A 13-week sub-chronic dietary toxicity study of a cruciferin-rich canola protein isolate in rats

The objective was to evaluate the safety of a cruciferin-rich canola protein isolate (Puratein®) when fed as a protein source at various dietary levels to rats for 13-weeks. The study included four groups (20 animals/sex/group) of young Sprague Dawley rats. They were fed ad libitum with an AIN-93 G based protein-free diet added respectively with 5%, 10% and 20% (w/w) Puratein® (test article) or 20% (w/w) vitamin-free casein (control article). Protein levels were adjusted in all groups at 18% using vitamin-free casein. Body weights, food consumption, locomotor activity and behavioral and clinical pathology parameters were recorded at various points of the study, followed by macroscopic examination, determination of organ weights and microscopic tissue examination. There were no test article-related effects on body weight, food consumption, clinical observations, functional observational battery, motor activity, clinical pathology, or ophthalmic examinations. A slightly higher thyroid/parathyroid weight (g/100 g BW) noted in the 20% Puratein® group was not correlated with histopathological changes. The no-observed-effect-level (NOEL) was 10%, whereas the no-observed-adverse-effect-level (NOAEL) was the highest fed level of 20%, equivalent to 11.24 g/kg BW/day for males and 14.11 g/kg BW/day for females. The cruciferin-rich canola protein isolate (Puratein®) was considered safe under the conditions tested.