Phenolics from canola crude extracts protect cells from oxidative stress

Abstract

Background: By-products of canola oil production are currently discarded or low value commodities. This study investigates if these by-products are a significant source of extractable dietary phenols which could exhibit cellular antioxidants activity. Methods: Endogenous phenolic compounds obtained from canola oil deodistillates and canola meal using different extraction techniques were identified and examined for their in vitro antioxidant activities in “test tube” and cellular assays. Results: Sinapine was the predominant phenolic in the canola meal crude extract, while canolol was the only significant phenol in the accelerated solvent extract of canola meal. The deodistillate did not have canolol or sinapine present, but contained high molecular weight phenols of unknown identity. The “test tube” antioxidant assays indicated that canola meal crude extract and sinapic acid both exhibited stronger antioxidant potentials compared to the other extracts. A dose dependent cyto-protection effect was observed under oxidative challenge by H2O2, when cells were incubated with the canola meal accelerated solvent extract, deodistillate extract and sinapic acid. Conclusions: This study demonstrates that canola by-products can be the sources of health promoting phenols, for possible formulation into value added nutraceuticals.