AKT1 and malignant colon neoplasm: In contrast, the treatment of 5-Fu alone only showed mild and seemingly transient Akt inhibition, which is absent at high dosages of 5-Fu (Fig. 4a), implying that curcumin not only functions as an inhibitor of autophagy to synergize the cytotoxicity of 5-Fu in colon cancer cells, but also works as a cytotoxicity enhancer via directly inhibition of Akt activity.