Lactobacillus raises in vitro anticancer effect of geniposide in HSC-3 human oral squamous cell carcinoma cells

The present study determined the ability of the Lactobacillus rhamnosus GG strain (LGG) to enhance the anticancer effects of geniposide on HSC-3 human oral squamous carcinoma cells. LGG (1.0x10(3) CFU/ml) on its own had no impact on human oral keratinocytes and HSC-3 cancer cells. Geniposide (25 or 50 mu g/ml) had no impact on human oral keratinocytes, but exerted growth inhibitory effects on HSC-3 cancer cells, which were increased in the presence of LGG. Flow cytometric analysis and a nuclear staining assay with DAPI revealed that HSC-3 cancer cells treated with LGG-geniposide (1.0x10(3) CFU/ml LGG and 50 mu g/ml geniposide) had a higher apoptotic rate than cells in other treatment groups, particularly that treated with geniposide (50 mu g/ml) only. Geniposide also increased the mRNA and protein expression of caspase-3,-8 and-9 as well as B-cell lymphoma 2 (Bcl-2)-associated X protein, p53, p21, inhibitor of nuclear factor-kappa B (NF-kappa B) alpha, Fas and Fas ligand, while decreasing Bcl-2, Bcl extra large protein, inhibitor of apoptosis-1 and -2, NF-kappa B, cyclooxigenase-2 and inducible nitric oxide synthase in HSC-3 cells, which was increased in the presence of LGG. These results indicated that LGG enhanced the anticancer effects of geniposide in HSC-3 cells.