Chemopreventive Effects of Dietary Canola Oil on Colon Cancer Development

Abstract

Fatty acid composition of dietary fat plays a vital role in colon tumor development in animal models. Fats containing ω-6 fatty acids (e.g., corn oil) enhanced and ω-3 fatty acids (e.g., flaxseed oil) reduced chemically induced colon tumor development in rats. The objective of the present investigation was to study the effects of dietary canola oil, a source of ω-3 fatty acid on azoxymethane-induced colon cancer development in Fischer rats and compare with dietary corn oil.

Dietary canola oil significantly (P < 0.05) decreased colonic tumor incidence and tumor multiplicity as compared to dietary corn oil in rats. Fatty acid analysis showed that corn oil group had higher levels of ω-6 fatty acid levels, whereas the canola oil groups exhibited higher levels of ω-3 fatty acids from the colon and serum samples of rats. For the mechanistic study, COX-2 expression in the colon samples from the canola oil group was significantly lower (P < 0.05) as compared to the corn oil group.

Taken together, dietary canola oil may be chemopreventive for colon tumor development in Fischer rats as compared to possibly by increasing ω-3 fatty acid levels and decreasing COX-2 levels.

ACKNOWLEDGMENT

This study was supported by the National Canola Council.

Notes

^a Data represent mean derived from at least 5 samples.

^b Significantly higher in canola oil group than corn oil group (P < 0.05).

^c Significantly lower in canola oil group than corn oil group (P < 0.05).

^a Data represent mean derived from at least 5 samples.

^b Significantly higher in corn oil group than other groups (P < 0.05).

^c Significantly higher in canola oil group than corn oil group (P < 0.05).

^a Data represent mean derived from at least 5 samples.

^b Significantly higher in corn oil group than canola oil group (P < 0.05).

^c Significantly higher in canola oil group than corn oil group (P < 0.05).