Investigation of the anti-cancer and apoptotic properties of aqueous extract from fermented African locust bean seeds

Some fermented foods are reported to possess anti-cancer properties. Fermented African locust bean seeds is a condiment prepared from fermentation of Parkia biglobosa. It has been reportedly functional for various medicinal activities but not anti-cancer. The cytotoxic and apoptosis-inducing properties of the aqueous extract of the condiment were investigated in human cancer-hepatocellular (Hep-G2) and cervical (HeLa) and non-cancer cell lines. Cytotoxicity was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and clonogenic cell survival assays. Apoptotic cell death and DNA fragmentation were also investigated. The results revealed cytotoxicity to both cell lines in a dose-dependent manner (P < 0.05) and selective activities between cancer and non-cancer cells. The IC₅₀ values were 1.3 and 0.5 mg/mL for Hep-G2 and HeLa cells respectively. Furthermore, the extract induced apoptotic cell death in only Hep-G2 (73.03±0.73) cells. The morphologic photomicrographs correlated well with other findings, indicating the cell-specific cytotoxicity of the condiment.