Adlay bran is a waste product previously thought to have no commercial value, Its methanolic extract was fractionated using n-hexane (ABM-Hex), ethyl acetate (ABM-EtOAc), 1-butanol (ABM-BuOH), and water (ABM-$H_2O$). The ABM-EtOAc fraction exhibited a strongest inhibition against growth of human lung cancer cell A549 and human colorectal carcinoma cells HT-29 and COLO 205. Inhibition of cell cycle progression at $G_0/G_1$ transition, increase of cells at the sub-$G_1$ phase, and DNA ladders were observed in cells treated with ABM-EtOAc. The ABM-BuOH fraction showed the strongest inhibition of proinflammatory cytokines tumor necrosis factor (TNF)-$alpha$ and interlukin (IL)-$1{eta}$ in stimulated RAW 264.7 macrophages. Further, ABM-EtOAc and ABM-BuOH inhibited cyclooxygenase (COX)-2 expression in A549 and HT-29 carcinoma cells, while COX-l expression was not affected. These results reveal that both ABM-EtOAc and ABM-BuOH may aid the prevention of cancers and the applications in cancer chemotherapy.