Journal of Food Bioactives, ISSN 2637-8752 print, 2637-8779 online
Journal website www.isnff-jfb.com

Original Research

Volume 2, Number , June 2018, pages 91-97

5-Demethylnobiletin more potently inhibits colon cancer cell growth than nobiletin in vitro and in vivo

Figures

Figure 1.
Figure 1.

Effect of NOB and DMNB on the growth of HCT-116, HT-29 and COLO 205 cells.

(A) Chemical structures of NOB and DMNB. (B) Cell well treated with 0, 1, 2.5, 5, 10, 20 and 40 μM of NOB or DMNB for 24 h. Cell viability was determined by MTT assay. Data are expressed as mean ± SD. When there were significant differences among control, NOB and DMNB groups, they were further analyzed by one-way ANOVA and Duncan’s Multiple Range Test, with results being indicated by the letters a, b, c, and d.
Figure 2.
Figure 2.

Apoptotic effects of NOB and DMNB on COLO 205 cells.

(A) Cell morphology of the control group, 20 μM NOB group and 20 μM DMNB group. Cell well treated with 5, 10 and 20 μM of NOB or DMNB for 24 h. (B) The apoptosis ratio (%) was detected by flow cytometry and quantification of sub-G1 phase in COLO 205 cells. Data were expressed as mean ± SD. When there were significant differences among control, NOB and DMNB groups, they were further analyzed by one-way ANOVA and Duncan’s Multiple Range Test, and results are indicated by the letters a, b, and c. (C) The expression of PARP protein was detected by using a Western blot with a specific antibody.
Figure 3.
Figure 3.

DMNB effectively inhibits tumor growth of COLO 205 tumor xenografts in nude mice.

(A) The change of body weight and (B) tumor volume from each group during the experiment. (C) Representative xenograftic tumors from the vehicle-treated positive, NOB (50 mg/kg) and DMNB (50 and 100 mg/kg)-treated groups (day 21). (D) Final tumor weights were also measured and plotted. Data were expressed as mean ± SE. When there were significant differences among positive, NOB and DMNB groups, they were further analyzed by one-way ANOVA and Duncan’s Multiple Range Test, and results are indicated by the letters a and b.
Figure 4.
Figure 4.

Effects of DMNB on pro-death, inflammation and angiogenesis signaling pathways in tumor tissue.

Mice were treated as described in Materials and Methods. At the end of the experiment, tumor tissues were excised and protein lysates of homogenized tissue were measured for PARP, LC3, p53, COX-2 and VEGF expression by Western blot analysis. Quantification of target protein expression was normalized to β-actin using a densitometer by Image J software.
Figure 5.
Figure 5.

Schematic diagram showing the mechanisms underlying the anti-colon cancer effects of DMNB.

These anti-proliferative potencies were accompanied by inducing p53-regulated cell death signaling (apoptosis and autophagy) and cooperating inhibition of key cellular proteins (COX-2 and VEGF) associated with inflammation and angiogenesis. Abbreviation: DMNB, 5-demethylnobiletin; cPARP, cleaved poly-ADP-ribose polymerases; LC3II, light chain 3 II; COX-2, cyclooxygenase-2; and VEGF, vascular endothelial growth factor.