Evaluation of the Acute Toxicity and Genotoxicity of the Rice Biofortified with β-Glucan

  Objective  To provide a scientific evaluation of the food safety of the rice biofortified with β-glucan.

  Methods  The acute toxicity and genotoxicity of the rice were evaluated by 14-day feeding experiment, Ames experiment, erythrocyte micronucleus test and mouse lymphoma thymidine kinase gene (TK) mutation assay respectively.

  Results  In the acute toxicity test, there was no obvious toxicity of rice biofortified with β-glucan, and no abnormality was found in anatomical observation. The median lethal dose (LD₅₀) to rats and mice wereall greater than 15 mg/kg, which belonged to the actual non-toxic level. Whether with S₉ activation or not, no genotoxicity was found to the tested strains TA97a, TA98, TA100, TA102 and TA1535. No induction of polychromatic erythrocytes and inhibition of bone marrow were found in erythrocyte micronucleus test. The results of TK gene mutation assay did not show the mutagenicity of β-glucan bioaugmentation rice. All results of the three genotoxicity tests were negative.

  Conclusion  Under the current experimental conditions, β-glucan biofortified rice showed no obvious acute toxicity and genotoxicity.