascites.
Against the solid form of Sarcoma 37, the multiple intraperitoneal injections of lipid A also seem to exert some suppressive effects.Among the lipid A fractions used, at least, there were scarcely any differences in their antitumor effects.