An Evaluation of Oral Subchronic Toxicity of Maizinol (UP165), a Zea mays Leaf Extract

Maize (Zea mays) has been consumed by humans for millennia and represents the third most abundant crop grown globally. Maize and maize-derived products have a long history of safe consumption from bread and other cereal products in human diets worldwide. Aside from key dietary components like carbohydrates and proteins, the corn plant contains endogenous biomolecules like benzoxazinoids. Benzoxazinoids are a group of secondary metabolites produced in monocotyledons and some species of dicotyledons from the Acanthaceae, Ranunculaceae, Scrophulariaceae, Plantaginaceae, and Lamiaceae families, and benzoxazinoids play a vital role in plant physiology. The current research aims to evaluate the safety of Maizinol (UP165), an ethanolic corn leaf extract containing 0.2%-0.3% of the benzoxazinoid, benzoxazolinone 6-methoxy-2-benzoxazolinone (6-MBOA) in Sprague Dawley rats. Animals were orally dosed with 0-, 750-, 1500-, or 3000-mg Maizinol/kg body weight/day for 90 days and observed for mortality and morbidity. Results revealed that Maizinol was well tolerated at all tested doses, as no significant effects were observed in hematological, biochemical, and histological endpoints at all doses. A subchronic 90-day toxicity no-observed-adverse-effect level for UP165 in Sprague Dawley rats was determined to be 3000 mg/kg body weight/day.