-Oryzanol Improves Cognitive Function and Modulates Hippocampal Proteome in Mice

Rice (Oryza sativa L.) is the richest source of -oryzanol, a compound endowed with antioxidant and anti-inflammatory properties. -Oryzanol has been demonstrated to cross the blood-brain barrier in intact form and exert beneficial effects on brain function. This study aimed to clarify the effects of -oryzanol in the hippocampus in terms of cognitive function and protein expression. Adult mice were administered with -oryzanol 100 mg/kg or vehicle (control) once a day for 21 consecutive days following which cognitive behavior and hippocampal proteome were investigated. Cognitive tests using novel object recognition and Y-maze showed that long-term consumption of -oryzanol improves cognitive function in mice. To investigate the hippocampal proteome modulated by -oryzanol, 2D-difference gel electrophoresis (2D-DIGE) was performed. Interestingly, we found that -oryzanol modulates quantitative changes of proteins involved in synaptic plasticity and neuronal trafficking, neuroprotection and antioxidant activity, and mitochondria and energy metabolism. These findings suggested -oryzanol as a natural compound able to maintain and reinforce brain function. Although more intensive studies are needed, we propose -oryzanol as a putative dietary phytochemical for preserving brain reserve, the ability to tolerate age-related changes, thereby preventing clinical symptoms or signs of neurodegenerative diseases.