Antitumoral Activity of Slime-forming, Encapsulated Lctococcus lactis subsp. cremoris isolated from Scandinavian Ropy Sour Milk, "viili"

Abstract

This study was conducted to investigate the antitumor activity of slimeforming encapsulated Lactococcus lactis subsp. cremoris KVS 20 (L. cremoris KVS 20) isolated from Scandinavian ropy sour milk, "viili". Intraperitoneal (i. p.) injection of lyophilized L. cremoris KVS 20 cells resulted in the growth inhibition of ascitic and solid tumors of Sarcoma-180 (S-180) in ICR mice. Tumor growth was significantly retarded, and the weight mean survival time significantly increased when the preparation was injected at a dose of 50mg/kg for 9 successive days from the day after tumor inoculation. On the other hand, L. cremoris KVS 20 did not exhibit direct cytotoxicity against S-180 tumor cells. These findings suggest that the effectiveness of L. cremoris KVS 20 in preventing tumor growth is induced through enhanced host-mediated immunity.