Anti-proliferative and Apoptosis Inducing Activity of Lactobacillus brevis OPK-3 Isolated from Kimchi on Leukemia Cell Lines

In the present work we investigated the effects of lactic acid bacteria (LAB) isolated from kimchi on proliferation and apoptosis of cancer cells. The cell-free supernatant concentrate of Lactobacillus brevis OPK-3 significantly retarded the proliferation of human acute promyelocytic (HL60), human histiocytic (U937), and mouse lymphocytic (L1210) leukemia cell lines in vitro at concentrations over 2.25-9.0 mg/mL. The treatments of the concentrate leaded to the increased apoptosis and decreased mitochondrial transmembrane potential in cultured U937 leukemia cell lines. In addition, the treatments of the concentrate showed the increased expression of p53 gene in cultured U937 and HL60 leukemia cell lines. On the other hand, the cell-free supernatant concentrate of control L. brevis strain (KCCM 41028) showed a relatively little effect on the cancer cell proliferation, apoptosis, and mitochondrial transmembrane potential at the similar concentration ranges compared with the L. brevis OPK-3 samples. These results suggest that the consumption of L. brevis OPK-3 could be beneficial for the inhibitory action on leukemia cell proliferation and for the stimulatory action on the cancer cell apoptosis.