Nobiletin is capable of regulating certain anti-cancer pathways in a colon cancer cell line.

Abstract

Natural remedies have the potential to improve conventional cancer therapies and enhance patient outcomes. Citrus polymethoxyflavone nobiletin has been demonstrated to have anticancer effects on several cancer cell lines. In this study, the anti-cancer activity of nobiletin is investigated on Bax, Bcl-2, HO-1, VEGF, MMP-7, Akt, p70S6K, 4EBP1, tuberin, and hamartin. IC50 doses were 403.6µM, 264µM, and 40µM, respectively, at 24, 48, and 72h. Akt, Bax, Bcl-2, and p70S6K levels decreased at nobiletin concentrations greater than 100, 250, 500, and 1000µM, respectively. Nobiletin decreased HO-1 and VEGF levels at concentrations greater than 100µM. MMP-7 levels interestingly increased at 100µM but decreased at doses greater than 250µM. 4EBP1 levels increased, except from 2000 and 3000µM nobiletin concentrations. Tuberin levels increased at 10, 50, and 3000µM, decreased at 250µM, and remained unchanged at the rest of the concentrations. Nobiletin decreased hamartin levels; however, this decrease was statistically significant only at 10, 100, 250, 500, and 3000µM concentrations. Decreased Akt activity might be interpreted as nobiletin inhibiting mTORC1 activity and subsequently increased 4EBP1 and unchanged or decreased p70S6K protein levels. Akt activity can cause suppression of angiogenesis via decreased VEGF, MMP-7, and HO-1 levels at concentrations greater than 500µM. These results are significant as a nobiletin therapy could prevent colon cancer progression by inhibiting Akt signaling and angiogenesis.