TP53 and colonic neoplasm: The results of protein western blotting of p53 and p21 showed that the relative expression of p53 and p21 proteins in colon cancer cells treated with OA, Asp and their combination was up-regulated compared with the control group, suggesting that p53-mediated or unmediated cell cycle arrest and DNA repair processes occurred in cells treated with OA, Asp and OA + Asp.