Toxicological evaluation of an unextracted Aurantiochytrium limacinum biomass, a novel docosahexaenoic acid rich feed ingredient.

The purpose of this paper was to evaluate the toxicological potential of a heterotrophically grown unextracted Aurantiochytrium limacinum biomass (AURA) when used as a food additive. The following toxicological assessments were conducted on this novel docosahexaenoic acid rich feed ingredient: Mutagenic activity was tested by means of the Ames' test using five Salmonella typhimurium strains; clastogenic activity was investigated using the micronucleus test in male and female Sprague Dawley rats; genotoxic activity was assessed by means of the in vitro metaphase analysis tests in human lymphocytes; oral toxicity was tested by administration of AURA at various concentrations; eye and skin irritation was assessed in rabbits according to OECD guidelines; skin sensitivity was established in guinea pigs by means of the Buehler test. All conducted tests were considered valid under the experimental conditions. No significant mutagenic activity or clastogenic activity was observed. Genotoxic activity in human lymphocytes was not induced. Oral administration of 276 mg AURA/kg bw and 2000 mg AURA/kg bw resulted in no mortality or signs of acute toxicity. Daily administration of 1000 mg AURA/kg bw caused no mortality or biologically relevant signs of toxicity and was established as the No Observable Adverse Effect Level. AURA was also found to be a non-irritant for the eye and skin of the rabbit and was non-sensitizing to guinea pig skin.