Pre-clinical and cellular safety assessment of oral administered DHA rich microalgae oil from <i>Schizochytrium</i> sp. (Strain ATCC-20889): acute, sub-chronic and genotoxicity

The lack of toxicity data for DHA-rich oil from <i>Schizochytrium</i> sp. (Strain ATCC-20889) leads to its exclusion from the Qualified Presumption of Safety list. Therefore, present study addresses toxicity evaluation of DHA-rich microalgae oil using <i>ex-vivo</i> (cytotoxicity assay) and <i>in-vivo</i> methods (acute (OECD 423 guidelines), sub-chronic (OECD 452 guidelines), and genotoxicity assay). The <i>ex-vivo</i> results showed &gt;90% cell viability of Caco-2 cells after 48 h of treatment (200 µg/mL of DHA). Additionally, the <i>in-vivo</i> acute toxicity study found that microalgae oil was nontoxic and classified under category 5 molecule according to OECD 423 guidelines with a highest degree of safety at 2000 mg/kg b.w. The <i>in-vivo</i> sub-chronic study revealed no significant mortality and changes in feed intake, body weight, haematological, biochemical, neurological, and urine parameters after repeated 180-days administration of DHA-rich microalgae oil at 250 mg/kg, 500 mg/kg, and 1000 mg/kg. Moreover, histopathology evaluation, comet assay, chromosomal aberration, and micronuclei assay also confirmed the nontoxic behavior of DHA-rich oil. Thus, the results from the <i>ex-vivo</i> and <i>in-vivo</i> studies indicate that DHA-rich oil from <i>Schizochytrium</i> sp. (Strain ATCC-20889) is safe for use as a novel food, and can be included in infants, adults, pregnant women, and children formula.