TITLE:
Chemopreventive Potential of Canola Leafy Greens and Other Cruciferous Vegetables on Azoxymethane (AOM)-Induced Colon Cancer in Fisher-344 Male Rats
AUTHORS:
R. L. Miller-Cebert, J. Boateng, E. Cebert, L. Shackelford, M. Verghese
KEYWORDS:
Antioxidative Enzymes, Cancer, Canola, Cruciferous Vegetables, Detoxification Enzymes
JOURNAL NAME:
Food and Nutrition Sciences,
Vol.7 No.11,
September
22,
2016
ABSTRACT: Cruciferous vegetables have great health benefits, and their components may be significant
in the inhibition of colon tumors. The objective of this study was to investigate
and compare the chemopreventive potential of cabbage, turnip greens, collard
greens and canola greens on azoxymethane (AOM)-induced colon cancer. Following
a one-week acclimatization period, forty-two Fisher-344 male rats were randomly assigned
to five groups (treatment groups: n = 8; control: n = 10). Four groups were fed
treatment diets consisting of the selected cruciferous vegetables at 5%, while the C
group was fed AIN-93 growth diet. Colon tumors were induced by administration of
AOM at 7 and 8 weeks of age and rats were killed by CO2 asphyxiation at 45 weeks of
age. Results show a 42.85% tumors incidence in rats fed canola greens compared to
100% in the rats fed cabbage and the control. Rats fed control had higher tumors/
tumor bearing rat (TBR) ratio (4.5) compared to those seen in treatment groups (1 -
1.71). Significant differences (P ≤ 0.05) were noted in weight gain, cecal wall weight
and total cecal weight in the control compared to treatment groups. Hepatic catalase
(CAT) and Glutathione-S-Transferase (GST) activities (43.05 and 2.02 μmol/mg, respectively)
in rats fed canola were significantly higher (P ≤ 0.05) compared to the
control (10.22 and 0.58 μmol/mg) and other treatment groups. Superoxide dismutase
(SOD) activity (μmol/mg) in rats fed canola (0.29), cabbage (0.26) and turnip greens
(0.25) were similar, however, significantly higher (P ≤ 0.05) compared to the control
(0.09). Activities of glutathione peroxidase (GPX) increased in the order: collard
greens > canola greens > turnip greens > cabbage > control. Selected cruciferous vegetables,
including canola leafy greens, were effective in reducing incidence of AOM-induced colon tumors in Fisher-344 male rats and may be useful as dietary chemopreventive
agents.