Effect of consumption of blue maize tortilla on anxiety-like behaviour, learning, memory and hippocampal BDNF expression in a chronic stress model in rats

Background Pigmented maize consumption is of much interest because of its high anthocyanin content and multiple health benefits. Objetives: This study was aimed to assess the effect of consuming blue maize tortillas on the anxiolytic capacity, preserve emotional memory, and the expression of brain-derived neurotrophic factor (BDNF) in rats subjected to chronic stress. Methods: Sixty-four 3-month-old male Wistar rats were used, divided into eight groups (n = 8). Four groups were subjected to chronic stress by movement restriction (7 h/daily/7 consecutive days) and the remaining four groups were subjected to standard management. The treatments were commercial food, blue tortilla, anthocyanin extract, or white tortilla, administered for nine weeks to stressed or unstressed animals. In the eighth week, the animals were subjected to the restraint stress model. Subsequently, anxiety-like behaviour was assessed using the elevated plus-maze, and memory and emotional learning were evaluated by the step-down passive avoidance test. The animals were then sacrificed to quantify the relative expression of hippocampal BDNF by RT-qPCR. Results: The consumption of anthocyanin extract or tortilla made with blue corn decreased anxiety-like behaviours, additionally, it improved the ability to retain emotionally relevant information, and it upregulated BDNF mRNA expression. Perspective: Thus, the analyse of the impact of blue tortilla consumption on the nervous system is now necessary to guarantee the nutraceutical value of this food.