Abstract
Previous studies have demonstrated antitumor activity in squid ink. This study was carried out to clarify the key component of, and the role of tyrosinase in the antitumor activity. The antitumor fraction, which contains illexin-peptidoglycan, soluble melanin and tyrosinase activity, was isolated from the defatted ink using Tris-HCl buffer extraction, DEAE Sephacel and Sephacryl S-300 chromatography. During the isolation procedure, the behavior of the tyrosinase activity exhibited the same pattern as the antitumor activity. The antitumor fraction could be separated by Phenyl Sepharose CL-4B chromatography into three fractions: illexin-peptidoglycan, tyrosinase and the complex of the two. The fraction containing illexin-peptidoglycan and tyrosinase showed the highest activity against the Meth A tumor in BALB/c mice. This suggests that both these components are needed for the antitumor activity of squid ink.
