Anticancer principles from salivary gland extract of Octopus ageina

The present study was carried out to evaluate the anticancer potential of salivary gland extracts of Octopus ageina on in vitro and in vivo cancer models. LD₅₀ values of both anterior (AGE) and posterior gland extract (PGE) were analyzed using Swiss Albino mice. Different concentration of sublethal dose was subjected to hemolytic assay using 1% human erythrocytes. Since PGE did not show any hemolysis at concentration below 400 μg, it was chosen for the anticancer studies. Preliminary anticancer effect was tested on COLO 205 cells at three different concentrations, viz., 50, 75 and 100 μg mL^-1 medium. Among the above three doses, 100 μg mL^-1 medium was found to inhibit cell growth effectively after 24 h. The same effective dose was used to confirm the anticancer potential of PGE against 1.2-dimethylhydrazine (DMH) induced colon cancer in male Albino Wistar rats. After 30 weeks of the experimental period PGE showed promising effects by reduced tumor incidence and mean tumor size. The β-glucuronidase (intestine and colon) and mucinase (Colon and fecal contents) activity were significantly reduced after treatment with PGE when compared to the DMH treated rats. The above anticancer effect of PGE was further confirmed by the histopathological changes of the colon. Thus, PGE proves itself to have potent anticancer substance and further studies are warranted to isolate and identify the active component.