Abstract
BACKGROUND: Lactic acid bacteria (LAB) are beneficial probiotic organisms that contribute to improved nutrition, microbial balance, and immuno-enhancement of the intestinal tract, as well as anti-tumor activity. The aim of the present work was to study the growth inhibition of tumor cells by butanol extract of Bifidobacterium adolescentis isolated from healthy young Koreans. METHODS: The anti-proliferative activity of B. adolescentis isolates was assessed by XTT assays on three human colon cancer cell lines (Caco-2, HT-29, and SW480). The effects of B. adolescentis SPM0212 butanol extract on tumor necrosis factor-alpha (TNF-alpha) and nitric oxide (NO) production were tested using the murine macrophage RAW 264.7 cell line. RESULTS: The butanol extract of B. adolescentis SPM0212 dose-dependently inhibited the growth of Caco-2, HT-29, and SW480 cells by 70%, 30%, and 40%, respectively, at 200 microg/mL. Additionally, the butanol extract of B. adolescentis SPM0212 induced macrophage activation and significantly increased the production of TNF-alpha and NO, which regulate immune modulation and are cytotoxic to tumor cells. CONCLUSION: The butanol extract of B. adolescentis SPM0212 increased activity of the host immune system and may improve human health by helping to prevent colon cancer as a biological response modifier.