Acetone Extract of <i>Dioscorea alata</i> Inhibits Cell Proliferation in Cancer Cells

Dioscorea spp., White Yam has been shown to exhibit a wide\r\nrange of nutritional and medicinal properties. However, the compounds\r\nassociated with its medicinal functions have not been fully examined. The\r\npurpose of this study was to generate a chemoinformatic profile of the\r\nbioactive compounds present in Dioscorea. alata (D. alata) and to\r\ncharacterize their putative anti-cancer properties using prostate (DU145) and\r\nlung (A549) cancer cells. Chemoinformatic profiling of D. alata resulted in five\r\nbioactive extracts: hexane (DaJa-1), ether\r\n(DaJa-2), acetone (DaJa-3), ethanol (DaJa-4) and water (DaJa-5) were generated.\r\nThe analytes present in the five bioactive extracts were dissolved in 0.1% DMSO\r\nand their anti-cancer activity were determined. We observed that the acetone extract (DaJa3) was the only\r\nextract capable of inducing greater than 90% cell death of DU 145 cell at 100 μg/mL. The order of growth\r\ninhibition of the extracts in DU-145 cell is DaJa-3 (IC50, 31.45 μg/mL) \u003e\r\nDaJa-4 (IC50 60 μg/mL) \u003e DaJa-1 (IC50 \u003e 100 μg/mL) ≥ DaJa-2 (IC50 \u003e\r\n100 μg/mL) ≥ DaJa-5 (IC50 \u003e 100 μg/mL). MTT cell viability, dye exclusion,\r\ncaspase activity and microscopic assessment of apoptotic cells demonstrated\r\nthat DaJa-3 displayed cytotoxicity to both lung and prostate cancer cells. The\r\nA549 cells were more sensitive toward DaJa-3 with an IC50 value of\r\n22.28 μg/mL (CI 28.42 to 36.63 μg/mL), compared to that of DU145 cells with an\r\nIC50 value of 31.45 μg/mL (CI 27.58 to 35.86 μg/mL). It was also\r\nobserved that DaJa-3 induces differential anti-proliferative activity in the\r\ncancer cells. The apoptotic response induced by DaJa-3 paralleled the level of\r\ncell cytotoxicity observed in both cell lines. DaJa-3 induces G2 phase cell cycle arrest in DU145 cells but G1 arrest in A549 cells.\r\nThe level of key apoptotic regulator proteins was upregulated, suggested that DaJa-3 may be mediating its anti-cancer effect through activation\r\nof the intrinsic apoptotic pathway. Altogether, our data indicates that DaJa-3 derived from a staple food source (white Yam) contains\r\nunique active compounds that have specific biological properties that may\r\nprevent certain types of cancer or specific types of cancer.