An In Vitro and In Vivo Assessment of the Genotoxic Potential of Maizinol (UP165), a Zea mays Leaf Extract

Benzoxazinoids are secondary metabolites produced in monocotyledons and some dicotyledons from the Acanthaceae, Ranunculaceae, Scrophulariaceae, Plantaginaceae, and Lamiaceae families. Benzoxazinoids are commonly consumed in bread and cereal products that have been ingested for decades, which supports the safe use of benzoxazinoids as food ingredients. Powdered corn leaf extract (UP165), trade name Maizinol, containing 0.2%-0.3% w/w benzoxazinoid 6-methoxy-2-benzoxazolinone (6-MBOA), was the subject of genetic toxicity studies conducted according to Organisation for Economic Co-operation and Development (OECD) Test Guidelines (TG). The toxicity tests evaluated the safety of corn leaf extract (as Maizinol containing 0.2%-0.3% 6-MBOA) using a bacterial reverse mutation assay (OECD Test Guideline 471) at doses of 313, 625, 1250, 2500, or 5000 μg/plate; in vitro mammalian chromosomal aberration test (OECD TG 473) at concentrations of 9.77, 19.5, 39.1, or 78.1 μg/mL; and in vivo mammalian erythrocyte micronucleus test (OECD TG 474) at a dose of 750, 1500, or 3000 mg/kg body weight/day. Results demonstrate that Maizinol (UP165), at maximum test concentrations of 5000 μg/plate in the bacterial mutagenicity study, 78.1 μg/mL in the mammalian chromosomal aberration test, and a dose of 3000 mg/kg body weight in the rat micronucleus test, did not elicit genotoxic or mutagenic effects under the reported test conditions.